Re: Cassandra on high performance machine: virtualization vs Docker

[Jeff Jirsa]

Same technique works for production, too. Rack aware snitch will protect 
against placing replicas on the same host, as long as the rack info is correct 

-- 
Jeff Jirsa


> On Feb 27, 2018, at 8:43 PM, daemeon reiydelle  wrote:
> 
> Docker will provide less per node overhead. 
> 
> And yes, virtualizing smaller nodes out of a bigger physical makes sense. Of 
> course you lose the per node failure protection, but I guess this is not 
> production?
> 
> 
> <==>
> "Who do you think made the first stone spear? The Asperger guy.
> If you get rid of the autism genetics, there would be no Silicon Valley" 
> Temple Grandin
> Daemeon C.M. Reiydelle
> San Francisco 1.415.501.0198
> London 44 020 8144 9872
> 
> 
>> On Tue, Feb 27, 2018 at 8:26 PM, onmstester onmstester  
>> wrote:
>> What i've got to set up my Apache Cassandra cluster are some Servers with 20 
>> Core cpu * 2 Threads and 128 GB ram and 8 * 2TB disk. 
>> Just read all over the web: Do not use big nodes for your cluster, i'm 
>> convinced to run multiple nodes on a single physical server.
>> So the question is which technology should i use: Docker or Virtualiztion 
>> (ESX)? Any exprience?
>> 
>> Sent using Zoho Mail
>> 
>> 
>> 
> 

Re: Cassandra on high performance machine: virtualization vs Docker

[daemeon reiydelle]

Docker will provide less per node overhead.

And yes, virtualizing smaller nodes out of a bigger physical makes sense.
Of course you lose the per node failure protection, but I guess this is not
production?


<==>
"Who do you think made the first stone spear? The Asperger guy.
If you get rid of the autism genetics, there would be no Silicon Valley"
Temple Grandin


*Daemeon C.M. ReiydelleSan Francisco 1.415.501.0198London 44 020 8144 9872*


On Tue, Feb 27, 2018 at 8:26 PM, onmstester onmstester 
wrote:

> What i've got to set up my Apache Cassandra cluster are some Servers with
> 20 Core cpu * 2 Threads and 128 GB ram and 8 * 2TB disk.
> Just read all over the web: Do not use big nodes for your cluster, i'm
> convinced to run multiple nodes on a single physical server.
> So the question is which technology should i use: Docker or Virtualiztion
> (ESX)? Any exprience?
>
> Sent using Zoho Mail
>
>
>
>

Cassandra on high performance machine: virtualization vs Docker

[onmstester onmstester]

What i've got to set up my Apache Cassandra cluster are some Servers with 20 
Core cpu * 2 Threads and 128 GB ram and 8 * 2TB disk. 

Just read all over the web: Do not use big nodes for your cluster, i'm 
convinced to run multiple nodes on a single physical server.

So the question is which technology should i use: Docker or Virtualiztion 
(ESX)? Any exprience?



Sent using Zoho Mail

Re: Filling in the blank To Do sections on the Apache Cassandra web site

[George Webster]

This is an awesome effort. Thank you

Sent from my iPhone

> On Feb 27, 2018, at 1:17 PM, Carl Mueller  
> wrote:
> 
> Nice thanks
> 
> 
>> On Tue, Feb 27, 2018 at 12:03 PM, Jon Haddad  wrote:
>> There’s a section dedicated to contributing to Cassandra documentation in 
>> the docs as well: 
>> https://cassandra.apache.org/doc/latest/development/documentation.html
>> 
>> 
>> 
>>> On Feb 27, 2018, at 9:55 AM, Kenneth Brotman  
>>> wrote:
>>> 
>>> I was just getting ready to install sphinx.  Cool.  
>>>  
>>> From: Jon Haddad [mailto:jonathan.had...@gmail.com] On Behalf Of Jon Haddad
>>> Sent: Tuesday, February 27, 2018 9:51 AM
>>> To: user@cassandra.apache.org
>>> Subject: Re: Filling in the blank To Do sections on the Apache Cassandra 
>>> web site
>>>  
>>> The docs have been in tree for years :)
>>>  
>>> https://github.com/apache/cassandra/tree/trunk/doc
>>>  
>>> There’s even a docker image to build them so you don’t need to mess with 
>>> sphinx.  Check the README for instructions.
>>>  
>>> Jon
>>> 
>>> 
>>> On Feb 27, 2018, at 9:49 AM, Carl Mueller  
>>> wrote:
>>>  
>>> If there was a github for the docs, we could start posting content to it 
>>> for review. Not sure what the review/contribution process is on Apache. 
>>> Google searches on apache documentation and similar run into lots of noise 
>>> from actual projects.
>>> 
>>> I wouldn't mind trying to do a little doc work on the regular if there was 
>>> a wiki, a proven means to do collaborative docs. 
>>> 
>>>  
>>> On Tue, Feb 27, 2018 at 11:42 AM, Kenneth Brotman 
>>>  wrote:
>>> It’s just content for web pages.  There isn’t a working outline or any 
>>> draft on any of the JIRA’s yet.  I like to keep things simple.  Did I miss 
>>> something?  What does it matter right now?
>>>  
>>> Thanks Carl,
>>>  
>>> Kenneth Brotman
>>>  
>>> From: Carl Mueller [mailto:carl.muel...@smartthings.com] 
>>> Sent: Tuesday, February 27, 2018 8:50 AM
>>> To: user@cassandra.apache.org
>>> Subject: Re: Filling in the blank To Do sections on the Apache Cassandra 
>>> web site
>>>  
>>> so... are those pages in the code tree of github? I don't see them or a 
>>> directory structure under /doc. Is mirroring the documentation between the 
>>> apache site and a github source a big issue?
>>>  
>>> On Tue, Feb 27, 2018 at 7:50 AM, Kenneth Brotman 
>>>  wrote:
>>> I was debating that.  Splitting it up into smaller tasks makes each one 
>>> seem less over-whelming.  
>>>  
>>> Kenneth Brotman
>>>  
>>> From: Josh McKenzie [mailto:jmckenzie@apacheorg] 
>>> Sent: Tuesday, February 27, 2018 5:44 AM
>>> To: cassandra
>>> Subject: Re: Filling in the blank To Do sections on the Apache Cassandra 
>>> web site
>>>  
>>> Might help, organizationally, to put all these efforts under a single 
>>> ticket of "Improve web site Documentation" and add these as sub-tasks 
>>> Should be able to do that translation post-creation (i.e. in its current 
>>> state) if that's something that makes sense to you.
>>>  
>>> On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman 
>>>  wrote:
>>> Here are the related JIRA’s.  Please add content even if It’s not well 
>>> formed compositionally.  Myself or someone else will take it from there
>>>  
>>> https://issues.apache.org/jira/browse/CASSANDRA-14274  The troubleshooting 
>>> section of the web site is empty
>>> https://issues.apache.org/jira/browse/CASSANDRA-14273  The Bulk Loading web 
>>> page on the web site is empty
>>> https://issues.apache.org/jira/browse/CASSANDRA-14272  The Backups web page 
>>> on the web site is empty
>>> https://issues.apache.org/jira/browse/CASSANDRA-14271  The Hints web page 
>>> in the web site is empty
>>> https://issues.apache.org/jira/browse/CASSANDRA-14270  The Read repair web 
>>> page is empty
>>> https://issuesapache.org/jira/browse/CASSANDRA-14269  The Data Modeling 
>>> section of the web site is empty
>>> https://issues.apache.org/jira/browse/CASSANDRA-14268  The 
>>> Architecture:Guarantees web page is empty
>>> https://issuesapache.org/jira/browse/CASSANDRA-14267  The Dynamo web page 
>>> on the Apache Cassandra site is missing content
>>> https://issues.apache.org/jira/browse/CASSANDRA-14266  The Architecture 
>>> Overview web page on the Apache Cassandra site is empty
>>>  
>>> Thanks for pitching in  
>>>  
>>> Kenneth Brotman
>>>  
>>> From: Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID] 
>>> Sent: Monday, February 26, 2018 1:54 PM
>>> To: user@cassandra.apache.org
>>> Subject: RE: Filling in the blank To Do sections on the Apache Cassandra 
>>> web site
>>>  
>>> Nice!  Thanks for the help Oliver!
>>>  
>>> Kenneth Brotman
>>>  
>>> From: Oliver Ruebenacker [mailto:cur...@gmail.com] 
>>> Sent: Sunday, February 25, 2018 7:12 AM
>>> To: user@cassandra.apache.org
>>> Cc: dev@cassandra.apacheorg
>>> 

Batch too large exception

[Goutham reddy]

 Hi,
I have been getting batch too large exception when performing WRITE from
Client application. My insert size is 5MB, so I have to split the 10 insert
objects to insert at one go. It save some inserts and closes after some
uncertain time. And it is a wide column table, we do have 113 columns. Can
anyone kindly provide solution what was going wrong on my execution.
Appreciate your help.

Regards
Goutham Reddy

Re: Jon Haddad on Diagnosing Performance Problems in Production

[Kant Kodali]

+1 That was a nice talk! I don't know why I haven't come across that video
before!

On Tue, Feb 27, 2018 at 9:12 AM, Jonathan Haddad  wrote:

> There isn't a ton from that talk I'd consider "wrong" at this point, but
> some of it is a little stale.  I always start off looking at system
> metrics.  For a very thorough discussion on the matter check out Brendan
> Gregg's USE [1] method.  I did a blog post on my own about the talk [2]
> that has screenshots and might be helpful.  Generally speaking know your OS
> and the tools to examine each component.  Learn how to interpret the
> numbers you see, there's more information than a human can process in a
> lifetime but understanding some fundamentals of throughput vs latency &
> error rates and how to find out each of those metrics for cpu / memory /
> network / disk is a good start.
>
> More recently I did a talk at Data Day Texas, I posted the slides on
> Slideshare [3].  The focus there was more on perf tuning and less on
> performance troubleshooting, but I guess it's a matter of perspective which
> point your at.  The tools have changed a little (Prometheus instead of
> Graphite), and there's some new perf tuning tips like examining your read
> ahead and compression settings, generating flame graphs and using tools
> like YourKit and Java Flight Recorder, and the easiest win of all time,
> disabling dynamic snitch if your hardware is fast and you want sub ms
> p99s.  Turn up counter cache if you use counters (it still gets hit on the
> write path), and row cache is way more effective than people give it credit
> for under the right workloads.
>
> I've got a blog post in the works on JVM tuning, but for now I reference
> CASSANDRA-8150 [4] and Blake Eggleston's blog post [5] from back in our
> days at a small startup.
>
> Lastly, I'm doing a performance tuning series on our blog at The Last
> Pickle, with the first being on Flame Graphs [6].  I've got about 6 posts
> in the pipeline, just need to find time to get to them.
>
> Hope this helps,
> Jon
>
> [1] http://www.brendangregg.com/usemethod.html
> [2] http://rustyrazorblade.com/post/2014/2014-09-18-diagnosing-production/
> [3] https://www.slideshare.net/JonHaddad/performance-tuning-86995333
> [4] https://issues.apache.org/jira/browse/CASSANDRA-8150
> [5] http://blakeeggleston.com/cassandra-tuning-the-jvm-for-
> read-heavy-workloads.html
> [6] http://thelastpickle.com/blog/2018/01/16/cassandra-flame-graphs.html
>
>
>
> On Tue, Feb 27, 2018 at 8:56 AM Michael Shuler 
> wrote:
>
>> On 02/27/2018 10:20 AM, Nicolas Guyomar wrote:
>> > Is Jon blog
>> > post https://academy.datastax.com/planet-cassandra/blog/
>> cassandra-summit-recap-diagnosing-problems-in-production
>> > was relocated somewhere ?
>>
>> https://web.archive.org/web/20160322011022/planetcassandra.org/blog/
>> cassandra-summit-recap-diagnosing-problems-in-production
>>
>> --
>> Kind regards,
>> Michael
>>
>> -
>> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org
>> For additional commands, e-mail: user-h...@cassandra.apache.org
>>
>>

Re: Data Deleted After a few days of being off

[Oleksandr Shulgin]

On 27 Feb 2018 20:58, "A"  wrote:

No. I inserted using USING TTL 86400;


Well, that answers your question I believe?

--
Alex

Re: Data Deleted After a few days of being off

[A]

 No. I inserted using USING TTL 86400; 
On Monday, February 26, 2018, 11:45:07 PM PST, Oleksandr Shulgin 
 wrote:  
 
 On Tue, Feb 27, 2018 at 7:37 AM, A  wrote:


I started going through the logs and haven't noticed anything yet... Very 
unexpected behavior.

Maybe I'm asking the obvious, but were your inserts *without* a TTL?
--Alex
  

Re: Filling in the blank To Do sections on the Apache Cassandra web site

[Carl Mueller]

Nice thanks


On Tue, Feb 27, 2018 at 12:03 PM, Jon Haddad  wrote:

> There’s a section dedicated to contributing to Cassandra documentation in
> the docs as well: https://cassandra.apache.org/doc/latest/
> development/documentation.html
>
>
>
> On Feb 27, 2018, at 9:55 AM, Kenneth Brotman 
> wrote:
>
> I was just getting ready to install sphinx.  Cool.
>
> *From:* Jon Haddad [mailto:jonathan.had...@gmail.com
> ] *On Behalf Of *Jon Haddad
> *Sent:* Tuesday, February 27, 2018 9:51 AM
> *To:* user@cassandra.apache.org
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
> The docs have been in tree for years :)
>
> https://github.com/apache/cassandra/tree/trunk/doc
>
> There’s even a docker image to build them so you don’t need to mess with
> sphinx.  Check the README for instructions.
>
> Jon
>
>
> On Feb 27, 2018, at 9:49 AM, Carl Mueller 
> wrote:
>
>
> If there was a github for the docs, we could start posting content to it
> for review. Not sure what the review/contribution process is on Apache.
> Google searches on apache documentation and similar run into lots of noise
> from actual projects.
>
> I wouldn't mind trying to do a little doc work on the regular if there was
> a wiki, a proven means to do collaborative docs.
>
> On Tue, Feb 27, 2018 at 11:42 AM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
> It’s just content for web pages.  There isn’t a working outline or any
> draft on any of the JIRA’s yet.  I like to keep things simple.  Did I miss
> something?  What does it matter right now?
>
> Thanks Carl,
>
> Kenneth Brotman
>
> *From:* Carl Mueller [mailto:carl.muel...@smartthings.com]
> *Sent:* Tuesday, February 27, 2018 8:50 AM
> *To:* user@cassandra.apache.org
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
> so... are those pages in the code tree of github? I don't see them or a
> directory structure under /doc. Is mirroring the documentation between the
> apache site and a github source a big issue?
>
> On Tue, Feb 27, 2018 at 7:50 AM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
> I was debating that.  Splitting it up into smaller tasks makes each one
> seem less over-whelming.
>
> Kenneth Brotman
>
> *From:* Josh McKenzie [mailto:jmckenzie@apacheorg ]
> *Sent:* Tuesday, February 27, 2018 5:44 AM
> *To:* cassandra
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
> Might help, organizationally, to put all these efforts under a single
> ticket of "Improve web site Documentation" and add these as sub-tasks
> Should be able to do that translation post-creation (i.e. in its current
> state) if that's something that makes sense to you.
>
> On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
> Here are the related JIRA’s.  Please add content even if It’s not well
> formed compositionally.  Myself or someone else will take it from there
>
> https://issues.apache.org/jira/browse/CASSANDRA-14274  The
> troubleshooting section of the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14273  The Bulk Loading
> web page on the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14272  The Backups web
> page on the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14271  The Hints web page
> in the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14270  The Read repair
> web page is empty
> https://issuesapache.org/jira/browse/CASSANDRA-14269
>   The Data
> Modeling section of the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14268  The
> Architecture:Guarantees web page is empty
> https://issuesapache.org/jira/browse/CASSANDRA-14267
>   The Dynamo web
> page on the Apache Cassandra site is missing content
> https://issues.apache.org/jira/browse/CASSANDRA-14266  The Architecture
> Overview web page on the Apache Cassandra site is empty
>
> Thanks for pitching in
>
> Kenneth Brotman
>
> *From:* Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID]
> *Sent:* Monday, February 26, 2018 1:54 PM
> *To:* user@cassandra.apache.org
> *Subject:* RE: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
> Nice!  Thanks for the help Oliver!
>
> Kenneth Brotman
>
> *From:* Oliver Ruebenacker [mailto:cur...@gmail.com]
> *Sent:* Sunday, February 25, 2018 7:12 AM
> *To:* user@cassandra.apache.org
> *Cc:* dev@cassandra.apacheorg 
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
>  Hello,
>
>   I have some slides about Cassandra
> 

Re: Filling in the blank To Do sections on the Apache Cassandra web site

[Jon Haddad]

There’s a section dedicated to contributing to Cassandra documentation in the 
docs as well: 
https://cassandra.apache.org/doc/latest/development/documentation.html 



> On Feb 27, 2018, at 9:55 AM, Kenneth Brotman  
> wrote:
> 
> I was just getting ready to install sphinx.  Cool.  
>  
> From: Jon Haddad [mailto:jonathan.had...@gmail.com] On Behalf Of Jon Haddad
> Sent: Tuesday, February 27, 2018 9:51 AM
> To: user@cassandra.apache.org
> Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
> site
>  
> The docs have been in tree for years :)
>  
> https://github.com/apache/cassandra/tree/trunk/doc 
> 
>  
> There’s even a docker image to build them so you don’t need to mess with 
> sphinx.  Check the README for instructions.
>  
> Jon
> 
> 
> On Feb 27, 2018, at 9:49 AM, Carl Mueller  > wrote:
>  
> If there was a github for the docs, we could start posting content to it for 
> review. Not sure what the review/contribution process is on Apache. Google 
> searches on apache documentation and similar run into lots of noise from 
> actual projects.
> 
> I wouldn't mind trying to do a little doc work on the regular if there was a 
> wiki, a proven means to do collaborative docs. 
> 
>  
> On Tue, Feb 27, 2018 at 11:42 AM, Kenneth Brotman 
> > wrote:
> It’s just content for web pages.  There isn’t a working outline or any draft 
> on any of the JIRA’s yet.  I like to keep things simple.  Did I miss 
> something?  What does it matter right now?
>  
> Thanks Carl,
>  
> Kenneth Brotman
>  
> From: Carl Mueller [mailto:carl.muel...@smartthings.com 
> ] 
> Sent: Tuesday, February 27, 2018 8:50 AM
> To: user@cassandra.apache.org 
> Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
> site
>  
> so... are those pages in the code tree of github? I don't see them or a 
> directory structure under /doc. Is mirroring the documentation between the 
> apache site and a github source a big issue?
>  
> On Tue, Feb 27, 2018 at 7:50 AM, Kenneth Brotman 
> > wrote:
> I was debating that.  Splitting it up into smaller tasks makes each one seem 
> less over-whelming.  
>  
> Kenneth Brotman
>  
> From: Josh McKenzie [mailto:jmckenzie@apacheorg 
> ] 
> Sent: Tuesday, February 27, 2018 5:44 AM
> To: cassandra
> Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
> site
>  
> Might help, organizationally, to put all these efforts under a single ticket 
> of "Improve web site Documentation" and add these as sub-tasks Should be able 
> to do that translation post-creation (i.e. in its current state) if that's 
> something that makes sense to you.
>  
> On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman 
> > wrote:
> Here are the related JIRA’s.  Please add content even if It’s not well formed 
> compositionally.  Myself or someone else will take it from there
>  
> https://issues.apache.org/jira/browse/CASSANDRA-14274 
>   The troubleshooting 
> section of the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14273 
>   The Bulk Loading web 
> page on the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14272 
>   The Backups web page 
> on the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14271 
>   The Hints web page 
> in the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14270 
>   The Read repair web 
> page is empty
> https://issuesapache.org/jira/browse/CASSANDRA-14269 
>   The Data Modeling 
> section of the web site is empty
> https://issues.apache.org/jira/browse/CASSANDRA-14268 
>   The 
> Architecture:Guarantees web page is empty
> https://issuesapache.org/jira/browse/CASSANDRA-14267 
>   The Dynamo web page 
> on the Apache Cassandra site is missing content
> https://issues.apache.org/jira/browse/CASSANDRA-14266 
>   The Architecture 
> Overview web page on the Apache Cassandra site is empty
>  
> Thanks for pitching in  
>  
> Kenneth Brotman
>  
> From: Kenneth 

RE: Filling in the blank To Do sections on the Apache Cassandra web site

[Kenneth Brotman]

I was just getting ready to install sphinx.  Cool.  

 

From: Jon Haddad [mailto:jonathan.had...@gmail.com] On Behalf Of Jon Haddad
Sent: Tuesday, February 27, 2018 9:51 AM
To: user@cassandra.apache.org
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

The docs have been in tree for years :)

 

https://github.com/apache/cassandra/tree/trunk/doc

 

There’s even a docker image to build them so you don’t need to mess with 
sphinx.  Check the README for instructions.

 

Jon





On Feb 27, 2018, at 9:49 AM, Carl Mueller  wrote:

 

If there was a github for the docs, we could start posting content to it for 
review. Not sure what the review/contribution process is on Apache. Google 
searches on apache documentation and similar run into lots of noise from actual 
projects.

I wouldn't mind trying to do a little doc work on the regular if there was a 
wiki, a proven means to do collaborative docs. 

 

On Tue, Feb 27, 2018 at 11:42 AM, Kenneth Brotman 
 wrote:

It’s just content for web pages.  There isn’t a working outline or any draft on 
any of the JIRA’s yet.  I like to keep things simple.  Did I miss something?  
What does it matter right now?

 

Thanks Carl,

 

Kenneth Brotman

 

From: Carl Mueller [mailto:carl.muel...@smartthings.com] 
Sent: Tuesday, February 27, 2018 8:50 AM
To: user@cassandra.apache.org
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

so... are those pages in the code tree of github? I don't see them or a 
directory structure under /doc. Is mirroring the documentation between the 
apache site and a github source a big issue?

 

On Tue, Feb 27, 2018 at 7:50 AM, Kenneth Brotman  
wrote:

I was debating that.  Splitting it up into smaller tasks makes each one seem 
less over-whelming.  

 

Kenneth Brotman

 

From: Josh McKenzie [mailto:jmckenzie@apacheorg  ] 
Sent: Tuesday, February 27, 2018 5:44 AM
To: cassandra
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

Might help, organizationally, to put all these efforts under a single ticket of 
"Improve web site Documentation" and add these as sub-tasks Should be able to 
do that translation post-creation (i.e. in its current state) if that's 
something that makes sense to you.

 

On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman  
wrote:

Here are the related JIRA’s.  Please add content even if It’s not well formed 
compositionally.  Myself or someone else will take it from there

 

https://issues.apache.org/jira/browse/CASSANDRA-14274  The troubleshooting 
section of the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14273  The Bulk Loading web 
page on the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14272  The Backups web page on 
the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14271  The Hints web page in 
the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14270  The Read repair web page 
is empty

https://issuesapache.org/jira/browse/CASSANDRA-14269 
   The Data Modeling 
section of the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14268  The 
Architecture:Guarantees web page is empty

https://issuesapache.org/jira/browse/CASSANDRA-14267 
   The Dynamo web page 
on the Apache Cassandra site is missing content

https://issues.apache.org/jira/browse/CASSANDRA-14266  The Architecture 
Overview web page on the Apache Cassandra site is empty

 

Thanks for pitching in  

 

Kenneth Brotman

 

From: Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID] 
Sent: Monday, February 26, 2018 1:54 PM
To: user@cassandra.apache.org
Subject: RE: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

Nice!  Thanks for the help Oliver!

 

Kenneth Brotman

 

From: Oliver Ruebenacker [mailto:cur...@gmail.com] 
Sent: Sunday, February 25, 2018 7:12 AM
To: user@cassandra.apache.org
Cc: dev@cassandra.apacheorg  
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

 

 Hello,

  I have some slides about Cassandra 

 , feel free to borrow.

 Best, Oliver

 

On Fri, Feb 23, 2018 at 7:28 PM, Kenneth Brotman  
wrote:

These nine web pages on the Apache Cassandra web site have blank To Do 
sections.  Most of the web pages are completely blank.  Mind you there is a lot 
of hard work already done on the documentation.  I’ll make JIRA’s for any of 
the blank sections where there is not already a JIRA.  Then it will be on to 
writing up those sections.  If you have 

Re: Filling in the blank To Do sections on the Apache Cassandra web site

[Jon Haddad]

The docs have been in tree for years :)

https://github.com/apache/cassandra/tree/trunk/doc 


There’s even a docker image to build them so you don’t need to mess with 
sphinx.  Check the README for instructions.

Jon

> On Feb 27, 2018, at 9:49 AM, Carl Mueller  
> wrote:
> 
> If there was a github for the docs, we could start posting content to it for 
> review. Not sure what the review/contribution process is on Apache. Google 
> searches on apache documentation and similar run into lots of noise from 
> actual projects.
> 
> I wouldn't mind trying to do a little doc work on the regular if there was a 
> wiki, a proven means to do collaborative docs. 
> 
> 
> On Tue, Feb 27, 2018 at 11:42 AM, Kenneth Brotman 
> > wrote:
> It’s just content for web pages.  There isn’t a working outline or any draft 
> on any of the JIRA’s yet.  I like to keep things simple.  Did I miss 
> something?  What does it matter right now?
> 
>  
> 
> Thanks Carl,
> 
>  
> 
> Kenneth Brotman
> 
>  
> 
> From: Carl Mueller [mailto:carl.muel...@smartthings.com 
> ] 
> Sent: Tuesday, February 27, 2018 8:50 AM
> To: user@cassandra.apache.org 
> Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
> site
> 
>  
> 
> so... are those pages in the code tree of github? I don't see them or a 
> directory structure under /doc. Is mirroring the documentation between the 
> apache site and a github source a big issue?
> 
>  
> 
> On Tue, Feb 27, 2018 at 7:50 AM, Kenneth Brotman 
> > wrote:
> 
> I was debating that.  Splitting it up into smaller tasks makes each one seem 
> less over-whelming. 
> 
>  
> 
> Kenneth Brotman
> 
>  
> 
> From: Josh McKenzie [mailto:jmckenzie@apacheorg 
> ] 
> Sent: Tuesday, February 27, 2018 5:44 AM
> To: cassandra
> Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
> site
> 
>  
> 
> Might help, organizationally, to put all these efforts under a single ticket 
> of "Improve web site Documentation" and add these as sub-tasks Should be able 
> to do that translation post-creation (i.e. in its current state) if that's 
> something that makes sense to you.
> 
>  
> 
> On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman 
> > wrote:
> 
> Here are the related JIRA’s.  Please add content even if It’s not well formed 
> compositionally.  Myself or someone else will take it from there
> 
>  
> 
> https://issues.apache.org/jira/browse/CASSANDRA-14274 
>   The troubleshooting 
> section of the web site is empty
> 
> https://issues.apache.org/jira/browse/CASSANDRA-14273 
>   The Bulk Loading web 
> page on the web site is empty
> 
> https://issues.apache.org/jira/browse/CASSANDRA-14272 
>   The Backups web page 
> on the web site is empty
> 
> https://issues.apache.org/jira/browse/CASSANDRA-14271 
>   The Hints web page 
> in the web site is empty
> 
> https://issues.apache.org/jira/browse/CASSANDRA-14270 
>   The Read repair web 
> page is empty
> 
> https://issuesapache.org/jira/browse/CASSANDRA-14269 
>   The Data Modeling 
> section of the web site is empty
> 
> https://issues.apache.org/jira/browse/CASSANDRA-14268 
>   The 
> Architecture:Guarantees web page is empty
> 
> https://issuesapache.org/jira/browse/CASSANDRA-14267 
>   The Dynamo web page 
> on the Apache Cassandra site is missing content
> 
> https://issues.apache.org/jira/browse/CASSANDRA-14266 
>   The Architecture 
> Overview web page on the Apache Cassandra site is empty
> 
>  
> 
> Thanks for pitching in 
> 
>  
> 
> Kenneth Brotman
> 
>  
> 
> From: Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID 
> ] 
> Sent: Monday, February 26, 2018 1:54 PM
> To: user@cassandra.apache.org 
> Subject: RE: Filling in the blank To Do sections on the Apache Cassandra web 
> site
> 
>  
> 
> Nice!  Thanks for the help Oliver!
> 
>  
> 
> Kenneth Brotman
> 
>  
> 
> From: Oliver Ruebenacker [mailto:cur...@gmail.com ] 
> Sent: Sunday, February 25, 2018 7:12 AM
> To: user@cassandra.apache.org 
> Cc: dev@cassandra.apacheorg 

Re: Filling in the blank To Do sections on the Apache Cassandra web site

[Carl Mueller]

If there was a github for the docs, we could start posting content to it
for review. Not sure what the review/contribution process is on Apache.
Google searches on apache documentation and similar run into lots of noise
from actual projects.

I wouldn't mind trying to do a little doc work on the regular if there was
a wiki, a proven means to do collaborative docs.


On Tue, Feb 27, 2018 at 11:42 AM, Kenneth Brotman <
kenbrot...@yahoo.com.invalid> wrote:

> It’s just content for web pages.  There isn’t a working outline or any
> draft on any of the JIRA’s yet.  I like to keep things simple.  Did I miss
> something?  What does it matter right now?
>
>
>
> Thanks Carl,
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Carl Mueller [mailto:carl.muel...@smartthings.com]
> *Sent:* Tuesday, February 27, 2018 8:50 AM
> *To:* user@cassandra.apache.org
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
> so... are those pages in the code tree of github? I don't see them or a
> directory structure under /doc. Is mirroring the documentation between the
> apache site and a github source a big issue?
>
>
>
> On Tue, Feb 27, 2018 at 7:50 AM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
>
> I was debating that.  Splitting it up into smaller tasks makes each one
> seem less over-whelming.
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Josh McKenzie [mailto:jmckenzie@apacheorg ]
> *Sent:* Tuesday, February 27, 2018 5:44 AM
> *To:* cassandra
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
> Might help, organizationally, to put all these efforts under a single
> ticket of "Improve web site Documentation" and add these as sub-tasks
> Should be able to do that translation post-creation (i.e. in its current
> state) if that's something that makes sense to you.
>
>
>
> On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
>
> Here are the related JIRA’s.  Please add content even if It’s not well
> formed compositionally.  Myself or someone else will take it from there
>
>
>
> https://issues.apache.org/jira/browse/CASSANDRA-14274  The
> troubleshooting section of the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14273  The Bulk Loading
> web page on the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14272  The Backups web
> page on the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14271  The Hints web page
> in the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14270  The Read repair
> web page is empty
>
> https://issuesapache.org/jira/browse/CASSANDRA-14269
>   The Data
> Modeling section of the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14268  The
> Architecture:Guarantees web page is empty
>
> https://issuesapache.org/jira/browse/CASSANDRA-14267
>   The Dynamo web
> page on the Apache Cassandra site is missing content
>
> https://issues.apache.org/jira/browse/CASSANDRA-14266  The Architecture
> Overview web page on the Apache Cassandra site is empty
>
>
>
> Thanks for pitching in
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID]
> *Sent:* Monday, February 26, 2018 1:54 PM
> *To:* user@cassandra.apache.org
> *Subject:* RE: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
> Nice!  Thanks for the help Oliver!
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Oliver Ruebenacker [mailto:cur...@gmail.com]
> *Sent:* Sunday, February 25, 2018 7:12 AM
> *To:* user@cassandra.apache.org
> *Cc:* dev@cassandra.apacheorg 
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
>
>
>  Hello,
>
>   I have some slides about Cassandra
> ,
> feel free to borrow.
>
>  Best, Oliver
>
>
>
> On Fri, Feb 23, 2018 at 7:28 PM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
>
> These nine web pages on the Apache Cassandra web site have blank To Do
> sections.  Most of the web pages are completely blank.  Mind you there is a
> lot of hard work already done on the documentation.  I’ll make JIRA’s for
> any of the blank sections where there is not already a JIRA.  Then it will
> be on to writing up those sections.  *If you have any text to help me get
> started for any of these sections that would be really cool. *
>
>
>
> http://cassandra.apache.org/doc/latest/architecture/overview.html
>
>
>
> http://cassandra.apacheorg/doc/latest/architecture/dynamo.html
> 
>
>
>
> http://cassandra.apache.org/doc/latest/architecture/guarantees.html
> 

Re: Version Rollback

[Jeff Jirsa]

MOST minor versions support rollback - the exceptions are those where internode 
protocol changes (3.0.14 being the only one in recent memory), or where sstable 
format changes (again rare). No major versions support rollback - the only way 
to do it is to upgrade in a way that you can effectively reinstall the old 
version without data loss.

The steps usually look like:

Test in a lab
Test in a lab again
Test in a lab a few more times
Snapshot everything 

If you have a passive data center:
- upgrade one instance
- check to see if it’s happy
- upgrade another
- check to see if it’s happy
- continue until the passive dc is done
- if at any point they’re unhappy rebuild (wipe and restream the old version) 
the dc from the active dc

On the active DCs, you’ll want to canary it one replica at a time so you can 
treat a failed upgrade like a bad disk:
- upgrade one instance
- check if it’s happy; if it’s not treat it like a failed disk and replace it 
with the old version
- if you’re using single token, do another instance in a different replica set, 
repeat until you’re out of different replicas. 
- if you’re using vnodes but a rack aware snitch and have more racks than your 
RF, do another instance in the same rack as the canary, repeat until you’re out 
of instances in that rack

This is typically your point of no return - as soon as you have two replicas in 
the new version there’s no more rollback practical. 



-- 
Jeff Jirsa


> On Feb 27, 2018, at 9:22 AM, Carl Mueller  
> wrote:
> 
> My speculation is that IF (bigif) the sstable formats are compatible between 
> the versions, which probably isn't the case for major versions, then you 
> could drop back. 
> 
> If the sstables changed format, then you'll probably need to figure out how 
> to rewrite the sstables in the older format and then sstableloader them in 
> the older-version cluster if need be. Alas, while there is an sstable 
> upgrader, there isn't a downgrader AFAIK. 
> 
> And I don't have an intimate view of version-by-version sstable format 
> changes and compatibilities. You'd probably need to check the upgrade 
> instructions (which you presumably did if you're upgrading versions) to tell.
> 
> Basically, version rollback is pretty unlikely to be done.
> 
> The OTHER option:
> 
> 1) build a new cluster with the new version, no new data. 
> 
> 2) code your driver interfaces to interface with both clusters. Write to 
> both, but read preferentially from the new, then fall through to the old. 
> Yes, that gets hairy on multiple row queries. Port your data with sstable 
> loading from the old to the new gradually. 
> 
> When you've done a full load of all the data from old to new, and you're 
> satisfied with the new cluster stability, retire the old cluster.
> 
> For merging two multirow sets you'll probably need your multirow queries to 
> return the partition hash value (or extract the code that generates the 
> hash), and have two simulaneous java-driver ResultSets going, and merge their 
> results, providing the illusion of a single database query. You'll need to 
> pay attention to both the row key ordering and column key ordering to ensure 
> the combined results are properly ordered.
> 
> Writes will be slowed by the double-writes, reads you'll be bound by the 
> worse performing cluster.
> 
>> On Tue, Feb 27, 2018 at 8:23 AM, Kenneth Brotman 
>>  wrote:
>> Could you tell us the size and configuration of your Cassandra cluster?
>> 
>>  
>> 
>> Kenneth Brotman
>> 
>>  
>> 
>> From: shalom sagges [mailto:shalomsag...@gmail.com] 
>> Sent: Tuesday, February 27, 2018 6:19 AM
>> To: user@cassandra.apache.org
>> Subject: Version Rollback
>> 
>>  
>> 
>> Hi All,
>> 
>> I'm planning to upgrade my C* cluster to version 3.x and was wondering 
>> what's the best way to perform a rollback if need be.
>> 
>> If I used snapshot restoration, I would be facing data loss, depends when I 
>> took the snapshot (i.e. a rollback might be required after upgrading half 
>> the cluster for example).
>> 
>> If I add another DC to the cluster with the old version, then I could point 
>> the apps to talk to that DC if anything bad happens, but building it is 
>> really time consuming and requires a lot of resources.
>> 
>> Can anyone provide recommendations on this matter? Any ideas on how to make 
>> the upgrade foolproof, or at least "really really safe"?
>> 
>>  
>> 
>> Thanks!
>> 
>>  
>> 
> 

RE: Filling in the blank To Do sections on the Apache Cassandra web site

[Kenneth Brotman]

It’s just content for web pages.  There isn’t a working outline or any draft on 
any of the JIRA’s yet.  I like to keep things simple.  Did I miss something?  
What does it matter right now?

 

Thanks Carl,

 

Kenneth Brotman

 

From: Carl Mueller [mailto:carl.muel...@smartthings.com] 
Sent: Tuesday, February 27, 2018 8:50 AM
To: user@cassandra.apache.org
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

so... are those pages in the code tree of github? I don't see them or a 
directory structure under /doc. Is mirroring the documentation between the 
apache site and a github source a big issue?

 

On Tue, Feb 27, 2018 at 7:50 AM, Kenneth Brotman  
wrote:

I was debating that.  Splitting it up into smaller tasks makes each one seem 
less over-whelming.  

 

Kenneth Brotman

 

From: Josh McKenzie [mailto:jmckenzie@apacheorg  ] 
Sent: Tuesday, February 27, 2018 5:44 AM
To: cassandra
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

Might help, organizationally, to put all these efforts under a single ticket of 
"Improve web site Documentation" and add these as sub-tasks Should be able to 
do that translation post-creation (i.e. in its current state) if that's 
something that makes sense to you.

 

On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman  
wrote:

Here are the related JIRA’s.  Please add content even if It’s not well formed 
compositionally.  Myself or someone else will take it from there

 

https://issues.apache.org/jira/browse/CASSANDRA-14274  The troubleshooting 
section of the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14273  The Bulk Loading web 
page on the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14272  The Backups web page on 
the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14271  The Hints web page in 
the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14270  The Read repair web page 
is empty

https://issuesapache.org/jira/browse/CASSANDRA-14269 
   The Data Modeling 
section of the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14268  The 
Architecture:Guarantees web page is empty

https://issuesapache.org/jira/browse/CASSANDRA-14267 
   The Dynamo web page 
on the Apache Cassandra site is missing content

https://issues.apache.org/jira/browse/CASSANDRA-14266  The Architecture 
Overview web page on the Apache Cassandra site is empty

 

Thanks for pitching in  

 

Kenneth Brotman

 

From: Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID] 
Sent: Monday, February 26, 2018 1:54 PM
To: user@cassandra.apache.org
Subject: RE: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

Nice!  Thanks for the help Oliver!

 

Kenneth Brotman

 

From: Oliver Ruebenacker [mailto:cur...@gmail.com] 
Sent: Sunday, February 25, 2018 7:12 AM
To: user@cassandra.apache.org
Cc: dev@cassandra.apacheorg  
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

 

 Hello,

  I have some slides about Cassandra 

 , feel free to borrow.

 Best, Oliver

 

On Fri, Feb 23, 2018 at 7:28 PM, Kenneth Brotman  
wrote:

These nine web pages on the Apache Cassandra web site have blank To Do 
sections.  Most of the web pages are completely blank.  Mind you there is a lot 
of hard work already done on the documentation.  I’ll make JIRA’s for any of 
the blank sections where there is not already a JIRA.  Then it will be on to 
writing up those sections.  If you have any text to help me get started for any 
of these sections that would be really cool. 

 

http://cassandra.apache.org/doc/latest/architecture/overview.html

 

http://cassandra.apacheorg/doc/latest/architecture/dynamo.html 
 

 

http://cassandra.apache.org/doc/latest/architecture/guarantees.html 
 

 

http://cassandra.apache.org/doc/latest/data_modeling/index.html

 

http://cassandra.apacheorg/doc/latest/operating/read_repair.html 
 

 

http://cassandra.apache.org/doc/latest/operating/hints.html

 

http://cassandra.apache.org/doc/latest/operating/backups.html

 

http://cassandra.apache.org/doc/latest/operating/bulk_loading.html

 

http://cassandra.apache.org/doc/latest/troubleshooting/index.html

 

Kenneth Brotman

 




-- 

Oliver Ruebenacker

Senior Software Engineer, Diabetes Portal 
 , Broad Institute 

Re: JMX metrics for CL

[Horia Mocioi]

Hello,

There are no such metrics that I am aware of.

One way you could do this is to have your own implementation of QueryHandler 
and your own metrics and filter the queries based on the CL and increment the 
according metric.

Then, in cassandra-env.sh you could specify to use your class using  
-Dcassandra.custom_query_handler_class.

HTH,
Horia
On tis, 2018-02-27 at 08:26 +, Kyrylo Lebediev wrote:

Hello!


Is it possible to get counters  from C* side regarding CQL queries executed 
since startup for each CL?
For example:
CL ONE: NNN queries
CL QUORUM: MMM queries
etc

Regards,

Kyrill

RE: Version Rollback

[Kenneth Brotman]

I wonder if you could use Apache Spark to do it?

 

Kenneth Brotman

 

From: Carl Mueller [mailto:carl.muel...@smartthings.com] 
Sent: Tuesday, February 27, 2018 9:22 AM
To: user@cassandra.apache.org
Subject: Re: Version Rollback

 

My speculation is that IF (bigif) the sstable formats are compatible between 
the versions, which probably isn't the case for major versions, then you could 
drop back. 

If the sstables changed format, then you'll probably need to figure out how to 
rewrite the sstables in the older format and then sstableloader them in the 
older-version cluster if need be. Alas, while there is an sstable upgrader, 
there isn't a downgrader AFAIK. 

And I don't have an intimate view of version-by-version sstable format changes 
and compatibilities. You'd probably need to check the upgrade instructions 
(which you presumably did if you're upgrading versions) to tell.

Basically, version rollback is pretty unlikely to be done.

The OTHER option:

1) build a new cluster with the new version, no new data. 

2) code your driver interfaces to interface with both clusters. Write to both, 
but read preferentially from the new, then fall through to the old. Yes, that 
gets hairy on multiple row queries. Port your data with sstable loading from 
the old to the new gradually. 

When you've done a full load of all the data from old to new, and you're 
satisfied with the new cluster stability, retire the old cluster.

For merging two multirow sets you'll probably need your multirow queries to 
return the partition hash value (or extract the code that generates the hash), 
and have two simulaneous java-driver ResultSets going, and merge their results, 
providing the illusion of a single database query. You'll need to pay attention 
to both the row key ordering and column key ordering to ensure the combined 
results are properly ordered.

Writes will be slowed by the double-writes, reads you'll be bound by the worse 
performing cluster.

 

On Tue, Feb 27, 2018 at 8:23 AM, Kenneth Brotman  
wrote:

Could you tell us the size and configuration of your Cassandra cluster?

 

Kenneth Brotman

 

From: shalom sagges [mailto:shalomsag...@gmail.com] 
Sent: Tuesday, February 27, 2018 6:19 AM
To: user@cassandra.apache.org
Subject: Version Rollback

 

Hi All, 

I'm planning to upgrade my C* cluster to version 3.x and was wondering what's 
the best way to perform a rollback if need be. 

If I used snapshot restoration, I would be facing data loss, depends when I 
took the snapshot (i.e. a rollback might be required after upgrading half the 
cluster for example). 

If I add another DC to the cluster with the old version, then I could point the 
apps to talk to that DC if anything bad happens, but building it is really time 
consuming and requires a lot of resources. 

Can anyone provide recommendations on this matter? Any ideas on how to make the 
upgrade foolproof, or at least "really really safe"? 

 

Thanks!

 

 

Re: Data Deleted After a few days of being off

[Carl Mueller]

Does cassandra still function if the commitlog dir has no writes? Will the
data still go into the memtable and serve queries?

On Tue, Feb 27, 2018 at 1:37 AM, Oleksandr Shulgin <
oleksandr.shul...@zalando.de> wrote:

> On Tue, Feb 27, 2018 at 7:37 AM, A  wrote:
>
>>
>> I started going through the logs and haven't noticed anything yet... Very
>> unexpected behavior.
>>
>
> Maybe I'm asking the obvious, but were your inserts *without* a TTL?
>
> --
> Alex
>
>

Re: Version Rollback

[Carl Mueller]

My speculation is that IF (bigif) the sstable formats are compatible
between the versions, which probably isn't the case for major versions,
then you could drop back.

If the sstables changed format, then you'll probably need to figure out how
to rewrite the sstables in the older format and then sstableloader them in
the older-version cluster if need be. Alas, while there is an sstable
upgrader, there isn't a downgrader AFAIK.

And I don't have an intimate view of version-by-version sstable format
changes and compatibilities. You'd probably need to check the upgrade
instructions (which you presumably did if you're upgrading versions) to
tell.

Basically, version rollback is pretty unlikely to be done.

The OTHER option:

1) build a new cluster with the new version, no new data.

2) code your driver interfaces to interface with both clusters. Write to
both, but read preferentially from the new, then fall through to the old.
Yes, that gets hairy on multiple row queries. Port your data with sstable
loading from the old to the new gradually.

When you've done a full load of all the data from old to new, and you're
satisfied with the new cluster stability, retire the old cluster.

For merging two multirow sets you'll probably need your multirow queries to
return the partition hash value (or extract the code that generates the
hash), and have two simulaneous java-driver ResultSets going, and merge
their results, providing the illusion of a single database query. You'll
need to pay attention to both the row key ordering and column key ordering
to ensure the combined results are properly ordered.

Writes will be slowed by the double-writes, reads you'll be bound by the
worse performing cluster.

On Tue, Feb 27, 2018 at 8:23 AM, Kenneth Brotman <
kenbrot...@yahoo.com.invalid> wrote:

> Could you tell us the size and configuration of your Cassandra cluster?
>
>
>
> Kenneth Brotman
>
>
>
> *From:* shalom sagges [mailto:shalomsag...@gmail.com]
> *Sent:* Tuesday, February 27, 2018 6:19 AM
> *To:* user@cassandra.apache.org
> *Subject:* Version Rollback
>
>
>
> Hi All,
>
> I'm planning to upgrade my C* cluster to version 3.x and was wondering
> what's the best way to perform a rollback if need be.
>
> If I used snapshot restoration, I would be facing data loss, depends when
> I took the snapshot (i.e. a rollback might be required after upgrading half
> the cluster for example).
>
> If I add another DC to the cluster with the old version, then I could
> point the apps to talk to that DC if anything bad happens, but building it
> is really time consuming and requires a lot of resources.
>
> Can anyone provide recommendations on this matter? Any ideas on how to
> make the upgrade foolproof, or at least "really really safe"?
>
>
>
> Thanks!
>
>
>

Re: Jon Haddad on Diagnosing Performance Problems in Production

[Jonathan Haddad]

There isn't a ton from that talk I'd consider "wrong" at this point, but
some of it is a little stale.  I always start off looking at system
metrics.  For a very thorough discussion on the matter check out Brendan
Gregg's USE [1] method.  I did a blog post on my own about the talk [2]
that has screenshots and might be helpful.  Generally speaking know your OS
and the tools to examine each component.  Learn how to interpret the
numbers you see, there's more information than a human can process in a
lifetime but understanding some fundamentals of throughput vs latency &
error rates and how to find out each of those metrics for cpu / memory /
network / disk is a good start.

More recently I did a talk at Data Day Texas, I posted the slides on
Slideshare [3].  The focus there was more on perf tuning and less on
performance troubleshooting, but I guess it's a matter of perspective which
point your at.  The tools have changed a little (Prometheus instead of
Graphite), and there's some new perf tuning tips like examining your read
ahead and compression settings, generating flame graphs and using tools
like YourKit and Java Flight Recorder, and the easiest win of all time,
disabling dynamic snitch if your hardware is fast and you want sub ms
p99s.  Turn up counter cache if you use counters (it still gets hit on the
write path), and row cache is way more effective than people give it credit
for under the right workloads.

I've got a blog post in the works on JVM tuning, but for now I reference
CASSANDRA-8150 [4] and Blake Eggleston's blog post [5] from back in our
days at a small startup.

Lastly, I'm doing a performance tuning series on our blog at The Last
Pickle, with the first being on Flame Graphs [6].  I've got about 6 posts
in the pipeline, just need to find time to get to them.

Hope this helps,
Jon

[1] http://www.brendangregg.com/usemethod.html
[2] http://rustyrazorblade.com/post/2014/2014-09-18-diagnosing-production/
[3] https://www.slideshare.net/JonHaddad/performance-tuning-86995333
[4] https://issues.apache.org/jira/browse/CASSANDRA-8150
[5]
http://blakeeggleston.com/cassandra-tuning-the-jvm-for-read-heavy-workloads.html
[6] http://thelastpickle.com/blog/2018/01/16/cassandra-flame-graphs.html



On Tue, Feb 27, 2018 at 8:56 AM Michael Shuler 
wrote:

> On 02/27/2018 10:20 AM, Nicolas Guyomar wrote:
> > Is Jon blog
> > post
> https://academy.datastax.com/planet-cassandra/blog/cassandra-summit-recap-diagnosing-problems-in-production
> > was relocated somewhere ?
>
>
> https://web.archive.org/web/20160322011022/planetcassandra.org/blog/cassandra-summit-recap-diagnosing-problems-in-production
>
> --
> Kind regards,
> Michael
>
> -
> To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org
> For additional commands, e-mail: user-h...@cassandra.apache.org
>
>

RE: Jon Haddad on Diagnosing Performance Problems in Production

[ZAIDI, ASAD A]

Perhaps Mr. Hadad himself  will share it again somewhere; he was kind enough to 
share it once at datastax!


From: Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID]
Sent: Tuesday, February 27, 2018 10:39 AM
To: user@cassandra.apache.org
Subject: RE: Jon Haddad on Diagnosing Performance Problems in Production

Nicolas,

I think you had the link to the other version I was thinking of.  I couldn’t 
find it.  I think it might have gotten taken down; a lot of other stuff seems 
to be gone too.  Maybe it will be back.  Maybe they are just redoing stuff.  
Either way, it’s another sign of Mom and Dad drifting apart – I’m not sure 
who’s Mom and who’s Dad: DataStax or ASF.  Hopefully, for the sake of everyone 
in the family they will reconcile.

It’s gems like that presentation that will keep us vital.

Kenneth Brotman

From: Nicolas Guyomar [mailto:nicolas.guyo...@gmail.com]
Sent: Tuesday, February 27, 2018 8:21 AM
To: user@cassandra.apache.org
Subject: Re: Jon Haddad on Diagnosing Performance Problems in Production

Is Jon blog post 
https://academy.datastax.com/planet-cassandra/blog/cassandra-summit-recap-diagnosing-problems-in-production
 was relocated somewhere ?

On 27 February 2018 at 16:34, Kenneth Brotman 
> wrote:
One presentation that I hope can get updated is Jon Haddad’s very thorough 
presentation on Diagnosing Performance Problems in Production.  I’ve seen 
another version somewhere where I believe he says something like “This should 
help you fix 99% of the problems you see.”  Seems right.

I’m sure it will be well attended and well viewed for some time.  Here’s the 
version I found: 
https://www.youtube.com/watch?v=2JlUpgsEdN8

If Jon did a new version I’d probably stop and watch it three times right now.

If we started with that video inline on the Apache Cassandra web site in the 
troubleshooting section, that would help a lot of people because of the quality 
of the content and the density of the content.

Kenneth Brotman

Re: Jon Haddad on Diagnosing Performance Problems in Production

[Michael Shuler]

On 02/27/2018 10:20 AM, Nicolas Guyomar wrote:
> Is Jon blog
> post 
> https://academy.datastax.com/planet-cassandra/blog/cassandra-summit-recap-diagnosing-problems-in-production
> was relocated somewhere ?

https://web.archive.org/web/20160322011022/planetcassandra.org/blog/cassandra-summit-recap-diagnosing-problems-in-production

-- 
Kind regards,
Michael

-
To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org
For additional commands, e-mail: user-h...@cassandra.apache.org

Re: Filling in the blank To Do sections on the Apache Cassandra web site

[Carl Mueller]

so... are those pages in the code tree of github? I don't see them or a
directory structure under /doc. Is mirroring the documentation between the
apache site and a github source a big issue?

On Tue, Feb 27, 2018 at 7:50 AM, Kenneth Brotman <
kenbrot...@yahoo.com.invalid> wrote:

> I was debating that.  Splitting it up into smaller tasks makes each one
> seem less over-whelming.
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Josh McKenzie [mailto:jmcken...@apache.org]
> *Sent:* Tuesday, February 27, 2018 5:44 AM
> *To:* cassandra
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
> Might help, organizationally, to put all these efforts under a single
> ticket of "Improve web site Documentation" and add these as sub-tasks.
> Should be able to do that translation post-creation (i.e. in its current
> state) if that's something that makes sense to you.
>
>
>
> On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
>
> Here are the related JIRA’s.  Please add content even if It’s not well
> formed compositionally.  Myself or someone else will take it from there
>
>
>
> https://issues.apache.org/jira/browse/CASSANDRA-14274  The
> troubleshooting section of the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14273  The Bulk Loading
> web page on the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14272  The Backups web
> page on the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14271  The Hints web page
> in the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14270  The Read repair
> web page is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14269  The Data Modeling
> section of the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14268  The
> Architecture:Guarantees web page is empty
>
> https://issuesapache.org/jira/browse/CASSANDRA-14267
>   The Dynamo web
> page on the Apache Cassandra site is missing content
>
> https://issues.apache.org/jira/browse/CASSANDRA-14266  The Architecture
> Overview web page on the Apache Cassandra site is empty
>
>
>
> Thanks for pitching in
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID]
> *Sent:* Monday, February 26, 2018 1:54 PM
> *To:* user@cassandra.apache.org
> *Subject:* RE: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
> Nice!  Thanks for the help Oliver!
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Oliver Ruebenacker [mailto:cur...@gmail.com]
> *Sent:* Sunday, February 25, 2018 7:12 AM
> *To:* user@cassandra.apache.org
> *Cc:* d...@cassandra.apache.org
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
>
>
>  Hello,
>
>   I have some slides about Cassandra
> ,
> feel free to borrow.
>
>  Best, Oliver
>
>
>
> On Fri, Feb 23, 2018 at 7:28 PM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
>
> These nine web pages on the Apache Cassandra web site have blank To Do
> sections.  Most of the web pages are completely blank.  Mind you there is a
> lot of hard work already done on the documentation.  I’ll make JIRA’s for
> any of the blank sections where there is not already a JIRA.  Then it will
> be on to writing up those sections.  *If you have any text to help me get
> started for any of these sections that would be really cool. *
>
>
>
> http://cassandra.apache.org/doc/latest/architecture/overview.html
>
>
>
> http://cassandra.apache.org/doc/latest/architecture/dynamo.html
>
>
>
> http://cassandra.apache.org/doc/latest/architecture/guarantees.html
> 
>
>
>
> http://cassandra.apache.org/doc/latest/data_modeling/index.html
>
>
>
> http://cassandra.apacheorg/doc/latest/operating/read_repair.html
> 
>
>
>
> http://cassandra.apache.org/doc/latest/operating/hints.html
>
>
>
> http://cassandra.apache.org/doc/latest/operating/backups.html
>
>
>
> http://cassandra.apache.org/doc/latest/operating/bulk_loading.html
>
>
>
> http://cassandra.apache.org/doc/latest/troubleshooting/index.html
>
>
>
> Kenneth Brotman
>
>
>
>
>
>
> --
>
> Oliver Ruebenacker
>
> Senior Software Engineer, Diabetes Portal
> , Broad Institute
> 
>
>
>
>
>

RE: Cassandra Summit 2019 / Cassandra Summit 2018

[Kenneth Brotman]

The Meet Up groups might be a good way to implement a distributed asynchronous 
event that can still be optionally attended in person.  We could make a nice 
kit for a few meetings for them that ties together with the event and connects 
them as participates in it.  

 

Here is the Meetup website with the Cassandra groups loaded: 
https://www.meetup.com/find/?allMeetups=false 

 
=Cassandra=Infinity=Sacramento%2C+CA=Sacramento%2C+CA=default
 .  

I stopped counting after I easily got to 10,000 members.

 

Kenneth Brotman

 

From: Rahul Singh [mailto:rahul.xavier.si...@gmail.com] 
Sent: Tuesday, February 27, 2018 6:27 AM
To: user@cassandra.apache.org
Subject: Re: Cassandra Summit 2019 / Cassandra Summit 2018

 

I can help organize. I organize three meetups in the area here and know several 
venues that would be able to lend space if needed.

We can host about 20-30 people at our office or get a location through a 
coworking spot / one of the universities ( Georgetown or George Washington)

The community should do something this year — even if it is semi - Virtual. 
I’ve seen some decent implementations of it in other disciplines. Some
Combination of physical get together on a certain day around the world with 
groups presenting locally and then some folks presenting on a global hangout. 
Breaking momentum is the worst killer of community.

We can rally around one date and see how we do. You can count on DC Cassandra 
committing to make our part of it happen. Best,


--
Rahul Singh
rahul.si...@anant.us

Anant Corporation


On Feb 27, 2018, 5:43 AM -0600, Carlos Rolo , wrote:



Hello all, 

 

I'm interested planning/organizing a small kinda of NGCC in Lisbon, Portugal in 
late May early June. Just waiting for the venue to confirm possible dates.

 

Would be a 1day event kinda last year, is this something people would be 
interested? I can push a google form for accessing the interest today.

 




Regards,

 

Carlos Juzarte Rolo

Cassandra Consultant / Datastax Certified Architect / Cassandra MVP

 

Pythian - Love your data

 

rolo@pythian | Twitter: @cjrolo | Skype: cjr2k3 | Linkedin: 
linkedin.com/in/carlosjuzarterolo


Mobile: +351 918 918 100  

  www.pythian.com

 

On Tue, Feb 27, 2018 at 11:39 AM, Kenneth Brotman 
 wrote:

Event planning is fun as long as you can pace it out properly.  Once you set a 
firm date for an event the pressure on you to keep everything on track is nerve 
racking.  To do something on the order of Cassandra Summit 2016, I think we are 
should plan for 2020.  It’s too late for 2018 and even trying to meet the 
timeline for everything that would have to come together makes 2019 too nerve 
racking a target date.  The steps should be:

Form a planning committee

Bring potential sponsors into the planning early

Select an event planning vendor to guide us and to do the heavy 
lifting for us



In the meantime, we could have a World-wide Distributed Asynchronous Cassandra 
Convention which offers four benefits:

It allows us to address the fact that we are a world-wide group 
that needs a way to reach everyone in a way where no one is geographically 
disadvantaged

No travel time, no travel expenses and no ticket fees makes it 
accessible to a lot of people that otherwise would have to miss out

The lower production costs and simpler administrative workload allows us to 
reach implementation sooner 

It’s cutting edge, world class innovation like Cassandra



Kenneth Brotman

 

From: Jeff Jirsa [mailto:jji...@gmail.com]
Sent: Monday, February 26, 2018 9:38 PM
To: cassandra
Subject: Re: Cassandra Summit 2019 / Cassandra Summit 2018

 

Instaclustr sponsored the 2017 NGCC (Next Gen Cassandra Conference), which was 
developer/development focused (vs user focused).

 

For 2018, we're looking at options for both a developer conference and a user 
conference. There's a lot of logistics involved, and I think it's fairly 
obvious that most of the PMC members aren't professional event planners, so 
it's possible that either/both conferences may not happen, but we're doing our 
best to try to put something together.

 

 

On Mon, Feb 26, 2018 at 3:00 PM, Rahul Singh  
wrote:

I think some of the Instaclustr folks had done one last year which I really 
wanted to go to.. Distributed / Async both would be easier to get people to 
write papers, make slides, do youtube videos with.. and then we could do a 
virtual web conf of the best submissions. 


On Feb 26, 2018, 1:04 PM -0600, Kenneth Brotman , 
wrote:

Is there any planning yet for a Cassandra Summit 2019 or Cassandra Summit 2018 

RE: Jon Haddad on Diagnosing Performance Problems in Production

[Kenneth Brotman]

Nicolas,

 

I think you had the link to the other version I was thinking of.  I couldn’t 
find it.  I think it might have gotten taken down; a lot of other stuff seems 
to be gone too.  Maybe it will be back.  Maybe they are just redoing stuff.  
Either way, it’s another sign of Mom and Dad drifting apart – I’m not sure 
who’s Mom and who’s Dad: DataStax or ASF.  Hopefully, for the sake of everyone 
in the family they will reconcile.

 

It’s gems like that presentation that will keep us vital.  

 

Kenneth Brotman

 

From: Nicolas Guyomar [mailto:nicolas.guyo...@gmail.com] 
Sent: Tuesday, February 27, 2018 8:21 AM
To: user@cassandra.apache.org
Subject: Re: Jon Haddad on Diagnosing Performance Problems in Production

 

Is Jon blog post 
https://academy.datastax.com/planet-cassandra/blog/cassandra-summit-recap-diagnosing-problems-in-production
 was relocated somewhere ?

 

On 27 February 2018 at 16:34, Kenneth Brotman  
wrote:

One presentation that I hope can get updated is Jon Haddad’s very thorough 
presentation on Diagnosing Performance Problems in Production.  I’ve seen 
another version somewhere where I believe he says something like “This should 
help you fix 99% of the problems you see.”  Seems right.

 

I’m sure it will be well attended and well viewed for some time.  Here’s the 
version I found: https://www.youtube.com/watch?v=2JlUpgsEdN8

 

If Jon did a new version I’d probably stop and watch it three times right now.  

 

If we started with that video inline on the Apache Cassandra web site in the 
troubleshooting section, that would help a lot of people because of the quality 
of the content and the density of the content.  

 

Kenneth Brotman

 

RE: Cassandra Daemon not coming up

[Rahul Singh]

Were there any changes to the system such as permissions, etc. Did you add 
users / change auth scheme?

On Feb 27, 2018, 10:27 AM -0600, ZAIDI, ASAD A , wrote:
> Can you check if you’ve enough disk space available ?
> ~Asad
>
> From: mahesh rajamani [mailto:rajamani.mah...@gmail.com]
> Sent: Tuesday, February 27, 2018 10:11 AM
> To: user@cassandra.apache.org
> Subject: Cassandra Daemon not coming up
>
> I am using Cassandra 3.0.9 version on a 12 node cluster. I have multiple node 
> down after a restart. The cassandra VM is not coming up with an asset error 
> as below. On running in debug mode it is failing while doing operation on " 
> resource_role_permissons_index" in system_auth keyspace. Please let me know 
> how to bring the cassandra running from this state.
>
> Logs from system.log
>
> INFO  [main] 2018-02-27 15:43:24,005 ColumnFamilyStore.java:389 - 
> Initializing system_schema.columns
> INFO  [main] 2018-02-27 15:43:24,012 ColumnFamilyStore.java:389 - 
> Initializing system_schema.triggers
> INFO  [main] 2018-02-27 15:43:24,019 ColumnFamilyStore.java:389 - 
> Initializing system_schema.dropped_columns
> INFO  [main] 2018-02-27 15:43:24,029 ColumnFamilyStore.java:389 - 
> Initializing system_schema.views
> INFO  [main] 2018-02-27 15:43:24,038 ColumnFamilyStore.java:389 - 
> Initializing system_schema.types
> INFO  [main] 2018-02-27 15:43:24,049 ColumnFamilyStore.java:389 - 
> Initializing system_schema.functions
> INFO  [main] 2018-02-27 15:43:24,061 ColumnFamilyStore.java:389 - 
> Initializing system_schema.aggregates
> INFO  [main] 2018-02-27 15:43:24,072 ColumnFamilyStore.java:389 - 
> Initializing system_schema.indexes
> ERROR [main] 2018-02-27 15:43:24,127 CassandraDaemon.java:709 - Exception 
> encountered during startup
> java.lang.AssertionError: null
>         at 
> org.apache.cassandra.db.marshal.CompositeType.getInstance(CompositeType.java:103)
>  ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.config.CFMetaData.rebuild(CFMetaData.java:311) 
> ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at org.apache.cassandra.config.CFMetaData.(CFMetaData.java:288) 
> ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at org.apache.cassandra.config.CFMetaData.create(CFMetaData.java:366) 
> ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.schema.SchemaKeyspace.fetchTable(SchemaKeyspace.java:954)
>  ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.schema.SchemaKeyspace.fetchTables(SchemaKeyspace.java:928)
>  ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.schema.SchemaKeyspace.fetchKeyspace(SchemaKeyspace.java:891)
>  ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.schema.SchemaKeyspace.fetchKeyspacesWithout(SchemaKeyspace.java:868)
>  ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.schema.SchemaKeyspace.fetchNonSystemKeyspaces(SchemaKeyspace.java:856)
>  ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at org.apache.cassandra.config.Schema.loadFromDisk(Schema.java:136) 
> ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at org.apache.cassandra.config.Schema.loadFromDisk(Schema.java:126) 
> ~[apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:239) 
> [apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:568)
>  [apache-cassandra-3.0.9.jar:3.0.9]
>         at 
> org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:696) 
> [apache-cassandra-3.0.9.jar:3.0.9]
>
> --
> Regards,
> Mahesh Rajamani

RE: Cassandra Daemon not coming up

[ZAIDI, ASAD A]

Can you check if you’ve enough disk space available ?
~Asad

From: mahesh rajamani [mailto:rajamani.mah...@gmail.com]
Sent: Tuesday, February 27, 2018 10:11 AM
To: user@cassandra.apache.org
Subject: Cassandra Daemon not coming up

I am using Cassandra 3.0.9 version on a 12 node cluster. I have multiple node 
down after a restart. The cassandra VM is not coming up with an asset error as 
below. On running in debug mode it is failing while doing operation on " 
resource_role_permissons_index" in system_auth keyspace. Please let me know how 
to bring the cassandra running from this state.

Logs from system.log

INFO  [main] 2018-02-27 15:43:24,005 ColumnFamilyStore.java:389 - Initializing 
system_schema.columns
INFO  [main] 2018-02-27 15:43:24,012 ColumnFamilyStore.java:389 - Initializing 
system_schema.triggers
INFO  [main] 2018-02-27 15:43:24,019 ColumnFamilyStore.java:389 - Initializing 
system_schema.dropped_columns
INFO  [main] 2018-02-27 15:43:24,029 ColumnFamilyStore.java:389 - Initializing 
system_schema.views
INFO  [main] 2018-02-27 15:43:24,038 ColumnFamilyStore.java:389 - Initializing 
system_schema.types
INFO  [main] 2018-02-27 15:43:24,049 ColumnFamilyStore.java:389 - Initializing 
system_schema.functions
INFO  [main] 2018-02-27 15:43:24,061 ColumnFamilyStore.java:389 - Initializing 
system_schema.aggregates
INFO  [main] 2018-02-27 15:43:24,072 ColumnFamilyStore.java:389 - Initializing 
system_schema.indexes
ERROR [main] 2018-02-27 15:43:24,127 CassandraDaemon.java:709 - Exception 
encountered during startup
java.lang.AssertionError: null
at 
org.apache.cassandra.db.marshal.CompositeType.getInstance(CompositeType.java:103)
 ~[apache-cassandra-3.0.9.jar:3.0.9]
at org.apache.cassandra.config.CFMetaData.rebuild(CFMetaData.java:311) 
~[apache-cassandra-3.0.9.jar:3.0.9]
at org.apache.cassandra.config.CFMetaData.(CFMetaData.java:288) 
~[apache-cassandra-3.0.9.jar:3.0.9]
at org.apache.cassandra.config.CFMetaData.create(CFMetaData.java:366) 
~[apache-cassandra-3.0.9.jar:3.0.9]
at 
org.apache.cassandra.schema.SchemaKeyspace.fetchTable(SchemaKeyspace.java:954) 
~[apache-cassandra-3.0.9.jar:3.0.9]
at 
org.apache.cassandra.schema.SchemaKeyspace.fetchTables(SchemaKeyspace.java:928) 
~[apache-cassandra-3.0.9.jar:3.0.9]
at 
org.apache.cassandra.schema.SchemaKeyspace.fetchKeyspace(SchemaKeyspace.java:891)
 ~[apache-cassandra-3.0.9.jar:3.0.9]
at 
org.apache.cassandra.schema.SchemaKeyspace.fetchKeyspacesWithout(SchemaKeyspace.java:868)
 ~[apache-cassandra-3.0.9.jar:3.0.9]
at 
org.apache.cassandra.schema.SchemaKeyspace.fetchNonSystemKeyspaces(SchemaKeyspace.java:856)
 ~[apache-cassandra-3.0.9.jar:3.0.9]
at org.apache.cassandra.config.Schema.loadFromDisk(Schema.java:136) 
~[apache-cassandra-3.0.9.jar:3.0.9]
at org.apache.cassandra.config.Schema.loadFromDisk(Schema.java:126) 
~[apache-cassandra-3.0.9.jar:3.0.9]
at 
org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:239) 
[apache-cassandra-3.0.9.jar:3.0.9]
at 
org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:568) 
[apache-cassandra-3.0.9.jar:3.0.9]
at 
org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:696) 
[apache-cassandra-3.0.9.jar:3.0.9]

--
Regards,
Mahesh Rajamani

Re: Jon Haddad on Diagnosing Performance Problems in Production

[Nicolas Guyomar]

Is Jon blog post
https://academy.datastax.com/planet-cassandra/blog/cassandra-summit-recap-diagnosing-problems-in-production
was relocated somewhere ?

On 27 February 2018 at 16:34, Kenneth Brotman 
wrote:

> One presentation that I hope can get updated is Jon Haddad’s very thorough
> presentation on Diagnosing Performance Problems in Production.  I’ve seen
> another version somewhere where I believe he says something like “This
> should help you fix 99% of the problems you see.”  Seems right.
>
>
>
> I’m sure it will be well attended and well viewed for some time.  Here’s
> the version I found: https://www.youtube.com/watch?v=2JlUpgsEdN8
>
>
>
> If Jon did a new version I’d probably stop and watch it three times right
> now.
>
>
>
> If we started with that video inline on the Apache Cassandra web site in
> the troubleshooting section, that would help a lot of people because of the
> quality of the content and the density of the content.
>
>
>
> Kenneth Brotman
>

Cassandra Daemon not coming up

[mahesh rajamani]

I am using Cassandra 3.0.9 version on a 12 node cluster. I have multiple
node down after a restart. The cassandra VM is not coming up with an asset
error as below. On running in debug mode it is failing while doing
operation on " resource_role_permissons_index" in system_auth keyspace.
Please let me know how to bring the cassandra running from this state.

Logs from system.log

INFO  [main] 2018-02-27 15:43:24,005 ColumnFamilyStore.java:389 -
Initializing system_schema.columns

INFO  [main] 2018-02-27 15:43:24,012 ColumnFamilyStore.java:389 -
Initializing system_schema.triggers

INFO  [main] 2018-02-27 15:43:24,019 ColumnFamilyStore.java:389 -
Initializing system_schema.dropped_columns

INFO  [main] 2018-02-27 15:43:24,029 ColumnFamilyStore.java:389 -
Initializing system_schema.views

INFO  [main] 2018-02-27 15:43:24,038 ColumnFamilyStore.java:389 -
Initializing system_schema.types

INFO  [main] 2018-02-27 15:43:24,049 ColumnFamilyStore.java:389 -
Initializing system_schema.functions

INFO  [main] 2018-02-27 15:43:24,061 ColumnFamilyStore.java:389 -
Initializing system_schema.aggregates

INFO  [main] 2018-02-27 15:43:24,072 ColumnFamilyStore.java:389 -
Initializing system_schema.indexes

ERROR [main] 2018-02-27 15:43:24,127 CassandraDaemon.java:709 - Exception
encountered during startup

java.lang.AssertionError: null


at
org.apache.cassandra.db.marshal.CompositeType.getInstance(CompositeType.java:103)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.config.CFMetaData.rebuild(CFMetaData.java:311)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.config.CFMetaData.(CFMetaData.java:288)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.config.CFMetaData.create(CFMetaData.java:366)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.schema.SchemaKeyspace.fetchTable(SchemaKeyspace.java:954)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.schema.SchemaKeyspace.fetchTables(SchemaKeyspace.java:928)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.schema.SchemaKeyspace.fetchKeyspace(SchemaKeyspace.java:891)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.schema.SchemaKeyspace.fetchKeyspacesWithout(SchemaKeyspace.java:868)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.schema.SchemaKeyspace.fetchNonSystemKeyspaces(SchemaKeyspace.java:856)
~[apache-cassandra-3.0.9.jar:3.0.9]

at org.apache.cassandra.config.Schema.loadFromDisk(Schema.java:136)
~[apache-cassandra-3.0.9.jar:3.0.9]

at org.apache.cassandra.config.Schema.loadFromDisk(Schema.java:126)
~[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:239)
[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:568)
[apache-cassandra-3.0.9.jar:3.0.9]

at
org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:696)
[apache-cassandra-3.0.9.jar:3.0.9]

-- 
Regards,
Mahesh Rajamani

Re: Driver consistency issue

[Jeff Jirsa]

Please don’t cross-post multiple lists.

Datastax list removed

Abishek, do you have auth enabled? Does the system auth keyspace have rf=3?


-- 
Jeff Jirsa


> On Feb 27, 2018, at 2:59 AM, Nicolas Guyomar  
> wrote:
> 
> Hi,
> 
> Adding the java-driver ML for further question, because this does look like a 
> bug
> 
> Are you able to reproduce it a clean environnement using the same C* version 
> and driver version ? 
> 
> 
>> On 27 February 2018 at 10:05, Abhishek Kumar Maheshwari 
>>  wrote:
>> Hi Alex,
>> 
>> i have only One DC (with name DC1) and have only one keyspace. So i dont 
>> think so both of the scenario is possible. (yes in my case QUORUM is  
>> equivalent of ALL)
>> 
>> cqlsh> SELECT * FROM system_schema.keyspaces  where keyspace_name='adlog' ;
>> 
>>  keyspace_name | durable_writes | replication
>> ---++---
>>  adlog |   True | {'DC1': '2', 'class': 
>> 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
>> 
>> 
>>> On Tue, Feb 27, 2018 at 2:27 PM, Oleksandr Shulgin 
>>>  wrote:
 On Tue, Feb 27, 2018 at 9:45 AM, Abhishek Kumar Maheshwari 
  wrote:
 
 i have a KeySpace in Cassandra (cassandra version 3.0.9- total 12 Servers 
 )With below definition:
 
 {'DC1': '2', 'class': 
 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
 
 Some time i am getting below exception
 
>>> 
>>> [snip] 
 Caused by: com.datastax.driver.core.exceptions.WriteTimeoutException: 
 Cassandra timeout during write query at consistency QUORUM (3 replica were 
 required but only 2 acknowledged the write)
 at 
 com.datastax.driver.core.exceptions.WriteTimeoutException.copy(WriteTimeoutException.java:100)
 at 
 com.datastax.driver.core.Responses$Error.asException(Responses.java:134)
 at 
 com.datastax.driver.core.RequestHandler$SpeculativeExecution.onSet(RequestHandler.java:525)
 at 
 com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1077)
 
 why its waiting for acknowledged from 3rd server as replication factor is 
 2?
>>> 
>>> I see two possibilities:
>>> 
>>> 1) The data in this keyspace is replicated to another DC, so there is also 
>>> 'DC2': '2', for example, but you didn't show it.  In this case QUORUM 
>>> requires more than 2 nodes.
>>> 2) The write was targeting a table in a different keyspace than you think.
>>> 
>>> In any case QUORUM (or LOCAL_QUORUM) with RF=2 is equivalent of ALL.  Not 
>>> sure why would you use it in the first place.
>>> 
>>> For consistency levels involving quorum you want to go with RF=3 in a 
>>> single DC.  For multi DC you should think if you want QUORUM or EACH_QUORUM 
>>> for your writes and figure out the RFs from that.
>>> 
>>> Cheers,
>>> --
>>> Alex
>>> 
>> 
>> 
>> 
>> -- 
>> Thanks & Regards,
>> Abhishek Kumar Maheshwari
>> +91- 805591 (Mobile)
>> 
>> Times Internet Ltd. | A Times of India Group Company
>> 
>> FC - 6, Sector 16A, Film City,  Noida,  U.P. 201301 | INDIA
>> 
>> P Please do not print this email unless it is absolutely necessary. Spread 
>> environmental awareness.
>> 
> 

Jon Haddad on Diagnosing Performance Problems in Production

[Kenneth Brotman]

One presentation that I hope can get updated is Jon Haddad's very thorough
presentation on Diagnosing Performance Problems in Production.  I've seen
another version somewhere where I believe he says something like "This
should help you fix 99% of the problems you see."  Seems right.

 

I'm sure it will be well attended and well viewed for some time.  Here's the
version I found: https://www.youtube.com/watch?v=2JlUpgsEdN8

 

If Jon did a new version I'd probably stop and watch it three times right
now.  

 

If we started with that video inline on the Apache Cassandra web site in the
troubleshooting section, that would help a lot of people because of the
quality of the content and the density of the content.  

 

Kenneth Brotman

Re: Cassandra Summit 2019 / Cassandra Summit 2018

[Rahul Singh]

I can help organize. I organize three meetups in the area here and know several 
venues that would be able to lend space if needed.

We can host about 20-30 people at our office or get a location through a 
coworking spot / one of the universities ( Georgetown or George Washington)

The community should do something this year — even if it is semi - Virtual. 
I’ve seen some decent implementations of it in other disciplines. Some
Combination of physical get together on a certain day around the world with 
groups presenting locally and then some folks presenting on a global hangout. 
Breaking momentum is the worst killer of community.

We can rally around one date and see how we do. You can count on DC Cassandra 
committing to make our part of it happen. Best,

--
Rahul Singh
rahul.si...@anant.us

Anant Corporation

On Feb 27, 2018, 5:43 AM -0600, Carlos Rolo , wrote:
> Hello all,
>
> I'm interested planning/organizing a small kinda of NGCC in Lisbon, Portugal 
> in late May early June. Just waiting for the venue to confirm possible dates.
>
> Would be a 1day event kinda last year, is this something people would be 
> interested? I can push a google form for accessing the interest today.
>
>
> Regards,
>
> Carlos Juzarte Rolo
> Cassandra Consultant / Datastax Certified Architect / Cassandra MVP
>
> Pythian - Love your data
>
> rolo@pythian | Twitter: @cjrolo | Skype: cjr2k3 | Linkedin: 
> linkedin.com/in/carlosjuzarterolo
> Mobile: +351 918 918 100
> www.pythian.com
>
> > On Tue, Feb 27, 2018 at 11:39 AM, Kenneth Brotman 
> >  wrote:
> > > Event planning is fun as long as you can pace it out properly.  Once you 
> > > set a firm date for an event the pressure on you to keep everything on 
> > > track is nerve racking.  To do something on the order of Cassandra Summit 
> > > 2016, I think we are should plan for 2020.  It’s too late for 2018 and 
> > > even trying to meet the timeline for everything that would have to come 
> > > together makes 2019 too nerve racking a target date.  The steps should be:
> > >     Form a planning committee
> > >     Bring potential sponsors into the planning early
> > >     Select an event planning vendor to guide us and to do the 
> > > heavy lifting for us
> > >
> > > In the meantime, we could have a World-wide Distributed Asynchronous 
> > > Cassandra Convention which offers four benefits:
> > >     It allows us to address the fact that we are a world-wide 
> > > group that needs a way to reach everyone in a way where no one is 
> > > geographically disadvantaged
> > >     No travel time, no travel expenses and no ticket fees 
> > > makes it accessible to a lot of people that otherwise would have to miss 
> > > out
> > > The lower production costs and simpler administrative workload allows us 
> > > to reach implementation sooner
> > >     It’s cutting edge, world class innovation like Cassandra
> > >
> > > Kenneth Brotman
> > >
> > > From: Jeff Jirsa [mailto:jji...@gmail.com]
> > > Sent: Monday, February 26, 2018 9:38 PM
> > > To: cassandra
> > > Subject: Re: Cassandra Summit 2019 / Cassandra Summit 2018
> > >
> > > Instaclustr sponsored the 2017 NGCC (Next Gen Cassandra Conference), 
> > > which was developer/development focused (vs user focused).
> > >
> > > For 2018, we're looking at options for both a developer conference and a 
> > > user conference. There's a lot of logistics involved, and I think it's 
> > > fairly obvious that most of the PMC members aren't professional event 
> > > planners, so it's possible that either/both conferences may not happen, 
> > > but we're doing our best to try to put something together.
> > >
> > >
> > > On Mon, Feb 26, 2018 at 3:00 PM, Rahul Singh 
> > >  wrote:
> > > I think some of the Instaclustr folks had done one last year which I 
> > > really wanted to go to.. Distributed / Async both would be easier to get 
> > > people to write papers, make slides, do youtube videos with.. and then we 
> > > could do a virtual web conf of the best submissions.
> > >
> > > On Feb 26, 2018, 1:04 PM -0600, Kenneth Brotman 
> > > , wrote:
> > >
> > > Is there any planning yet for a Cassandra Summit 2019 or Cassandra Summit 
> > > 2018 (probably too late)?
> > >
> > > Is there a planning committee?
> > >
> > > Who wants there to be a Cassandra Summit 2019 and who thinks there is a 
> > > better way?
> > >
> > > We could try a Cassandra Distributed Summit 2019 where we meet virtually 
> > > and perhaps asynchronously, but there would be a lot more energy and 
> > > bonding if it’s not virtual.  I’m up for any of these.
> > >
> > > Kenneth Brotman
> > >
> > >
> > >
>
>
> --
>
>

RE: Version Rollback

[Kenneth Brotman]

Could you tell us the size and configuration of your Cassandra cluster?

 

Kenneth Brotman

 

From: shalom sagges [mailto:shalomsag...@gmail.com] 
Sent: Tuesday, February 27, 2018 6:19 AM
To: user@cassandra.apache.org
Subject: Version Rollback

 

Hi All, 

I'm planning to upgrade my C* cluster to version 3.x and was wondering what's 
the best way to perform a rollback if need be. 

If I used snapshot restoration, I would be facing data loss, depends when I 
took the snapshot (i.e. a rollback might be required after upgrading half the 
cluster for example). 

If I add another DC to the cluster with the old version, then I could point the 
apps to talk to that DC if anything bad happens, but building it is really time 
consuming and requires a lot of resources. 

Can anyone provide recommendations on this matter? Any ideas on how to make the 
upgrade foolproof, or at least "really really safe"? 

 

Thanks!

 

Version Rollback

[shalom sagges]

Hi All,

I'm planning to upgrade my C* cluster to version 3.x and was wondering
what's the best way to perform a rollback if need be.

If I used snapshot restoration, I would be facing data loss, depends when I
took the snapshot (i.e. a rollback might be required after upgrading half
the cluster for example).

If I add another DC to the cluster with the old version, then I could point
the apps to talk to that DC if anything bad happens, but building it is
really time consuming and requires a lot of resources.

Can anyone provide recommendations on this matter? Any ideas on how to make
the upgrade foolproof, or at least "really really safe"?

Thanks!

RE: Filling in the blank To Do sections on the Apache Cassandra web site

[Kenneth Brotman]

I was debating that.  Splitting it up into smaller tasks makes each one seem 
less over-whelming.  

 

Kenneth Brotman

 

From: Josh McKenzie [mailto:jmcken...@apache.org] 
Sent: Tuesday, February 27, 2018 5:44 AM
To: cassandra
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

Might help, organizationally, to put all these efforts under a single ticket of 
"Improve web site Documentation" and add these as sub-tasks. Should be able to 
do that translation post-creation (i.e. in its current state) if that's 
something that makes sense to you.

 

On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman  
wrote:

Here are the related JIRA’s.  Please add content even if It’s not well formed 
compositionally.  Myself or someone else will take it from there

 

https://issues.apache.org/jira/browse/CASSANDRA-14274  The troubleshooting 
section of the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14273  The Bulk Loading web 
page on the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14272  The Backups web page on 
the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14271  The Hints web page in 
the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14270  The Read repair web page 
is empty

https://issues.apache.org/jira/browse/CASSANDRA-14269  The Data Modeling 
section of the web site is empty

https://issues.apache.org/jira/browse/CASSANDRA-14268  The 
Architecture:Guarantees web page is empty

https://issuesapache.org/jira/browse/CASSANDRA-14267 
   The Dynamo web page 
on the Apache Cassandra site is missing content

https://issues.apache.org/jira/browse/CASSANDRA-14266  The Architecture 
Overview web page on the Apache Cassandra site is empty

 

Thanks for pitching in  

 

Kenneth Brotman

 

From: Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID] 
Sent: Monday, February 26, 2018 1:54 PM
To: user@cassandra.apache.org
Subject: RE: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

Nice!  Thanks for the help Oliver!

 

Kenneth Brotman

 

From: Oliver Ruebenacker [mailto:cur...@gmail.com] 
Sent: Sunday, February 25, 2018 7:12 AM
To: user@cassandra.apache.org
Cc: d...@cassandra.apache.org
Subject: Re: Filling in the blank To Do sections on the Apache Cassandra web 
site

 

 

 Hello,

  I have some slides about Cassandra 

 , feel free to borrow.

 Best, Oliver

 

On Fri, Feb 23, 2018 at 7:28 PM, Kenneth Brotman  
wrote:

These nine web pages on the Apache Cassandra web site have blank To Do 
sections.  Most of the web pages are completely blank.  Mind you there is a lot 
of hard work already done on the documentation.  I’ll make JIRA’s for any of 
the blank sections where there is not already a JIRA.  Then it will be on to 
writing up those sections.  If you have any text to help me get started for any 
of these sections that would be really cool. 

 

http://cassandra.apache.org/doc/latest/architecture/overview.html

 

http://cassandra.apache.org/doc/latest/architecture/dynamo.html

 

http://cassandra.apache.org/doc/latest/architecture/guarantees.html 
 

 

http://cassandra.apache.org/doc/latest/data_modeling/index.html

 

http://cassandra.apacheorg/doc/latest/operating/read_repair.html 
 

 

http://cassandra.apache.org/doc/latest/operating/hints.html

 

http://cassandra.apache.org/doc/latest/operating/backups.html

 

http://cassandra.apache.org/doc/latest/operating/bulk_loading.html

 

http://cassandra.apache.org/doc/latest/troubleshooting/index.html

 

Kenneth Brotman

 




-- 

Oliver Ruebenacker

Senior Software Engineer, Diabetes Portal 
 , Broad Institute 
 

 

 

Re: Filling in the blank To Do sections on the Apache Cassandra web site

[Josh McKenzie]

Might help, organizationally, to put all these efforts under a single
ticket of "Improve web site Documentation" and add these as sub-tasks.
Should be able to do that translation post-creation (i.e. in its current
state) if that's something that makes sense to you.

On Mon, Feb 26, 2018 at 5:24 PM, Kenneth Brotman <
kenbrot...@yahoo.com.invalid> wrote:

> Here are the related JIRA’s.  Please add content even if It’s not well
> formed compositionally.  Myself or someone else will take it from there.
>
>
>
> https://issues.apache.org/jira/browse/CASSANDRA-14274  The
> troubleshooting section of the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14273  The Bulk Loading
> web page on the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14272  The Backups web
> page on the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14271  The Hints web page
> in the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14270  The Read repair
> web page is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14269  The Data Modeling
> section of the web site is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14268  The
> Architecture:Guarantees web page is empty
>
> https://issues.apache.org/jira/browse/CASSANDRA-14267  The Dynamo web
> page on the Apache Cassandra site is missing content
>
> https://issues.apache.org/jira/browse/CASSANDRA-14266  The Architecture
> Overview web page on the Apache Cassandra site is empty
>
>
>
> Thanks for pitching in.
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Kenneth Brotman [mailto:kenbrot...@yahoo.com.INVALID]
> *Sent:* Monday, February 26, 2018 1:54 PM
> *To:* user@cassandra.apache.org
> *Subject:* RE: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
> Nice!  Thanks for the help Oliver!
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Oliver Ruebenacker [mailto:cur...@gmail.com]
> *Sent:* Sunday, February 25, 2018 7:12 AM
> *To:* user@cassandra.apache.org
> *Cc:* d...@cassandra.apache.org
> *Subject:* Re: Filling in the blank To Do sections on the Apache
> Cassandra web site
>
>
>
>
>
>  Hello,
>
>   I have some slides about Cassandra
> ,
> feel free to borrow.
>
>  Best, Oliver
>
>
>
> On Fri, Feb 23, 2018 at 7:28 PM, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid> wrote:
>
> These nine web pages on the Apache Cassandra web site have blank To Do
> sections.  Most of the web pages are completely blank.  Mind you there is a
> lot of hard work already done on the documentation.  I’ll make JIRA’s for
> any of the blank sections where there is not already a JIRA.  Then it will
> be on to writing up those sections.  *If you have any text to help me get
> started for any of these sections that would be really cool. *
>
>
>
> http://cassandra.apache.org/doc/latest/architecture/overview.html
>
>
>
> http://cassandra.apache.org/doc/latest/architecture/dynamo.html
>
>
>
> http://cassandra.apache.org/doc/latest/architecture/guarantees.html
>
>
>
> http://cassandra.apache.org/doc/latest/data_modeling/index.html
>
>
>
> http://cassandra.apache.org/doc/latest/operating/read_repair.html
>
>
>
> http://cassandra.apache.org/doc/latest/operating/hints.html
>
>
>
> http://cassandra.apache.org/doc/latest/operating/backups.html
>
>
>
> http://cassandra.apache.org/doc/latest/operating/bulk_loading.html
>
>
>
> http://cassandra.apache.org/doc/latest/troubleshooting/index.html
>
>
>
> Kenneth Brotman
>
>
>
>
>
>
> --
>
> Oliver Ruebenacker
>
> Senior Software Engineer, Diabetes Portal
> , Broad Institute
> 
>
>
>

Re: Driver consistency issue

[horschi]

Hi Abhishek & everyone else,

might it be related to https://issues.apache.org/jira/browse/CASSANDRA-7868
?

regards,
Christian



On Tue, Feb 27, 2018 at 12:46 PM, Abhishek Kumar Maheshwari <
abhishek.maheshw...@timesinternet.in> wrote:

> Hi,
>
> Not always. Randomly i am getting this exception. (one observation, mostly
> i got this exception when i add new node in cluster.)
>
> On Tue, Feb 27, 2018 at 4:29 PM, Nicolas Guyomar <
> nicolas.guyo...@gmail.com> wrote:
>
>> Hi,
>>
>> Adding the java-driver ML for further question, because this does look
>> like a bug
>>
>> Are you able to reproduce it a clean environnement using the same C*
>> version and driver version ?
>>
>>
>> On 27 February 2018 at 10:05, Abhishek Kumar Maheshwari <
>> abhishek.maheshw...@timesinternet.in> wrote:
>>
>>> Hi Alex,
>>>
>>> i have only One DC (with name DC1) and have only one keyspace. So i dont
>>> think so both of the scenario is possible. (yes in my case QUORUM is  
>>> equivalent
>>> of ALL)
>>>
>>> cqlsh> SELECT * FROM system_schema.keyspaces  where
>>> keyspace_name='adlog' ;
>>>
>>>  keyspace_name | durable_writes | replication
>>> ---++---
>>> 
>>>  adlog |   True | {'DC1': '2', 'class':
>>> 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
>>>
>>>
>>> On Tue, Feb 27, 2018 at 2:27 PM, Oleksandr Shulgin <
>>> oleksandr.shul...@zalando.de> wrote:
>>>
 On Tue, Feb 27, 2018 at 9:45 AM, Abhishek Kumar Maheshwari <
 abhishek.maheshw...@timesinternet.in> wrote:

>
> i have a KeySpace in Cassandra (cassandra version 3.0.9- total 12
> Servers )With below definition:
>
> {'DC1': '2', 'class': 'org.apache.cassandra.locator.
> NetworkTopologyStrategy'}
>
> Some time i am getting below exception
>
> [snip]

> Caused by: com.datastax.driver.core.exceptions.WriteTimeoutException:
> Cassandra timeout during write query at consistency QUORUM (3 replica were
> required but only 2 acknowledged the write)
> at com.datastax.driver.core.excep
> tions.WriteTimeoutException.copy(WriteTimeoutException.java:100)
> at com.datastax.driver.core.Respo
> nses$Error.asException(Responses.java:134)
> at com.datastax.driver.core.Reque
> stHandler$SpeculativeExecution.onSet(RequestHandler.java:525)
> at com.datastax.driver.core.Conne
> ction$Dispatcher.channelRead0(Connection.java:1077)
>
> why its waiting for acknowledged from 3rd server as replication
> factor is 2?
>

 I see two possibilities:

 1) The data in this keyspace is replicated to another DC, so there is
 also 'DC2': '2', for example, but you didn't show it.  In this case QUORUM
 requires more than 2 nodes.
 2) The write was targeting a table in a different keyspace than you
 think.

 In any case QUORUM (or LOCAL_QUORUM) with RF=2 is equivalent of ALL.
 Not sure why would you use it in the first place.

 For consistency levels involving quorum you want to go with RF=3 in a
 single DC.  For multi DC you should think if you want QUORUM or EACH_QUORUM
 for your writes and figure out the RFs from that.

 Cheers,
 --
 Alex


>>>
>>>
>>> --
>>>
>>> *Thanks & Regards,*
>>> *Abhishek Kumar Maheshwari*
>>> *+91- 805591 <+91%208%2005591> (Mobile)*
>>>
>>> Times Internet Ltd. | A Times of India Group Company
>>>
>>> FC - 6, Sector 16A, Film City,  Noida,  U.P. 201301 | INDIA
>>>
>>> *P** Please do not print this email unless it is absolutely necessary.
>>> Spread environmental awareness.*
>>>
>>
>>
>
>
> --
>
> *Thanks & Regards,*
> *Abhishek Kumar Maheshwari*
> *+91- 805591 <+91%208%2005591> (Mobile)*
>
> Times Internet Ltd. | A Times of India Group Company
>
> FC - 6, Sector 16A, Film City,  Noida,  U.P. 201301 | INDIA
>
> *P** Please do not print this email unless it is absolutely necessary.
> Spread environmental awareness.*
>

Re: Driver consistency issue

[Abhishek Kumar Maheshwari]

Hi,

Not always. Randomly i am getting this exception. (one observation, mostly
i got this exception when i add new node in cluster.)

On Tue, Feb 27, 2018 at 4:29 PM, Nicolas Guyomar 
wrote:

> Hi,
>
> Adding the java-driver ML for further question, because this does look
> like a bug
>
> Are you able to reproduce it a clean environnement using the same C*
> version and driver version ?
>
>
> On 27 February 2018 at 10:05, Abhishek Kumar Maheshwari <
> abhishek.maheshw...@timesinternet.in> wrote:
>
>> Hi Alex,
>>
>> i have only One DC (with name DC1) and have only one keyspace. So i dont
>> think so both of the scenario is possible. (yes in my case QUORUM is  
>> equivalent
>> of ALL)
>>
>> cqlsh> SELECT * FROM system_schema.keyspaces  where keyspace_name='adlog'
>> ;
>>
>>  keyspace_name | durable_writes | replication
>> ---++---
>> 
>>  adlog |   True | {'DC1': '2', 'class':
>> 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
>>
>>
>> On Tue, Feb 27, 2018 at 2:27 PM, Oleksandr Shulgin <
>> oleksandr.shul...@zalando.de> wrote:
>>
>>> On Tue, Feb 27, 2018 at 9:45 AM, Abhishek Kumar Maheshwari <
>>> abhishek.maheshw...@timesinternet.in> wrote:
>>>

 i have a KeySpace in Cassandra (cassandra version 3.0.9- total 12
 Servers )With below definition:

 {'DC1': '2', 'class': 'org.apache.cassandra.locator.
 NetworkTopologyStrategy'}

 Some time i am getting below exception

 [snip]
>>>
 Caused by: com.datastax.driver.core.exceptions.WriteTimeoutException:
 Cassandra timeout during write query at consistency QUORUM (3 replica were
 required but only 2 acknowledged the write)
 at com.datastax.driver.core.exceptions.WriteTimeoutException.co
 py(WriteTimeoutException.java:100)
 at com.datastax.driver.core.Responses$Error.asException(Respons
 es.java:134)
 at com.datastax.driver.core.RequestHandler$SpeculativeExecution
 .onSet(RequestHandler.java:525)
 at com.datastax.driver.core.Connection$Dispatcher.channelRead0(
 Connection.java:1077)

 why its waiting for acknowledged from 3rd server as replication factor
 is 2?

>>>
>>> I see two possibilities:
>>>
>>> 1) The data in this keyspace is replicated to another DC, so there is
>>> also 'DC2': '2', for example, but you didn't show it.  In this case QUORUM
>>> requires more than 2 nodes.
>>> 2) The write was targeting a table in a different keyspace than you
>>> think.
>>>
>>> In any case QUORUM (or LOCAL_QUORUM) with RF=2 is equivalent of ALL.
>>> Not sure why would you use it in the first place.
>>>
>>> For consistency levels involving quorum you want to go with RF=3 in a
>>> single DC.  For multi DC you should think if you want QUORUM or EACH_QUORUM
>>> for your writes and figure out the RFs from that.
>>>
>>> Cheers,
>>> --
>>> Alex
>>>
>>>
>>
>>
>> --
>>
>> *Thanks & Regards,*
>> *Abhishek Kumar Maheshwari*
>> *+91- 805591 <+91%208%2005591> (Mobile)*
>>
>> Times Internet Ltd. | A Times of India Group Company
>>
>> FC - 6, Sector 16A, Film City,  Noida,  U.P. 201301 | INDIA
>>
>> *P** Please do not print this email unless it is absolutely necessary.
>> Spread environmental awareness.*
>>
>
>


-- 

*Thanks & Regards,*
*Abhishek Kumar Maheshwari*
*+91- 805591 (Mobile)*

Times Internet Ltd. | A Times of India Group Company

FC - 6, Sector 16A, Film City,  Noida,  U.P. 201301 | INDIA

*P** Please do not print this email unless it is absolutely necessary.
Spread environmental awareness.*

Re: Cassandra Summit 2019 / Cassandra Summit 2018

[Carlos Rolo]

Hello all,

I'm interested planning/organizing a small kinda of NGCC in Lisbon,
Portugal in late May early June. Just waiting for the venue to confirm
possible dates.

Would be a 1day event kinda last year, is this something people would be
interested? I can push a google form for accessing the interest today.


Regards,

Carlos Juzarte Rolo
Cassandra Consultant / Datastax Certified Architect / Cassandra MVP

Pythian - Love your data

rolo@pythian | Twitter: @cjrolo | Skype: cjr2k3 | Linkedin:
*linkedin.com/in/carlosjuzarterolo
*
Mobile: +351 918 918 100
www.pythian.com

On Tue, Feb 27, 2018 at 11:39 AM, Kenneth Brotman <
kenbrot...@yahoo.com.invalid> wrote:

> Event planning is fun as long as you can pace it out properly.  Once you
> set a firm date for an event the pressure on you to keep everything on
> track is nerve racking.  To do something on the order of Cassandra Summit
> 2016, I think we are should plan for 2020.  It’s too late for 2018 and even
> trying to meet the timeline for everything that would have to come together
> makes 2019 too nerve racking a target date.  The steps should be:
>
> Form a planning committee
>
> Bring potential sponsors into the planning early
>
> Select an event planning vendor to guide us and to do the
> heavy lifting for us
>
>
>
> In the meantime, we could have a World-wide Distributed Asynchronous
> Cassandra Convention which offers four benefits:
>
> It allows us to address the fact that we are a world-wide
> group that needs a way to reach everyone in a way where no one is
> geographically disadvantaged
>
> No travel time, no travel expenses and no ticket fees
> makes it accessible to a lot of people that otherwise would have to miss out
>
> The lower production costs and simpler administrative workload allows us
> to reach implementation sooner
>
> It’s cutting edge, world class innovation like Cassandra
>
>
>
> Kenneth Brotman
>
>
>
> *From:* Jeff Jirsa [mailto:jji...@gmail.com]
> *Sent:* Monday, February 26, 2018 9:38 PM
> *To:* cassandra
> *Subject:* Re: Cassandra Summit 2019 / Cassandra Summit 2018
>
>
>
> Instaclustr sponsored the 2017 NGCC (Next Gen Cassandra Conference), which
> was developer/development focused (vs user focused).
>
>
>
> For 2018, we're looking at options for both a developer conference and a
> user conference. There's a lot of logistics involved, and I think it's
> fairly obvious that most of the PMC members aren't professional event
> planners, so it's possible that either/both conferences may not happen, but
> we're doing our best to try to put something together.
>
>
>
>
>
> On Mon, Feb 26, 2018 at 3:00 PM, Rahul Singh 
> wrote:
>
> I think some of the Instaclustr folks had done one last year which I
> really wanted to go to.. Distributed / Async both would be easier to get
> people to write papers, make slides, do youtube videos with.. and then we
> could do a virtual web conf of the best submissions.
>
>
> On Feb 26, 2018, 1:04 PM -0600, Kenneth Brotman <
> kenbrot...@yahoo.com.invalid>, wrote:
>
> Is there any planning yet for a Cassandra Summit 2019 or Cassandra Summit
> 2018 (probably too late)?
>
>
>
> Is there a planning committee?
>
>
>
> Who wants there to be a Cassandra Summit 2019 and who thinks there is a
> better way?
>
>
>
> We could try a Cassandra Distributed Summit 2019 where we meet virtually
> and perhaps asynchronously, but there would be a lot more energy and
> bonding if it’s not virtual.  I’m up for any of these.
>
>
>
> Kenneth Brotman
>
>
>
>
>
>
>

-- 


--

RE: Cassandra Summit 2019 / Cassandra Summit 2018

[Kenneth Brotman]

Event planning is fun as long as you can pace it out properly.  Once you set a 
firm date for an event the pressure on you to keep everything on track is nerve 
racking.  To do something on the order of Cassandra Summit 2016, I think we are 
should plan for 2020.  It’s too late for 2018 and even trying to meet the 
timeline for everything that would have to come together makes 2019 too nerve 
racking a target date.  The steps should be:

Form a planning committee

Bring potential sponsors into the planning early

Select an event planning vendor to guide us and to do the heavy 
lifting for us



In the meantime, we could have a World-wide Distributed Asynchronous Cassandra 
Convention which offers four benefits:

It allows us to address the fact that we are a world-wide group 
that needs a way to reach everyone in a way where no one is geographically 
disadvantaged

No travel time, no travel expenses and no ticket fees makes it 
accessible to a lot of people that otherwise would have to miss out

The lower production costs and simpler administrative workload allows us to 
reach implementation sooner 

It’s cutting edge, world class innovation like Cassandra



Kenneth Brotman

 

From: Jeff Jirsa [mailto:jji...@gmail.com] 
Sent: Monday, February 26, 2018 9:38 PM
To: cassandra
Subject: Re: Cassandra Summit 2019 / Cassandra Summit 2018

 

Instaclustr sponsored the 2017 NGCC (Next Gen Cassandra Conference), which was 
developer/development focused (vs user focused).

 

For 2018, we're looking at options for both a developer conference and a user 
conference. There's a lot of logistics involved, and I think it's fairly 
obvious that most of the PMC members aren't professional event planners, so 
it's possible that either/both conferences may not happen, but we're doing our 
best to try to put something together.

 

 

On Mon, Feb 26, 2018 at 3:00 PM, Rahul Singh  
wrote:

I think some of the Instaclustr folks had done one last year which I really 
wanted to go to.. Distributed / Async both would be easier to get people to 
write papers, make slides, do youtube videos with.. and then we could do a 
virtual web conf of the best submissions. 


On Feb 26, 2018, 1:04 PM -0600, Kenneth Brotman , 
wrote:



Is there any planning yet for a Cassandra Summit 2019 or Cassandra Summit 2018 
(probably too late)?

 

Is there a planning committee?

 

Who wants there to be a Cassandra Summit 2019 and who thinks there is a better 
way?

 

We could try a Cassandra Distributed Summit 2019 where we meet virtually and 
perhaps asynchronously, but there would be a lot more energy and bonding if 
it’s not virtual.  I’m up for any of these.

 

Kenneth Brotman

 

 

 

Re: Driver consistency issue

[Nicolas Guyomar]

Hi,

Adding the java-driver ML for further question, because this does look like
a bug

Are you able to reproduce it a clean environnement using the same C*
version and driver version ?


On 27 February 2018 at 10:05, Abhishek Kumar Maheshwari <
abhishek.maheshw...@timesinternet.in> wrote:

> Hi Alex,
>
> i have only One DC (with name DC1) and have only one keyspace. So i dont
> think so both of the scenario is possible. (yes in my case QUORUM is  
> equivalent
> of ALL)
>
> cqlsh> SELECT * FROM system_schema.keyspaces  where keyspace_name='adlog' ;
>
>  keyspace_name | durable_writes | replication
> ---++---
> 
>  adlog |   True | {'DC1': '2', 'class':
> 'org.apache.cassandra.locator.NetworkTopologyStrategy'}
>
>
> On Tue, Feb 27, 2018 at 2:27 PM, Oleksandr Shulgin <
> oleksandr.shul...@zalando.de> wrote:
>
>> On Tue, Feb 27, 2018 at 9:45 AM, Abhishek Kumar Maheshwari <
>> abhishek.maheshw...@timesinternet.in> wrote:
>>
>>>
>>> i have a KeySpace in Cassandra (cassandra version 3.0.9- total 12
>>> Servers )With below definition:
>>>
>>> {'DC1': '2', 'class': 'org.apache.cassandra.locator.
>>> NetworkTopologyStrategy'}
>>>
>>> Some time i am getting below exception
>>>
>>> [snip]
>>
>>> Caused by: com.datastax.driver.core.exceptions.WriteTimeoutException:
>>> Cassandra timeout during write query at consistency QUORUM (3 replica were
>>> required but only 2 acknowledged the write)
>>> at com.datastax.driver.core.exceptions.WriteTimeoutException.co
>>> py(WriteTimeoutException.java:100)
>>> at com.datastax.driver.core.Responses$Error.asException(Respons
>>> es.java:134)
>>> at com.datastax.driver.core.RequestHandler$SpeculativeExecution
>>> .onSet(RequestHandler.java:525)
>>> at com.datastax.driver.core.Connection$Dispatcher.channelRead0(
>>> Connection.java:1077)
>>>
>>> why its waiting for acknowledged from 3rd server as replication factor
>>> is 2?
>>>
>>
>> I see two possibilities:
>>
>> 1) The data in this keyspace is replicated to another DC, so there is
>> also 'DC2': '2', for example, but you didn't show it.  In this case QUORUM
>> requires more than 2 nodes.
>> 2) The write was targeting a table in a different keyspace than you think.
>>
>> In any case QUORUM (or LOCAL_QUORUM) with RF=2 is equivalent of ALL.  Not
>> sure why would you use it in the first place.
>>
>> For consistency levels involving quorum you want to go with RF=3 in a
>> single DC.  For multi DC you should think if you want QUORUM or EACH_QUORUM
>> for your writes and figure out the RFs from that.
>>
>> Cheers,
>> --
>> Alex
>>
>>
>
>
> --
>
> *Thanks & Regards,*
> *Abhishek Kumar Maheshwari*
> *+91- 805591 <+91%208%2005591> (Mobile)*
>
> Times Internet Ltd. | A Times of India Group Company
>
> FC - 6, Sector 16A, Film City,  Noida,  U.P. 201301 | INDIA
>
> *P** Please do not print this email unless it is absolutely necessary.
> Spread environmental awareness.*
>

Re: Tracing cql code being run through the drive

[Venkata Harikrishna Nukala]

I think you are looking for this:
https://docs.datastax.com/en/developer/java-driver/2.1/manual/logging/#logging-query-latencies

You can use com.datastax.driver.core.QueryLogger.NORMAL /SLOW /ERROR to see
the queries executed. We are using only slow & error logs in production.
Normal is good for development mode.



On Thu, Feb 22, 2018 at 6:25 PM Lucas Benevides 
wrote:

> I don't know if it you help you, but when the debug log is turned on, it
> displays the slow queries.
> To consider slow, the parameter  read_request_timeout_in_ms is
> considered.
> Maybe if you decrease it, you can monitor your queries, with $tail -F
> debug.log
>
> Just an idea, I've never made it. Surely it must be made in a development
> environment.
>
> Lucas B. Dias
>
> 2018-02-22 8:27 GMT-03:00 Jonathan Baynes :
>
>> Hi Community,
>>
>>
>>
>> Can anyone help me understand what class’s id need to set logging on , if
>> I want to capture the cql commands being run through the driver, similar to
>> how profiler (MSSQL) would work? I need to see what’s being run, and if the
>> query is actually getting to cassandra?
>>
>>
>>
>> Has anyone had any experience in doing this?
>>
>>
>>
>> Thanks in advance.
>>
>>
>>
>> J
>>
>>
>>
>> *Jonathan Baynes*
>>
>> DBA
>> Tradeweb Europe Limited
>>
>> Moor Place  •  1 Fore Street Avenue
>> 
>>   •
>> London
>> EC2Y 9DT
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>> <+44%2020%207776%203201>  •  M +44 (0)7884111546 <+44%207884%20111546>
>>
>> jonathan.bay...@tradeweb.com
>>
>>
>>
>> [image: cid:image001.jpg@01CD26AD.4165F110]
>> 
>> follow us:  *[image: cid:image002.jpg@01CD26AD.4165F110]*
>> 
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>> 
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>> To see our privacy policy, visit our website @ www.tradeweb.com
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>> .
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>
>

Re: Driver consistency issue

[Abhishek Kumar Maheshwari]

Hi Alex,

i have only One DC (with name DC1) and have only one keyspace. So i dont
think so both of the scenario is possible. (yes in my case QUORUM is
equivalent
of ALL)

cqlsh> SELECT * FROM system_schema.keyspaces  where keyspace_name='adlog' ;

 keyspace_name | durable_writes | replication
---++---
 adlog |   True | {'DC1': '2', 'class':
'org.apache.cassandra.locator.NetworkTopologyStrategy'}


On Tue, Feb 27, 2018 at 2:27 PM, Oleksandr Shulgin <
oleksandr.shul...@zalando.de> wrote:

> On Tue, Feb 27, 2018 at 9:45 AM, Abhishek Kumar Maheshwari <
> abhishek.maheshw...@timesinternet.in> wrote:
>
>>
>> i have a KeySpace in Cassandra (cassandra version 3.0.9- total 12 Servers
>> )With below definition:
>>
>> {'DC1': '2', 'class': 'org.apache.cassandra.locator.
>> NetworkTopologyStrategy'}
>>
>> Some time i am getting below exception
>>
>> [snip]
>
>> Caused by: com.datastax.driver.core.exceptions.WriteTimeoutException:
>> Cassandra timeout during write query at consistency QUORUM (3 replica were
>> required but only 2 acknowledged the write)
>> at com.datastax.driver.core.exceptions.WriteTimeoutException.co
>> py(WriteTimeoutException.java:100)
>> at com.datastax.driver.core.Responses$Error.asException(Respons
>> es.java:134)
>> at com.datastax.driver.core.RequestHandler$SpeculativeExecution
>> .onSet(RequestHandler.java:525)
>> at com.datastax.driver.core.Connection$Dispatcher.channelRead0(
>> Connection.java:1077)
>>
>> why its waiting for acknowledged from 3rd server as replication factor
>> is 2?
>>
>
> I see two possibilities:
>
> 1) The data in this keyspace is replicated to another DC, so there is also
> 'DC2': '2', for example, but you didn't show it.  In this case QUORUM
> requires more than 2 nodes.
> 2) The write was targeting a table in a different keyspace than you think.
>
> In any case QUORUM (or LOCAL_QUORUM) with RF=2 is equivalent of ALL.  Not
> sure why would you use it in the first place.
>
> For consistency levels involving quorum you want to go with RF=3 in a
> single DC.  For multi DC you should think if you want QUORUM or EACH_QUORUM
> for your writes and figure out the RFs from that.
>
> Cheers,
> --
> Alex
>
>


-- 

*Thanks & Regards,*
*Abhishek Kumar Maheshwari*
*+91- 805591 (Mobile)*

Times Internet Ltd. | A Times of India Group Company

FC - 6, Sector 16A, Film City,  Noida,  U.P. 201301 | INDIA

*P** Please do not print this email unless it is absolutely necessary.
Spread environmental awareness.*

Re: Driver consistency issue

[Oleksandr Shulgin]

On Tue, Feb 27, 2018 at 9:45 AM, Abhishek Kumar Maheshwari <
abhishek.maheshw...@timesinternet.in> wrote:

>
> i have a KeySpace in Cassandra (cassandra version 3.0.9- total 12 Servers
> )With below definition:
>
> {'DC1': '2', 'class': 'org.apache.cassandra.locator.
> NetworkTopologyStrategy'}
>
> Some time i am getting below exception
>
> [snip]

> Caused by: com.datastax.driver.core.exceptions.WriteTimeoutException:
> Cassandra timeout during write query at consistency QUORUM (3 replica were
> required but only 2 acknowledged the write)
> at com.datastax.driver.core.exceptions.WriteTimeoutException.
> copy(WriteTimeoutException.java:100)
> at com.datastax.driver.core.Responses$Error.asException(Respons
> es.java:134)
> at com.datastax.driver.core.RequestHandler$SpeculativeExecution
> .onSet(RequestHandler.java:525)
> at com.datastax.driver.core.Connection$Dispatcher.channelRead0(
> Connection.java:1077)
>
> why its waiting for acknowledged from 3rd server as replication factor is
> 2?
>

I see two possibilities:

1) The data in this keyspace is replicated to another DC, so there is also
'DC2': '2', for example, but you didn't show it.  In this case QUORUM
requires more than 2 nodes.
2) The write was targeting a table in a different keyspace than you think.

In any case QUORUM (or LOCAL_QUORUM) with RF=2 is equivalent of ALL.  Not
sure why would you use it in the first place.

For consistency levels involving quorum you want to go with RF=3 in a
single DC.  For multi DC you should think if you want QUORUM or EACH_QUORUM
for your writes and figure out the RFs from that.

Cheers,
--
Alex

Driver consistency issue

[Abhishek Kumar Maheshwari]

Hi All,

i have a KeySpace in Cassandra (cassandra version 3.0.9- total 12 Servers
)With below definition:

{'DC1': '2', 'class':
'org.apache.cassandra.locator.NetworkTopologyStrategy'}

Some time i am getting below exception

com.datastax.driver.core.exceptions.WriteTimeoutException: Cassandra
timeout during write query at consistency QUORUM (3 replica were required
but only 2 acknowledged the write)
at
com.datastax.driver.core.exceptions.WriteTimeoutException.copy(WriteTimeoutException.java:73)
at
com.datastax.driver.core.exceptions.WriteTimeoutException.copy(WriteTimeoutException.java:26)
at
com.datastax.driver.core.DriverThrowables.propagateCause(DriverThrowables.java:37)
at
com.datastax.driver.core.DefaultResultSetFuture.getUninterruptibly(DefaultResultSetFuture.java:245)
at
com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:68)
at
com.toi.stream.data.AdImprLogDaoImpl.updateImpr(AdImprLogDaoImpl.java:158)
at
com.toi.stream.service.AdClickLogAndAdimprLogServiceImpl.updateGoalsOnImpr(AdClickLogAndAdimprLogServiceImpl.java:522)
at
com.toi.stream.service.ConversionBillingLastAttributionServiceV2Impl.attribute(ConversionBillingLastAttributionServiceV2Impl.java:456)
at
com.toi.stream.service.ConversionBillingLastAttributionServiceV2Impl.attributeAdTracker(ConversionBillingLastAttributionServiceV2Impl.java:228)
at
com.toi.stream.process.AdTrackerStreamProcessorV2.process(AdTrackerStreamProcessorV2.java:86)
at
com.toi.stream.kafka.KafkaGroupConsumer.run(KafkaGroupConsumer.java:175)
at java.lang.Thread.run(Thread.java:748)
Caused by: com.datastax.driver.core.exceptions.WriteTimeoutException:
Cassandra timeout during write query at consistency QUORUM (3 replica were
required but only 2 acknowledged the write)
at
com.datastax.driver.core.exceptions.WriteTimeoutException.copy(WriteTimeoutException.java:100)
at
com.datastax.driver.core.Responses$Error.asException(Responses.java:134)
at
com.datastax.driver.core.RequestHandler$SpeculativeExecution.onSet(RequestHandler.java:525)
at
com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1077)

why its waiting for acknowledged from 3rd server as replication factor is 2?


-- 

*Thanks & Regards,*
*Abhishek Kumar Maheshwari*
*+91- 805591 (Mobile)*

Times Internet Ltd. | A Times of India Group Company

FC - 6, Sector 16A, Film City,  Noida,  U.P. 201301 | INDIA

*P** Please do not print this email unless it is absolutely necessary.
Spread environmental awareness.*