Re: Debug logging enabled by default since 2.2

[Paulo Motta]

The reasoning to have debug.log enabled by default after
CASSANDRA-10241 is to have a "safety log" that you can use when you
want to troubleshoot issues after the fact, that is verbose enough
that you can reconstruct events that may have caused a problem, but
should have negligible performance impact. The way we found to
implement this was the following:
- INFO: Human-readable operator log.
- DEBUG: Safety-log to be used for troubleshooting and bug reporting.
- TRACE: C* Programmer Debugging.

If debug.log is causing performance problems we should definitely fix
it, but this has been very useful to troubleshoot complex production
issues since it has been added.

2018-03-17 16:35 GMT-03:00 Michael Kjellman :
> ive never understood this change. and it’s been explained to me multiple 
> times.
>
> DEBUG shouldn’t run by default in prod. and it certainly shouldn’t be enabled 
> by default for users.
>
> but hey, what do i know! just my 2 cents.
>
>> On Mar 17, 2018, at 10:55 AM, J. D. Jordan  wrote:
>>
>> We went through an exercise of setting things up so that DEBUG logging was 
>> asynchronous would give people a “production” debug log. 
>> https://issues.apache.org/jira/browse/CASSANDRA-10241
>> If there are some things going out at DEBUG that cause performance issues 
>> then most likely those should be moved to TRACE so that debug logging can 
>> stay enabled for all the useful information found there.
>>
>> -Jeremiah
>>
>>> On Mar 17, 2018, at 1:49 PM, Alexander Dejanovski  
>>> wrote:
>>>
>>> Hi folks,
>>>
>>> we've been upgrading clusters from 2.0 to 2.2 recently and we've noticed
>>> that debug logging was causing serious performance issues in some cases,
>>> specifically because of its use in the query pager.
>>>
>>> I've opened a ticket with some benchmarks and flame graphs :
>>> https://issues.apache.org/jira/browse/CASSANDRA-14318
>>>
>>> The problem should be less serious in the read path with Cassandra 3.0 and
>>> above as the query pager code has been reworked and doesn't log at debug
>>> level.
>>> I think that debug logging shouldn't be turned on by default though, since
>>> we see it doesn't come for free and that it lowers read performance in 2.2.
>>>
>>> Was there any specific reason why it was enabled by default in 2.2 ?
>>>
>>> Is anyone opposed to disabling debug logging by default in all branches ?
>>>
>>> --
>>> -
>>> Alexander Dejanovski
>>> France
>>> @alexanderdeja
>>>
>>> Consultant
>>> Apache Cassandra Consulting
>>> http://www.thelastpickle.com
>
> -
> To unsubscribe, e-mail: dev-unsubscr...@cassandra.apache.org
> For additional commands, e-mail: dev-h...@cassandra.apache.org
>

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

Re: Debug logging enabled by default since 2.2

[Michael Kjellman]

ive never understood this change. and it’s been explained to me multiple times.

DEBUG shouldn’t run by default in prod. and it certainly shouldn’t be enabled 
by default for users.

but hey, what do i know! just my 2 cents. 

> On Mar 17, 2018, at 10:55 AM, J. D. Jordan  wrote:
> 
> We went through an exercise of setting things up so that DEBUG logging was 
> asynchronous would give people a “production” debug log. 
> https://issues.apache.org/jira/browse/CASSANDRA-10241
> If there are some things going out at DEBUG that cause performance issues 
> then most likely those should be moved to TRACE so that debug logging can 
> stay enabled for all the useful information found there.
> 
> -Jeremiah
> 
>> On Mar 17, 2018, at 1:49 PM, Alexander Dejanovski  
>> wrote:
>> 
>> Hi folks,
>> 
>> we've been upgrading clusters from 2.0 to 2.2 recently and we've noticed
>> that debug logging was causing serious performance issues in some cases,
>> specifically because of its use in the query pager.
>> 
>> I've opened a ticket with some benchmarks and flame graphs :
>> https://issues.apache.org/jira/browse/CASSANDRA-14318
>> 
>> The problem should be less serious in the read path with Cassandra 3.0 and
>> above as the query pager code has been reworked and doesn't log at debug
>> level.
>> I think that debug logging shouldn't be turned on by default though, since
>> we see it doesn't come for free and that it lowers read performance in 2.2.
>> 
>> Was there any specific reason why it was enabled by default in 2.2 ?
>> 
>> Is anyone opposed to disabling debug logging by default in all branches ?
>> 
>> -- 
>> -
>> Alexander Dejanovski
>> France
>> @alexanderdeja
>> 
>> Consultant
>> Apache Cassandra Consulting
>> http://www.thelastpickle.com

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

Re: Debug logging enabled by default since 2.2

[J. D. Jordan]

We went through an exercise of setting things up so that DEBUG logging was 
asynchronous would give people a “production” debug log. 
https://issues.apache.org/jira/browse/CASSANDRA-10241
If there are some things going out at DEBUG that cause performance issues then 
most likely those should be moved to TRACE so that debug logging can stay 
enabled for all the useful information found there.

-Jeremiah

> On Mar 17, 2018, at 1:49 PM, Alexander Dejanovski  
> wrote:
> 
> Hi folks,
> 
> we've been upgrading clusters from 2.0 to 2.2 recently and we've noticed
> that debug logging was causing serious performance issues in some cases,
> specifically because of its use in the query pager.
> 
> I've opened a ticket with some benchmarks and flame graphs :
> https://issues.apache.org/jira/browse/CASSANDRA-14318
> 
> The problem should be less serious in the read path with Cassandra 3.0 and
> above as the query pager code has been reworked and doesn't log at debug
> level.
> I think that debug logging shouldn't be turned on by default though, since
> we see it doesn't come for free and that it lowers read performance in 2.2.
> 
> Was there any specific reason why it was enabled by default in 2.2 ?
> 
> Is anyone opposed to disabling debug logging by default in all branches ?
> 
> -- 
> -
> Alexander Dejanovski
> France
> @alexanderdeja
> 
> Consultant
> Apache Cassandra Consulting
> http://www.thelastpickle.com

Debug logging enabled by default since 2.2

[Alexander Dejanovski]

Hi folks,

we've been upgrading clusters from 2.0 to 2.2 recently and we've noticed
that debug logging was causing serious performance issues in some cases,
specifically because of its use in the query pager.

I've opened a ticket with some benchmarks and flame graphs :
https://issues.apache.org/jira/browse/CASSANDRA-14318

The problem should be less serious in the read path with Cassandra 3.0 and
above as the query pager code has been reworked and doesn't log at debug
level.
I think that debug logging shouldn't be turned on by default though, since
we see it doesn't come for free and that it lowers read performance in 2.2.

Was there any specific reason why it was enabled by default in 2.2 ?

Is anyone opposed to disabling debug logging by default in all branches ?

-- 
-
Alexander Dejanovski
France
@alexanderdeja

Consultant
Apache Cassandra Consulting
http://www.thelastpickle.com

RE: A JIRA proposing a seperate repository for the online documentation

[Rahul Singh]

Static site generator just takes content from flat files or apis (that can be 
managed from a headless cms) and creates static files or progressive web apps 
that are optimized for speed. Nothing to do with multi-media or dynamic in 
terms of client side javascript / css. It’s just an old technology with a new 
name. Thats how we used to generate sites back in 1990s.. :)

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

Anant Corporation

On Mar 17, 2018, 10:03 AM -0400, Kenneth Brotman 
, wrote:
> How about if we look at the website a little differently. Isn't it an 
> opportunity to showcase Cassandra and related technologies like search! 
> Shouldn't we be an extraordinary advocate and example of the technology 
> ourselves?
>
> Rahul, your comment on the different users with different use cases was very 
> wise.
>
> I've been writing html a long time; since about 1990. You're asking me to 
> learn a weird little program, a static site generator just to change 
> something I can already do without using a program at all.
>
> Another weird thing: Wouldn't we want a website that is dynamic and 
> multi-media rich?
>
> Kenneth Brotman
>
>
> -Original Message-
> From: Rahul Singh [mailto:rahul.xavier.si...@gmail.com]
> Sent: Saturday, March 17, 2018 5:57 AM
> To: dev@cassandra.apache.org
> Subject: RE: A JIRA proposing a seperate repository for the online 
> documentation
>
> I’ve previously deep dived into Static Site generators and there are numerous 
> ones.
>
> http://leaves.anant.us/#!/leaf/7255?tag=static.site
>
> I don’t like changing technology for the sake of change. I think it’s a 
> stupid waste of time. In one hand I agree, the substance is more important 
> than the form. On the other hand. I [insert f-bomb] hate writing HTML / CSS, 
> or restructured text. Markdown is much easier. Hugo is one of many that if 
> setup right, it can save a ton of time and make it more accessible for people 
> to contribute.
>
> There is a difference however in developer documentation for developers of 
> cassandra, user documentation for cassandra users, documentation for and 
> administrators. They are different users and have different use cases. Some 
> need reference style docs, others need guides.
>
> Some good examples, (the software quality not-withstanding), correlate with 
> software propularity are Wordpress. I am not wild about Wordpress, but their 
> codex.wordpress.org has been generally a good “user doc.”
>
> Envision the outcome even if you have to mimic someone else. I don’t mind 
> stealing/copying if it gets us one step further than we are. The reaper docs 
> look easy to maintain and I could care less about Hugo, Hexo, Jekyll, Hyde, 
> KafkasMom, EinsteinsDog, ShrodingersCat static site generator.
>
> I think action should come before decision in open source. Prove something 
> before suggesting a change. Jon’s reaper example is good. If anyone has 
> something better, show it. Prove it.
>
> --
> Rahul Singh
> rahul.si...@anant.us
>
> Anant Corporation
>
> On Mar 16, 2018, 6:54 PM -0400, Kenneth Brotman 
> , wrote:
> > There is no need for another program. Keep the code in html, css and js 
> > People can modify that and show proposed changes in that. No need to 
> > convert back and forth from other formats. If someone is doing something 
> > more involved, they probably already have a program themselves.
> >
> > -Original Message-
> > From: beggles...@apple.com [mailto:beggles...@apple.com]
> > Sent: Friday, March 16, 2018 3:16 PM
> > To: dev@cassandra.apache.org
> > Subject: Re: A JIRA proposing a seperate repository for the online
> > documentation
> >
> > It would probably be more productive to list some specific concerns you 
> > have with Hugo. Then explain why you think they make using it a bad idea 
> > Then offer some alternatives.
> >
> > On 3/16/18, 1:18 PM, "Kenneth Brotman"  wrote:
> >
> > Thanks for that Eric Evans.
> >
> > I'm not sure Hugo is the way to go. I don't see how I would generate the 
> > quality of work I would want with it. It seems like another example of 
> > coders learning and using a more complicated program to generate the code 
> > they could have already generated - it’s a disease in the I.T. industry 
> > right now. But I could be wrong.
> >
> > Here's the thing. I've been spending a lot of my time for the past three 
> > weeks now trying to help with the website. That is a tiny website. I've 
> > never worked with a website that tiny. Bear with me.
> >
> > I'm studying Jeff Carpenter and Eben Hewitt's book: Cassandra The 
> > Definitive Guide 
> > https://www.amazon.com/Cassandra-Definitive-Guide-Distributed-Scale/dp/1491933666/ref=sr_1_1?ie=UTF8=1521230539=8-1=cassandra+the+definitive+guide
> >  and have already have a terrible itch to start contributing some code. I 
> > just want to get set up to do that. The book seems to be a good way to get 
> > familiar 

RE: A JIRA proposing a seperate repository for the online documentation

[Kenneth Brotman]

How about if we look at the website a little differently.  Isn't it an 
opportunity to showcase Cassandra and related technologies like search!  
Shouldn't we be an extraordinary advocate and example of the technology 
ourselves?  

Rahul, your comment on the different users with different use cases was very 
wise.  

I've been writing html a long time; since about 1990.  You're asking me to 
learn a weird little program, a static site generator just to change something 
I can already do without using a program at all.  

Another weird thing: Wouldn't we want a website that is dynamic and multi-media 
rich?

Kenneth Brotman


-Original Message-
From: Rahul Singh [mailto:rahul.xavier.si...@gmail.com] 
Sent: Saturday, March 17, 2018 5:57 AM
To: dev@cassandra.apache.org
Subject: RE: A JIRA proposing a seperate repository for the online documentation

I’ve previously deep dived into Static Site generators and there are numerous 
ones.

http://leaves.anant.us/#!/leaf/7255?tag=static.site

I don’t like changing technology for the sake of change. I think it’s a stupid 
waste of time. In one hand I agree, the substance is more important than the 
form. On the other hand. I [insert f-bomb] hate writing HTML / CSS, or 
restructured text. Markdown is much easier. Hugo is one of many that if setup 
right, it can save a ton of time and make it more accessible for people to 
contribute.

There is a difference however in developer documentation for developers of 
cassandra, user documentation for cassandra users, documentation for and 
administrators. They are different users and have different use cases. Some 
need reference style docs, others need guides.

Some good examples, (the software quality not-withstanding), correlate with 
software propularity are Wordpress. I am not wild about Wordpress, but their 
codex.wordpress.org has been generally a good “user doc.”

Envision the outcome even if you have to mimic someone else. I don’t mind 
stealing/copying if it gets us one step further than we are. The reaper docs 
look easy to maintain and I could care less about Hugo, Hexo, Jekyll, Hyde, 
KafkasMom, EinsteinsDog, ShrodingersCat static site generator.

I think action should come before decision in open source. Prove something 
before suggesting a change. Jon’s reaper example is good. If anyone has 
something better, show it. Prove it.

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

Anant Corporation

On Mar 16, 2018, 6:54 PM -0400, Kenneth Brotman , 
wrote:
> There is no need for another program. Keep the code in html, css and js 
> People can modify that and show proposed changes in that. No need to convert 
> back and forth from other formats. If someone is doing something more 
> involved, they probably already have a program themselves.
>
> -Original Message-
> From: beggles...@apple.com [mailto:beggles...@apple.com]
> Sent: Friday, March 16, 2018 3:16 PM
> To: dev@cassandra.apache.org
> Subject: Re: A JIRA proposing a seperate repository for the online 
> documentation
>
> It would probably be more productive to list some specific concerns you have 
> with Hugo. Then explain why you think they make using it a bad idea Then 
> offer some alternatives.
>
> On 3/16/18, 1:18 PM, "Kenneth Brotman"  wrote:
>
> Thanks for that Eric Evans.
>
> I'm not sure Hugo is the way to go. I don't see how I would generate the 
> quality of work I would want with it. It seems like another example of coders 
> learning and using a more complicated program to generate the code they could 
> have already generated - it’s a disease in the I.T. industry right now. But I 
> could be wrong.
>
> Here's the thing. I've been spending a lot of my time for the past three 
> weeks now trying to help with the website. That is a tiny website. I've never 
> worked with a website that tiny. Bear with me.
>
> I'm studying Jeff Carpenter and Eben Hewitt's book: Cassandra The Definitive 
> Guide 
> https://www.amazon.com/Cassandra-Definitive-Guide-Distributed-Scale/dp/1491933666/ref=sr_1_1?ie=UTF8=1521230539=8-1=cassandra+the+definitive+guide
>  and have already have a terrible itch to start contributing some code. I 
> just want to get set up to do that. The book seems to be a good way to get 
> familiar with the internals and the code of Cassandra.
>
> I can only do so much for the group at one time just like anyone else. I'll 
> only do top quality work. I'll only be a part of top quality work. It could 
> be that I won't feel comfortable with what the group wants to do for the 
> website.
>
> Please keep working on it as it is really embarrassing, terrible, substandard 
> unacceptable beneath professional standards...
>
> I will contribute if it's possible for me to do so. Let's see what we decide 
> to do going forward for the website.
>
> Kenneth Brotman
> (Cassandra coder?)
>
> -Original Message-
> From: Eric Evans [mailto:john.eric.ev...@gmail.com]
> Sent: Friday, March 

RE: A JIRA proposing a seperate repository for the online documentation

[Rahul Singh]

I’ve previously deep dived into Static Site generators and there are numerous 
ones.

http://leaves.anant.us/#!/leaf/7255?tag=static.site

I don’t like changing technology for the sake of change. I think it’s a stupid 
waste of time. In one hand I agree, the substance is more important than the 
form. On the other hand. I [insert f-bomb] hate writing HTML / CSS, or 
restructured text. Markdown is much easier. Hugo is one of many that if setup 
right, it can save a ton of time and make it more accessible for people to 
contribute.

There is a difference however in developer documentation for developers of 
cassandra, user documentation for cassandra users, documentation for and 
administrators. They are different users and have different use cases. Some 
need reference style docs, others need guides.

Some good examples, (the software quality not-withstanding), correlate with 
software propularity are Wordpress. I am not wild about Wordpress, but their 
codex.wordpress.org has been generally a good “user doc.”

Envision the outcome even if you have to mimic someone else. I don’t mind 
stealing/copying if it gets us one step further than we are. The reaper docs 
look easy to maintain and I could care less about Hugo, Hexo, Jekyll, Hyde, 
KafkasMom, EinsteinsDog, ShrodingersCat static site generator.

I think action should come before decision in open source. Prove something 
before suggesting a change. Jon’s reaper example is good. If anyone has 
something better, show it. Prove it.

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

Anant Corporation

On Mar 16, 2018, 6:54 PM -0400, Kenneth Brotman , 
wrote:
> There is no need for another program. Keep the code in html, css and js. 
> People can modify that and show proposed changes in that. No need to convert 
> back and forth from other formats. If someone is doing something more 
> involved, they probably already have a program themselves.
>
> -Original Message-
> From: beggles...@apple.com [mailto:beggles...@apple.com]
> Sent: Friday, March 16, 2018 3:16 PM
> To: dev@cassandra.apache.org
> Subject: Re: A JIRA proposing a seperate repository for the online 
> documentation
>
> It would probably be more productive to list some specific concerns you have 
> with Hugo. Then explain why you think they make using it a bad idea. Then 
> offer some alternatives.
>
> On 3/16/18, 1:18 PM, "Kenneth Brotman"  wrote:
>
> Thanks for that Eric Evans.
>
> I'm not sure Hugo is the way to go. I don't see how I would generate the 
> quality of work I would want with it. It seems like another example of coders 
> learning and using a more complicated program to generate the code they could 
> have already generated - it’s a disease in the I.T. industry right now. But I 
> could be wrong.
>
> Here's the thing. I've been spending a lot of my time for the past three 
> weeks now trying to help with the website. That is a tiny website. I've never 
> worked with a website that tiny. Bear with me.
>
> I'm studying Jeff Carpenter and Eben Hewitt's book: Cassandra The Definitive 
> Guide 
> https://www.amazon.com/Cassandra-Definitive-Guide-Distributed-Scale/dp/1491933666/ref=sr_1_1?ie=UTF8=1521230539=8-1=cassandra+the+definitive+guide
>  and have already have a terrible itch to start contributing some code. I 
> just want to get set up to do that. The book seems to be a good way to get 
> familiar with the internals and the code of Cassandra.
>
> I can only do so much for the group at one time just like anyone else. I'll 
> only do top quality work. I'll only be a part of top quality work. It could 
> be that I won't feel comfortable with what the group wants to do for the 
> website.
>
> Please keep working on it as it is really embarrassing, terrible, substandard 
> unacceptable beneath professional standards...
>
> I will contribute if it's possible for me to do so. Let's see what we decide 
> to do going forward for the website.
>
> Kenneth Brotman
> (Cassandra coder?)
>
> -Original Message-
> From: Eric Evans [mailto:john.eric.ev...@gmail.com]
> Sent: Friday, March 16, 2018 7:59 AM
> To: dev@cassandra.apache.org
> Subject: Re: A JIRA proposing a seperate repository for the online 
> documentation
>
> On Thu, Mar 15, 2018 at 11:40 AM, Kenneth Brotman 
>  wrote:
> > Well pickle my cucumbers Jon! It's good to know that you have experience 
> > with Hugo, see it as a good fit and that all has been well. I look forward 
> > to the jira epic!
> >
> > How exactly does the group make such a decision: Call for final discussion? 
> > Call for vote? Wait for the PMC to vote?
>
> Good question!
>
> Decisions like this are made by consensus; As the person who is attempting to 
> do something, you discuss your ideas with the group, listen to the feedback 
> of others, and develop consensus around a direction.
>
> This is more difficult than demanding your way, or having someone(s) in a 
> position