Cassandra Summit 2015 Roll Call!

[Robert Coli]

Cassandra Summit 2015 is upon us!

Every year, the conference gets bigger and bigger, and the chance of IRL
meeting people you've "met" online gets smaller and smaller.

To improve everyone's chances, if you are attending the summit :

1) respond on-thread with a brief introduction (and physical description of
yourself if you want others to be able to spot you!)
2) join #cassandra on freenode IRC (irc.freenode.org) to chat and connect
with other attendees!

MY CONTRIBUTION :
--
I will be at the summit on Wednesday and Thursday. I am 5'8" or so, and
will be wearing glasses and either a red or blue "Eventbrite Engineering"
t-shirt with a graphic logo of gears on it. Come say hello! :D

=Rob

Re: Cassandra Summit 2015 Roll Call!

[Eric Plowe]

I'am here! Beaded guy, in a blue gingham shirt. I'll be at the reception.



On Tue, Sep 22, 2015 at 2:59 PM, Jonathan Haddad  wrote:

> Yo.  It's me.  Haddad, aka rustyrazorblade.  6'1", hair probably in a bun
> and a beard.  Helping with training today, giving a talk on pyspark & on
> the python driver tomorrow.  I'll be at the MVP dinner.  Wearing a DataStax
> training t shirt today, not sure about the rest of the time though.
>
> Here I am:
> https://pbs.twimg.com/profile_images/555812979187265536/uFbfp2q1.jpeg
>
> Thanks Rob for starting the thread, good idea.
>
> Please feel free to come say hi even if we're never talked, I love meeting
> people in the community.
>
> Jon
>
>
> On Tue, Sep 22, 2015 at 11:42 AM Russell Bradberry 
> wrote:
>
>> I will be wearing a red t-shirt that says SimpleReach and I will be at
>> the reception tonight, the MVP dinner and the summit both days.  I'm about
>> 5'11" and probably going to be the best looking person there. ;)
>>
>> See you all at the summit.
>>
>> On Tue, Sep 22, 2015 at 11:27 AM, Robert Coli 
>> wrote:
>>
>>> Cassandra Summit 2015 is upon us!
>>>
>>> Every year, the conference gets bigger and bigger, and the chance of IRL
>>> meeting people you've "met" online gets smaller and smaller.
>>>
>>> To improve everyone's chances, if you are attending the summit :
>>>
>>> 1) respond on-thread with a brief introduction (and physical description
>>> of yourself if you want others to be able to spot you!)
>>> 2) join #cassandra on freenode IRC (irc.freenode.org) to chat and
>>> connect with other attendees!
>>>
>>> MY CONTRIBUTION :
>>> --
>>> I will be at the summit on Wednesday and Thursday. I am 5'8" or so, and
>>> will be wearing glasses and either a red or blue "Eventbrite Engineering"
>>> t-shirt with a graphic logo of gears on it. Come say hello! :D
>>>
>>> =Rob
>>>
>>>
>>

Re: Cassandra Summit 2015 Roll Call!

[Russell Bradberry]

I will be wearing a red t-shirt that says SimpleReach and I will be at the
reception tonight, the MVP dinner and the summit both days.  I'm about
5'11" and probably going to be the best looking person there. ;)

See you all at the summit.

On Tue, Sep 22, 2015 at 11:27 AM, Robert Coli  wrote:

> Cassandra Summit 2015 is upon us!
>
> Every year, the conference gets bigger and bigger, and the chance of IRL
> meeting people you've "met" online gets smaller and smaller.
>
> To improve everyone's chances, if you are attending the summit :
>
> 1) respond on-thread with a brief introduction (and physical description
> of yourself if you want others to be able to spot you!)
> 2) join #cassandra on freenode IRC (irc.freenode.org) to chat and connect
> with other attendees!
>
> MY CONTRIBUTION :
> --
> I will be at the summit on Wednesday and Thursday. I am 5'8" or so, and
> will be wearing glasses and either a red or blue "Eventbrite Engineering"
> t-shirt with a graphic logo of gears on it. Come say hello! :D
>
> =Rob
>
>

Re: Cassandra Summit 2015 Roll Call!

[Jonathan Haddad]

Yo.  It's me.  Haddad, aka rustyrazorblade.  6'1", hair probably in a bun
and a beard.  Helping with training today, giving a talk on pyspark & on
the python driver tomorrow.  I'll be at the MVP dinner.  Wearing a DataStax
training t shirt today, not sure about the rest of the time though.

Here I am:
https://pbs.twimg.com/profile_images/555812979187265536/uFbfp2q1.jpeg

Thanks Rob for starting the thread, good idea.

Please feel free to come say hi even if we're never talked, I love meeting
people in the community.

Jon


On Tue, Sep 22, 2015 at 11:42 AM Russell Bradberry 
wrote:

> I will be wearing a red t-shirt that says SimpleReach and I will be at the
> reception tonight, the MVP dinner and the summit both days.  I'm about
> 5'11" and probably going to be the best looking person there. ;)
>
> See you all at the summit.
>
> On Tue, Sep 22, 2015 at 11:27 AM, Robert Coli 
> wrote:
>
>> Cassandra Summit 2015 is upon us!
>>
>> Every year, the conference gets bigger and bigger, and the chance of IRL
>> meeting people you've "met" online gets smaller and smaller.
>>
>> To improve everyone's chances, if you are attending the summit :
>>
>> 1) respond on-thread with a brief introduction (and physical description
>> of yourself if you want others to be able to spot you!)
>> 2) join #cassandra on freenode IRC (irc.freenode.org) to chat and
>> connect with other attendees!
>>
>> MY CONTRIBUTION :
>> --
>> I will be at the summit on Wednesday and Thursday. I am 5'8" or so, and
>> will be wearing glasses and either a red or blue "Eventbrite Engineering"
>> t-shirt with a graphic logo of gears on it. Come say hello! :D
>>
>> =Rob
>>
>>
>

Re: High read latency

[Jaydeep Chovatia]

select * from test where a = ? and b = ?

On Tue, Sep 22, 2015 at 10:27 AM, sai krishnam raju potturi <
pskraj...@gmail.com> wrote:

> thanks for the information. Posting the query too would be of help.
>
> On Tue, Sep 22, 2015 at 11:56 AM, Jaydeep Chovatia <
> chovatia.jayd...@gmail.com> wrote:
>
>> Please find required details here:
>>
>> -  Number of req/s
>>
>> 2k reads/s
>>
>> -  Schema details
>>
>> create table test {
>>
>> a timeuuid,
>>
>> b bigint,
>>
>> c int,
>>
>> d int static,
>>
>> e int static,
>>
>> f int static,
>>
>> g int static,
>>
>> h int,
>>
>> i text,
>>
>> j text,
>>
>> k text,
>>
>> l text,
>>
>> m set
>>
>> n bigint
>>
>> o bigint
>>
>> p bigint
>>
>> q bigint
>>
>> r int
>>
>> s text
>>
>> t bigint
>>
>> u text
>>
>> v text
>>
>> w text
>>
>> x bigint
>>
>> y bigint
>>
>> z bigint,
>>
>> primary key ((a, b), c)
>>
>> };
>>
>> -  JVM settings about the heap
>>
>> Default settings
>>
>> -  Execution time of the GC
>>
>> Avg. 400ms. I do not see long pauses of GC anywhere in the log file.
>>
>> On Tue, Sep 22, 2015 at 5:34 AM, Leleu Eric 
>> wrote:
>>
>>> Hi,
>>>
>>>
>>>
>>>
>>>
>>> Before speaking about tuning, can you provide some additional
>>> information ?
>>>
>>>
>>>
>>> -  Number of req/s
>>>
>>> -  Schema details
>>>
>>> -  JVM settings about the heap
>>>
>>> -  Execution time of the GC
>>>
>>>
>>>
>>> 43ms for a read latency may be acceptable according to the number of
>>> request per second.
>>>
>>>
>>>
>>>
>>>
>>> Eric
>>>
>>>
>>>
>>> *De :* Jaydeep Chovatia [mailto:chovatia.jayd...@gmail.com]
>>> *Envoyé :* mardi 22 septembre 2015 00:07
>>> *À :* user@cassandra.apache.org
>>> *Objet :* High read latency
>>>
>>>
>>>
>>> Hi,
>>>
>>>
>>>
>>> My application issues more read requests than write, I do see that under
>>> load cfstats for one of the table is quite high around 43ms
>>>
>>>
>>>
>>> Local read count: 114479357
>>>
>>> Local read latency: 43.442 ms
>>>
>>> Local write count: 22288868
>>>
>>> Local write latency: 0.609 ms
>>>
>>>
>>>
>>>
>>>
>>> Here is my node configuration:
>>>
>>> RF=3, Read/Write with QUORUM, 64GB RAM, 48 CPU core. I have only 5 GB of
>>> data on each node (and for experiment purpose I stored data in tmpfs)
>>>
>>>
>>>
>>> I've tried increasing concurrent_read count upto 512 but no help in read
>>> latency. CPU/Memory/IO looks fine on system.
>>>
>>>
>>>
>>> Any idea what should I tune?
>>>
>>>
>>>
>>> Jaydeep
>>>
>>> --
>>>
>>> Ce message et les pièces jointes sont confidentiels et réservés à
>>> l'usage exclusif de ses destinataires. Il peut également être protégé par
>>> le secret professionnel. Si vous recevez ce message par erreur, merci d'en
>>> avertir immédiatement l'expéditeur et de le détruire. L'intégrité du
>>> message ne pouvant être assurée sur Internet, la responsabilité de
>>> Worldline ne pourra être recherchée quant au contenu de ce message. Bien
>>> que les meilleurs efforts soient faits pour maintenir cette transmission
>>> exempte de tout virus, l'expéditeur ne donne aucune garantie à cet égard et
>>> sa responsabilité ne saurait être recherchée pour tout dommage résultant
>>> d'un virus transmis.
>>>
>>> This e-mail and the documents attached are confidential and intended
>>> solely for the addressee; it may also be privileged. If you receive this
>>> e-mail in error, please notify the sender immediately and destroy it. As
>>> its integrity cannot be secured on the Internet, the Worldline liability
>>> cannot be triggered for the message content. Although the sender endeavours
>>> to maintain a computer virus-free network, the sender does not warrant that
>>> this transmission is virus-free and will not be liable for any damages
>>> resulting from any virus transmitted.
>>>
>>
>>
>

Re: High read latency

[sai krishnam raju potturi]

thanks for the information. Posting the query too would be of help.

On Tue, Sep 22, 2015 at 11:56 AM, Jaydeep Chovatia <
chovatia.jayd...@gmail.com> wrote:

> Please find required details here:
>
> -  Number of req/s
>
> 2k reads/s
>
> -  Schema details
>
> create table test {
>
> a timeuuid,
>
> b bigint,
>
> c int,
>
> d int static,
>
> e int static,
>
> f int static,
>
> g int static,
>
> h int,
>
> i text,
>
> j text,
>
> k text,
>
> l text,
>
> m set
>
> n bigint
>
> o bigint
>
> p bigint
>
> q bigint
>
> r int
>
> s text
>
> t bigint
>
> u text
>
> v text
>
> w text
>
> x bigint
>
> y bigint
>
> z bigint,
>
> primary key ((a, b), c)
>
> };
>
> -  JVM settings about the heap
>
> Default settings
>
> -  Execution time of the GC
>
> Avg. 400ms. I do not see long pauses of GC anywhere in the log file.
>
> On Tue, Sep 22, 2015 at 5:34 AM, Leleu Eric 
> wrote:
>
>> Hi,
>>
>>
>>
>>
>>
>> Before speaking about tuning, can you provide some additional information
>> ?
>>
>>
>>
>> -  Number of req/s
>>
>> -  Schema details
>>
>> -  JVM settings about the heap
>>
>> -  Execution time of the GC
>>
>>
>>
>> 43ms for a read latency may be acceptable according to the number of
>> request per second.
>>
>>
>>
>>
>>
>> Eric
>>
>>
>>
>> *De :* Jaydeep Chovatia [mailto:chovatia.jayd...@gmail.com]
>> *Envoyé :* mardi 22 septembre 2015 00:07
>> *À :* user@cassandra.apache.org
>> *Objet :* High read latency
>>
>>
>>
>> Hi,
>>
>>
>>
>> My application issues more read requests than write, I do see that under
>> load cfstats for one of the table is quite high around 43ms
>>
>>
>>
>> Local read count: 114479357
>>
>> Local read latency: 43.442 ms
>>
>> Local write count: 22288868
>>
>> Local write latency: 0.609 ms
>>
>>
>>
>>
>>
>> Here is my node configuration:
>>
>> RF=3, Read/Write with QUORUM, 64GB RAM, 48 CPU core. I have only 5 GB of
>> data on each node (and for experiment purpose I stored data in tmpfs)
>>
>>
>>
>> I've tried increasing concurrent_read count upto 512 but no help in read
>> latency. CPU/Memory/IO looks fine on system.
>>
>>
>>
>> Any idea what should I tune?
>>
>>
>>
>> Jaydeep
>>
>> --
>>
>> Ce message et les pièces jointes sont confidentiels et réservés à l'usage
>> exclusif de ses destinataires. Il peut également être protégé par le secret
>> professionnel. Si vous recevez ce message par erreur, merci d'en avertir
>> immédiatement l'expéditeur et de le détruire. L'intégrité du message ne
>> pouvant être assurée sur Internet, la responsabilité de Worldline ne pourra
>> être recherchée quant au contenu de ce message. Bien que les meilleurs
>> efforts soient faits pour maintenir cette transmission exempte de tout
>> virus, l'expéditeur ne donne aucune garantie à cet égard et sa
>> responsabilité ne saurait être recherchée pour tout dommage résultant d'un
>> virus transmis.
>>
>> This e-mail and the documents attached are confidential and intended
>> solely for the addressee; it may also be privileged. If you receive this
>> e-mail in error, please notify the sender immediately and destroy it. As
>> its integrity cannot be secured on the Internet, the Worldline liability
>> cannot be triggered for the message content. Although the sender endeavours
>> to maintain a computer virus-free network, the sender does not warrant that
>> this transmission is virus-free and will not be liable for any damages
>> resulting from any virus transmitted.
>>
>
>

Re: ScyllaDB, a new open source, Cassandra-compatible NoSQL

[Sachin Nikam]

Tzach,
Can you point to any documentation on scylladb site which talks about
how/why scylla db performs better than Cassandra while using the same
architecture?
Regards
Sachin

On Tue, Sep 22, 2015 at 9:18 AM, Tzach Livyatan 
wrote:

> Hello Cassandra users,
>
> We are pleased to announce a new member of the Cassandra Ecosystem -
> ScyllaDB
> ScyllaDB is a new, open source, Cassandra-compatible NoSQL data store,
> written with the goal of delivering superior performance and consistent low
> latency.  Today, ScyllaDB runs 1M tps per server with sub 1ms latency.
>
> ScyllaDB  supports CQL, is compatible with Cassandra drivers, and works
> out of the box with Cassandra tools like cqlsh, Spark connector, nodetool
> and cassandra-stress. ScyllaDB is a drop-in replacement solution for the
> Cassandra server side packages.
>
> Scylla is implemented using the new shared-nothing Seastar
>  framework for extreme performance on
> modern multicore hardware, and the Data Plane Development Kit (DPDK) for
> high-speed low-latency networking.
>
> Try Scylla Now - http://www.scylladb.com
>
> We will be at Cassandra summit 2015, you are welcome to visit our booth to
> hear more and see a demo.
> Avi Kivity, our CTO, will host a session on Scylla on Thursday, 1:50 PM -
> 2:30 PM in rooms M1 - M3.
>
> Regards
> Tzach
> scylladb
>
>

Throttling Cassandra Load

[Anuj Wadehra]

Hi,

We are using Cassandra 2.0.14 with Hector 1.1.4. Each node in cluster has an 
application using Hector and a Cassandra instance.

I want suggestions on the approach we are taking for throttling Cassandra load. 

Problem Statement: 
Misbehaved clients can bring down Cassandra clusters by putting excessive load. 
We want to prevent overloading of Cassandra cluster.

Solution Proposed:
1.  Run a Test for each application scenario involving Cassandra. Keep on 
putting more requests in each application Scenario till performance starts 
deteriorating for the scenario and note the max connection achieved during the 
tests as follows:

For Example: 
Scenario A=60 
Scenario B=70
Scneario C=90

Set rpc_max_threads= max(All scenarios)=90

2. In Hector, set MaxActive connections per host=90 

3. As Hector maintains connections PER HOST, Number of open connections by a 
Hector client on a node increases with cluster size.

e.g. On a 3 node cluster, each Hector client will open total of 90 * 3 
connections
   On a 15 node cluster, each Hector client will open total of 90 * 15 
connections

So, we have set rpc_server_type=hsha to support large client connections. Not 
sure whether https://issues.apache.org/jira/i#browse/CASSANDRA-7309 is a 
concern??

4. At application level, we check cluster load by ADDING active connections 
created by Hector on EACH node of cluster. If they are already around 95% of ( 
90 * (num of Nodes)),we reject tasks to prevent overload.

5. We see that Hector only closes idle connections when borrowing clients from 
pool .And immediately after closing idle connections, it creates a new one. So, 
if active connections increase they seldom go down and remain open(except in 
few exception scenarios). So, we cant rely on ThriftClients JMX metrics by 
Cassandra to know ACTIVE connections. ThriftClients show open connections 
rather than active.Is there a better way to know active Cassandra connections 
on a Cassandra node?? or check Cassandra load to prevent more tasks if a node 
is already overloaded?


I am looking for suggestions on above approach and more ideas on throttling 
Cassandra load ?

Thanks
Anuj

Re: Help with tombstones and compaction

[Venkatesh Arivazhagan]

Thank you so much Jeff! I will bump to Cassandra 2.1.9 and update this
thread with the results!

Thanks,
Venkatesh

On Mon, Sep 21, 2015 at 2:19 PM, Jeff Jirsa 
wrote:

> The timestamp involed here isn’t the one defined in the schema, it’s the
> timestamp written on each cell when you apply a mutation (write).
>
> That timestamp is the one returned by WRITETIME(), and visible in
> sstablemetadata – it’s not visible in the schema directly.
>
> Failing to have the proper unit (milliseconds vs microseconds) could
> certainly cause confusion.
>
>
>
> From: Venkatesh Arivazhagan
> Reply-To: "user@cassandra.apache.org"
> Date: Monday, September 21, 2015 at 1:41 PM
> To: "user@cassandra.apache.org"
> Subject: Re: Help with tombstones and compaction
>
> Thank you for your reply Jeff!
>
> I will switch to Cassandra 2.1.9.
>
> Quick follow up question: Does the schema, settings I have setup look
> alright? My timestamp column's type is blob - I was wondering if this could
> confuse DTCS?
>
> On Sun, Sep 20, 2015 at 3:37 PM, Jeff Jirsa 
> wrote:
>
>> 2.1.4 is getting pretty old. There’s a DTCS deletion tweak in 2.1.5 (
>> https://issues.apache.org/jira/browse/CASSANDRA-8359 ) that may help you.
>>
>> 2.1.5 and 2.1.6 have some memory leak issues in DTCS, so go to 2.1.7 or
>> newer (probably 2.1.9 unless you have a compelling reason not to go to
>> 2.1.9)
>>
>>
>> From: Venkatesh Arivazhagan
>> Reply-To: "user@cassandra.apache.org"
>> Date: Sunday, September 20, 2015 at 2:48 PM
>> To: "user@cassandra.apache.org"
>> Subject: Help with tombstones and compaction
>>
>> Hi Guys,
>>
>> I have a Cassandra 2.1.4 cluster with 14 nodes. I am using it primarily
>> for storing time series data collected via KairosDB.
>> The default TTL for data inserted into the column family named
>> data_points is 12hrs. I have also set the gc_grace_seconds to 12 hrs.
>> In-spite of this my disk space keeps on increasing and it looks like
>> tombstones are never dropped.
>>
>> It looks like compactions are happening on a regular basis. The SSTable
>> count does not seem outrageous either. It is constantly between ~10 to ~22.
>>
>> Am I doing anything wrong? Is there a way to mitigate this?
>>
>> Attached:
>> * DESC output for my keyspace
>> * Disk usage graph
>> * LiveSSTable Count graph
>>
>>
>> --
>>
>> CREATE KEYSPACE kairosdb WITH replication = {'class': 'SimpleStrategy',
>> 'replication_factor': '3'}  AND durable_writes = true;
>>
>> CREATE TABLE kairosdb.data_points (
>> key blob,
>> column1 blob,
>> value blob,
>> PRIMARY KEY (key, column1)
>> ) WITH COMPACT STORAGE
>> AND CLUSTERING ORDER BY (column1 ASC)
>> AND bloom_filter_fp_chance = 0.01
>> AND caching = '{"keys":"ALL", "rows_per_partition":"NONE"}'
>> AND comment = ''
>> AND compaction = {'max_sstable_age_days': '365', 'base_time_seconds':
>> '3600', 'max_threshold': '32', 'timestamp_resolution': 'MILLISECONDS',
>> 'enabled': 'true', 'tombstone_compaction_interval': '1', 'min_threshold':
>> '4', 'tombstone_threshold': '.1', 'class':
>> 'org.apache.cassandra.db.compaction.DateTieredCompactionStrategy'}
>> AND compression = {'sstable_compression':
>> 'org.apache.cassandra.io.compress.LZ4Compressor'}
>> AND dclocal_read_repair_chance = 0.1
>> AND default_time_to_live = 43200
>> AND gc_grace_seconds = 43200
>> AND max_index_interval = 2048
>> AND memtable_flush_period_in_ms = 0
>> AND min_index_interval = 128
>> AND read_repair_chance = 0.1
>> AND speculative_retry = 'NONE';
>>
>> CREATE TABLE kairosdb.row_key_index (
>> key blob,
>> column1 blob,
>> value blob,
>> PRIMARY KEY (key, column1)
>> ) WITH COMPACT STORAGE
>> AND CLUSTERING ORDER BY (column1 ASC)
>> AND bloom_filter_fp_chance = 0.01
>> AND caching = '{"keys":"ALL", "rows_per_partition":"NONE"}'
>> AND comment = ''
>> AND compaction = {'min_threshold': '4', 'class':
>> 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy',
>> 'max_threshold': '32'}
>> AND compression = {'sstable_compression':
>> 'org.apache.cassandra.io.compress.LZ4Compressor'}
>> AND dclocal_read_repair_chance = 0.1
>> AND default_time_to_live = 0
>> AND gc_grace_seconds = 43200
>> AND max_index_interval = 2048
>> AND memtable_flush_period_in_ms = 0
>> AND min_index_interval = 128
>> AND read_repair_chance = 0.1
>> AND speculative_retry = 'NONE';
>>
>> CREATE TABLE kairosdb.string_index (
>> key blob,
>> column1 text,
>> value blob,
>> PRIMARY KEY (key, column1)
>> ) WITH COMPACT STORAGE
>> AND CLUSTERING ORDER BY (column1 ASC)
>> AND bloom_filter_fp_chance = 0.01
>> AND caching = '{"keys":"ALL", "rows_per_partition":"NONE"}'
>> AND comment = ''
>> AND compaction = {'min_threshold': '4', 'class':

Re: ScyllaDB, a new open source, Cassandra-compatible NoSQL

[Minh Do]

First glance at their github, it looks like they re-implemented Cassandra
in C++.  90% components in Cassandra are
in scylladb, i.e. compaction, repair, CQL, gossip, SStable.


With C++, I believe this helps performance to some extent up to a point
when compaction has not run yet.
Then, it will be disk IO to be the dominant factor in the performance
measurement as the more traffics to a node the more degrading
the performance is across the cluster.

Also, they only support Thrift protocol so it won't work with Java Driver
with the new asynchronous protocol.  I doubt their tests
are truly a fair one.

On Tue, Sep 22, 2015 at 2:13 PM, Venkatesh Arivazhagan <
venkey.a...@gmail.com> wrote:

> I came across this article:
> zdnet.com/article/kvm-creators-open-source-fast-cassandra-drop-in-replacement-scylla/
>
> Tzach, I would love to know/understand moree about ScyllaDB too. Also the
> benchmark seems to have only 1 DB Server. Do you have benchmark numbers
> where more than 1 DB servers were involved? :)
>
>
> On Tue, Sep 22, 2015 at 1:40 PM, Sachin Nikam  wrote:
>
>> Tzach,
>> Can you point to any documentation on scylladb site which talks about
>> how/why scylla db performs better than Cassandra while using the same
>> architecture?
>> Regards
>> Sachin
>>
>> On Tue, Sep 22, 2015 at 9:18 AM, Tzach Livyatan <
>> tz...@cloudius-systems.com> wrote:
>>
>>> Hello Cassandra users,
>>>
>>> We are pleased to announce a new member of the Cassandra Ecosystem -
>>> ScyllaDB
>>> ScyllaDB is a new, open source, Cassandra-compatible NoSQL data store,
>>> written with the goal of delivering superior performance and consistent low
>>> latency.  Today, ScyllaDB runs 1M tps per server with sub 1ms latency.
>>>
>>> ScyllaDB  supports CQL, is compatible with Cassandra drivers, and works
>>> out of the box with Cassandra tools like cqlsh, Spark connector, nodetool
>>> and cassandra-stress. ScyllaDB is a drop-in replacement solution for the
>>> Cassandra server side packages.
>>>
>>> Scylla is implemented using the new shared-nothing Seastar
>>>  framework for extreme performance on
>>> modern multicore hardware, and the Data Plane Development Kit (DPDK) for
>>> high-speed low-latency networking.
>>>
>>> Try Scylla Now - http://www.scylladb.com
>>>
>>> We will be at Cassandra summit 2015, you are welcome to visit our booth
>>> to hear more and see a demo.
>>> Avi Kivity, our CTO, will host a session on Scylla on Thursday, 1:50 PM
>>> - 2:30 PM in rooms M1 - M3.
>>>
>>> Regards
>>> Tzach
>>> scylladb
>>>
>>>
>>
>

Re: ScyllaDB, a new open source, Cassandra-compatible NoSQL

[Venkatesh Arivazhagan]

I came across this article:
zdnet.com/article/kvm-creators-open-source-fast-cassandra-drop-in-replacement-scylla/

Tzach, I would love to know/understand moree about ScyllaDB too. Also the
benchmark seems to have only 1 DB Server. Do you have benchmark numbers
where more than 1 DB servers were involved? :)


On Tue, Sep 22, 2015 at 1:40 PM, Sachin Nikam  wrote:

> Tzach,
> Can you point to any documentation on scylladb site which talks about
> how/why scylla db performs better than Cassandra while using the same
> architecture?
> Regards
> Sachin
>
> On Tue, Sep 22, 2015 at 9:18 AM, Tzach Livyatan <
> tz...@cloudius-systems.com> wrote:
>
>> Hello Cassandra users,
>>
>> We are pleased to announce a new member of the Cassandra Ecosystem -
>> ScyllaDB
>> ScyllaDB is a new, open source, Cassandra-compatible NoSQL data store,
>> written with the goal of delivering superior performance and consistent low
>> latency.  Today, ScyllaDB runs 1M tps per server with sub 1ms latency.
>>
>> ScyllaDB  supports CQL, is compatible with Cassandra drivers, and works
>> out of the box with Cassandra tools like cqlsh, Spark connector, nodetool
>> and cassandra-stress. ScyllaDB is a drop-in replacement solution for the
>> Cassandra server side packages.
>>
>> Scylla is implemented using the new shared-nothing Seastar
>>  framework for extreme performance on
>> modern multicore hardware, and the Data Plane Development Kit (DPDK) for
>> high-speed low-latency networking.
>>
>> Try Scylla Now - http://www.scylladb.com
>>
>> We will be at Cassandra summit 2015, you are welcome to visit our booth
>> to hear more and see a demo.
>> Avi Kivity, our CTO, will host a session on Scylla on Thursday, 1:50 PM -
>> 2:30 PM in rooms M1 - M3.
>>
>> Regards
>> Tzach
>> scylladb
>>
>>
>

Re: Throttling Cassandra Load

[Robert Coli]

On Tue, Sep 22, 2015 at 1:06 PM, Anuj Wadehra 
wrote:

> We are using Cassandra 2.0.14 with Hector 1.1.4. Each node in cluster has
> an application using Hector and a Cassandra instance.
>

Why are you using Hector?

=Rob

Re: ScyllaDB, a new open source, Cassandra-compatible NoSQL

[Tzach Livyatan]

On Wed, Sep 23, 2015 at 12:20 AM, Minh Do  wrote:

> First glance at their github, it looks like they re-implemented Cassandra
> in C++.  90% components in Cassandra are
> in scylladb, i.e. compaction, repair, CQL, gossip, SStable.
>

True

>
>
> With C++, I believe this helps performance to some extent up to a point
> when compaction has not run yet.
> Then, it will be disk IO to be the dominant factor in the performance
> measurement as the more traffics to a node the more degrading
> the performance is across the cluster.
>
Also, they only support Thrift protocol so it won't work with Java Driver
> with the new asynchronous protocol.  I doubt their tests
> are truly a fair one.
>

Scylla currently only support CQL
For more info, I suggest to continue the discussion at the new Scylla list
https://groups.google.com/forum/#!forum/scylladb-users



>
> On Tue, Sep 22, 2015 at 2:13 PM, Venkatesh Arivazhagan <
> venkey.a...@gmail.com> wrote:
>
>> I came across this article:
>> zdnet.com/article/kvm-creators-open-source-fast-cassandra-drop-in-replacement-scylla/
>>
>> Tzach, I would love to know/understand moree about ScyllaDB too. Also the
>> benchmark seems to have only 1 DB Server. Do you have benchmark numbers
>> where more than 1 DB servers were involved? :)
>>
>>
>> On Tue, Sep 22, 2015 at 1:40 PM, Sachin Nikam  wrote:
>>
>>> Tzach,
>>> Can you point to any documentation on scylladb site which talks about
>>> how/why scylla db performs better than Cassandra while using the same
>>> architecture?
>>> Regards
>>> Sachin
>>>
>>> On Tue, Sep 22, 2015 at 9:18 AM, Tzach Livyatan <
>>> tz...@cloudius-systems.com> wrote:
>>>
 Hello Cassandra users,

 We are pleased to announce a new member of the Cassandra Ecosystem -
 ScyllaDB
 ScyllaDB is a new, open source, Cassandra-compatible NoSQL data store,
 written with the goal of delivering superior performance and consistent low
 latency.  Today, ScyllaDB runs 1M tps per server with sub 1ms latency.

 ScyllaDB  supports CQL, is compatible with Cassandra drivers, and works
 out of the box with Cassandra tools like cqlsh, Spark connector, nodetool
 and cassandra-stress. ScyllaDB is a drop-in replacement solution for the
 Cassandra server side packages.

 Scylla is implemented using the new shared-nothing Seastar
  framework for extreme performance on
 modern multicore hardware, and the Data Plane Development Kit (DPDK) for
 high-speed low-latency networking.

 Try Scylla Now - http://www.scylladb.com

 We will be at Cassandra summit 2015, you are welcome to visit our booth
 to hear more and see a demo.
 Avi Kivity, our CTO, will host a session on Scylla on Thursday, 1:50 PM
 - 2:30 PM in rooms M1 - M3.

 Regards
 Tzach
 scylladb


>>>
>>
>

Re: ScyllaDB, a new open source, Cassandra-compatible NoSQL

[Tzach Livyatan]

On Wed, Sep 23, 2015 at 12:13 AM, Venkatesh Arivazhagan <
venkey.a...@gmail.com> wrote:

> I came across this article:
> zdnet.com/article/kvm-creators-open-source-fast-cassandra-drop-in-replacement-scylla/
>
> Tzach, I would love to know/understand moree about ScyllaDB too. Also the
> benchmark seems to have only 1 DB Server. Do you have benchmark numbers
> where more than 1 DB servers were involved? :)
>
Benchmark specs are here
http://www.scylladb.com/technology/cassandra-vs-scylla-benchmark/
Yes, it is one server.
More benchmarks, with more servers, will be publish soon.



>
>
> On Tue, Sep 22, 2015 at 1:40 PM, Sachin Nikam  wrote:
>
>> Tzach,
>> Can you point to any documentation on scylladb site which talks about
>> how/why scylla db performs better than Cassandra while using the same
>> architecture?
>> Regards
>> Sachin
>>
>> On Tue, Sep 22, 2015 at 9:18 AM, Tzach Livyatan <
>> tz...@cloudius-systems.com> wrote:
>>
>>> Hello Cassandra users,
>>>
>>> We are pleased to announce a new member of the Cassandra Ecosystem -
>>> ScyllaDB
>>> ScyllaDB is a new, open source, Cassandra-compatible NoSQL data store,
>>> written with the goal of delivering superior performance and consistent low
>>> latency.  Today, ScyllaDB runs 1M tps per server with sub 1ms latency.
>>>
>>> ScyllaDB  supports CQL, is compatible with Cassandra drivers, and works
>>> out of the box with Cassandra tools like cqlsh, Spark connector, nodetool
>>> and cassandra-stress. ScyllaDB is a drop-in replacement solution for the
>>> Cassandra server side packages.
>>>
>>> Scylla is implemented using the new shared-nothing Seastar
>>>  framework for extreme performance on
>>> modern multicore hardware, and the Data Plane Development Kit (DPDK) for
>>> high-speed low-latency networking.
>>>
>>> Try Scylla Now - http://www.scylladb.com
>>>
>>> We will be at Cassandra summit 2015, you are welcome to visit our booth
>>> to hear more and see a demo.
>>> Avi Kivity, our CTO, will host a session on Scylla on Thursday, 1:50 PM
>>> - 2:30 PM in rooms M1 - M3.
>>>
>>> Regards
>>> Tzach
>>> scylladb
>>>
>>>
>>
>

Re: ScyllaDB, a new open source, Cassandra-compatible NoSQL

[Peter Lin]

very interesting. I'm glad to see someone building a drop in replacement
for Cassandra.

On Tue, Sep 22, 2015 at 5:40 PM, Tzach Livyatan 
wrote:

> Hi Sachin
>
> On Tue, Sep 22, 2015 at 11:40 PM, Sachin Nikam  wrote:
>
>> Tzach,
>> Can you point to any documentation on scylladb site which talks about
>> how/why scylla db performs better than Cassandra while using the same
>> architecture?
>>
> see here
> http://www.scylladb.com/technology/architecture/
>
>
>> Regards
>> Sachin
>>
>> On Tue, Sep 22, 2015 at 9:18 AM, Tzach Livyatan <
>> tz...@cloudius-systems.com> wrote:
>>
>>> Hello Cassandra users,
>>>
>>> We are pleased to announce a new member of the Cassandra Ecosystem -
>>> ScyllaDB
>>> ScyllaDB is a new, open source, Cassandra-compatible NoSQL data store,
>>> written with the goal of delivering superior performance and consistent low
>>> latency.  Today, ScyllaDB runs 1M tps per server with sub 1ms latency.
>>>
>>> ScyllaDB  supports CQL, is compatible with Cassandra drivers, and works
>>> out of the box with Cassandra tools like cqlsh, Spark connector, nodetool
>>> and cassandra-stress. ScyllaDB is a drop-in replacement solution for the
>>> Cassandra server side packages.
>>>
>>> Scylla is implemented using the new shared-nothing Seastar
>>>  framework for extreme performance on
>>> modern multicore hardware, and the Data Plane Development Kit (DPDK) for
>>> high-speed low-latency networking.
>>>
>>> Try Scylla Now - http://www.scylladb.com
>>>
>>> We will be at Cassandra summit 2015, you are welcome to visit our booth
>>> to hear more and see a demo.
>>> Avi Kivity, our CTO, will host a session on Scylla on Thursday, 1:50 PM
>>> - 2:30 PM in rooms M1 - M3.
>>>
>>> Regards
>>> Tzach
>>> scylladb
>>>
>>>
>>
>

Re: ScyllaDB, a new open source, Cassandra-compatible NoSQL

[Tzach Livyatan]

Hi Sachin

On Tue, Sep 22, 2015 at 11:40 PM, Sachin Nikam  wrote:

> Tzach,
> Can you point to any documentation on scylladb site which talks about
> how/why scylla db performs better than Cassandra while using the same
> architecture?
>
see here
http://www.scylladb.com/technology/architecture/


> Regards
> Sachin
>
> On Tue, Sep 22, 2015 at 9:18 AM, Tzach Livyatan <
> tz...@cloudius-systems.com> wrote:
>
>> Hello Cassandra users,
>>
>> We are pleased to announce a new member of the Cassandra Ecosystem -
>> ScyllaDB
>> ScyllaDB is a new, open source, Cassandra-compatible NoSQL data store,
>> written with the goal of delivering superior performance and consistent low
>> latency.  Today, ScyllaDB runs 1M tps per server with sub 1ms latency.
>>
>> ScyllaDB  supports CQL, is compatible with Cassandra drivers, and works
>> out of the box with Cassandra tools like cqlsh, Spark connector, nodetool
>> and cassandra-stress. ScyllaDB is a drop-in replacement solution for the
>> Cassandra server side packages.
>>
>> Scylla is implemented using the new shared-nothing Seastar
>>  framework for extreme performance on
>> modern multicore hardware, and the Data Plane Development Kit (DPDK) for
>> high-speed low-latency networking.
>>
>> Try Scylla Now - http://www.scylladb.com
>>
>> We will be at Cassandra summit 2015, you are welcome to visit our booth
>> to hear more and see a demo.
>> Avi Kivity, our CTO, will host a session on Scylla on Thursday, 1:50 PM -
>> 2:30 PM in rooms M1 - M3.
>>
>> Regards
>> Tzach
>> scylladb
>>
>>
>

RE: Cassandra Summit 2015 Roll Call!

[Mohammed Guller]

Hey everyone,
I will be at the summit too on Wed and Thu.  I am giving a talk on Thursday at 
2.40pm.

Would love to meet everyone on this list in person.  Here is an old picture of 
mine:
https://events.mfactormeetings.com/accounts/register123/mfactor/datastax/events/dstaxsummit2015/guller.jpg

Mohammed

From: Carlos Alonso [mailto:i...@mrcalonso.com]
Sent: Tuesday, September 22, 2015 5:23 PM
To: user@cassandra.apache.org
Subject: Re: Cassandra Summit 2015 Roll Call!

Hi guys.

I'm already here and I'll be the whole Summit. I'll be doing a live demo on 
Thursday on troubleshooting Cassandra production issues as a developer.

This is me!! https://twitter.com/calonso/status/646352711454097408

Carlos Alonso | Software Engineer | @calonso

On 22 September 2015 at 15:27, Jeff Jirsa 
> wrote:
I’m here. Will be speaking Wednesday on DTCS for time series workloads: 
http://cassandrasummit-datastax.com/agenda/real-world-dtcs-for-operators/

Picture if you recognize me, say hi: 
https://events.mfactormeetings.com/accounts/register123/mfactor/datastax/events/dstaxsummit2015/jirsa.jpg
 (probably wearing glasses and carrying a black Crowdstrike backpack)

- Jeff


From: Robert Coli
Reply-To: "user@cassandra.apache.org"
Date: Tuesday, September 22, 2015 at 11:27 AM
To: "user@cassandra.apache.org"
Subject: Cassandra Summit 2015 Roll Call!

Cassandra Summit 2015 is upon us!

Every year, the conference gets bigger and bigger, and the chance of IRL 
meeting people you've "met" online gets smaller and smaller.

To improve everyone's chances, if you are attending the summit :

1) respond on-thread with a brief introduction (and physical description of 
yourself if you want others to be able to spot you!)
2) join #cassandra on freenode IRC (irc.freenode.org) 
to chat and connect with other attendees!

MY CONTRIBUTION :
--
I will be at the summit on Wednesday and Thursday. I am 5'8" or so, and will be 
wearing glasses and either a red or blue "Eventbrite Engineering" t-shirt with 
a graphic logo of gears on it. Come say hello! :D

=Rob

Re: Cassandra Summit 2015 Roll Call!

[Steve Robenalt]

I am here. Wearing my assorted Cassandra shirts from meetups and
conferences. Would be happy to meet anyone from this mailing list because
the conversations here have been very valuable as I have ramped up with
Cassandra. And I passed my developer certification today. :-)  I am
identifiable from my LinkedIn picture.

Steve



On Tue, Sep 22, 2015 at 8:19 PM, Mohammed Guller 
wrote:

> Hey everyone,
>
> I will be at the summit too on Wed and Thu.  I am giving a talk on
> Thursday at 2.40pm.
>
>
>
> Would love to meet everyone on this list in person.  Here is an old
> picture of mine:
>
>
> https://events.mfactormeetings.com/accounts/register123/mfactor/datastax/events/dstaxsummit2015/guller.jpg
>
>
>
> Mohammed
>
>
>
> *From:* Carlos Alonso [mailto:i...@mrcalonso.com]
> *Sent:* Tuesday, September 22, 2015 5:23 PM
> *To:* user@cassandra.apache.org
> *Subject:* Re: Cassandra Summit 2015 Roll Call!
>
>
>
> Hi guys.
>
>
>
> I'm already here and I'll be the whole Summit. I'll be doing a live demo
> on Thursday on troubleshooting Cassandra production issues as a developer.
>
>
>
> This is me!! https://twitter.com/calonso/status/646352711454097408
>
>
> Carlos Alonso | Software Engineer | @calonso 
>
>
>
> On 22 September 2015 at 15:27, Jeff Jirsa 
> wrote:
>
> I’m here. Will be speaking Wednesday on DTCS for time series workloads:
> http://cassandrasummit-datastax.com/agenda/real-world-dtcs-for-operators/
>
>
>
> Picture if you recognize me, say hi:
> https://events.mfactormeetings.com/accounts/register123/mfactor/datastax/events/dstaxsummit2015/jirsa.jpg
>  (probably
> wearing glasses and carrying a black Crowdstrike backpack)
>
>
>
> - Jeff
>
>
>
>
>
> *From: *Robert Coli
> *Reply-To: *"user@cassandra.apache.org"
> *Date: *Tuesday, September 22, 2015 at 11:27 AM
> *To: *"user@cassandra.apache.org"
> *Subject: *Cassandra Summit 2015 Roll Call!
>
>
>
> Cassandra Summit 2015 is upon us!
>
>
>
> Every year, the conference gets bigger and bigger, and the chance of IRL
> meeting people you've "met" online gets smaller and smaller.
>
>
>
> To improve everyone's chances, if you are attending the summit :
>
>
>
> 1) respond on-thread with a brief introduction (and physical description
> of yourself if you want others to be able to spot you!)
>
> 2) join #cassandra on freenode IRC (irc.freenode.org) to chat and connect
> with other attendees!
>
>
>
> MY CONTRIBUTION :
>
> --
>
> I will be at the summit on Wednesday and Thursday. I am 5'8" or so, and
> will be wearing glasses and either a red or blue "Eventbrite Engineering"
> t-shirt with a graphic logo of gears on it. Come say hello! :D
>
>
>
> =Rob
>
>
>
>
>



-- 
Steve Robenalt
Software Architect
sroben...@highwire.org 
(office/cell): 916-505-1785

HighWire Press, Inc.
425 Broadway St, Redwood City, CA 94063
www.highwire.org

Technology for Scholarly Communication

Re: Throttling Cassandra Load

[Anuj Wadehra]

Hi Robert,


We will be moving to CQL incrementally. But that would take some time (at least 
6 mths). Till then we need a solution for throttling load. Can you comment on 
the approach mentioned and any better ideas for achieving that?




Thanks

Anuj

Sent from Yahoo Mail on Android

From:"Robert Coli" 
Date:Wed, 23 Sep, 2015 at 2:43 am
Subject:Re: Throttling Cassandra Load

On Tue, Sep 22, 2015 at 1:06 PM, Anuj Wadehra  wrote:

We are using Cassandra 2.0.14 with Hector 1.1.4. Each node in cluster has an 
application using Hector and a Cassandra instance.


Why are you using Hector?


=Rob

 

Re: Unable to remove dead node from cluster.

[Dikang Gu]

ping.

On Mon, Sep 21, 2015 at 11:51 AM, Dikang Gu  wrote:

> I have tried all of them, neither of them worked.
> 1. decommission: the host had hardware issue, and I can not connect to it.
> 2. remove, there is not HostID, so the removenode did not work.
> 3. unsafeAssassinateEndpoint, it will throw NPE as I pasted before, can we
> fix it?
>
> Thanks
> Dikang.
>
> On Mon, Sep 21, 2015 at 11:11 AM, Sebastian Estevez <
> sebastian.este...@datastax.com> wrote:
>
>> Order is decommission, remove, assassinate.
>>
>> Which have you tried?
>> On Sep 21, 2015 10:47 AM, "Dikang Gu"  wrote:
>>
>>> Hi there,
>>>
>>> I have a dead node in our cluster, which is a wired state right now, and
>>> can not be removed from cluster.
>>>
>>> The nodestatus shows:
>>> Datacenter: DC1
>>> ===
>>> Status=Up/Down
>>> |/ State=Normal/Leaving/Joining/Moving
>>> --  Address  Load   Tokens  OwnsHost ID
>>>   Rack
>>> DN  10.210.165.55?  256 ?   null
>>>  r1
>>>
>>> I tried the unsafeAssassinateEndpoint, but got exception like:
>>> 2015-09-18_23:21:40.79760 INFO  23:21:40 InetAddress /10.210.165.55 is
>>> now DOWN
>>> 2015-09-18_23:21:40.80667 ERROR 23:21:40 Exception in thread
>>> Thread[GossipStage:1,5,main]
>>> 2015-09-18_23:21:40.80668 java.lang.NullPointerException: null
>>> 2015-09-18_23:21:40.80669   at
>>> org.apache.cassandra.service.StorageService.getApplicationStateValue(StorageService.java:1584)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80669   at
>>> org.apache.cassandra.service.StorageService.getTokensFor(StorageService.java:1592)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80670   at
>>> org.apache.cassandra.service.StorageService.handleStateLeft(StorageService.java:1822)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80671   at
>>> org.apache.cassandra.service.StorageService.onChange(StorageService.java:1495)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80671   at
>>> org.apache.cassandra.service.StorageService.onJoin(StorageService.java:2121)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80672   at
>>> org.apache.cassandra.gms.Gossiper.handleMajorStateChange(Gossiper.java:1009)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80673   at
>>> org.apache.cassandra.gms.Gossiper.applyStateLocally(Gossiper.java:1113)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80673   at
>>> org.apache.cassandra.gms.GossipDigestAck2VerbHandler.doVerb(GossipDigestAck2VerbHandler.java:49)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80673   at
>>> org.apache.cassandra.net.MessageDeliveryTask.run(MessageDeliveryTask.java:62)
>>> ~[apache-cassandra-2.1.8+git20150804.076b0b1.jar:2.1.8+git20150804.076b0b1]
>>> 2015-09-18_23:21:40.80674   at
>>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
>>> ~[na:1.7.0_45]
>>> 2015-09-18_23:21:40.80674   at
>>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
>>> ~[na:1.7.0_45]
>>> 2015-09-18_23:21:40.80674   at java.lang.Thread.run(Thread.java:744)
>>> ~[na:1.7.0_45]
>>> 2015-09-18_23:21:40.85812 WARN  23:21:40 Not marking nodes down due to
>>> local pause of 10852378435 > 50
>>>
>>> Any suggestions about how to remove it?
>>> Thanks.
>>>
>>> --
>>> Dikang
>>>
>>>
>
>
> --
> Dikang
>
>


-- 
Dikang

Re: Cassandra Summit 2015 Roll Call!

[Jeff Jirsa]

I’m here. Will be speaking Wednesday on DTCS for time series workloads: 
http://cassandrasummit-datastax.com/agenda/real-world-dtcs-for-operators/

Picture if you recognize me, say hi: 
https://events.mfactormeetings.com/accounts/register123/mfactor/datastax/events/dstaxsummit2015/jirsa.jpg
 (probably wearing glasses and carrying a black Crowdstrike backpack)

- Jeff


From:  Robert Coli
Reply-To:  "user@cassandra.apache.org"
Date:  Tuesday, September 22, 2015 at 11:27 AM
To:  "user@cassandra.apache.org"
Subject:  Cassandra Summit 2015 Roll Call!

Cassandra Summit 2015 is upon us! 

Every year, the conference gets bigger and bigger, and the chance of IRL 
meeting people you've "met" online gets smaller and smaller.

To improve everyone's chances, if you are attending the summit :

1) respond on-thread with a brief introduction (and physical description of 
yourself if you want others to be able to spot you!)
2) join #cassandra on freenode IRC (irc.freenode.org) to chat and connect with 
other attendees!

MY CONTRIBUTION :
--
I will be at the summit on Wednesday and Thursday. I am 5'8" or so, and will be 
wearing glasses and either a red or blue "Eventbrite Engineering" t-shirt with 
a graphic logo of gears on it. Come say hello! :D

=Rob




smime.p7s
Description: S/MIME cryptographic signature

Re: Cassandra Summit 2015 Roll Call!

[Carlos Alonso]

Hi guys.

I'm already here and I'll be the whole Summit. I'll be doing a live demo on
Thursday on troubleshooting Cassandra production issues as a developer.

This is me!! https://twitter.com/calonso/status/646352711454097408

Carlos Alonso | Software Engineer | @calonso 

On 22 September 2015 at 15:27, Jeff Jirsa 
wrote:

> I’m here. Will be speaking Wednesday on DTCS for time series workloads:
> http://cassandrasummit-datastax.com/agenda/real-world-dtcs-for-operators/
>
> Picture if you recognize me, say hi:
> https://events.mfactormeetings.com/accounts/register123/mfactor/datastax/events/dstaxsummit2015/jirsa.jpg
>  (probably
> wearing glasses and carrying a black Crowdstrike backpack)
>
> - Jeff
>
>
> From: Robert Coli
> Reply-To: "user@cassandra.apache.org"
> Date: Tuesday, September 22, 2015 at 11:27 AM
> To: "user@cassandra.apache.org"
> Subject: Cassandra Summit 2015 Roll Call!
>
> Cassandra Summit 2015 is upon us!
>
> Every year, the conference gets bigger and bigger, and the chance of IRL
> meeting people you've "met" online gets smaller and smaller.
>
> To improve everyone's chances, if you are attending the summit :
>
> 1) respond on-thread with a brief introduction (and physical description
> of yourself if you want others to be able to spot you!)
> 2) join #cassandra on freenode IRC (irc.freenode.org) to chat and connect
> with other attendees!
>
> MY CONTRIBUTION :
> --
> I will be at the summit on Wednesday and Thursday. I am 5'8" or so, and
> will be wearing glasses and either a red or blue "Eventbrite Engineering"
> t-shirt with a graphic logo of gears on it. Come say hello! :D
>
> =Rob
>
>

Re: High read latency

[Jaydeep Chovatia]

Please find required details here:

-  Number of req/s

2k reads/s

-  Schema details

create table test {

a timeuuid,

b bigint,

c int,

d int static,

e int static,

f int static,

g int static,

h int,

i text,

j text,

k text,

l text,

m set

n bigint

o bigint

p bigint

q bigint

r int

s text

t bigint

u text

v text

w text

x bigint

y bigint

z bigint,

primary key ((a, b), c)

};

-  JVM settings about the heap

Default settings

-  Execution time of the GC

Avg. 400ms. I do not see long pauses of GC anywhere in the log file.

On Tue, Sep 22, 2015 at 5:34 AM, Leleu Eric 
wrote:

> Hi,
>
>
>
>
>
> Before speaking about tuning, can you provide some additional information ?
>
>
>
> -  Number of req/s
>
> -  Schema details
>
> -  JVM settings about the heap
>
> -  Execution time of the GC
>
>
>
> 43ms for a read latency may be acceptable according to the number of
> request per second.
>
>
>
>
>
> Eric
>
>
>
> *De :* Jaydeep Chovatia [mailto:chovatia.jayd...@gmail.com]
> *Envoyé :* mardi 22 septembre 2015 00:07
> *À :* user@cassandra.apache.org
> *Objet :* High read latency
>
>
>
> Hi,
>
>
>
> My application issues more read requests than write, I do see that under
> load cfstats for one of the table is quite high around 43ms
>
>
>
> Local read count: 114479357
>
> Local read latency: 43.442 ms
>
> Local write count: 22288868
>
> Local write latency: 0.609 ms
>
>
>
>
>
> Here is my node configuration:
>
> RF=3, Read/Write with QUORUM, 64GB RAM, 48 CPU core. I have only 5 GB of
> data on each node (and for experiment purpose I stored data in tmpfs)
>
>
>
> I've tried increasing concurrent_read count upto 512 but no help in read
> latency. CPU/Memory/IO looks fine on system.
>
>
>
> Any idea what should I tune?
>
>
>
> Jaydeep
>
> --
>
> Ce message et les pièces jointes sont confidentiels et réservés à l'usage
> exclusif de ses destinataires. Il peut également être protégé par le secret
> professionnel. Si vous recevez ce message par erreur, merci d'en avertir
> immédiatement l'expéditeur et de le détruire. L'intégrité du message ne
> pouvant être assurée sur Internet, la responsabilité de Worldline ne pourra
> être recherchée quant au contenu de ce message. Bien que les meilleurs
> efforts soient faits pour maintenir cette transmission exempte de tout
> virus, l'expéditeur ne donne aucune garantie à cet égard et sa
> responsabilité ne saurait être recherchée pour tout dommage résultant d'un
> virus transmis.
>
> This e-mail and the documents attached are confidential and intended
> solely for the addressee; it may also be privileged. If you receive this
> e-mail in error, please notify the sender immediately and destroy it. As
> its integrity cannot be secured on the Internet, the Worldline liability
> cannot be triggered for the message content. Although the sender endeavours
> to maintain a computer virus-free network, the sender does not warrant that
> this transmission is virus-free and will not be liable for any damages
> resulting from any virus transmitted.
>

ScyllaDB, a new open source, Cassandra-compatible NoSQL

[Tzach Livyatan]

Hello Cassandra users,

We are pleased to announce a new member of the Cassandra Ecosystem -
ScyllaDB
ScyllaDB is a new, open source, Cassandra-compatible NoSQL data store,
written with the goal of delivering superior performance and consistent low
latency.  Today, ScyllaDB runs 1M tps per server with sub 1ms latency.

ScyllaDB  supports CQL, is compatible with Cassandra drivers, and works out
of the box with Cassandra tools like cqlsh, Spark connector, nodetool and
cassandra-stress. ScyllaDB is a drop-in replacement solution for the
Cassandra server side packages.

Scylla is implemented using the new shared-nothing Seastar
 framework for extreme performance on
modern multicore hardware, and the Data Plane Development Kit (DPDK) for
high-speed low-latency networking.

Try Scylla Now - http://www.scylladb.com

We will be at Cassandra summit 2015, you are welcome to visit our booth to
hear more and see a demo.
Avi Kivity, our CTO, will host a session on Scylla on Thursday, 1:50 PM -
2:30 PM in rooms M1 - M3.

Regards
Tzach
scylladb

Re: memory usage problem of Metadata.tokenMap.tokenToHost

[horschi]

Hi Joseph,

I think 2000 keyspaces might be just too much. Fewer keyspaces (and CFs)
will probably work much better.

kind regards,
Christian


On Tue, Sep 22, 2015 at 9:29 AM, joseph gao  wrote:

> Hi, anybody could help me?
>
> 2015-09-21 0:47 GMT+08:00 joseph gao :
>
>> ps : that's the code in java drive , in MetaData.TokenMap.build:
>>
>> for (KeyspaceMetadata keyspace : keyspaces)
>> {
>> ReplicationStrategy strategy = keyspace.replicationStrategy();
>> Map ksTokens = (strategy == null)
>> ? makeNonReplicatedMap(tokenToPrimary)
>> : strategy.computeTokenToReplicaMap(tokenToPrimary, ring);
>>
>> tokenToHosts.put(keyspace.getName(), ksTokens);
>>
>> tokenToPrimary is all same, ring is all same, and if strategy is all
>> same , strategy.computeTokenToReplicaMap would return 'same' map but
>> different object( cause every calling returns a new HashMap
>>
>> 2015-09-21 0:22 GMT+08:00 joseph gao :
>>
>>> cassandra: 2.1.7
>>> java driver: datastax java driver 2.1.6
>>>
>>> Here is the problem:
>>>My application uses 2000+ keyspaces, and will dynamically create
>>> keyspaces and tables. And then in java client, the
>>> Metadata.tokenMap.tokenToHost would use about 1g memory. so this will cause
>>> a lot of  full gc.
>>>As I see, the key of the tokenToHost is keyspace, and the value is a
>>> tokenId_to_replicateNodes map.
>>>
>>>When I try to solve this problem, I find something not sure: all
>>> keyspaces have same 'tokenId_to_replicateNodes' map.
>>> My replication strategy of all keyspaces is : simpleStrategy and
>>> replicationFactor is 3
>>>
>>> So would it be possible if keyspaces use same strategy, the value of
>>> tokenToHost map use a same map. So it would extremely reduce the memory
>>> usage
>>>
>>>  thanks a lot
>>>
>>> --
>>> --
>>> Joseph Gao
>>> PhoneNum:15210513582
>>> QQ: 409343351
>>>
>>
>>
>>
>> --
>> --
>> Joseph Gao
>> PhoneNum:15210513582
>> QQ: 409343351
>>
>
>
>
> --
> --
> Joseph Gao
> PhoneNum:15210513582
> QQ: 409343351
>

Re: memory usage problem of Metadata.tokenMap.tokenToHost

[joseph gao]

Hi, anybody could help me?

2015-09-21 0:47 GMT+08:00 joseph gao :

> ps : that's the code in java drive , in MetaData.TokenMap.build:
>
> for (KeyspaceMetadata keyspace : keyspaces)
> {
> ReplicationStrategy strategy = keyspace.replicationStrategy();
> Map ksTokens = (strategy == null)
> ? makeNonReplicatedMap(tokenToPrimary)
> : strategy.computeTokenToReplicaMap(tokenToPrimary, ring);
>
> tokenToHosts.put(keyspace.getName(), ksTokens);
>
> tokenToPrimary is all same, ring is all same, and if strategy is all same
> , strategy.computeTokenToReplicaMap would return 'same' map but different
> object( cause every calling returns a new HashMap
>
> 2015-09-21 0:22 GMT+08:00 joseph gao :
>
>> cassandra: 2.1.7
>> java driver: datastax java driver 2.1.6
>>
>> Here is the problem:
>>My application uses 2000+ keyspaces, and will dynamically create
>> keyspaces and tables. And then in java client, the
>> Metadata.tokenMap.tokenToHost would use about 1g memory. so this will cause
>> a lot of  full gc.
>>As I see, the key of the tokenToHost is keyspace, and the value is a
>> tokenId_to_replicateNodes map.
>>
>>When I try to solve this problem, I find something not sure: all
>> keyspaces have same 'tokenId_to_replicateNodes' map.
>> My replication strategy of all keyspaces is : simpleStrategy and
>> replicationFactor is 3
>>
>> So would it be possible if keyspaces use same strategy, the value of
>> tokenToHost map use a same map. So it would extremely reduce the memory
>> usage
>>
>>  thanks a lot
>>
>> --
>> --
>> Joseph Gao
>> PhoneNum:15210513582
>> QQ: 409343351
>>
>
>
>
> --
> --
> Joseph Gao
> PhoneNum:15210513582
> QQ: 409343351
>



-- 
--
Joseph Gao
PhoneNum:15210513582
QQ: 409343351

RE: High read latency

[Leleu Eric]

Hi,


Before speaking about tuning, can you provide some additional information ?


-  Number of req/s

-  Schema details

-  JVM settings about the heap

-  Execution time of the GC

43ms for a read latency may be acceptable according to the number of request 
per second.


Eric

De : Jaydeep Chovatia [mailto:chovatia.jayd...@gmail.com]
Envoyé : mardi 22 septembre 2015 00:07
À : user@cassandra.apache.org
Objet : High read latency

Hi,

My application issues more read requests than write, I do see that under load 
cfstats for one of the table is quite high around 43ms

Local read count: 114479357
Local read latency: 43.442 ms
Local write count: 22288868
Local write latency: 0.609 ms


Here is my node configuration:
RF=3, Read/Write with QUORUM, 64GB RAM, 48 CPU core. I have only 5 GB of data 
on each node (and for experiment purpose I stored data in tmpfs)

I've tried increasing concurrent_read count upto 512 but no help in read 
latency. CPU/Memory/IO looks fine on system.

Any idea what should I tune?

Jaydeep



Ce message et les pièces jointes sont confidentiels et réservés à l'usage 
exclusif de ses destinataires. Il peut également être protégé par le secret 
professionnel. Si vous recevez ce message par erreur, merci d'en avertir 
immédiatement l'expéditeur et de le détruire. L'intégrité du message ne pouvant 
être assurée sur Internet, la responsabilité de Worldline ne pourra être 
recherchée quant au contenu de ce message. Bien que les meilleurs efforts 
soient faits pour maintenir cette transmission exempte de tout virus, 
l'expéditeur ne donne aucune garantie à cet égard et sa responsabilité ne 
saurait être recherchée pour tout dommage résultant d'un virus transmis.

This e-mail and the documents attached are confidential and intended solely for 
the addressee; it may also be privileged. If you receive this e-mail in error, 
please notify the sender immediately and destroy it. As its integrity cannot be 
secured on the Internet, the Worldline liability cannot be triggered for the 
message content. Although the sender endeavours to maintain a computer 
virus-free network, the sender does not warrant that this transmission is 
virus-free and will not be liable for any damages resulting from any virus 
transmitted.

To batch or not to batch: A question for fast inserts

[Gerard Maas]

General advice advocates for individual async inserts as the fastest way to
insert data into Cassandra. Our insertion mechanism is based on that model
and recently we have been evaluating performance, looking to measure and
optimize our ingestion rate.

I side-tracked some punctual benchmarks and stumbled on the observations of
unlogged inserts being *A LOT* faster than the async counterparts.

In our tests, unlogged batch shows increased throughput and lower cluster
CPU usage, so I'm wondering where the tradeoff might be.

I compiled those observations in this document that I'm sharing and opening
up for comments.  Are we observing some artifact or should we set the
record straight for unlogged batches to achieve better insertion throughput?

https://docs.google.com/document/d/1qSIJ46cmjKggxm1yxboI-KhYJh1gnA6RK-FkfUg6FrI

Let me know.

Kind regards,

Gerard.