Re: Is there a C* summit this year?

[Max C]

Hi Kant,

I reached out to Datastax with this very question a few months ago, here's the 
response I received:

"Great to hear that you enjoyed yourself last year, we surely enjoyed having 
you and the other community folks! In regards to the actual summit, we  will 
not be holding the Cassandra Summit in 2017. We do plan to reschedule for early 
2018 and working with the ASF to do so. Hope to see you then!"

That's all I know — maybe someone from Datastax or ASF will chime in with more 
info.

- Max

> On May 19, 2017, at 10:35pm, Kant Kodali  wrote:
> 
> Hi All,
> 
> I was wondering if there is going to be a C* summit this year? If so, when 
> can we expect?
> 
> Thanks!

High network traffic and cpu after read query

[Andrii Biletskyi]

Hi all,

Running Cassandra 3.9 on 5 node cluster (c4.2xlarge machines).

We have loaded quite huge 350M rows table. Also there are some other read
and write operations happening *on other small tables*, but the load is
very little, cpu is normally less than 10%, network traffic from and to
nodes is less than 10 Mb/sec for each node.

Now when I run read intensive query (like select count(1) on that huge
table) obviously Casandra is under pressure, cpu is high etc. If that's
important the query is done via Presto.
The query returns successfully after 40 minutes, but the cluster doesn't
return to normal state. Cpu stays very high (~ 90%) for a very long period
of time, and more strangely network traffic between nodes is more than 100
Mb/sec. Again, this is the situation after query has completed hours ago.

Metrics doesn't show nothing suspicious like read repairs or compactions.
Please advice what should I look at to understand the root cause of that
high network traffic and cpu usage.

Thanks in advance,
Andrii

Re: Is it safe to upgrade 2.2.6 to 3.0.13?

[Stefano Ortolani]

Hi Varun,

can you elaborate a bit more? I have seen a schema change being pushed, but
that was just the first restart. After that, everything has been smooth so
far (including several schema changes, all of them verified via "describe").

Thanks!
Stefano

On Sat, May 20, 2017 at 2:10 AM, Varun Gupta  wrote:

> We upgraded from 2.2.5 to 3.0.11 and it works fine. I will suggest not to
> go with 3.013, we are seeing some issues with schema mismatch due to which
> we had to rollback to 3.0.11.
>
> Thanks,
> Varun
>
> On May 19, 2017, at 7:43 AM, Stefano Ortolani  wrote:
>
> Here (https://github.com/apache/cassandra/blob/cassandra-3.0/NEWS.txt) is
> stated that the minimum supported version for the 2.2.X branch is 2.2.2.
>
> On Fri, May 19, 2017 at 2:16 PM, Nicolas Guyomar <
> nicolas.guyo...@gmail.com> wrote:
>
>> Hi Xihui,
>>
>> I was looking for this documentation also, but I believe datastax removed
>> it, and it is not available yet on the apache website
>>
>> As far as I remember, intermediate version was needed if  C* Version <
>> 2.1.7.
>>
>> You should be safe starting from 2.2.6, but testing the upgrade on a
>> dedicated platform is always a good idea.
>>
>> Nicolas
>>
>> On 19 May 2017 at 09:02, Xihui He  wrote:
>>
>>> Hi All,
>>>
>>> We are planning to upgrade our production cluster to 3.x, but I can't
>>> find the upgrade guide anymore.
>>> Can I upgrade to 3.0.13 from 2.2.6 directly? Is a interim version
>>> necessary?
>>>
>>> Thanks,
>>> Xihui
>>>
>>
>>
>

Re: Is it safe to upgrade 2.2.6 to 3.0.13?

[Cogumelos Maravilha]

It's better wait for 3.0.14

https://issues.apache.org/jira/browse/CASSANDRA/fixforversion/12340362/?selectedTab=com.atlassian.jira.jira-projects-plugin:version-summary-panel

Cheers.

On 05/20/2017 11:31 AM, Stefano Ortolani wrote:
> Hi Varun, 
>
> can you elaborate a bit more? I have seen a schema change being
> pushed, but that was just the first restart. After that, everything
> has been smooth so far (including several schema changes, all of them
> verified via "describe").
>
> Thanks!
> Stefano
>
> On Sat, May 20, 2017 at 2:10 AM, Varun Gupta  > wrote:
>
> We upgraded from 2.2.5 to 3.0.11 and it works fine. I will suggest
> not to go with 3.013, we are seeing some issues with schema
> mismatch due to which we had to rollback to 3.0.11.
>
> Thanks,
> Varun
>
> On May 19, 2017, at 7:43 AM, Stefano Ortolani  > wrote:
>
>> Here
>> (https://github.com/apache/cassandra/blob/cassandra-3.0/NEWS.txt
>> )
>> is stated that the minimum supported version for the 2.2.X branch
>> is 2.2.2.
>>
>> On Fri, May 19, 2017 at 2:16 PM, Nicolas Guyomar
>> mailto:nicolas.guyo...@gmail.com>> wrote:
>>
>> Hi Xihui,
>>
>> I was looking for this documentation also, but I believe
>> datastax removed it, and it is not available yet on the
>> apache website
>>
>> As far as I remember, intermediate version was needed if  C*
>> Version < 2.1.7.
>>
>> You should be safe starting from 2.2.6, but testing the
>> upgrade on a dedicated platform is always a good idea.
>>
>> Nicolas
>>
>> On 19 May 2017 at 09:02, Xihui He > > wrote:
>>
>> Hi All,
>>
>> We are planning to upgrade our production cluster to 3.x,
>> but I can't find the upgrade guide anymore.
>> Can I upgrade to 3.0.13 from 2.2.6 directly? Is a interim
>> version necessary?
>>
>> Thanks,
>> Xihui
>>
>>
>>
>

Re: Apache Cassandra - Configuration Management

[Oskar Kjellin]

If you're on AWS you can use Netflix Priam 


> On 17 May 2017, at 18:40, Abhishek Gupta  wrote:
> 
> Hi Zaidi,
> 
> We use Chef for the configuration management of our 14 node cluster.
> 
> You can have a look at Chef or maybe some other config management tools too 
> like Ansible and Puppet.
> 
> 
> 
> Thanks,
> Abhishek
> 
>> On May 17, 2017 10:08 PM, "DuyHai Doan"  wrote:
>> For configuration management there are tons of tools out there:
>> 
>> - ansible
>> - chef
>> - puppet
>> - saltstack
>> 
>> I surely forgot a few others 
>> 
>> 
>>> On Wed, May 17, 2017 at 6:33 PM, ZAIDI, ASAD A  wrote:
>>> Good Morning Folks –
>>> 
>>>  
>>> 
>>> I’m running 14 nodes Cassandra cluster in two data centers , each node is 
>>> has roughly 1.5TB. we’re anticipating more load therefore we’ll be 
>>> expanding cluster with additional nodes.
>>> 
>>> At this time, I’m kind of struggling to keep consistent cassandra.yaml file 
>>> on each server – at this time, I’m maintaining yaml file manually. The only 
>>> tool I’ve is splunk  which  is only to ‘monitor‘ threads.
>>> 
>>>  
>>> 
>>> Would you guy please suggest  open source tool that can help maintain the 
>>> cluster. I’ll really appreciate your reply – Thanks/Asad
>>> 
>> 

Re: Is it safe to upgrade 2.2.6 to 3.0.13?

[Xihui He]

Thank you all for your kind advises.

On 20 May 2017 at 18:41, Cogumelos Maravilha 
wrote:

> It's better wait for 3.0.14
>
> https://issues.apache.org/jira/browse/CASSANDRA/fixforversion/12340362/?
> selectedTab=com.atlassian.jira.jira-projects-plugin:version-summary-panel
>
> Cheers.
>
>
> On 05/20/2017 11:31 AM, Stefano Ortolani wrote:
>
> Hi Varun,
>
> can you elaborate a bit more? I have seen a schema change being pushed,
> but that was just the first restart. After that, everything has been smooth
> so far (including several schema changes, all of them verified via
> "describe").
>
> Thanks!
> Stefano
>
> On Sat, May 20, 2017 at 2:10 AM, Varun Gupta  wrote:
>
>> We upgraded from 2.2.5 to 3.0.11 and it works fine. I will suggest not to
>> go with 3.013, we are seeing some issues with schema mismatch due to which
>> we had to rollback to 3.0.11.
>>
>> Thanks,
>> Varun
>>
>> On May 19, 2017, at 7:43 AM, Stefano Ortolani  wrote:
>>
>> Here (https://github.com/apache/cassandra/blob/cassandra-3.0/NEWS.txt)
>> is stated that the minimum supported version for the 2.2.X branch is 2.2.2.
>>
>> On Fri, May 19, 2017 at 2:16 PM, Nicolas Guyomar <
>> nicolas.guyo...@gmail.com> wrote:
>>
>>> Hi Xihui,
>>>
>>> I was looking for this documentation also, but I believe datastax
>>> removed it, and it is not available yet on the apache website
>>>
>>> As far as I remember, intermediate version was needed if  C* Version <
>>> 2.1.7.
>>>
>>> You should be safe starting from 2.2.6, but testing the upgrade on a
>>> dedicated platform is always a good idea.
>>>
>>> Nicolas
>>>
>>> On 19 May 2017 at 09:02, Xihui He  wrote:
>>>
 Hi All,

 We are planning to upgrade our production cluster to 3.x, but I can't
 find the upgrade guide anymore.
 Can I upgrade to 3.0.13 from 2.2.6 directly? Is a interim version
 necessary?

 Thanks,
 Xihui

>>>
>>>
>>
>
>

Re: Reg:- Data Modelling Concepts

[Gedeon Kamga]

One issue that will be encountered with this data model is the unbounded
partition growth. Partition will continue to grow indefinitely over time
and there will be a risk to hit the limit of 2 billions columns per
partition.

Consider a composite partition key.

Thanks,
Gedeon


On Wed, May 17, 2017 at 10:56 PM, Anthony Grasso 
wrote:

> Hi Nandan,
>
> If there is a requirement to answer a query "What are the changes to a
> book made by a particular user?", then yes the schema you have proposed can
> work. To obtain the list of updates for a book by a user from the
> *book_title_by_user* table will require the partition key (*book_title*),
> the first clustering key (*book_id*), and the second clustering key (
> *user_id*).
>
> i.e. SELECT * FROM book_title_by_user WHERE book_title= AND
> book_id= AND user_id=;
>
> If the book_id is unnecessary for answering the above query, it may be
> worth changing the primary key ordering of the *book_title_by_user* table
> to the following.
>
> CREATE TABLE book_title_by_user(
>   book_title text,
>   book_id uuid,
>   user_id uuid ,
>   ts timeuuid,
>   PRIMARY KEY (book_title, user_id, book_id, ts)
> );
>
> This will then simplify the select statement to
>
> SELECT * FROM book_title_by_user WHERE book_title= AND
> user_id=;
>
> Kind regards,
> Anthony
>
> On 17 May 2017 at 13:05, @Nandan@  wrote:
>
>> Hi Jon,
>>
>> We need to keep tracking of all updates like 'User' of our platform can
>> check what changes made before.
>> I am thinking in this way..
>> CREATE TABLE book_info (
>> book_id uuid,
>> book_title text,
>> author_name text,
>> updated_at timestamp,
>> PRIMARY KEY(book_id));
>> This table will contain details about all book with unique updated
>> details.
>> CREATE TABLE book_title_by_user(
>> book_title text,
>> book_id uuid,
>> user_id uuid ,
>> ts timeuuid,
>> primary key(book_title,book_id,user_id,ts));
>> This table wil contain details of multiple old updates of book which can
>> be done by mulplie users like MANY TO MANY .
>>
>> What do you think on this?
>>
>> On Wed, May 17, 2017 at 9:44 AM, Jonathan Haddad 
>> wrote:
>>
>>> I don't understand why you need to store the old value a second time.
>>> If you know that the value went from A -> B -> C, just store the new value,
>>> not the old.  You can see that it changed from A->B->C without storing it
>>> twice.
>>>
>>> On Tue, May 16, 2017 at 6:36 PM @Nandan@ 
>>> wrote:
>>>
 The requirement is to create DB in which we have to keep data of
 Updated values as well as which user update the particular book details and
 what they update.

 We are like to create a schema which store book info, as well as the
 history of the update, made based on book_title, author, publisher, price
 changed.
 Like we want to store what was old data and what new data updated.. and
 also want to check which user updated the relevant change. Because suppose
 if some changes not made correctly then they can check changes and revert
 based on old values.
 We are trying to make a USER based Schema.

 For example:-
 id:- 1
 Name: - Harry Poter
 Author : - JK Rolling

 New Update Done by user_id 2:-
 id :- 1
 Name:- Harry Pottor
 Author:- J.K. Rolls

 Update history also need to store as :-
 User_id :- 2
 Old Author :- JK Rolling
 New Author :- J.K. Rolls

 So I need to update the details of Book which is done by UPSERT. But
 also I have to keep details like which user updated and what updated.


 One thing that helps define the schema is knowing what queries will be
 made to the database up front.
 Few queries that the database needs to answer.
 What are the current details of a book?
 What is the most recent update to a particular book?
 What are the updates that have been made to a particular book?
 What are the details for a particular update?


 Update frequently will be like Update will happen based on Title, name,
 Author, price , publisher like. So not very high frequently.

 Best Regards,
 Nandan

>>>
>>
>

Re: Decommissioned node cluster shows as down

[Gedeon Kamga]

If the nodetool status shows DN, then you will need to tell the cluster to
remove the memory of that node by running removenode. If that doesn't work,
you may run assassinate - the ultimate command to shutdown the node.

Thanks,
Gedeon

On Tue, May 16, 2017 at 12:01 PM, Mark Furlong 
wrote:

> I have a node I decommissioned on a large ring using 2.1.12. The node
> completed the decommission process and is no longer communicating with the
> rest of the cluster. However when I run a nodetool status on any node in
> the cluster it shows the node as ‘DN’. Why is this and should I just run a
> removenode now?
>
>
>
> *Thanks,*
>
> *Mark Furlong*
>
> Sr. Database Administrator
>
> *mfurl...@ancestry.com *
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