Connection issue in Cassandra

[Adeel Akbar]

Hi,

I have created 2 node cluster and use with application. My application 
unable to connect with database. Please find below logs;



 NoConnectionAvailable at /

ConnectionPool limit of size 2 overflow 2 reached, unable to obtain connection 
after 30 seconds

Request Method: GET
Request URL:http://172.16.100.131/
Django Version: 1.4
Exception Type: NoConnectionAvailable
Exception Value:

ConnectionPool limit of size 2 overflow 2 reached, unable to obtain connection 
after 30 seconds

Exception Location: 
/usr/local/lib/python2.6/site-packages/pycassa-1.0.8-py2.6.egg/pycassa/pool.py 
in get, line 738

Python Executable:  /usr/local/bin/python
Python Version: 2.6.4
Python Path:

['/var/www/bs_ping',
 '/usr/local/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/amqplib-0.6.1-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/BeautifulSoup-3.1.0.1-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/python_dateutil-1.4.1-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/feedparser-4.1-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/python_twitter-0.6-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/simplejson-2.0.9-py2.6-linux-i686.egg',
 '/usr/local/lib/python2.6/site-packages/txAMQP-0.3-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/Twisted-8.2.0-py2.6-linux-i686.egg',
 
'/usr/local/lib/python2.6/site-packages/zope.interface-3.5.2-py2.6-linux-i686.egg',
 '/usr/local/lib/python2.6/site-packages/UnicodeUtils-0.3.2-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/pytz-2009p-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/ScriptUtils-0.5.5-py2.6.egg',
 
'/usr/local/lib/python2.6/site-packages/MySQL_python-1.2.3c1-py2.6-linux-i686.egg',
 '/usr/local/lib/python2.6/site-packages/python_memcached-1.44-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/coverage-3.2b1-py2.6-linux-i686.egg',
 '/usr/local/lib/python2.6/site-packages/flup-1.0.3.dev_20091027-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/oauth-1.0.1-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/pyOpenSSL-0.10-py2.6-linux-i686.egg',
 '/usr/local/lib/python2.6/site-packages/pycassa-1.0.8-py2.6.egg',
 
'/usr/local/lib/python2.6/site-packages/wadofstuff_django_serializers-1.1.0-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/jsonpickle-0.4.0-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/django_compressor-1.1.2-py2.6.egg',
 '/usr/local/lib/python2.6/site-packages/django_appconf-0.5-py2.6.egg',
 '/usr/local/lib/python26.zip',
 '/usr/local/lib/python2.6',
 '/usr/local/lib/python2.6/plat-linux2',
 '/usr/local/lib/python2.6/lib-tk',
 '/usr/local/lib/python2.6/lib-old',
 '/usr/local/lib/python2.6/lib-dynload',
 '/usr/local/lib/python2.6/site-packages',
 '/usr/local/lib/python2.6/site-packages/PIL',
 '/var/www/bs_ping/',
 '/var/www']

Server time:Wed, 25 Jul 2012 13:17:33 +0500


--


Thanks & Regards

*Adeel**Akbar*

Is there any way to limit the off heap memory usage for cassandra 1.1.X ?

[Thomas Spengler]

Is there any way to limit the off heap memory usage for cassandra 1.1.X

Thx


-- 
Thomas Spengler

Fwd: {kundera-discuss} Kundera 2.0.7 Released

[Vivek Mishra]

-- Forwarded message --
From: Amry 
Date: Wed, Jul 25, 2012 at 4:41 PM
Subject: {kundera-discuss} Kundera 2.0.7 Released
To: kundera-disc...@googlegroups.com


Hi All,

We are happy to announce release of Kundera 2.0.7.

Kundera is a JPA 2.0 based, object-datastore papping library for NoSQL
datastores. The idea behind Kundera is to make working with NoSQL Databases
drop-dead simple and fun. It currently supports Cassandra, HBase, MongoDB
and relational databases.

Major Changes in this release:
---
* HBase 0.92.1 migration
* Hadoop 1.0.2 migration
* Cassandra 1.1.2 migration
* MongoDB 2.0.4 migration
* JPA EntityTransaction commit and rollback
* JTA Transactions integration over web server
* Kundera-REST API
* Support for Counter column in cassandra
* Inverted wide-row indexing support for Cassandra
* Login Authentication support for Cassandra and MongoDB
* Filters and filters list for HBase
* Deprecated Lucene based indexing for HBase.
* Datastore specific configuration files for specifying:
- Replication factor
- Placement strategy
- Consistency level per operation.
- Counter column family configuration
- Inverted indexing switch
- Zookeeper host and port
- Hbase column family configurations
- MongoDB servers list, read preference and socket timeout. ...etc.


To download, use or contribute to Kundera, visit:
http://github.com/impetus-opensource/Kundera
Latest released tag version is kundera-2.0.7. Kundera maven libraries are
now available at:
https://oss.sonatype.org/content/repositories/releases/com/impetus

Sample codes and examples for using Kundera can be found here:
http://github.com/impetus-opensource/Kundera-Examples
and
https://github.com/impetus-opensource/Kundera/tree/trunk/kundera-tests

Thank you all for your contributions!

Regards,
Kundera Team.

[Feedback needed] New MacOSX preferences pane plugin to control a local Cassandra Server

[Rémy Saissy]

Hi,
I have written a preferences pane plugin to control a Cassandra Server
installed on MacOSX.
It is based on the UI of the MySQL preferences pane.

I'd like to have your feedback about it.
 - Is it useful for you?
 - What do you think could be improved / added?

You can find it on my github at
https://github.com/remysaissy/cassandra-macosx-prefspane
No need to build from sources, there is a release of course :).

Feel free to add issues on the github or even send some code.
Thanks a lot!
Regards,

--
Rémy Saissy
Photos: http://picasaweb.google.com/remy.saissy
Blog: http://blog.remysaissy.com

filtered value count

[Abhijit Chanda]

Hi All,

Can any one suggest me how to retrieve the result count after multiple
filtration operations performed on multiple column families something
similar like join query result count in normal RDBMS.   I guess its not
possible in Cassandra, still asking? Or any other alternative to do the same

Regards,
Abhijit

Re: virtual memory of all cassandra-nodes is growing extremly since Cassandra 1.1.0

[Tyler Hobbs]

Are you actually seeing any problems from this? High virtual memory usage
on its own really doesn't mean anything. See
http://wiki.apache.org/cassandra/FAQ#mmap

On Wed, Jul 25, 2012 at 1:21 AM, Thomas Spengler <
thomas.speng...@toptarif.de> wrote:

> No one has any idea?
>
> we tryed
>
> update to 1.1.2
> DiskAccessMode standard, indexAccessMode standard
> row_cache_size_in_mb: 0
> key_cache_size_in_mb: 0
>
>
> Our next try will to change
>
> SerializingCacheProvider to ConcurrentLinkedHashCacheProvider
>
> any other proposals are welcom
>
> On 07/04/2012 02:13 PM, Thomas Spengler wrote:
> > Hi @all,
> >
> > since our upgrade form cassandra 1.0.3 to 1.1.0 the virtual memory usage
> > of the cassandra-nodes explodes
> >
> > our setup is:
> > * 5 - centos 5.8 nodes
> > * each 4 CPU's and 8 GB RAM
> > * each node holds about 100 GB on data
> > * each jvm's uses 2GB Ram
> > * DiskAccessMode is standard, indexAccessMode is standard
> >
> > The memory usage grows upto the whole memory is used.
> >
> > Just for information, as we had cassandra 1.0.3, we used
> > * DiskAccessMode is standard, indexAccessMode is mmap
> > * and the ram-usage was ~4GB
> >
> >
> > can anyone help?
> >
> >
> > With Regards
> >
>
>
> --
> Thomas Spengler
> Chief Technology Officer
> 
>
> TopTarif Internet GmbH, Pappelallee 78-79, D-10437 Berlin
> Tel.: (030) 2000912 0 | Fax: (030) 2000912 100
> thomas.speng...@toptarif.de | www.toptarif.de
>
> Amtsgericht Charlottenburg, HRB 113287 B
> Geschäftsführer: Dr. Rainer Brosch, Dr. Carolin Gabor
> -
>
>
>


-- 
Tyler Hobbs
DataStax 

Re: Connection issue in Cassandra

[Tyler Hobbs]

That's a pretty old version of pycassa; it was release before 0.7.0 came
out.  I suggest upgrading.

It's possible this was caused by an old bug, but in general, this indicates
that you have more threads trying to use the ConnectionPool concurrently
than there are connections.

On Wed, Jul 25, 2012 at 3:30 AM, Adeel Akbar
wrote:

>  Hi,
>
> I have created 2 node cluster and use with application. My application
> unable to connect with database. Please find below logs;
>
>  NoConnectionAvailable at /
>
> ConnectionPool limit of size 2 overflow 2 reached, unable to obtain 
> connection after 30 seconds
>
>Request Method: GET  Request URL: http://172.16.100.131/  Django
> Version: 1.4  Exception Type: NoConnectionAvailable  Exception Value:
>
> ConnectionPool limit of size 2 overflow 2 reached, unable to obtain 
> connection after 30 seconds
>
>   Exception Location: 
> /usr/local/lib/python2.6/site-packages/pycassa-1.0.8-py2.6.egg/pycassa/pool.py
> in get, line 738  Python Executable: /usr/local/bin/python  Python
> Version: 2.6.4  Python Path:
>
> ['/var/www/bs_ping',
>  '/usr/local/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/amqplib-0.6.1-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/BeautifulSoup-3.1.0.1-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/python_dateutil-1.4.1-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/feedparser-4.1-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/python_twitter-0.6-py2.6.egg',
>  
> '/usr/local/lib/python2.6/site-packages/simplejson-2.0.9-py2.6-linux-i686.egg',
>  '/usr/local/lib/python2.6/site-packages/txAMQP-0.3-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/Twisted-8.2.0-py2.6-linux-i686.egg',
>  
> '/usr/local/lib/python2.6/site-packages/zope.interface-3.5.2-py2.6-linux-i686.egg',
>  '/usr/local/lib/python2.6/site-packages/UnicodeUtils-0.3.2-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/pytz-2009p-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/ScriptUtils-0.5.5-py2.6.egg',
>  
> '/usr/local/lib/python2.6/site-packages/MySQL_python-1.2.3c1-py2.6-linux-i686.egg',
>  '/usr/local/lib/python2.6/site-packages/python_memcached-1.44-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/coverage-3.2b1-py2.6-linux-i686.egg',
>  '/usr/local/lib/python2.6/site-packages/flup-1.0.3.dev_20091027-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/oauth-1.0.1-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/pyOpenSSL-0.10-py2.6-linux-i686.egg',
>  '/usr/local/lib/python2.6/site-packages/pycassa-1.0.8-py2.6.egg',
>  
> '/usr/local/lib/python2.6/site-packages/wadofstuff_django_serializers-1.1.0-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/jsonpickle-0.4.0-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/django_compressor-1.1.2-py2.6.egg',
>  '/usr/local/lib/python2.6/site-packages/django_appconf-0.5-py2.6.egg',
>  '/usr/local/lib/python26.zip',
>  '/usr/local/lib/python2.6',
>  '/usr/local/lib/python2.6/plat-linux2',
>  '/usr/local/lib/python2.6/lib-tk',
>  '/usr/local/lib/python2.6/lib-old',
>  '/usr/local/lib/python2.6/lib-dynload',
>  '/usr/local/lib/python2.6/site-packages',
>  '/usr/local/lib/python2.6/site-packages/PIL',
>  '/var/www/bs_ping/',
>  '/var/www']
>
>   Server time: Wed, 25 Jul 2012 13:17:33 +0500
> --
>
>
> Thanks & Regards
>
> *Adeel** Akbar*
>



-- 
Tyler Hobbs
DataStax 

Re: Cassandra Throughput

[Tyler Hobbs]

Barring unusual circumstances, no.  Typically, the throughput should be
pretty similar for both consistency levels, with slightly higher latency
for QUORUM.

On Tue, Jul 24, 2012 at 5:32 PM, Code Box  wrote:

> Can it happen that the throughput with CL=QUORUM is > throughput with CL=1
> on a three node cluster with replication factor of 3 ?




-- 
Tyler Hobbs
DataStax 

Re: Bringing a dead node back up after fixing hardware issues

[Eran Chinthaka Withana]

Hi Brandon,

> Increasing CL is tricky for us for now, as our RF on that datacenter is 2

> > and CL is set to ONE. If we make the CL to be LOCAL_QUORUM, then, if a
> node
> > goes down we will have trouble. I will try to increase the RF to 3 in
> that
> > data center and set the CL to LOCAL_QUORUM if nothing works out.
>
> Increasing the RF and and using LOCAL_QUORUM is the right thing in
> this case.  By choosing CL.ONE, you are agreeing that read misses are
> acceptable.  If they are not, then adjusting your RF/CL is the only
> path.
>

Alright, lets assume I want to go on this route. I have RF=2 in the data
center and I believe I need at least RF=3 to set the replication to
LOCAL_QUORUM and hide the node failures. But if I increase the RF to 3 now
then won't it trigger more read misses until repair completes? Given this
is a production cluster which can not afford downtime, how can we do this?

Thanks,
Eran