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Posted to user@cassandra.apache.org by Tomas Nunez <to...@groupalia.com> on 2012/12/18 10:37:49 UTC
Monitoring the number of client connections
Hi!
I want to know how many client connections has each one of my cluster nodes
(to check if my load balancing is spreading in a balanced way, to check if
increase in the cluster load can be related to an increase in the number of
connections, and things like that). I was thinking about going with
netstat, counting ESTABLISHED connections to port 9160, but then I thought
maybe there is some way in cassandra to get that information (maybe a
counter of connections in the JMX?). I've tried installing MX4J and going
over all MBeans, but I haven't found any with a promising name, they all
seem unrelated to this information. And I can't find anything skimming the
manual, so...
Can you think a better way than "netstat" to get this information? Better
yet, is there anything similar to "Show processlist" in mysql?
Thanks!
--
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Re: Monitoring the number of client connections
Posted by Edward Capriolo <ed...@gmail.com>.
In the TCP mib for SNMP (Simple Network Management Protocol) this
information is available
http://www.simpleweb.org/ietf/mibs/mibSynHiLite.php?category=IETF&module=TCP-MIB
On Wed, Dec 19, 2012 at 12:22 AM, Michael Kjellman
<mk...@barracuda.com>wrote:
> netstat + cron is your friend at this point in time
>
> On Dec 18, 2012, at 8:25 PM, "aaron morton" <aa...@thelastpickle.com>
> wrote:
>
> AFAIK the count connections is not exposed.
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 18/12/2012, at 10:37 PM, Tomas Nunez <to...@groupalia.com> wrote:
>
> Hi!
>
> I want to know how many client connections has each one of my cluster
> nodes (to check if my load balancing is spreading in a balanced way, to
> check if increase in the cluster load can be related to an increase in the
> number of connections, and things like that). I was thinking about going
> with netstat, counting ESTABLISHED connections to port 9160, but then I
> thought maybe there is some way in cassandra to get that information (maybe
> a counter of connections in the JMX?). I've tried installing MX4J and going
> over all MBeans, but I haven't found any with a promising name, they all
> seem unrelated to this information. And I can't find anything skimming the
> manual, so...
>
> Can you think a better way than "netstat" to get this information? Better
> yet, is there anything similar to "Show processlist" in mysql?
>
> Thanks!
>
> --
> <groupalia.jpg> <http://es.groupalia.com/>
> www.groupalia.com <http://es.groupalia.com/> Tomàs Núñez IT-Sysprod Tel. +
> 34 93 159 31 00 Fax. + 34 93 396 18 52 Llull, 95-97, 2º planta, 08005
> BarcelonaSkype: tomas.nunez.groupalia tomas.nunez@groupalia.com<no...@groupalia.com>
> <twitter.png> Twitter <http://twitter.com/#%21/groupaliaes>
> <facebook.png> Facebook <https://www.facebook.com/GroupaliaEspana>
> <linkedin.png> Linkedin <http://www.linkedin.com/company/groupalia>
>
>
>
> ----------------------------------
> Join Barracuda Networks in the fight against hunger.
> To learn how you can help in your community, please visit:
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>
>
Re: Monitoring the number of client connections
Posted by Michael Kjellman <mk...@barracuda.com>.
netstat + cron is your friend at this point in time
On Dec 18, 2012, at 8:25 PM, "aaron morton" <aa...@thelastpickle.com>> wrote:
AFAIK the count connections is not exposed.
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 18/12/2012, at 10:37 PM, Tomas Nunez <to...@groupalia.com>> wrote:
Hi!
I want to know how many client connections has each one of my cluster nodes (to check if my load balancing is spreading in a balanced way, to check if increase in the cluster load can be related to an increase in the number of connections, and things like that). I was thinking about going with netstat, counting ESTABLISHED connections to port 9160, but then I thought maybe there is some way in cassandra to get that information (maybe a counter of connections in the JMX?). I've tried installing MX4J and going over all MBeans, but I haven't found any with a promising name, they all seem unrelated to this information. And I can't find anything skimming the manual, so...
Can you think a better way than "netstat" to get this information? Better yet, is there anything similar to "Show processlist" in mysql?
Thanks!
--
<groupalia.jpg><http://es.groupalia.com/>
www.groupalia.com<http://es.groupalia.com/>
Tomàs Núñez
IT-Sysprod
Tel. + 34 93 159 31 00
Fax. + 34 93 396 18 52
Llull, 95-97, 2º planta, 08005 Barcelona
Skype: tomas.nunez.groupalia
tomas.nunez@groupalia.com<ma...@groupalia.com>
<twitter.png> Twitter<http://twitter.com/#%21/groupaliaes> <facebook.png> Facebook<https://www.facebook.com/GroupaliaEspana> <linkedin.png> Linkedin<http://www.linkedin.com/company/groupalia>
Join Barracuda Networks in the fight against hunger.
To learn how you can help in your community, please visit: http://on.fb.me/UAdL4f
Re: Monitoring the number of client connections
Posted by aaron morton <aa...@thelastpickle.com>.
AFAIK the count connections is not exposed.
Cheers
-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 18/12/2012, at 10:37 PM, Tomas Nunez <to...@groupalia.com> wrote:
> Hi!
>
> I want to know how many client connections has each one of my cluster nodes (to check if my load balancing is spreading in a balanced way, to check if increase in the cluster load can be related to an increase in the number of connections, and things like that). I was thinking about going with netstat, counting ESTABLISHED connections to port 9160, but then I thought maybe there is some way in cassandra to get that information (maybe a counter of connections in the JMX?). I've tried installing MX4J and going over all MBeans, but I haven't found any with a promising name, they all seem unrelated to this information. And I can't find anything skimming the manual, so...
>
> Can you think a better way than "netstat" to get this information? Better yet, is there anything similar to "Show processlist" in mysql?
>
> Thanks!
>
> --
> <groupalia.jpg>
> www.groupalia.com
> Tomàs Núñez
> IT-Sysprod
> Tel. + 34 93 159 31 00
> Fax. + 34 93 396 18 52
> Llull, 95-97, 2º planta, 08005 Barcelona
> Skype: tomas.nunez.groupalia
> tomas.nunez@groupalia.com
> <twitter.png> Twitter <facebook.png> Facebook <linkedin.png> Linkedin
>
Re: Monitoring the number of client connections
Posted by Rob Coli <rc...@palominodb.com>.
For those playing along at home, I have filed
https://issues.apache.org/jira/browse/CASSANDRA-5084 ("Cassandra
should expose connected client state via JMX") as a result of this
thread.
=Rob
--
=Robert Coli
AIM>ALK - rcoli@palominodb.com
YAHOO - rcoli.palominob
SKYPE - rcoli_palominodb
Re: Monitoring the number of client connections
Posted by Rob Coli <rc...@palominodb.com>.
On Thu, Dec 20, 2012 at 12:41 PM, Rob Coli <rc...@palominodb.com> wrote:
> So, by default Cassandra does in fact use one thread per thrift connection.
Also of note is that even with hsha, an *active* connection (where
synchronous storage backend is doing something) consumes a thread.
Some more background at :
https://issues.apache.org/jira/browse/CASSANDRA-4277
=Rob
--
=Robert Coli
AIM>ALK - rcoli@palominodb.com
YAHOO - rcoli.palominob
SKYPE - rcoli_palominodb
Re: Monitoring the number of client connections
Posted by Rob Coli <rc...@palominodb.com>.
On Wed, Dec 19, 2012 at 4:20 PM, Hiller, Dean <De...@nrel.gov> wrote:
> What????? I thought cassandra was using nio so thread per connection is not true?
Here's the monkey test I used to verify my conjecture.
1) ps -eLf |grep jsvc |grep cassandra | wc -l # note number of threads
2) for name in {1..300}; do cassandra-cli -h `hostname` -k validkeyspace & done
3) ps -eLf |grep jsvc | grep cassandra | wc -l # note much higher
number of threads
4) for name in {1..300}; do kill "%$name" done
5) ps -eLf |grep jsvc | grep cassandra | wc -l # note that thread
count drops like a rock as connections are GCed
Via aaron_morton, here's the relevant chunk of cassandra.yaml :
https://github.com/apache/cassandra/blob/trunk/conf/cassandra.yaml#L347
"
# sync -> One thread per thrift connection.
..
# hsha -> Stands for "half synchronous, half asynchronous."
..
# The default is sync because on Windows hsha is about 30% slower. On Linux,
# sync/hsha performance is about the same, with hsha of course using
less memory.
"
So, by default Cassandra does in fact use one thread per thrift connection.
=Rob
--
=Robert Coli
AIM>ALK - rcoli@palominodb.com
YAHOO - rcoli.palominob
SKYPE - rcoli_palominodb
Re: Monitoring the number of client connections
Posted by "Hiller, Dean" <De...@nrel.gov>.
What????? I thought cassandra was using nio so thread per connection is not true?
Dean
From: Rob Coli <rc...@palominodb.com>>
Reply-To: "user@cassandra.apache.org<ma...@cassandra.apache.org>" <us...@cassandra.apache.org>>
Date: Wednesday, December 19, 2012 4:49 PM
To: "user@cassandra.apache.org<ma...@cassandra.apache.org>" <us...@cassandra.apache.org>>
Subject: Re: Monitoring the number of client connections
On Tue, Dec 18, 2012 at 1:37 AM, Tomas Nunez <to...@groupalia.com>> wrote:
Can you think a better way than "netstat" to get this information? Better yet, is there anything similar to "Show processlist" in mysql?
An easy/not very accurate proxy for this is the thread count within the jvm. An open connection has a thread associated with it.
ps -eLf
etc.
=Rob
--
=Robert Coli
AIM>ALK - rcoli@palominodb.com<ma...@palominodb.com>
YAHOO - rcoli.palominob
SKYPE - rcoli_palominodb
Re: Monitoring the number of client connections
Posted by Rob Coli <rc...@palominodb.com>.
On Tue, Dec 18, 2012 at 1:37 AM, Tomas Nunez <to...@groupalia.com>wrote:
> Can you think a better way than "netstat" to get this information? Better
> yet, is there anything similar to "Show processlist" in mysql?
An easy/not very accurate proxy for this is the thread count within the
jvm. An open connection has a thread associated with it.
ps -eLf
etc.
=Rob
--
=Robert Coli
AIM>ALK - rcoli@palominodb.com
YAHOO - rcoli.palominob
SKYPE - rcoli_palominodb