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 « Return to Thread: HBase Thrift for CDH3U3 leaking file descriptors/socket connections to Zookeeper

Re: HBase Thrift for CDH3U3 leaking file descriptors/socket connections to Zookeeper

by Dhaval Y Shah :: Rate this Message:

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Hi Joey.. Did you get a chance to look at the code? I digged through this a bit further but didn't get much.. I added logging to the TThreadPoolServer class and the thread pool there is pretty small.. I looked through the ThriftServer class and the Hbase.java file generated by thrift and there aren't many places where HBase configurations are created..The ones where they are created look exactly the same as CDH3B4 which works correctly which is confusing the hell out of me now


Cool thanks Joey... What I also noticed is that the number of threads spawned by the Thrift server also goes to > 16000 when the number of file descriptors is going to > 32000.. Probably we are not re-using threads in a correct way and we are missing the option to limit the number of threads (which I guess is fixed for 0.94 as per what I read in a jira ticket)

Joey Echeverria-2 wrote:
I don't have the code in front of me, but I bet we're not reusing the Configuration object when getting the HTable handle. I'll take a look at when the regression went in this evening.

-Joey

Sent from my iPhone

On Apr 27, 2012, at 14:02, Dhaval Y Shah <prince_mithibai@yahoo.co.in> wrote:

>
> We have an app written in Ruby which uses HBase as the backing store.. It
> uses
> Thrift to connect to it.. We were using HBase from Cloudera's CDH3B4 distro
> until
> now and it worked fine.. I just upgraded our Hadoop install to CDH3U3 (which
> is
> the latest stable CDH release at this point) and in a matter of hours all
> Thrift
> servers went down..
>
> Upon further investigation I realized that it was hitting the limit on the
> number
> of allowed file descriptors (which is pretty high at 32k).. This problem
> occurs if
> I use thrift in any configuration (hsha, framed transport, threadpool)
> except the
> nonblocking mode.. Digging further I realized a couple of things:
> 1. Even with light load (1-2 processes hitting the thrift server in quick
> succession), thrift is spinning up new threads and each of the threads is
> maintaining a socket connection to zookeeper.. In a matter on minutes (with
> this
> load test), thrift has > 32k open connections with > 8k threads having
> connection
> to zookeeper which do not seem to die even after a day..
> 2. The logs show approx 3-4 open connections (presumably for each thread):
> java    53588 hbase 4135r  FIFO                0,6             177426 pipe
> java    53588 hbase 4136w  FIFO                0,6             177426 pipe
> java    53588 hbase 4137r  0000               0,11         0   177427
> eventpoll
> java    53588 hbase 4138u  IPv4             177428                TCP
> njhaddev05:49729->njhaddev01:2181 (ESTABLISH
> ED)
>
> CDH3B4 with the exact same configurations and the exact same setup works
> fine but
> CDH3U3 does not.. Using Thrift in nonblocking mode isn't really an option
> because
> of the low throughput and single threaded nature..
>
> Any help is greatly appreciated..
>
> --
> View this message in context: http://old.nabble.com/HBase-Thrift-for-CDH3U3-leaking-file-descriptors-socket-connections-to-Zookeeper-tp33760461p33760461.html
> Sent from the HBase User mailing list archive at Nabble.com.
>

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