Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Zookeeper, mail # user - excessive client timeouts tied to NIO select(timeout)


Copy link to this message
-
excessive client timeouts tied to NIO select(timeout)
Brian Tarbox 2013-02-26, 17:15
The main client loop involves sending keep-alive pings in-between calls to
the NIO selector.select call which looks for data from the server
(including ping responses).

What I've found is that the select() which takes a timeout value takes a
hugely varying time to complete.

When asking for a max 6 second timeout on the select call I'm in fact
staying in the call for 15-25 seconds.  Which leads to starving the keep
alives which leads to timeouts.

Looking at the NIO documentation of the timeout parameter to select it says:
timeout - If positive, block for up to timeout milliseconds, *more or less*
*
*
Has anyone else seen this or have a suggestion for a work around?  This
seems like a basic flaw.  If I can't count on timely return from select it
seems to break the how keep-alive scheme.

Thanks in advance for any help!

Brian Tarbox

--
http://about.me/BrianTarbox