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From Niraj Aswani <niraj.asw...@klevu.com>
Subject Re: CLOSE_WAIT and high search latency
Date Tue, 23 Feb 2016 11:54:15 GMT
Hi Jacques,

Thank you for your reply. I'll give these parameters a try and report back.
Do you think having higher number of CLOSE_WAIT connections affects the
over all search delivery speed?

Regards,
Niraj

On Tue, Feb 23, 2016 at 2:57 PM, Jacques du Rand <jacques@pricecheck.co.za>
wrote:

> Try to fiddle with your tcp settings:
>
>  /etc/sysctl.conf
> net.ipv4.tcp_fin_timeout = 30
> net.ipv4.tcp_keepalive_intvl = 2
> net.ipv4.tcp_keepalive_probes = 2
> net.ipv4.tcp_keepalive_time = 180
>
> That should help.
>
>
> On 23 February 2016 at 07:13, Niraj Aswani <nirajaswani@gmail.com> wrote:
>
> > Hi,
> >
> > I am on solr 4.8.1 and running master-slave setup with lots of cores
> (>3K).
> > Internally I maintain an instance of HTTPSolrServer for each core that is
> > reused for querying the respective cores. A request is received by an
> > intermediary tomcat and forwarded to another tomcat running Solr.
> >
> > Over the period we see high search latency. Some requests start to take
> too
> > long and eventually result into timeouts.
> >
> > Investigating this, I see that, over the period, a high number of
> > CLOSE_WAIT sockets (>3300) are building up. Running `netstat -p` seems to
> > suggest that these sockets were initiated by the intermediary tomcats
> when
> > communicating to the Solr.
> >
> > Questions are:
> >
> > - Why do we see such high number of CLOSE_WAiT sockets? Shouldn't the
> > HTTPSolrServer take care of closing these connections after communicating
> > with the Solr server?
> >
> > - Does the high number of CLOSE_WAIT have anything to do with search
> > latency?
> >
> > Any suggestion on the matter is highly appreciated!
> >
> > Regards,
> > Niraj
> >
>
>
>
> --
> Jacques du Rand
> Senior R&D  Programmer
>
> T: +27214688017
> F: +27862160617
> E: jacques@pricecheck.co.za
> <
> https://mail.naspers.com/owa/redir.aspx?SURL=uQ0aY47BwKkgYjLPs4CuWJgrQlRUZlf73Ere0TGrauf5NrymvPnSCG0AYQBpAGwAdABvADoAagBhAGMAcQB1AGUAcwBAAHAAcgBpAGMAZQBjAGgAZQBjAGsALgBjAG8ALgB6AGEA&URL=mailto%3ajacques%40pricecheck.co.za
> >
>

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