Check the Solr log file and see if something is happening at those slow
queries. Maybe an auto-commit?
-- Jack Krupansky
-----Original Message-----
From: Andy Lester
Sent: Wednesday, August 08, 2012 11:30 AM
To: solr-user@lucene.apache.org
Subject: Solr makes long requests about once a minute
I'm having a problem with Solr under Tomcat unexpectedly taking a long time
to respond to queries. As part of some stress testing, I wrote a bot that
just does random word searches on my Solr install, and my responses
typically come back in 10-50 ms. The queries are just 1-3 random words from
/usr/share/dict/words, and I cap off the results at 2500 hits.
The queries run just fine and I typically get responses up to 50ms for large
result sets. Here's an example of my log:
TIME HITS MS SEARCH WORDS
12:33:20 1 5 hoovey Aruru kwachas
12:33:20 8 5 blinis twyver
12:33:20 2500 34 prework burlily sunshine
12:33:20 1928 30 rendu Solly
12:33:20 unnethe
12:33:20 gadwell afterpeak
12:33:20 792 14 steen
12:33:20 4 7 blanchi repaving
12:33:20 32 6 torbanite Storz ungag
12:33:20 7 5 chemostat
12:33:20 15 6 Guauaenok Adao lakist
12:33:20 6 6 bechance viny
12:33:20 20 6 chagigah
12:33:22 532 2404 bonne
12:33:22 143 9 nonman Norrie
12:33:22 24 6 repealers
12:33:22 Pfosi laniard locutory
12:33:22 51 6 sexipolar wordsmith enshield
12:33:22 loggiest Aryanise koels
12:33:22 fogyish unforcing
12:33:22 4 5 Millvale chokies
12:33:22 5 6 Melfa ripal Olva
12:33:22 15 6 apio Heraea latimeria
12:33:22 4 5 nonnitric parleying
See that one line where it 2404ms to return? I get those about once a
minute, but not at a regular interval. I ran this for two hours and got 122
spikes in 120 minutes. I ran it overnight and came in to work to find that
there were 1283 spikes in 1260 minutes. So that one-a-minute is a pattern.
As I write this, I'm in IRC with Chris Hostetter and he says:
--snip--
Probably need to tweak your garbage collector settings to something that
doesn't involve "stop the world" ... the specifics of the changes largely
depend on what JVM you are using, what options you already have set, etc.
markrmiller wrote a good blog about this a little while back:
http://searchhub.org/dev/2011/03/27/garbage-collection-bootcamp-1-0/
There's also some notes here in the LucidWorks Solr Ref Guide:
http://lucidworks.lucidimagination.com/display/solr/JVM+Settings
--snip--
GC certainly sounds like a reasonable suspect. Any other suggestions? Any
hints on Solr-specific GC tuning? I'm currently scouring Google.
Thanks,
xoa
--
Andy Lester => a...@petdance.com => www.petdance.com => AIM:petdance
