Re: [enhancement] fts-solr low performance

azurIt azurit at
Mon Mar 5 11:07:30 EET 2018

>we have activated fts-solr about a week ago and immediately started to  
>experience really *low* performance with MOVE and EXPUNGE commands.  
>After several days of googling, tcpdumping and straceing i was able to  
>find and resolve the problem.
>We are using Dovecot 2.2.27 from Debian Jessie (jessie-backports),  
>which is doing a soft commit in solr after every MOVE or EXPUNGE  
>command - this behavior cannot be, currently, changed. The problem is  
>that this was causing every MOVE/EXPUNGE to take about 6 seconds to  
>complete. The problem appears to be in very old version of Solr -  
>3.6.2 (!!). This is the only version which is shipped with current  
>(Jessie) and also next (Stretch) version of Debian, don't ask my why,  
>i don't understand it either. Solr versions below 4.0 are NOT  
>supporting soft commits, so all commits are hard and this was the  
>problem. Finally, i decided to patch our Dovecot to not send a commit  
>at all and everything started to be super fast. I'm doing hard commits  
>every minute via cron so the only consequence of this is that you  
>cannot search for messages delivered before less then a minute (which  
>you, usually, don't need to do anyway).
>While googling i also find out that Solr supports autoCommit function  
>(and from version 4.0 also autoSoftCommit), so there's no reason for  
>Dovecot to handle this on it's own (and potentially doing hundreds or  
>thousands of soft commits every second) - you can just set Solr to,  
>for example, do autoSoftCommit every second and autoCommit every minute:
>Also this wiki page should be updated with warning about old versoins  
>of Solr not supporting soft commits (you could also mention the  
>auto[Soft]Commit function):
>I suggest to allow completely disable Solr commits in Dovecot by  
>configuration, so people like me can handle this easily. What do you  


any news on this? Even Solr documentation suggests to NOT doing commits from applications:

Thanks for not ignoring me.


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