Re: Re: Too many open files (was Re: spinlock problems reported earlier) - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Re: Too many open files (was Re: spinlock problems reported earlier)
Date
Msg-id 200012240005.TAA02768@candle.pha.pa.us
Whole thread Raw
In response to Re: Re: Too many open files (was Re: spinlock problems reported earlier)  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
> (1) A dbadmin who hasn't read the run-time configuration doc page (that
> you did such a nice job with) is going to have lots of performance
> issues besides this one.
> 
> (2) The last thing *I* want to hear is stories of a default Postgres
> installation causing system-wide instability.  But if we don't insert
> an open-files limit that's tighter than the "customary operating system
> limit", that's exactly the situation we have, at least on several
> popular platforms.

IMHO, let's remember we keep a cache of file descriptors open for
performance. How many file do we really need open in the cache?  I can't
imagine any performance reason to have hundreds of open file descriptors
cached.  A file open is not that big a deal.

Just because the OS says we can open 1000 files doesn't mean we should
open them just to keep a nice cache.

We are keeping them open just for performance reasons, not because we
actually need them to get work done.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 


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