Re: Performance issues lately.

[Jorgen Lundman <lundman@lundman.net>]

No real reason, tried various different settings but to no real advantage.

Now I have:

Filesystem             size   used  avail capacity  Mounted on
swap                    19G   7.7G    11G    42%    /tmp

# grep cache DB_CONFIG
set_cachesize 8 0 1

# time /usr/local/BerkeleyDB.4.8/bin/db_stat -d id2entry.bdb
real    6m6.099s

# time cp id2entry.bdb /dev/null
real    0m0.040s
(It's not on disk)

I thought to delete id2entry.bdb, and use slapindex to re-generate it but that 
appears not to be a supported feature. slapindex can not run without a valid 
id2entry.bdb. This is why I tried slapcat, rm *, slapadd. But no difference in 
speed up.

If I truss with -u *:* (All inter-library calls) I get no "single" large system 
call, just a lot of work somewhere (that does not call read/write etc). Alas, 
the number of lines in truss file is:
 6209933 /var/tmp/db_stat_truss


Lund

Quanah Gibson-Mount wrote:
> --On Sunday, November 14, 2010 7:13 PM +0900 Jorgen Lundman
> <lundman@lundman.net> wrote:
>
> > dbconfig set_cachesize 4 0 8
>
> Why are you breaking your cache into segments? This has always had a
> negative performance impact in all tests I've done, and stopped being
> necessary to do with BDB 4.3 and later.
>
> --Quanah
>
>
>
> --
>
> Quanah Gibson-Mount
> Principal Software Engineer
> Zimbra, Inc
> --------------------
> Zimbra :: the leader in open source messaging and collaboration

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