Re: (ITS#7657) Alias dereferencing with MDB slow compared with BDB

[hyc@symas.com]

Mark.Cairney@ed.ac.uk wrote:
> Full_Name: Mark Cairney
> Version: 2.4.35-RE24
> OS: SL 6.4 64-bit
> URL: ftp://ftp.openldap.org/incoming/
> Submission from: (NULL) (129.215.200.23)
>
>
> Having migrated the database of our production service running 2.4.35 from BDB
> to MDB alias de-referencing stopped working completely (this has already been
> reported in ITS# 7557).
>
> Upgrading to the RE 24 now has alias derefencing working but it is considerably
> slower than BDB was for the same search.
>
> To confirm this I downgraded one of our nodes (we run 4 nodes in multi-master)
> and on that node the search results are once more acceptable:
>
> With MDB:
> time ldapsearch -H ldaps://alder.authorise.is.ed.ac.uk:636 -b
> 'ou=staff,ou=law,ou=hss,dc=authorise,dc=ed,dc=ac,dc=uk' -a always
> "(&(eduniSchoolCode=S26)(eduniCategory=101)(eduniIDStatus=300))"
>
> # numResponses: 425
> # numEntries: 424
>
> real	0m26.490s
> user	0m0.028s
> sys	0m0.032s
>
>
> with BDB:
>
> time ldapsearch -H ldaps://oak.authorise.is.ed.ac.uk:636 -b
> 'ou=staff,ou=law,ou=hss,dc=authorise,dc=ed,dc=ac,dc=uk' -a always
> "(&(eduniSchoolCode=S26)(eduniCategory=101)(eduniIDStatus=300))"
>
> real	0m2.605s
> user	0m0.054s
> sys	0m0.006s
>
> If there's anything additional I can supply (log files, strace output) let me
> know.
>
> Our OpenLDAP DB currently has around 400,000 user accounts if that's relevant.

How many aliases?

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   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
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