Re: syncrepl problem with 2.4.19

["Dieter Kluenter" <dieter@dkluenter.de>]

Christoph Herrmann <C.Herrmann@science-computing.de> writes:

> Dear all,
>
> we want to update our openldap-2.3.39 infrastructure to openldap 2.4.19.
> For that we did some stress tests to an openldap-2.4.19 test infrastructure.
> we are running the tests in a single master environment with 5 slave servers,
> all with openldap-2.4.19. All machines are running ntpd and are in sync:
[...]
> this is our syncrepl config:
>
>  master/provider:
>
>     overlay syncprov
>     syncprov-checkpoint 100 10
>     syncprov-sessionlog 100
>
>
>  slave/consumer:
>
>     syncrepl rid=467
>         provider=ldap://ldapma01:389
>         type=refreshAndPersist
>         retry=2,30,15,40,60,+
>         searchbase="o=example,c=de"
>         filter="(objectClass=*)"
>         scope=sub
>         schemachecking=on
>         bindmethod=simple
>         binddn="cn=replica,ou=replica,o=example,c=de"
>         credentials="replica"
>
>     updateref ldap://ldapma01:389
>
>
> During the tests we always run in to problems with syncrepl. We are doing tests in the way:
>
> bind; add|modify|delete; unbind; wait for n ms; bind .... (10 =< n =< 100)
>
> depending on the time between the requests, about 1% of our write requests will not be
> synchronized to any off the slaves. It seems, the the master send the syncreplrequests out of sync,
> and all slaves reject syncing with the message: CSN too old, ignoring ... 
>
> What can we do, to solve that problem?

I found that disable logging on provider and consumers solved most of
my problems. in addition you should check the number of waiters and
increase the number of threads if required.

-Dieter

-- 
Dieter Klünter | Systemberatung
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