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Re: Using syncrepl in single slapd instance.

Laurence Field <Laurence.Field@cern.ch> writes:

> I have been investigating the use of syncrepl as a replacement for the
> mechanism we are currently using in our system and become stuck.  Here
> is the scenario to put the problem in context.
[...]
>
> At the moment the LDAP databases are updated externally via process
> that polls the LDAP server for all information, which is very
> inefficient. Syncrepl seems to be a better mechanism to use however, I
> am having difficulty with one scenario.  Using standard syncrepl with
> a relay, the site-level LDAP server can be configured with the
> following slapd.conf file.
>
> http://lfield.web.cern.ch/lfield/bdii-slapd.conf-basic-rep

this slapd.conf is malformed, the updateref parameter is missing.

> However, the site LDAP server is a Grid service and needs to publish
> itself.  If I try to  just to an LDAP add I get the following message,
> which I guess is due to the fact that this part of the database is now
> "owned" by the syncrepl process.
>
> ldap_add: Server is unwilling to perform (53)
>    additional info: shadow context; no update referral
>
> I tried to work around this problem by using another database and some
> more relays the result of which can be seen in the following file.
>
> http://lfield.web.cern.ch/lfield/bdii-slapd.conf
>
> However, this result with the following error, which suggests that I
> can't "mask" a database with a relay that points somewhere else.

this slapd.conf is malformed als well, the syncprov parameter has to
follow all database related parameters.
>
> bdii-slapd.conf: line 69: <suffix> namingContext
> "Mds-Vo-name=resource,o=internal" already served by a preceding bdb
> database serving namingContext "Mds-Vo-name=resource,o=internal"
>
> Does anyone have an example of how to do a syncrepl where a single
> slapd instance can act as both the consumer and producer?

have a look at tests/scripts/test019
>
> Also, has anyone done any scalability/reliability tests with syncrepl?

Yes I did, cascading databases up to 66 servers and multimaster
replication up to 14 hosts and up to 5 M entries. Hardware was Sun
Ultrasparc single core 8 GB, rackmounts.

-Dieter

-- 
Dieter Klünter | Systemberatung
http://dkluenter.de
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