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Re: Delta-syncrepl issues when missing schema
Scott Sanders wrote:
Hello OpenLDAP fans,
I have a situation which came to my attention inadvertantly after
creating a new replication slave for my directory. The directory holds a
number of posix user accounts, and some of these entries with the
posixAccount object class also have a sambaSamAccount object class. I
use delta-syncrepl for my slaves, because of how quickly I can set them
up at new locations. However, after creating this slave and setting up
auth through PAM on a linux machine to use the new slave I found I was
unable to log in, but other users could. After checking the contents of
ou=people on the slave, it seems no entries referencing any samba
attributes or samba object classes were replicated. As it turns out, I
had forgotten to include samba.schema in my slave slapd.conf.
Now, I set out to fix this on my own. Restarting the server after adding
the schema definition did not populate the samba entries on the slave. I
was instructed to try modifying one of the missing entries by the
wonderful users in #ldap, in hopes it would trigger syncrepl to send the
missing entry to the slave. This also had no effect. After 30 minutes of
frusteration I simply wiped out the openldap-data directory on the slave
and restarted LDAP. This did work. However, it recreated the whole
database on the slave, which could have taken a long time if my
directory was larger.
In the future I would like to know how to repair replication issues in a
less blunt manner. Any suggestions or comments would be appreciated.
I don't think there are too many alternatives. As the name says, delta
syncrepl takes advantage of having deltas, i.e. incremental
modifications, stored somewhere on the producer. Since the difference
between your producer and your consumer are not related to modifications
on the producer, there's little but a full refresh that could be done.
The full refresh implies that all entries are collected by the consumer,
so I don't see any difference (in terms of bandwidth) between a full
refresh and restarting from scratch. There'd be a small difference in
that some entries might not need to be modified.
Ing. Pierangelo Masarati
OpenLDAP Core Team
via Dossi, 8 - 27100 Pavia - ITALIA
Office: +39 02 23998309
Mobile: +39 333 4963172