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Re: Synchronization to distant locations over high-latency/low-bandwidth



--On Thursday, March 16, 2006 8:17 AM +0100 Jan-Piet Mens <jpm@retail-sc.com> wrote:

On Wed Mar 15 2006 at 19:19:40 CET, Quanah Gibson-Mount wrote:

I use the following across all my replicas:

syncrepl        rid=0
                       provider=ldap://MASTERALIAS.stanford.edu:389
... 
                       logbase="cn=accesslog"
logfilter="(&(objectClass=auditWriteObject)(reqResult=0))"


What happens when the consumer is started empty, as in "has never pulled
any data before"? Will it then initially perform a full syncrepl
replication to load itself and then switch to using logfilter=, or does
it always use logfilter= ?

If the ldap replica has no data, it falls back and does a full update from the master server, just like with normal syncrepl. If the replica's CSN is so old that it no longer appears in the changes found in the accesslog, it falls back and does a full update from the master server.

In other words, if I have the provider slapd purge its accesslog database
every twenty days, and a consumer is powered up on the thirtieth day,
what will it miss?

Nothing. It will just do a full resync from the master. :) Although at that point it is probably faster to just reload the replica via slapadd.

--Quanah


--
Quanah Gibson-Mount
Principal Software Developer
ITS/Shared Application Services
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html