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Re: (ITS#8444) Out-of-sync issue with memberOf overlay, Delta-syncrepl MMR and >2 nodes
- To: openldap-its@OpenLDAP.org
- Subject: Re: (ITS#8444) Out-of-sync issue with memberOf overlay, Delta-syncrepl MMR and >2 nodes
- From: firstname.lastname@example.org
- Date: Wed, 23 Aug 2017 13:43:33 +0000
- Auto-submitted: auto-generated (OpenLDAP-ITS)
It is caused by the cookie not containing CSN and a race between the
syncCookie check in do_syncrep2 and syncrepl_message_to_op.
This race is probably fine with plain syncrepl which is idempotent, but
deltasync changes get their own dn in each accesslog instance and some
can be applied twice unless we know how to find out we've already seen
them - they need to mention the CSN.
The CSN itself gets lost on at least one occasion - when there's a
checkpoint triggered. Not 100 % sure why the cookie gets eaten because
of it, the op pointer is different between the syncprov_op_response that
calls syncprov_checkpoint and the one that decides CSN hasn't changed.
Senior Software Engineer
Symas Corporation http://www.symas.com
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