Re: (ITS#7052) Spurious CSNs being recorded on syncrepl consumers.

[hyc@symas.com]

cmikk@qwest.net wrote:
> Full_Name: Chris Mikkelson
> Version: 2.4.26
> OS: FreeBSD
> URL: ftp://ftp.openldap.org/incoming/
> Submission from: (NULL) (204.147.85.37)
>
>
> When the provider sends a search response with state 'delete' with no / null
> cookie, the syncrepl consumer queues an locally-generated CSN and updates its
> context CSN with that. This appears to happen only with cookie-less deletion,
> not with cookie-less modification. I have not observed a cookie-less addition,
> so I do not know if it occurs there, too.

Thanks for the report. The bug only affected Deletes, not add or modify. Fixed 
in master.

> Example logs from a pure consumer (no server-id, replicating from a provider
> with server id 002):
>
> Sep 26 13:05:42 mpls-auth-02 slapd[57295]: do_syncrep2: rid=100 cookie=
> Sep 26 13:05:42 mpls-auth-02 slapd[57295]: syncrepl_entry: rid=100
> LDAP_RES_SEARCH_ENTRY(LDAP_SYNC_DELETE)
> Sep 26 13:05:42 mpls-auth-02 slapd[57295]: syncrepl_entry: rid=100 be_search
> (0)
> Sep 26 13:05:42 mpls-auth-02 slapd[57295]: syncrepl_entry: rid=100
> uid=<snip>,ou=improv,dc=qwest,dc=net
> Sep 26 13:05:42 mpls-auth-02 slapd[57295]: slap_queue_csn: queing 0x7ffffe3fa560
> 20110926130542.130924Z#000000#000#000000
> Sep 26 13:05:42 mpls-auth-02 slapd[57295]: slap_graduate_commit_csn: removing
> 0x8f58a8a90 20110926130542.130924Z#000000#000#000000
>
> This is problematic at our site because the provider cookie contains a SID 0 CSN
> from before we migrated to multimaster, and the SID 0 CSN recorded at the
> consumer renders the consumer state newer than the provider, breaking
> replication.
>
>


-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/