Full_Name: Arunkumar shanmugam Version: 2.4.33 OS: rhel5 URL: ftp://ftp.openldap.org/incoming/ Submission from: (NULL) (203.83.248.32) Hi, I've been having issues with syncrepl in openldap. This is plain syncrepl. I'm not using delta-syncrepl as I run with mirror mode on. I've noticed that when there are a large number of writes on the writemaster (Typically around 10 per second) the data on the readslave goes out of sync with the master, typically having entries which have been deleted on the master. The contextCSNs on both the readslaves and writemaster match eventually, but the data doesn't. I'm running the readslave in refreshOnly mode with an interval of 1 minute. I'm using a reasonably large DB of size ~ 2 GB. I turned on the sync logs and found lots of entries with "nonpresent_callback" and "syncrepl_del_nonpresent". Tested this and found it occurring in both 2.4.29 and 2.4.33 (Latest as of this time), and with BDB 4.2.36 as the backend. I was wondering if anyone has faced similar issues before, and if there exists a solution to this problem. I will send any relevant configuration and log snippets as needed. Thanks
--On Wednesday, January 23, 2013 11:59 AM +0000 arunkumar_1123@yahoo.com wrote: > Full_Name: Arunkumar shanmugam > Version: 2.4.33 > OS: rhel5 > URL: ftp://ftp.openldap.org/incoming/ > Submission from: (NULL) (203.83.248.32) > > > Hi, > > I've been having issues with syncrepl in openldap. This is plain > syncrepl. I'm not using delta-syncrepl as I run with mirror mode on. MMR has supported delta-syncrepl since 2.4.27. You should use it. --Quanah -- Quanah Gibson-Mount Sr. Member of Technical Staff Zimbra, Inc A Division of VMware, Inc. -------------------- Zimbra :: the leader in open source messaging and collaboration
> MMR has supported delta-syncrepl since 2.4.27. You should use it. I did consider delta-syncrepl, but given the high write load expected, I was not sure if it was the right decision. I am expecting an average load of 50-100 writes per second, and with 1 backup provider, and 10 consumers, it might get heavy on the provider which is serving the writes, given that OpenLDAP would be maintaining another DB for the access log. But with this syncrepl issue, it looks like I need to change the replication mode to refreshAndPersist anyway. As such it looks like delta syncrepl is also refreshAndPersist too. Is there any recommendation between simple refreshAndPersist and delta-syncrepl with refreshAndPersist for high write loads? Thanks PS: I see that delta syncrepl is compatible with MMR which I presume to be MultiMaster. I hope it works with Mirror Mode too. I did not find any documents supporting this.
Hello, I would strongly advise retrying with a current OpenLDAP release. Numerous sync replication bugs have been fixed since 2.4.33. Also, to answer your earlier question, there's no such thing as "mirror mode". "mirror mode" is entirely a concept. A system either is or isn't multimaster, which delta-syncrepl works with. See also: <http://www.openldap.org/its/index.cgi/?findid=8511> Regards, Quanah -- Quanah Gibson-Mount Product Architect Symas Corporation Packaged, certified, and supported LDAP solutions powered by OpenLDAP: <http://www.symas.com>
Likely fixed in later releases... can reopen if reproduced in current builds.
changed notes changed state Open to Closed moved from Incoming to Software Bugs