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(ITS#5661) contextCSN gets corrupted on the stand by mirror
Full_Name: Ali Pouya
OS: Linux 2.6
Submission from: (NULL) (18.104.22.168)
I think there is a documentation issue for OpenLdap 2.4.11 :
The chapter 17.4.4 of the Admin Guide recommends configuring TWO sycrepl
directives for each mirror side. If I do so, the contextCSN of the stand by
mirror gets corrupted very easily. But if I confugure the mirrors with only ONE
syncrepl directive it's OK.
The test environment :
I have a test directory with two mirrors A (sid=1) and B (sid=2) configured as
recommended in the Admin's Guide, and a replica C connected to A.
The directory contains 10 million objects, and I use the server A for writing
500 000 new ones.
Very often and without any apparent reason the contextCSN in the memory of B
gets suddenly corrupted while those of A and C are OK.
In this situation the contextCSN of B gets stuck but B continues to receive data
The value of contextCSN in base 64 is :
I note that only the part indicating the year (2008) is garbled. May be this
part is handled differently ?
At service shutdown B writes the corrupt contextCSN to the disk.
At service startup B reads the corrupt contextCSN from the disk and begins to
scan ALL of the data base.
Also it sends a sync request to A (a persitent search containing the corrupt
contextCSN in the control field) causing A to scan the WHOLE data base.
The replica C remains safe.
If I reverse the roles of A and B the corruption occurs on A (always on the
stand by mirror).
I have already encountered the contextCSN corruption problem in OpenLdap 2.3 and
this was one of my reasons to migrate to 2.4.11.
Thanks for your HELP