Howard Chu wrote:
Curt Blank wrote:
I'm looking for ideas here. ldap seems to deadlock once in a while
whereby it continues to accept connections as noted in the log file
but it does not return anything to the query, the query just hangs.
It's openldap 2.2.28 using Berkley db 4.2.52 as the backend on a SuSE
9.3 platform. All patches are up to snuff on the OS side.
I'm hoping for pointers to help see what might be going on.
As of today I started running db_deadlock in the background wit the
-a y option to see if that helps.
This deadlocking is getting people up in arms here because it is
disrupting authentication for the whole campus and I guess I can't
blame them.
There have been no deadlocks reported in OpenLDAP 2.2 after 2.2.20.
More likely you had an unclean shutdown and restarted without running
db_recover, so you have stale locks in the environment. You should
upgrade to 2.3 which does recovery automatically.
No, I know that isn't/wasn't the case, I manually ran db_recover with
the -v option ~16 hours before the last occurrence of this and the
server did not/was not shutdown in between nor did the slapd die and it
wasn't stopped/started. This last time (last Friday) our backup started
12 minutes after it was only accepting connections and not responding
with data and that really compounded the problem. The backup does a
db_checkpoint and it hung and stopping the slapd daemon did not correct
the problem. slapd stopped cleanly but when restarted it just sat there
and would not even accept connections. The db_checkpoint would not
complete and after about 10 minutes was killed. I know I know not the
best thing to do but when you have people on campus pissed because they
can't login time is one luxury that we do not have, and yes db_recover
was successfully run again before slapd was started. But, I'm a bit
leery of it right now....
One thing I failed to mention is that it appeared that a slurp
replication to this slave server started at the time slapd started only
accepting connections and not responding with data. So that's a write
and that is what got me to start thinking about a deadlock situation.
- Re: ldap deadlock? Curt Blank
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