Hi!
I have a 4 cpu machine with SLES 9 and OpenLDAP 2.3.35. This is master to about 65 slaves via syncreplication.
These slave were set up subsequently without any problem. In the last time every now and then the master cannot answer searches in time. Clients time out - i.e. Postfix doing address verification. This may have to do with writes to the master and the replication. The worst time was, when I had to reinitialize about 15 to 20 slaves and these slave checked the master to get in sync.* Other clients got no answer for a long long time. :(
The iron is idle. Load average is 0.00. There were limiting factors like file number etc, which limited process numbers, but this was solved in the mean time.
Which number of connections to the master does a replication slave open?
How can I find out, what is limiting slapd and keep him from responding in time? Log files does not give me a hint, but I don't really know what to search for.
* I take a "top level" ldif file to start the server up - ou=bla,o=foo, ou=log,ou=bla,o=foo and ou=humans,ou=bla,o=foo - and the latest hourly branch dump (these slave only replicate one branch from the master server) - ou=humans,ou=bla,o=foo - from the master to fill the server. In this case the slave contains all the data, but checks ALL entries to be "up to date". Is there a way to prevent this? The slave does only have to check for changes that happened in the last hour (since the dump).
Hans