Hello everyone.

I could find (very) few results while searching the internet for MDB_MAP_RESIZED error in OpenLDAP, and they were of no help.

I'll describe my setup and the circumstances of the error.

I have OpenLDAP (version 2.4.47) and LMDB (version 0.9.22) installed from Debian 10 default packages in a amd64 box.

Along with some usual settings (my slapd.conf file is attached), I set the main database up using the mdb backend with maxsize = 7516192768 (7GB). The on-disk base size (the data.mdb file) is 134MB. I also have loglevel = stats.

Everything seems to work flawless and fast, so all of a sudden syslog prints this message:

Apr 14 09:47:56 my-ldap-box slapd[20736]: mdb_opinfo_get: err MDB_MAP_RESIZED: Database contents grew beyond environment mapsize(-30785)

and seconds later, the slapd daemon stop to answer requests, although the service appears to be still running. This has happened 7 times since April 7, when I moved the data from an old server to this one.

I changed loglevel to 'stats trace args shell' and I realized that when the error occurs, there were always some ADD operations logged right before.

I inspected the logs today, April 14, right after the occurrence of the error and attached a file containing: 1) the error message, which appears at 09:47:56, 2) the messages logged before, since 09:47:50, 3) the messages logged after, until 09:48:01. This time on, slapd logged no more messages and appeared to be stuck for the clients.

At 09:53:41 I restarted the daemon. The log generated from this time until the first request answered is also attached.

For the record, I initially suspected of the replica server which was running alongside the main server and which showed the same behavior. This was because at then I associated the error with syncrepl operations. But even after I stop the replica, the error keeps ocurring in the main server.

Any clues? Thanks for your consideration.