OpenLDAP taker a long time (90s+) to shutdown

[Alexandre Rosenberg <arekkusu@r42.ch>]

Hello,

I run into a issue where OpenLDAP would not shutdown within 90s.
Sometimes shutdown is fast and sometimes not. This concern production 
server getting a fair amount of traffic.

The reason I am mentioning 90s is because this is the default timeout 
for sytemd service. After that time it sends SIGKILL to the process.

I am running latest OpenLDAP (2.45) with MDB database (~1GB).
The server is a consumer of another OpenLDAP Server.
Maybe more importantly following directive are present under the MDB 
database configuration.

	dbnosync
	checkpoint 500 5

I was wondering what is the expected time for OpenLDAP to shutdown.
Also I am unsure if the checkpoiont setting could be related.

Best,

Alex