Hello, I have migrated from HDB to MDB backend and I am seeing higher CPU usage on my MDB openldap consumers. Has anyone else seen the same? Testing in my stage environment showed MDB to use less or the same amount of CPU than HDB - but now with real traffic and a large dataset I see sustained high CPU utilization.
My production environment has the following specs: 6 consumer servers with 8vCPU x 16G RAM openldap version 2.4.45 Syncrepl enabled (with a single openldap provider server which is also MDB and has no issues and no high cpu). The database has ~230K users. data.mdb is about 1.8G in size. MDB database directives include: olcDbCheckpoint: 102400 10 olcDbNoSync: TRUE The rest are defaults. Indexing includes: olcDbIndex: businessCategory eq olcDbIndex: cn eq,sub olcDbIndex: description eq olcDbIndex: displayName eq,sub olcDbIndex: entryCSN eq olcDbIndex: entryUUID eq olcDbIndex: gidNumber eq olcDbIndex: givenName eq,sub olcDbIndex: mail eq olcDbIndex: member eq olcDbIndex: memberOf eq olcDbIndex: memberUid eq olcDbIndex: objectClass pres,eq olcDbIndex: sn eq,sub olcDbIndex: uid eq,sub olcDbIndex: uidNumber eq olcDbIndex: uniqueMember eq These consumer servers are used for reads only. The initial sync with the provider is ok but once the consumers are actively handling read requests, CPU jumps to 60% usage on average. Our HDB consumers had half the resources (4vCPU and 8GB RAM) and less than half the CPU usage (average of 25% utilization). I have tested adding other MDB directives (writemap, mapasync, nordahead) but cannot get CPU utilization to come down close to what we see with the HDB backend. I have also load tested in my stage environment and was unable to reproduce (MDB generally utilized the same or less resources than HDB, but never double). There has been no change in the data or traffic between migration. We have also reverted some servers back to HDB and then back to MDB to confirm the high utilization. Has anyone else come across this with MDB and if so, were you able to alleviate CPU utilization? I can provide more details if needed. Any input welcome. Thanks! Paul
