Zetan Drableg wrote:
openldap 2.4.57 on 16 core OracleLinux VMs with NVME disk. 8 nodes in n-way multi master configuration, MDB backend, 50k unique DNs. We see about 10,000 auths per minute per node.
Under heavy client load, the log shows many "deferring operation: binding" messages in the same second. slapd is using only 400% cpu (of 1600 possible).
Probably you could increase # of listeners. In a pure Bind-only workload slapd ought to be able to utilize 100% of all cores.
[2021-04-13 19:15:58] connection_input: conn=150474 deferring operation: binding
When I write LDIFs to one node like delete user or remove user from group, we see spikes in authentication latency metrics (what's normally .2 - .5 second response time goes up to 15-30 seconds) across all nodes in the cluster at the same time.
What knobs can be adjusted to allow for more concurrency? It seems like writes are impacting reads.
You need more information, like I/O wait %, network % utilization, to identify the cause of these latency spikes.
Nobody can suggest what to tune without knowing why the bottleneck occurs.