Was load testing against openldap (slapd-meta) where we were trying to submit 1000
concurrent bind requests. This was done using the JMeter load testing tool. In every run
approximately only 420-430 bind requests are successful and remaining 500+ bind requests
fail with "Communication Exception" error. We also tried with 500 bind requests
and the result was somewhat same - 420 odd successful and 70-80 failed with communication
What does a "Communication exception" actually mean? Connection refused,
connection timed out, what?
We've tested tens of thousands of concurrent connections with slapd. It is unlikely to
be the problem here.
We have openldap 2.4.56 installed on a RHEL 8.1 host with 32GB memory
and 8CPU. We have configured max open files for the slapd process to be 65K .
Our requirement is to support 6000 concurrent requests at minimum. Is there any
configuration that can be tweaked to support this amount of concurrent load ? I do see
"olcConcurrency" & "olcThreads" set to 0 and 16 respectively.
Should we be tweaking these to support the required load, if yes what should be the values
for those ? Please assist. Thank you for your help !
-- Howard Chu
CTO, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/