Shekhar S wrote:
Thanks for your response. It’s Connection Timeout.
Some additional info - i just went ahead and for sake of trying updated the olcthread
value to 1750 and post that was able to get 1650 concurrent connections
working concurrently consistently, but anything beyond that again randomly threw
connection timeout errors.
Since you're using back-meta, the limit is most likely on the target LDAP server.
One more thing you can try is to increase olcListenerThreads (no more than the number of
CPUs). But since raising olcThreads
affects your result, clearly the remote server is keeping slapd's threads tied up
waiting for responses.
You can also use back-asyncmeta in OpenLDAP 2.5 for better behavior without needing
thousands of slapd threads,
but the end result will be the same - it can only answer as fast as the remote server and
Message sent from a mobile device, please excuse typos and brevity.
> On Sep 13, 2021, at 9:28 PM, Howard Chu <hyc(a)symas.com> wrote:
> shekhar.shrinivasan(a)gmail.com wrote:
>> 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 exception.
> 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
>> 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/
-- Howard Chu
CTO, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/