On 21 Nov 2012, at 13:00, Phil Brown <phil.brown@port.ac.uk> wrote:

We have started seeing problems our radius server with the Error "Error: [ldap] All ldap connections are in use"

We have increased the "ldap_connections_number" from 5 to 20 which has largely resolved the issue.

we now receive over 100,000 authentications a day, is there any guide to "ldap_connections_number" for the number of authentications or should we just keep increasing the number until the issue goes away

For 2.0 I would usually make it as big as the thread pool. The only reason to make it smaller is if processing that many requests in parallel has a negative impact on the overal TPS (transactions per second) of the LDAP server, or if you get so few requests sent via a connection that it gets cleaned up via some intermmediary bit of networking equipment. If you have the time/resources you could do a plot of increasing numbers of parallel requests vs overall TPS, and find the sweet spot for your specific LDAP cluster/server. If you upgrade to 3.0 the connection pool code there allows you to specify elastic pools which automatically add or remove connections to/from the connection pool to cope with the current server load. -Arran