kde_gateway losing connections; needs tuning
kde_gateway has been working OK, but an increase in the number of agents results in connection failures.
Agents go OFFLINE but come back ONLINE when restarted. Agent running although reported down.
Part of this issue has been identified as a product defect under APAR IV19469 which is in 6.22 FP09 and higher.
Resolving the problem
Areas to check to see if tuning is needed:
1) If the gateways are on Unix or Linux check that the nofiles limit is set to either at least 8192 or unlimited.
this can be checked by running the command 'ulimit -n'
2) It is recommended that the pool parameter is set to 1000 rather than 500
The lines in the *gatewaycong.xml of
" <portpool name="poolhub">20000-20499</portpool>c " and
" <portpool name="poolwhp">20500-20999</portpool> "
imposes a limit of 500 connections to the TEMS and 500 connection to the WHP
neither of which appears reasonable if there are a large number of agents as each agent can have three connections at some times.
It is recommended to double each pool at least, in support of 1000 agents to the TEMS
and 1000 WHP connections.
Port pools syntax for 2048 connections would be similar to this for example:
<portpool name="pool">20000-21023 21024-22047</portpool>
3) If IV19469 (which is in 6.22 FP09 and higher) is not applied it is possible to increase the default values by modifying the *gatewayconfig.xml file on the line where the zone name is set:
<zone name="xxxxxxxx" maxconn="2041" minbufs="128" maxbufs="256">
Note that the default values for maxconn, minbufs and maxbufs are not shown normally in the xml file.