Problem

API Gateway instances have high CPU usage (up tp 50%) when idle.

Resolution

This can occur even when there is no Traffic. Please note that this use-case applis only to API Gateway instance configured for API Manager.

If Trace level is set to DATA, check if messages such as the following appear in the Trace output:

[7f78:c2400e570a00e61bba12c619] KPS: API Portal_PortalTimestamp: Initialising KPS client.
DEBUG 13/Apr/2016:14:51:20.250 [7f78:c2400e570a00e61bba12c619] KPS: API Portal_PortalTimestamp: Set read consistency level to: ONE
DEBUG 13/Apr/2016:14:51:20.251 [7f78:c2400e570a00e61bba12c619] KPS: API Portal_PortalTimestamp: Set write consistency level to: ANY
DATA 13/Apr/2016:14:51:20.255 [7f78:c2400e570a00e61bba12c619] Converting/refining property: id with value: 8ddaa7b3-26d7-4bc6-9aea-96526451ea1d to java.lang.String
DATA 13/Apr/2016:14:51:20.255 [7f78:c2400e570a00e61bba12c619] Converting/refining property: time with value: 1455791382777 to java.lang.Long
DATA 13/Apr/2016:14:51:20.255 [7f78:c2400e570a00e61bba12c619] Converting/refining property: entityId with value: 2e0dd07a-85b1-4b17-9204-81bf8fda342d to java.lang.String
DATA 13/Apr/2016:14:51:20.256 [7f78:c2400e570a00e61bba12c619] Converting/refining property: eventType with value: CREATEUPDATE to java.lang.String
DATA 13/Apr/2016:14:51:20.256 [7f78:c2400e570a00e61bba12c619] Converting/refining property: entityType with value: VIRTUALIZED_API to java.lang.String
DATA 13/Apr/2016:14:51:20.256 [7f78:c2400e570a00e61bba12c619] Converting/refining property: id with value: ab95d7d1-220b-4251-a232-4e9767ec3638 to java.lang.String
DATA 13/Apr/2016:14:51:20.256 [7f78:c2400e570a00e61bba12c619] Converting/refining property: time with value: 1454678103623 to java.lang.Long
DATA 13/Apr/2016:14:51:20.256 [7f78:c2400e570a00e61bba12c619] Converting/refining property: entityId with value: 8bb1fac8-7d35-42f9-85b5-d412aefe5700 to java.lang.String
DATA 13/Apr/2016:14:51:20.256 [7f78:c2400e570a00e61bba12c619] Converting/refining property: eventType with value: CREATEUPDATE to java.lang.String

If so, then the problem may be related to https://techweb.axway.com/jira/browse/RDAPI-198.

The solution here is to clear the API Portal_PortalTimestamp table via KPSadmin (take a bacup first) and then restart the API Gateway instance.