APAR status
Closed as program error.
Error description
When the Liberty server is started shortly after TCPIP is up, there is a timing window where there may not be routes to the DNS causing a the server's host name to fail to be resolved (since the DNS cannot be contacted). In a case like this, if the server tries to resolve the host name at a later time, the host name will resolve successfully. So, the server should retry starting the TCP Channel, versus needing to be restarted. The messages.log will show these errors: CWWKO0224E: TCP Channel defaultHttpEndpoint-ssl initialization failed. The host server_hostname and port server_port could not be resolved. APAR PH11895 added portOpenRetries which added retry logic for bind failures. But it also needs retry logic for hostname lookup failures.
Local fix
start the Liberty Server after TCPIP and other network applications like OMPROUTE are fully up
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM WebSphere Application * * Server Liberty * **************************************************************** * PROBLEM DESCRIPTION: Port opening retry logic was expanded. * * Retry attempts will be made on hostname * * lookup failures in addition to bind * * failures. * **************************************************************** * RECOMMENDATION: * **************************************************************** When a Liberty server is started on some systems (this mainly applies to some Z/OS system setups), there could be a timing window where the server's host name cannot be resolved due to a failure to contact a DNS, in this case the server fails to open the port. When this happens, the following error will be seen in messages.log: CWWKO0224E: TCP Channel endpoint_name initialization failed. The host server_hostname and port server_port could not be resolved. In such a case, the server would eventually be able to resolve the hostname and open the ports if it tried again later.
Problem conclusion
Port opening retry logic was expanded in Liberty. Each hostname lookup and/or port binding retry attempt will be tried 1 second after the previous one, up until the port opens successfully or the number of retries has been reached. To activate this logic add the portOpenRetries option to the tcpOptions under the httpEndpoint element in server.xml. The fix for this APAR is currently targeted for inclusion in fix pack 20.0.0.12 Please refer to the Recommended Updates page for delivery information: http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
Temporary fix
Ensure the subsystems which provide port access and DNS services is ready.
Comments
APAR Information
APAR number
PH30714
Reported component name
LIBERTY PROF -
Reported component ID
5655W6514
Reported release
CD0
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-10-20
Closed date
2020-10-23
Last modified date
2020-10-23
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
LIBERTY PROF -
Fixed component ID
5655W6514
Applicable component levels
[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Platform":[{"code":"PF054","label":"z\/OS"}],"Version":"CD0"}]
Document Information
Modified date:
24 October 2020