APAR status
Closed as new function.
Error description
When the webserver plugin has marked all servers in a server group down, requests mapped to this server group will not be forwarded. Plugin will forward a request if the RetryInterval for a marked down server has expired. A request is not forwarded when all servers are marked down and it is not time to retry any of the servers.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: IBM WebSphere Application Server web * * server plugin users * **************************************************************** * PROBLEM DESCRIPTION: When all servers in a cluster are * * marked as offline, the web server * * plugin does not attempt to forward * * requests. * **************************************************************** * RECOMMENDATION: * **************************************************************** The WebSphere web server plugin forwards requests from the web server to the Application server. When an application server fails to respond as expected, plugin marks the application server down and stops forwarding requests to that application server. Plugin will attempt to forward requests to the application server again after the plugin RetryInterval expires. Conditions can occur such that all servers in a cluster are marked offline. If this occurs, plugin does not attempt to forward the request and the client receives a "500 Internal Server Error" response. The web server plugin can be configured with backup servers for a cluster. When backup servers are defined, when all primary servers are marked offline, plugin routes the request to a backup server. If all primary servers and all backup servers are offline, plugin does not attempt to forward the request and the client receives a "500 Internal Server Error" response.
Problem conclusion
Code has been modified such that when plugin detects that all servers are offline in a particular cluster, plugin will set the internal status of all servers to online and attempt to route requests to the servers. If a server fails to respond as expected, it will be marked offline again. When primary servers and backup servers are defined, plugin will mark all the primary servers online when both all the primary and all the backup servers are offline. By marking the servers up in this situation, there is a chance that at least one of the servers has recovered and can respond to the client's request. Note that a request will fail and the client receives a 500 response on the request in which the last server in the cluster is marked down. The servers are marked up after the request has attempted all available servers and the request will not be retried after the servers are marked up. This code modification does not affect Plugin users with the Intelligent Managment feature enabled. Plugin's server status check which occurs after the RetryInterval expires is not affected and continues to function as described in original documentation. Additional plugin information regarding server status and backup servers is available: https://www.ibm.com/support/pages/understanding-ibm-web-server-p lug-failover-clustered-environment The fix for this APAR is targeted for inclusion in fix pack 8.5.5.23 and 9.0.5.13. For more information, see 'Recommended Updates for WebSphere Application Server': https://www.ibm.com/support/pages/node/715553
Temporary fix
Comments
APAR Information
APAR number
PH46938
Reported component name
WEBSPHERE APP S
Reported component ID
5724J0800
Reported release
900
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2022-06-02
Closed date
2022-06-13
Last modified date
2022-06-13
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
WEBSPHERE APP S
Fixed component ID
5724J0800
Applicable component levels
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"9.0"}]
Document Information
Modified date:
14 June 2022