pureScale

DB2

WAS Workload Balancing and Automatic Client Reroute

Database applications running in a DB2 pureScale environment can use the DB2 transaction-level or connection-level workload balancing (WLB) functionality. WLB balances application requests among all members of the DB2 pureScale cluster. When WLB is enabled the DB2 clients distribute workload or application request based on the capacity (that is, the priority or weight) values in a server list that the DB2 pureScale server returns. These capacity values indicate the current load on a DB2 pureScale member. A member with a capacity value below that of the other members in the server list is busier than other members. [...]

DB2 Java applications with the supported IBM Data Server Driver for JDBC and SQLJ (JCC driver) running in an IBM WebSphere Application Server environment can use the WLB or client affinities features to access databases on a DB2 pureScale cluster. [...]

You must add JCC data source property enableSysplexWLB and set the value to true to enable WLB. [...]

DB2 automatic client reroute (ACR) complements a continuously available DB2 pureScale cluster that offers 24/7 availability for clients connecting to mission-critical production systems. ACR is a feature in DB2 clients that takes application requests that are directed toward an offline DB2 pureScale member and reroutes them to active DB2 pureScale members. ACR is automatically enabled with WLB or client affinities so no additional steps are required to specify which member the application should connect to upon encountering an outage. [...]

To enable WebSphere Application Server to support seamless ACR, from the Purge policy list, select FailingConnectionOnly. (https://public.dhe.ibm.com/software/dw/data/dm-1206purescaleenablement/wlb.pdf)