2.6 Java Service Manager Pool Server

Each Java Service Manager instance can have a pool server interface. A pool server allows load balancing to be done. When a JSM client connects to a pool server the client is automatically redirected to one of the specified hosts in a round-robin process.

If a host:port entry specified in the pool.hosts list is not available, then the JSM client will go back to the pool server for another entry. The unavailable host machine must be running, so that the client TCP/IP socket connect attempt fails quickly and the client can return to the pool server. If the unavailable host machine is not running a long timeout delay will be experienced. This timeout delay can be up to 3 minutes on a IBM i machine.

In the following example the JSM client program connects to a pool server address instead of the JSM server address.

 

CHANGE     FIELD(#JSMSRV) TO('''LOCALHOST:4562''')

USE        BUILTIN(JSM_OPEN) WITH_ARGS(#JSMSRV) TO_GET(#JSMSTS #JSMMSG)

 

The following manager.properties entries control the pool server address and port. If no pool server interface is required comment out these entries in the manager.properties file.

 

# pool.tcp.port=4562

# pool.tcp.backlog=100

# pool.tcp.timeout=2000

# pool.tcp.interface=*all

# pool.hosts=HOST1:4560,HOST2:4560,HOST3:4560

 

The pool server uses the tcp.client.address property to control client connections.