Special characteristics in cluster operation

Multiple resource adapter instances may run together with multiple proxy instances in a cluster environment. The number of proxy instances does not have to be the same as the number of resource adapter instances. A maximum of 32 resource adapter instances and a maximum of 32 proxy instances are possible.

All the participating instances have an identical configuration, and in particular each resource adapter instance is deployed with the same BeanConnect RAR archive and therefore works with the same configuration values from ra.xml.

Cluster operation is possible for both outbound communication via OSI-TP / LU6.2 and for inbound communication.

In the case of cluster operation, the following configuration steps are necessary at the application server:

• Define the additional parameters and properties for cluster operation in the ra.xml file:

  • You must specify the addresses of all the proxy instances in the property proxyURL.

  • You must specify the addresses of all the resource adapter instances in the additional property resourceAdapterAddresses.

  • You can modify the parameters for the reallocation of the resource adapters and proxies in the properties proxyReconnectCount and proxyReconnectInterval.

  This is also possible via the Management Console as in standard operation, see "Adapting the ra.xml file" in Defining general properties in ra.xml . However, you may also adapt the ra.xml file manually.

• Perform the other configuration steps at the application server in exactly the same way as when using only one resource adapter, see Configuration steps for outbound and inbound communication .

proxyURL

In cluster operation, the proxyURL defines the assignment of the resource adapter instances to the proxy instances. If you are working with multiple proxy instances then you must specify the addresses of all the proxies, each separated by a semicolon.

Definition:	oltp://<host>:<port>/<name>; ... ;oltp://<host>:<port>/<name>
Explanation:	<host>	Host on which the associated proxy container is installed. <host> can be specified as a symbolic name or as an IPv4 address.
	<port>	Port number of the associated proxy container + 4
	<name>	Application name of the associated proxy container (BCU<port>)
	The individual entries must be separated by semicolons.
Default:	oltp://localhost:31004/BCU31004
Example:	<config-property> <description>BeanConnect Proxy URLs for OLTP outbound communication with 2 Proxies</description> <config-property-name>proxyURL</config-property-name> <config-property-type>java.lang.String </config-property-type> <config-property-value>oltp://proxyhost1:31004/BCU31004; oltp://proxyhost2:31004/BCU31004 </config-property-value> </config-property>

resourceAdapterAddresses

This property is only of any significance in a cluster configuration with several resource adapter instances and must not be specified at the same time as the resourceAdapterIndex property (see Special characteristics of multiple resource adapter mode ).

This property enables you to specify the addresses of all the computers on which instances of the BeanConnect resource adapter will be run. You can specify up to 32 semicolon delimited addresses.

You specify addresses in the format host[:port]. If you do not specify a port number, the port number specified under inboundListenerPort is used as the listener port for inbound communication. This must be greater than 0. If you specify a port number, this is used as the listener port for inbound communication. The specified value must be greater than 0.

If multiple resource adapter instances are to run under one and the same host address, then you must specify this host address the corresponding number of times in the list and assign each address a different port number.

Definition:	<host>[:<port>]; ... ;<host>[:<port>]
Explanation:	<host>	Host on which the associated resource adapter instance is running. <host> can be specified as a symbolic name or as an IPv4 address.
	<port>	Port number of the associated resource adapter instance for inbound communication.
	The individual entries must be separated by semicolons.
Default:	There is no default value
Example:	<config-property> <config-property-name>resourceAdapterAddresses </config-property-name> <config-property-type>java.lang.String </config-property-type> <config-property-value> host1:31099;host2:31099;host3:31099 </config-property-value> </config-property>

proxyReconnectCount

This property is only of any significance in a cluster configuration with multiple resource adapter instances and multiple proxy instances. proxyReconnectCount controls the usage-driven reassignment of a resource adapter instance to a proxy application. This mechanism is activated as soon as multiple resource adapter instances are assigned to a proxy application.

Definition:	<number>
Explanation:	<number> specifies the number of connection requests (calls to getConnection()) after which a reassignment between the resource adapter instance and the proxy application is necessary. If the value 0 is specified for <number> then usage-driven reassignment is deactivated
Default:	100
Example:	<config-property> <config-property-name>proxyReconnectCount </config-property-name> <config-property-type>java.lang.String </config-property-type> <config-property-value>200 </config-property-value> </config-property>

proxyReconnectInterval

This property is only of any significance in a cluster configuration with multiple resource adapter instances and multiple proxy instances. proxyReconnectInterval controls the time-driven reassignment of a resource adapter instance to a proxy application. This mechanism is activated as soon as multiple resource adapter instances are assigned to a proxy application.

Definition:	<minutes>
Explanation:	<minutes> specifies the time in minutes after which a reassignment between the resource adapter instance and the proxy application is necessary. If the value 0 is specified for <minutes> then time-driven reassignment is deactivated.
Default:	10
Example:	<config-property> <config-property-name>proxyReconnectInterval </config-property-name> <config-property-type>java.lang.String </config-property-type> <config-property-value>5 </config-property-value> </config-property>

If a cluster configuration is operated with more resource adapter instances than proxy instances (i.e. there is always at least one proxy instance which is assigned more than one resource adapter instance), then the usage-driven and time-driven reassignment should be deactivated or, at the very least, values larger than the defaults should be set in order to avoid performance losses.