Setting up UM for use by Apama

For Apama to use the UM message bus, there are some required UM tasks. These steps will be familiar to experienced UM users.

Plan and implement the configuration of the UM cluster that Apama will use. The recommendation is to have at least three UM realms in a cluster because this supports UM quorum rules for ensuring that there is never more than one master in a cluster. However, if you can have only two UM realms you can use the isPrime flag to correctly configure a two-realm cluster. For details about configuring a UM cluster, see the topics in the Universal Messaging documentation that describe the following:

3. Use UM's Enterprise Manager or UM client APIs to set the access control lists of the UM server to allow the user that the correlator is running on. See UM documentation for details.

4. If you will use the default channel mode, precreate, use UM's Enterprise Manager or client APIs to add the channels that Apama will use. For a description of precreate behavior, see Enabling automatic creation of UM channels.

When you add channels set the channel attributes as follows. Together, these attributes provide behavior similar to that provided by using the Apama correlator utility, engine_connect.

Set Channel Capacity to 20000 or some suitable number, at least 2000 events. A number higher than 20,000 would allows larger bursts of events to be processed before applying flow control but would not affect overall throughput.

These channel attributes provide automatic flow control. If a receiver is slow then event publishers block until the receivers have consumed events.

If you use the mixed or autocreate channel modes then any channels created by Apama have these attributes.

Other channel attributes are allowed. However, it is possible to set UM channel attributes in a way that might prevent all events from being delivered to all intended receivers, which includes correlators. For example, UM can be configured to conflate or throttle the number of events going through a channel, which might cause some events to not be delivered. Remember that delivery of events is subject to the configuration of the UM channel. Consult the UM documentation for more details before you set channel attributes that are different from the recommended attributes.

5. Ensure that Apama can locate the UM libraries. Do either of the following, which ever is easiest for your deployment.

In your UM configuration properties file, set the um.install.dir property to the location in the UM installation of the libraries for that platform. This is the properties file that you can specify when you start a correlator (-UMconfig option) or in an adapter configuration file (um-properties attribute). For example, if you installed UM on a Windows 64 machine in the default location, you would specify:

You can use forward or back slashes on Windows, but if you use back slashes you must escape each one with a back slash: \\.

Before running the correlator, IAF, or an Apama deployment script, add the location of the UM libraries for your platform to your environment's PATH or LD_LIBRARY_PATH. You can do this either in the environment in which you start the Apama components in or in the system's environment. For example, on Windows you can select Computer > Properties > Advanced System Settings > Environment Variables.