By default, the configuration option missingChannelMode is set to create so that a Universal Messaging channel can be automatically created if it does not already exist when an Apama application needs to use it. See also Configuring the connection to Universal Messaging (dynamicChainManagers).

When a Universal Messaging channel is automatically created, which is helpful for getting started, it has the attributes described in Setting up Universal Messaging for use by Apama. If you want a Universal Messaging channel to have any other attributes, then you must create the channel in Universal Messaging before any Apama component sends to or subscribes to the channel.

In production, it is usually better to change missingChannelMode to error and to configure the channels explicitly as described in Setting up Universal Messaging for use by Apama.

You can specify the ACL (access control list) permissions for the channel being created in a YAML configuration file using the createChannelPermissions option. See Configuring the connection to Universal Messaging (dynamicChainManagers).