Apama 10.15.5 | Connecting Apama Applications to External Components | Standard Connectivity Plug-ins | The Universal Messaging Transport Connectivity Plug-in | Configuring the Universal Messaging connectivity plug-in | Channel lookup caching
 
Channel lookup caching
After Apama looks up a channel name to determine whether it is a Universal Messaging channel, Apama caches the result and does not look it up again. Consequently, the following situation is possible:
1. You use Universal Messaging interfaces to create channels.
2. You start a correlator with missingChannelMode set to ignore.
3. Apama looks up, for example, channelA and determines that it is not a Universal Messaging channel.
4. You use Universal Messaging interfaces to create, for example, channelA.
For Apama to recognize channelA as a Universal Messaging channel, you must either restart the correlator or issue a flushChannelCache request using the engine_management tool (see also Shutting down and managing components):
engine_management -r flushChannelCache
This operation may take a long time since it verifies the existence of every channel subscribed to in the correlator on Universal Messaging. Therefore, we recommend that you ensure all your channels have been created on Universal Messaging before starting your Apama application.