Apama 10.15.3 | Connecting Apama Applications to External Components | Working with Connectivity Plug-ins | Using Connectivity Plug-ins | Static and dynamic connectivity chains
 
Static and dynamic connectivity chains
Chains can be created statically using a YAML configuration file or dynamically at runtime. How the chains are created depends on the type of transport:
*Some transports have a dynamic chain manager which manages chain creation in a transport-specific way. New chains are created, for example:
*in response to external requests (for example, for each connection made to the HTTP server connectivity plug-in), or
*when an Apama channel with a particular prefix is first used from EPL (for example, the Universal Messaging connectivity plug-in creates a chain by default when a channel beginning with um: is used from EPL, in a monitor.subscribe(...) method or a send ... to statement).
These transports always have a dynamicChainManagers section in their YAML configuration file. The connectivity chains are created dynamically by a transport chain manager plug-in, using chain definitions specified in dynamicChains. See Configuration file for connectivity plug-ins for information on how to configure dynamic chain managers and dynamic chains in a YAML configuration file.
For more information on dynamic chain managers, see Requirements of a transport chain manager plug-in class.
*For transports that do not provide a dynamic chain manager, chains are created either
*statically using the startChains section of the YAML file, or
*dynamically from EPL using ConnectivityPlugins.createDynamicChain. See Creating dynamic chains from EPL.
A transport that permits user-controlled chain creation never has a dynamicChainManagers section in its YAML configuration file.
See the documentation for each transport in Standard Connectivity Plug-ins on how chains are created. See Configuration file for connectivity plug-ins for more details on startChains, dynamicChains and dynamicChainManagers.