Mapping example

Apama 10.15.0 | Connecting Apama Applications to External Components | Working with IAF Plug-ins | Out of Band Connection Notifications | Mapping example

Mapping example

Out of band events will only be received by codecs and transports if the semantic mapper is configured to allow them through. The semantic mapper should be configured as for any other set of events which it may wish to pass down. For more information on creating semantic mapping rules, see The <event> mapping rules.

For example:

<event package="com.apama.oob" name="ReceiverDisconnected"
       direction="upstream" encoder="$CODEC$" inject="false">
  <id-rules>
    <upstream />
  </id-rules>
  <mapping-rules>
    <map type="string" default="OutOfBandReceiverDisconnected"
transport="_name" />
    <map apama="physicalId" transport="physicalId" default="" type="string" />
    <map apama="logicalId" transport="logicalId" default="" type="string" />
  </mapping-rules>
</event>
<event package="com.apama.oob" name="ReceiverConnected"
       direction="upstream" encoder="$CODEC$" inject="false">
  <id-rules>
    <upstream />
  </id-rules>
  <mapping-rules>
    <map type="string" default="OutOfBandReceiverConnected"
transport="_name" />
    <map apama="name" transport="appname" default="" type="string" />
    <map apama="host" transport="address" default="" type="string" />
    <map apama="physicalId" transport="physicalId" default="" type="string" />
    <map apama="logicalId" transport="logicalId" default="" type="string" />
  </mapping-rules>
</event>
<event package="com.apama.oob" name="SenderDisconnected"
       direction="upstream" encoder="$CODEC$" inject="false">
  <id-rules>
    <upstream />
  </id-rules>
  <mapping-rules>
    <map type="string" default="OutOfBandSenderDisconnected"
transport="_name" />
    <map apama="physicalId" transport="physicalId" default="" type="string" />
    <map apama="logicalId" transport="logicalId" default="" type="string" />
  </mapping-rules>
</event>
<event package="com.apama.oob" name="SenderConnected" direction="upstream"
       encoder="$CODEC$" inject="false">
  <id-rules>
  <upstream />
  </id-rules>
  <mapping-rules>
    <map type="string" default="OutOfBandSenderConnected" transport="_name" />
    <map apama="name" transport="appname" default="" type="string" />
    <map apama="host" transport="address" default="" type="string" />
    <map apama="physicalId" transport="physicalId" default="" type="string" />
    <map apama="logicalId" transport="logicalId" default="" type="string" />
  </mapping-rules>
</event>

The events are transmitted to signify the following events:

ReceiverConnected — an external receiver has connected; the IAF can now send events to it.

ReceiverDisconnected — an external receiver has disconnected; events will not be sent to this external receiver until it reconnects.

SenderConnected — an external sender has connected. This external sender may send events following this event.

SenderDisconnected — an external sender has disconnected. No more events will be received from this sender until a new SenderConnected message event is received.

However, adapters can make use of a disconnect message to not transmit events until such time as a connect occurs. For example, an adapter can coalesce events or tell external system to stop sending. Note that if multiple senders and receivers are connected and disconnected, the adapter will need to keep track of which one is connected.