This example is found in pex_harness/examples/eventstage . The eventstage example demonstrates how a Pipeline can send data on the Clipboard to another running pipeline by issuing an outgoing event. This functionality is encapsulated in the EventStage class of the pex_harness.

The current pipeline example has 2 application stages:

App1Stage
EventStage

The initial App1Stage is a dummy application stage that places data on the Clipboard under a designated key (denoted "outgoingKey" in this case). Prior to running the example, the full path to the directory pex_harness/examples/stages should be added to the PYTHONPATH:

% export PYTHONPATH ${PWD}/../stages:${PYTHONPATH} (bash)

% setenv PYTHONPATH ${PWD}/../stages:${PYTHONPATH} (tcsh)

The eventstage policy file (policy/eventstage.paf) is then configured to output the data under this key in an event. The notation

keysToPublish: "outgoingEvent=outgoingKey"

signals that the key "outgoingKey" is pulled from the Clipboard and its contents issued within an event of topic "outgoingEvent".

A utility script "listenEvent.py" may first be executed in a separate shell to start up a listener that blocks for an event of topic outgoingEvent.

% python listenEvent.py

By default this example will run with the Pipeline with one Slice on a single node. Edit the MPI machinefile "nodelist.scr" to specify the hostname of the current host.

The pipeline is then executed via

% launchPipeline.py eventstage_pipeline_policy.paf <some-run-id>

such as

% launchPipeline.py eventstage_pipeline_policy.paf test_23

if an ActiveMQbroker other than the LSST default (lsst8.ncsa.uiuc.edu) is used, this needs to be specified in the pipeline policy file (under "eventBrokerHost") and the listener python script.