RuntimeService execution query returns empty list

[serid]

Hi All,

I am completely new to Apache Activiti and doing some basic stuff trying to understand how it all works.
I have a very basic bpmn file consisting only of start, service task and stop.
I have implemented the service task using JavaDelegate.
Using activiti with spring boot.

After starting the process I try to get executions for the process:

List<Execution> executions = runtimeService.createExecutionQuery().list();
List<ProcessInstance> pis = runtimeService.createProcessInstanceQuery().list();
LOGGER.info("Executions: " + executions.size());
LOGGER.info("PIs: " + pis.size());
‍‍‍‍‍‍

and am always getting empty lists. Can anybody please explain why is that ?

Thanks,
Adrian

[martin_grofcik]

Hi Adrian,

is process already finished? (If yes there is no execution active in it)

Regards
Martin

[serid]

Hi Martin,

No - the process is still running.
I made sure it is by running:

<code>
new Thread("Activiti Thread") {
          
   @Override
   public void run() {
      runtimeService.startProcessInstanceByKey("myRealProcessTest");
   }
          
}.start();
         
synchronized (this) {
   wait(3000);
}

List<Execution> executions = runtimeService.createExecutionQuery().list();
List<ProcessInstance> pis = runtimeService.createProcessInstanceQuery().list();
LOGGER.info("Executions: " + executions.size());
LOGGER.info("PIs: " + pis.size());
</code>

The service task is running for 30 seconds and I am getting every 3 seconds info in logs of its status.

So no - I start the process, wait 3 seconds to make sure that the task starts (which I can see in logs) and then
I query for the executions - gives empty list after which I still get updates from the task.


Thanks,
Adrian

[martin_grofcik]

Hi Adrian,

I can only guess (jUnit test could help a lot: https://forums.activiti.org/content/sticky-how-write-unit-test)
The problem could be that:
1. process starts execution and service task waits for 30s.
2. the db transaction is not committed to the DB - that's why the queries executed from different transactions do not return any execution.

Regards
Martin

[warper]

My moneys on "2. the db transaction is not committed".
Since it looks like synchronous process, it is not commited to DB up to the end.

[serid]

Hi guys,

Thanks very much for your replies and sorry for delay in replying - went for a short holidays …
Right - it would make sense - it is synchronous process.

It might be slightly now off topic but here is what I try to achieve:

1) I have my own wrapper around JavaDelegate - it's purpose is to implement a progress handling so on my UI when particular activiti (JavaDelegate) is running I get a progress bar which is updated now and then.
2) Of course I don't want to limit process definition to include only JavaDelegates. So I also want to display information about how many
activities there are defined in a process, how many of them have already run (so I can see how many left to run) and what is the current activiti name running.

So far what I have done to achieve it is that I have my own service layer which starts the process and it implements the ActivitiEventListener.
On PROCESS_STARTED I do:

<code>
List<String> completedTasks = new ArrayList<String>();
runtimeService.setVariable(event.getExecutionId(), "completed-tasks", completedTasks);
</code>

and on ACTIVITI_COMPLETED I do:

<code>
List<String> tasks = (List<String>) runtimeService.getVariable(event.getExecutionId(), "completed-tasks");
if (ActivitiActivityEvent.class.isAssignableFrom(event.getClass())) {
   ActivitiActivityEvent activitiEvent = (ActivitiActivityEvent) event;
   tasks.add(activitiEvent.getActivityName());
}
</code>

So here is my problem:

1) The process can be asynchronous so my assumption (have not verified it yet) is that event.getExecutionId() will be different for each activity ?
In that case - is there a way to get the "most parent" id of the process which would be the BPMN execution ID ?
2) A process defined in BPMN file can be set to be synchronous - so it seems I cannot use the execution query as it will be empty …

The bottom line is - how do I get at any point the number of activities in a process with ability to say which ones have already completed ?



Many thanks for your input - much appreciated.

Adrian

[warper]

Hi Adrian!

is there a way to get the "most parent" id of the process which would be the BPMN execution ID

Yes. You can traverse from any execution up by getSuperExecution()/getParent()
AFAIK process_instance_id is execution_id of first/top process execution.

You can do similar search directly in database, but I have no ready selects for it.

The bottom line is - how do I get at any point the number of activities in a process with ability to say which ones have already completed ?

You can write counters into separate data store, not into process variables, and not related to activiti transactions.

[serid]

Hi,

Thanks for prompt reply.

Indeed it looks like proc_inst_id_ is execution_id_ which is the top process execution (looked at act_hi_actinst table) …
If that is the case than my previous code which uses event.getExecutionId() should work regardless whether the process uses asynchronous activities or not and seems to be the best bet I can think of right now without creating additional DB table to store it. Of course I will need to test it but my testing capabilities are rather thin right now as I still don't have the full picture of the Apache Activiti cause it's all new to me.


Thanks very much for all your help.

Adrian