Fetching currently executing tasks for a flow - camunda

We just started with camunda and looking for api which can give us all tasks which are currently getting executed. I know that it does provide state information like PENDING and COMPLETED but I am particularly interested in "EXECUTING" state. Is there a way to find it? Is it safe to assume that if task is not in COMPLETED/ERROR and PENDING state, then it is getting executed?
note: using camunda 7.9.0 - Jboss packaging

Assuming that you are talking about user tasks, the safest way is to perform a claim() on the task when a user starts working.
Then you can assume that every task that has an assignee is currently being worked on.

Related

Why is my Web Job remain running even after it finished the task

I published my web job (trigerred type) in azure and it keep on running after my team add Console.Readline(). it seems the culprit here.
The Job Finished after done it's task and not waiting for the cpu.
Please check the below following steps that helps to fix the issue:
Console.ReadLine() should not be present in the Web Job Code.
Recheck the code if there is any infinite loop running which causes this kind of issue.
There are many differences between the Triggered and Continuous Web Job that gives an idea on stopping the Web Jobs. For that information, visit this SO Answer given by #Jay Gong.
I published my web job (trigerred type) in azure
Actually, Web Jobs main aim is of 2 ways either in triggered or Continuous running.
As you didn't give any code snippet, the ideal way is to use the host.Run() for the Triggered Web Jobs and host.Start() for the Continuous Web Jobs Type in the program.cscode file.

How to complete a service task using camunda rest api

I am using Camunda workflows to automate various processes. I have come across a scenario where the process is not moving from a service task. Usually, we call the task/{taskid}/complete to complete the task, but since the process is stuck on a service task, I am not able to complete that task. Can anybody help me find a way to complete the service task?
You are using a service task. That basically means "a machine should do something". The "normal" implementation is to provide code (a java Delegate or a connector endpoint) that is called by the process engine to execute this task.
The alternativ is to use the "external task" pattern. Think of external tasks as "user tasks for computers". So the process waits, tells subscribed clients that a job is to be done and waits for their completion.
I suppose your process uses the second option? (you can check in the modeler under "Implementation"). So completion can be done through the external task API, see docs.
/external-task/{id}/complete
If it is a connector then you likely will see when checking the log that retries have occurred and that the transaction rolled back. After addressing the underlying issue the service task (email) should be sent without explicitly triggering the service task and the following user task (Approval) should be created.

Is there a way to finish manual task synchronously (without waiting for async result) if some precondition is satisfied?

I am using AWS SWF and flow framework. I wanted to make my activities idempotent so that a workflow can be restarted from the beginning after any failure. Many of the activities are manual tasks (#ManualActivityCompletion) which need to be completed asynchronously.
Is there a way to finish manual tasks like normal tasks if I know that it is already complete? This way a new manual task will not be scheduled everytime the workflow is retried.
Or, is there a way to retry a workflow so that it starts from the point it failed?
Currently there is no way to override activity completion behavior at runtime. The work around is to complete activity using ManualActivityCompletionClient from within activity implementation.
There is no supported way to retry workflow to start from the point of failure.

How to implement SWF exponential retries using the aws sdk

I'm trying to implement a jruby SWF activity worker using AWS SDK v2.
I cannot use the aws-flow-ruby framework since it's not compatible with jruby(forking), so I wrote a worker that uses threading.
https://github.com/djpate/jflow if people are interested.
Anyway, in the framework they implement retries and It seems that it actually schedules the same activity later if an activity failed.
I found everywhere in the AWS docs and cannot find how to send that signal back to SWF using the SDK http://docs.aws.amazon.com/sdkforruby/api/Aws/SWF/Client.html
Anyone know where I should look?
From the question, I believe you are somewhat confused about what SWF is / how it works.
Activities don't run and are not retried in isolation. Everything happens in the context of a workflow. The workflow definition tell you when to retry and how to behave if activities fail/timeout etc.
The worker that processes the workflow definition and schedules the next thing that needs to happen is referred to as a decider. (you will see decider and workflow used interchangeably). It's called a decider because based on the current state it makes the decision on what the next activity that needs to be scheduled is. The decider normally takes the workflow history as input when making this input.
In Flow for example, the retry is encoded in the workflow logic. Basically if the activity fails you can just schedule it.
So to finally answer your question: if your target is to only implement the activity workers you don't need to implement any retry logic as that happens at the decider level. You should make sure that the activities are compatible with the decider (you need to make sure the history and the input/output convention are the same).
If your target is to implement your own framework on top of SWF you need to actually do the hard work needed to make the decider work.

aws swf - get workflow execution id from within the workflow

I am using Amazon SWF service to automate some recurring tasks.
I am trying to use signals to execute some commands on remote machines. After the commands are finished executing, I'd like to send a signal back to the workflow to indicate success or failure.
The question is how can I find the workflow execution id programmatically? This is required for the remote machines to send a signal.
Thanks
Per http://docs.aws.amazon.com/AWSRubySDK/latest/AWS/SimpleWorkflow/WorkflowExecution.html, shouldn't
your_workflow_execution_variable.run_id
get you exactly what you're looking for?