Currently i have to define each process variable before execution of the process and pass it to the startProcessInstanceBy* functions of Activiti. I wonder if it's possible to define these with default values in the process definition XML? This way i can avoid changing Java code if my process needs new variables for execution. Can i achieve this somehow?
you can use a script task just after your start event to set up these variables
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I have an Apache Beam job running on Google Cloud Dataflow, and as part of its initialization it needs to run some basic sanity/availability checks on services, pub/sub subscriptions, GCS blobs, etc. It's a streaming pipeline intended to run ad infinitum that processes hundreds of thousands of pub/sub messages.
Currently it needs a whole heap of required, variable parameters: which Google Cloud project it needs to run in, which bucket and directory prefix it's going to be storing files in, which pub/sub subscriptions it needs to read from, and so on. It does some work with these parameters before pipeline.run is called - validation, string splitting, and the like. In its current form in order to start a job we've been passing these parameters to to a PipelineOptionsFactory and issuing a new compile every single time, but it seems like there should be a better way. I've set up the parameters to be ValueProvider objects, but because they're being called outside of pipeline.run, Maven complains at compile time that ValueProvider.get() is being called outside of a runtime context (which, yes, it is.)
I've tried using NestedValueProviders as in the Google "Creating Templates" document, but my IDE complains if I try to use NestedValueProvider.of to return a string as shown in the document. The only way I've been able to get NestedValueProviders to compile is as follows:
NestedValueProvider<String, String> pid = NestedValueProvider.of(
pipelineOptions.getDataflowProjectId(),
(SerializableFunction<String, String>) s -> s
);
(String pid = NestedValueProvider.of(...) results in the following error: "incompatible types: no instance(s) of type variable(s) T,X exist so that org.apache.beam.sdk.options.ValueProvider.NestedValueProvider conforms to java.lang.String")
I have the following in my pipelineOptions:
ValueProvider<String> getDataflowProjectId();
void setDataflowProjectId(ValueProvider<String> value);
Because of the volume of messages we're going to be processing, adding these checks at the front of the pipeline for every message that comes through isn't really practical; we'll hit daily account administrative limits on some of these calls pretty quickly.
Are templates the right approach for what I want to do? How do I go about actually productionizing this? Should (can?) I compile with maven into a jar, then just run the jar on a local dev/qa/prod box with my parameters and just not bother with ValueProviders at all? Or is it possible to provide a default to a ValueProvider and override it as part of the options passed to the template?
Any advice on how to proceed would be most appreciated. Thanks!
The way templates are currently implemented there is no point to perform "post-template creation" but "pre-pipeline start" initialization/validation.
All of the existing validation executes during template creation. If the validation detects that there the values aren't available (due to being a ValueProvider) the validation is skipped.
In some cases it is possible to approximate validation by adding runtime checks either as part of initial splitting of a custom source or part of the #Setup method of a DoFn. In the latter case, the #Setup method will run once for each instance of the DoFn that is created. If the pipeline is Batch, after 4 failures for a specific instance it will fail the pipeline.
Another option for productionizing pipelines is to build the JAR that runs the pipeline, and have a production process that runs that JAR to initiate the pipeline.
Regarding the compile error you received -- the NestedValueProvider returns a ValueProvider -- it isn't possible to get a String out of that. You could, however, put the validation code into the SerializableFunction that is run within the NestedValueProvider.
Although I believe this will currently re-run the validation everytime the value is accessed, it wouldn't be unreasonable to have the NestedValueProvider cache the translated value.
Is it possible to perform an action once a batch Dataflow job has finished processing all data? Specifically, I'd like to move the text file that the pipeline just processed to a different GCS bucket. I'm not sure where to place that in my pipeline to ensure it executes once after the data processing has completed.
I don't see why you need to do this post pipeline execution. You could use side outputs to write the file to multiple buckets, and save yourself the copy after the pipeline finishes.
If that's not going to work for you (for whatever reason), then you can simply run your pipeline in blocking execution mode i.e. use pipeline.run().waitUntilFinish(), and then just write the rest of your code (which does the copy) after that.
[..]
// do some stuff before the pipeline runs
Pipeline pipeline = ...
pipeline.run().waitUntilFinish();
// do something after the pipeline finishes here
[..]
A little trick I got from reading the source code of apache beam's PassThroughThenCleanup.java.
Right after your reader, create a side input that 'combine' the entire collection (in the source code, it is the View.asIterable() PTransform) and connect its output to a DoFn. This DoFn will be called only after the reader has finished reading ALL elements.
P.S. The code literally name the operation, cleanupSignalView which I found really clever
Note that you can achieve the same effect using Combine.globally() (java) or beam.CombineGlobally() (python). For more info check out section 4.2.4.3 here
I think two options can help you here:
1) Use TextIO to write to the bucket or folder you want, specifying the exact GCS path (for e.g. gs://sandbox/other-bucket)
2) Use Object Change Notifications in combination with Cloud Functions. You can find a good primer on doing this here and the SDK for GCS in JS here. What you will do in this option is basically setting up a trigger when something drops in a certain bucket, and move it to another one using your self-written Cloud Function.
Would the use of variables be the best method? In the similar way the EQQPIFJC does to manipulate JCL/TWS variables?
There are 2 main possibilities to pass some variables to a submitted job stream:
Replace the value in a variable table, and submit the job stream (occurrence). If you need to submit the same job stream multiple time, this method may be difficult to manage, since you cannot change the variable table value until the job stream has completed.
Use a JCL preparation job at the beginning of your job stream and then submit the job stream and use the JCL Preparation PIFs to specify your variable values or edit the job JCLs.
I'm using TFS2015 update 1. I want to pass information from one build step to the next, how is this possible?
That seems like a very simple task, but I can't figure out how that's suppose to work. Passing a variable to a build step is easy, but passing information from one step to the next seems to be impossible. I hope I'm wrong.
You can call the task.setvariable Logging Command, which sets a variable in the variable service of taskcontext. The first task can set a variable, and following tasks are able to use the variable. The variable is exposed to the following tasks as an environment variable.
Example:
##vso[task.setvariable variable=testvar;]testvalue
A custom plugin we wrote for an older version of Jenkins uses an EnvironmentContributingAction to provide environment variables to the execution so they could be used in future build steps and passed as parameters to downstream jobs.
While attempting to convert our build to workflow, I'm having trouble accessing these variables:
node {
// this step queries an API and puts the results in
// environment variables called FE1|BE1_INTERNAL_ADDRESS
step([$class: 'SomeClass', parameter: foo])
// this ends up echoing 'null and null'
echo "${env.FE1_INTERNAL_ADDRESS} and ${env.BE1_INTERNAL_ADDRESS}"
}
Is there a way to access the environment variable that was injected? Do I have to convert this functionality to a build wrapper instead?
EnvironmentContributingAction is currently limited to AbstractBuilds, which WorkflowRuns are not, so pending JENKINS-29537 which I just filed, your plugin would need to be modified somehow. Options include:
Have the builder add a plain Action instead, then register an EnvironmentContributor whose buildEnvironmentFor(Run, …) checks for its presence using Run.getAction(Class).
Switch to a SimpleBuildWrapper which defines the environment variables within a scope, then invoke it from Workflow using the wrap step.
Depend on workflow-step-api and define a custom Workflow Step with comparable functionality but directly returning a List<String> or whatever makes sense in your context. (code sample)
Since PR-2975 is merged, you are able to use new interface:
void buildEnvVars(#Nonnull Run<?, ?> run, #Nonnull EnvVars env, #CheckForNull Node node)
It will be used by old type of builds as well.