I am trying to implement parallelization within talend. I have it working, but now I don't know how to connect the parallelization work to the next part. Usually, you would click on the previous block and select OnSubjobOk. That option doesn't appear. Is there another component that I need to add that I don't know about?
Under the basic settings of tParallelize you would find the option Wait For. This have two options -
end of first subjob: sequence the relevant subjob to be executed at
the end of the first subjob
end of all subjobs: sequence the relevant subjob to be executed at the end of all
subjobs.
So, all you have to do is connect your next part - your sub job with the tParallelize component by selecting the trigger - synchronize(wait for all). This would ensure once all the parallel subjobs/components are executed the sub job connected with synchronize(wait for all) will be executed.
Related
Please see the image.
So here is a flow, wherein the first component executes a database query to find QAR_ID (single row), if it is found then all well. I am trying to put error handling into this. When no rows are found, it directs to tJava_11 which raises an java exception and that gets logged by another tJava component.
The problem I am facing is when it goes to error handling flow, it logs the error and just goes to the post-job section. However, I want Talend to take the OnSubJobOk route so that it continues with other steps instead of directly jumping to post-job section.
I know this is possible using subjobs but I don't want to keep creating 'n' number of subjobs.
Is there any way this can be done in the same job?
You could remove the runif and handle both scenarios in the get_QAR_ID into context component. ie query the database component's NB_LINE after variable, if it's <1 raise the error, else set the value. Your job would then flow to the onSubjobOk.
You can do something like this :
In tJava_1 you do your error logging if no row is returned by your query, and you continue to the next subjob. No need to throw an exception here only to catch it immediately after.
If any row is found, you continue to the next subjob (tJava_2) with an If trigger.
My company has a couple of joblets that we put in new jobs to do things like initialization of variables, get system information from the database and sending out error / warning emails. The issue we are running into is that if we go ahead and start creating the components of a job and realize that we forgot to include these 3 joblets, we have to basically re-create the job to ensure that the joblets are added first so they run first.
Is there any way to force these joblets to run first and possibly also in a certain order before moving on to the contents of the job being created? Please let me know if there is any information you may need that I'm missing as I have only been using Talend for a few days. The rest of the team has not been using it too much longer than I have, so they do not have the answer I'm looking for either. Thanks in advance!
In Joblets you can use the components Trigger_Input and Trigger_Output as connection-points for on subjob OK triggers. So you can connect joblets and other components in a job with triggers. Thus enforcing execution order.
But you cannot get a on subjob OK trigger from a tPreJob. I am thinking on triggering from a tPreJob to a tWarn (on component OK) and then from tWarn to the joblet (on subjob OK).
I need to execute a sequence of steps a specific number of times.. any pointers on what is the best way to do this in Spring Batch. I am able to implement executing a single step 'x' times. but my requirement is to execute a set of steps - based on a condition 'x' times.Any pointers will help.
Thanks
Lakshmi
You could put all steps in a job an start the whole job several times. There are different ways, how a job actually is launched in spring-batch. have a look at joboperator and launcher and then simply implement a loop around the launching of the job.
You can do this after the whole spring-context is initialized, so there will be no overhead concerning that. But you must by attention about the scope of your beans, especially the reader and writers.
Depending on your needs concerning failurehandling and restart, you also have pay attention how you manage the execution context of your job and steps.
You can simulate a loop with SB using a JobExecutionDecider:
Put it in front of all steps.
Store x in job execution context and check for x value into
decider: move to 'END' if x equals desidered value or increment it
and move to first step of set.
After last step move back to start (the decider).
In Talend Open Studio, how do I execute only one of my components? If I click Run, all active components will run. So far the only way I know to execute a single component is to deactivate all others in the Job.
How can I execute one component or subjob without having to deactivate all the other components in the job?
Well, I'm afraid you can't.
Two possible solutions :
Deactivating unwanted components / subjobs (like you already stated)
Decompose your job into multiple jobs. This may give you more flexibility. You can then use the tBufferOutput component to pass information from the child job to his parent.
Please correct me if I am wrong.
What I know about triggers is that they are triggered by events (Insert, Update, Delete). So we can run a stored procedure etc.. in the trigger.
This will give the application a good responsiveness because the query that the user interacts with, is quite small and this "other" longer time taking stuffs are taken care by the server internally as a separate task.
But I do not know about how the the triggers are handled inside the server. What I exactly want to know is what would happen in scenarios as given below.
Take Insert after trigger. And take trigger is executing a longer stored procedure. Then in the middle of the trigger there can be another insert. What I want to know is what will happen to that second trigger. If possible can I make that second trigger ignore itself.
marc_s has given the correct answer. I will copy it for the sake of completeness.
TRIGGERS ARE SYNCHRONOUS
If you want to have a asynchronous functionality go for a SQL broker implimenation.
Triggers are triggered by events - and then they are executed - right now. Since you cannot control when and how often they are triggered, you should keep the processing in those triggers to an absolute minimum - I always try to make - at most - an entry into another table (an "Audit" table) or possibly put a "marker" row into a "command" table. But the actual processing of that info - running stored procedures etc. - should be left to an outside job - don't do extensive processing in a trigger! This will reliably KILL all your performance\responsiveness.