[resolved] childjobs/subjobs

One Star

[resolved] childjobs/subjobs

Hi all, 
I create a simple Rest job using TOS, it merely implements CRUD operations on one single table in my DB, but, as you can see in the screensot, it's alreay huge and it'd be complicated to enrich it. 
I think there is a way to customize ws, creating subjobs, child jobs that could be called from a parent job... 
May I have some hints.. 
Thank you 

Accepted Solutions
Sixteen Stars

Re: [resolved] childjobs/subjobs

It looks like you have done everything right, but I omitted to tell you to set the "Propagate the child result to the output schema" to true. This is on the "Advanced settings" of the tRunJob.

This should sort it. 
Sorry I forgot to mention this, but hopefully you have picked up a few things by hacking away :-)

All Replies
Sixteen Stars

Re: [resolved] childjobs/subjobs

Wow that is busy :-)
You can use tRunJob components to separate out some of the logic if you like.
I notice that you have your connection being started before the tRESTRequest. You have to keep in mind that services are always on. They don't start and stop. So this means that your connection will be created when you initiate the Service in your Karaf (runtime) and it will not be renewed. Connections are a bit of a pain like this. You may want to investigate using connection pooling with Karaf and Spring to help solve this problem.
One Star

Re: [resolved] childjobs/subjobs

Thank you for your quick answer, 
I tried to use tRunJob, but I don't seem to understand how does it work.
 I have my endpoint Rest in my trestRequest "http://localhost:8182/getActors" for example,  then I want to have a childJob  which should allow me to get an actor by its id, but how can I pass the parameter "id" from the parent to the child ( I thought about context variable but not sure...) and how can I reconstruct the endpoint REST "http://localhost:8182/getActor/{id}" (I tried putting a new trestrequest with the same port but I had a conflict , if I change the port, that makes 2 different URLs, hence I can't access the childjob (assuming it's the correct way to proceed)  unless I retape the url which isn't what I want to do)
Thank you for your time.
Regards
Sixteen Stars

Re: [resolved] childjobs/subjobs

This is not that hard......but it is not necessarily that easy. It depends on your Talend experience. Basically you can use Context variables to send data to child jobs and you can return data to the parent job using the tBufferOutput component. I have several tutorials where I use this paradigm, but they are not basic tutorials. Take a look at this one (which is not a simple tutorial, but the content doesn't really matter) and search for "tRunJob" and "tBufferOutput". Read around those areas and you may be able to extrapolate for your purposes.
One Star

Re: [resolved] childjobs/subjobs

well, here's what I've done, but in vain
I'm not getting errors but nothing happens either... not even logs;

and I'm just trying to  retrieve all my films (I'm not even using variables) 
Regards
One Star

Re: [resolved] childjobs/subjobs

*and for my Talend experience, I'm really a perfect newbie, just making my first steps Smiley Tongue
so please excuse my questions, i know they are very very basics Smiley Sad
Sixteen Stars

Re: [resolved] childjobs/subjobs

In the parent job, you need to first capture the row variable for getFilms. If the variable is called "myVar", it will be called something like getFilms.myVar
In your child job, you need to create a context variable of the same type as getFilms.myVar. Now in the parent, go to your tRunJob and click on the green + under the context variable table. Select the variable you have just created in the child job. Then, in the values field, put getFilms.myVar (or whatever your row.column name is). That will pass the value to your child job.
In your child job, you can start with the tMySQLInput (get rid of the tFlowToIterate). In your tMySQLInput SQL, use your context variable for whatever you need. Remember that you are writing Java that generates a String. That can be tricky. 
Next you need to set the schema of the tRunJob in your parents job to be the same as the schema of the tBufferOutput.
Put in a tLogRow in to your child job to see what is happening. 
You will need to play around for a bit on this and there is a lot that you have wrong at the moment. But if you follow the steps above and read around the area, you should get it working.
One Star

Re: [resolved] childjobs/subjobs

Hi, 
after some readings, I managed to retrieve all films stored in my DB (just using tLogRow, I tried to use trestrequest-->trunjob-->trestresponse to print the result in my browser but no result, it remains empty :\)
I applied what you've explained to me to pass a variable from my parent job to its child, here's what I've done:
1. in the parent, I captured the variable getFilmId.FilmId

2. I created the same context variable in both parent and child jobs

*couldn't know how to set the script code to "context.FilmId" as mentioned in some tutorials 
but I got that error: 

however, I can get rid of this error if I use "context.FilmId" as a value for the captured variable "FilmId" in the parent Job (which seems to be kind of illogic since I want to capture the id from my tRestRequest!!); the output is null in my child :\ 

could you enlighten me please
Thank you 
Sixteen Stars

Re: [resolved] childjobs/subjobs

Your Job should not return the error message you are getting if "getFilmId.FilmId" actually exists. I take it you have set up your tRESTRequest to provide the FilmId in the Endpoint? I think you implied that what you had was working, so you must have done this. But you will need to ensure that the getFilmId.FilmId {row.column} exists and is named exactly like that.
I have quickly knocked up a simple version of what you are doing and this works. The first image shows the configuration of the tRESTRequest component. Remember the names are very important.
   
The second image shows the row.column value I have used. Notice the "row" is named exactly the same as the "Output Flow" and the "column" is named exactly the same as the name (inside brackets {}) of the "URI Pattern"
One Star

Re: [resolved] childjobs/subjobs

you were right, I have set up my tRestRequest to provide the FilmId in the Endpoint.
with your explanations, I managed to rectify my erros, the parent and child jobs are working perfectly now, 
I still have one little problem, I canno't display the results in my browser, the are displayed via the tLogRow component, as if mt tRestResponse comonent doesn't exist.. 
** I've put the tMysqlConnection and tMysqlCommit components in the sujobs so as to avoid to start connection before the tRestRequest..is it a better idea??! 
please find attached some screenshots of what I've done, 
Regards  
Sixteen Stars

Re: [resolved] childjobs/subjobs

All of your childjobs need to link to a tRestResponse in order to send the output back to the calling device. If you have not done this already, you will need to make sure that the schema that you use in your tBufferOUtput for each childjob is copied and configured in the tRunJob component. Then you can simply return the result of the childjob to the next component. You may wish to configure a standard/generic XML format to put you data in before sending it back to each of the tRESTResponse components.
When it comes to web services and connections, I usually make use of connection pooling with Spring in the Karaf. This enables management of lots of connections being opened close and means you can mitigate for high loads. It is not a simple thing to do though. So for the moment, I think that putting your connections in your subjobs *should* be OK. I have not tested this, so can't guarantee it.
One Star

Re: [resolved] childjobs/subjobs

Well, I tried to solve this one by myself but I couldn't.
I've done like you said, I copied the tBufferOutputbuffer schema in the tRunJob component, and linked the tRunJob to the tRestRequest component, however, I still have my results just in the logs :\
please find attached the screenshots of a sample af what I've done
Subjob Schema:

tBufferOutput Schema:

tRestResponse Schema:
Regards
Sixteen Stars

Re: [resolved] childjobs/subjobs

It looks like you have done everything right, but I omitted to tell you to set the "Propagate the child result to the output schema" to true. This is on the "Advanced settings" of the tRunJob.

This should sort it. 
Sorry I forgot to mention this, but hopefully you have picked up a few things by hacking away :-)
One Star

Re: [resolved] childjobs/subjobs

Thank you for the hint :-) 
it works perfectely