New post
Question
· Sep 11

Determine Job/Process State

#Key Question #InterSystems IRIS

Hi, I'm working on a large extraction from a database and need to parallelize the processes during the extraction.

Here's what happens:

  1. The user starts the extraction from.
  2. Several jobs are started using the Job <Method> instruction.

At the end, the user expects to find a document containing the results of all the extractions. What I'd like to do is start a new job that checks whether the previously started jobs have finished or are still working and consequently produce the document.

After starting each job, using $ZCHILD instruction I can get the ID of the last started job. I might create a list containing all these IDs, pass it to a method that checks if these jobs are still active and eventually produce the final result. The problem is that I can't figure out how to determine the status of a job given its Job ID.

I may use the retrieved ID to define a Job object using the command:

SET JobObj = ##class(%SYS.ProcessQuery).%OpenId($ZCHILD)

But after that, I can't figure out how to derive the job's status. There is a State property, but I can't understand which value indicates that the job has finished.

Thank you in advance if you can help me!

Discussion (8)4
Log in or sign up to continue
Pietro Di Leo · Sep 12

Hi Luis, thanks for responding me. 

However, I can't find the DEQ state in the documentation. 

Available states for the "State" property of the %SYS.ProcessQuery class are: 

LOCK - Executing a Lock command
OPEN - Opening a device
CLOS - Closing a device
USE - Using a device
READ - Read command
WRT - Write command
GET - Executing a $Get on a global
GSET - Setting a global
GKLL - Killing a global
GORD - $Order on a global
GQRY - $Query on a global
GDEF - $Data on a global
ZF - Executing a $ZF command
HANG - Executing a Hang command
JOB - Executing a Job command
EXAM - Executing a variable exam
BRD - Executing a broadcast
SUSP - Process is suspended
INCR - Executing a $Increment
BSET - Set $bitset
BGET - get $bitset
EVT - Waiting on event RUN - Process is running
 

0 0
Stuart Salzer · Sep 18

If you want to wait for a group of child jobs to finish, you can do this with simple (incremental) locks:

Each child begins with:

    LOCK +^JOIN($JOB) SET ^JOIN($JOB)=$HOROLOG

and ends with:

    KILL ^JOIN($JOB) LOCK -^JOIN($JOB)

The parent can test that all the children have finished with:

    LOCK ^JOIN

    IF $DATA(^JOIN)=0 WRITE !,"One of the children died!"

There are lots of ways to expand on this. Add timeouts on the locks. Add a subscript before $JOB in whatever global you use to communicate the process join to have multiple simultaneous process joins. The parent can also look inside the ^JOIN global to diagnose which process died and possibly restart it.

1 0