Enable Job History Logging

MATLAB Job Scheduler clusters with MATLAB Parallel Server™ release R2024a or later save job history information by default. To benefit from job history saving, update the MATLAB Parallel Server version of your cluster to the R2024a release or later.

You can control the saving of job history information using the SAVE_JOB_HISTORY parameter in the mjs_def file. For more information about the mjs_def file, see Define MATLAB Job Scheduler Startup Parameters.

Manage Job History Files

The MATLAB Job Scheduler saves job history data to the job_history folder in the CHECKPOINTBASE location on the headnode. Check the mjs_def file to find the location of the checkpoint folder.

The scheduler saves job history data to a set of ten rotating CSV files. By default, when the active job history CSV file reaches 1 GB in size, the scheduler archives the file. In practice, when the active job history file, job_history.0.csv, reaches the 1 GB size limit, the scheduler archives the file as job_history.1.csv and continues to write to the new job_history.0.csv file. Simultaneously, the scheduler deletes the oldest file job_history.9.csv and rotates the existing job history files as follows: job_history.1.csv becomes job_history.2.csv, job_history.2.csv becomes job_history.3.csv, and so on, until job_history.8.csv becomes job_history.9.csv. The combined size of all files in the database folder is limited to 10 GB.

The combined size of all files in the database folder is limited to 10 GB.

If the scheduler encounters any issues during the setup of job history logging (for example, failure to create a file or write to disk), the startjobmanager command returns an error.

Read Job History File

File system permissions allow only the admin user to access the job history files.

Each job history entry corresponds to the completed execution of a task. Below is a snippet of a job history CSV file.

User,Version,Mode,Type,Job,Task,Attempt,Start,Duration,State,Worker,Host
user2,R2024a,batch,independent,1,1,1,1697120886.345,45.868,finished,mjs-worker-1,wkr1hostid
user5,R2024a,interactive,parpool,2,39,1,1697121035.862,72.551,finished,mjs-worker-25,wkr25hostid
user5,R2024a,interactive,parpool,2,115,1,1697121035.862,72.49,finished,mjs-worker-94,wkr94hostid
user5,R2024a,interactive,parpool,2,2,1,1697121035.862,72.613,finished,mjs-worker-10,wkr10hostid
user5,R2024a,interactive,parpool,2,3,1,1697121035.862,72.621,finished,mjs-worker-100,wkr100hostid
user5,R2024a,interactive,parpool,2,40,1,1697121035.862,72.585,finished,mjs-worker-26,wkr26hostid

The first row in the CSV file lists the names of the data columns.

You can use any program that can read CSV files to view, extract, and analyze data from the job history files.