Manage and Access MATLAB Job Scheduler Job History
MATLAB® Job Scheduler clusters can save job history data. You can use job history data to gain insights into cluster usage.
Enable Saving Job History
MATLAB Job Scheduler clusters with MATLAB Parallel Server™ release R2024a or later save job history data 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 data 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 head node. 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 with filenames
numbered 0 through 9. Each CSV has a 1 GB size limit. By default, when the active job history
CSV file, job_history.0.csv, reaches 1 GB in size, the scheduler archives the
file as job_history.1.csv and continues to write to a new
job_history.0.csv file. Simultaneously, the scheduler deletes the oldest
file job_history.9.csv and renames 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 ten files in the database folder cannot exceed 10 GB.
If the scheduler encounters any issues when you set up job history saving, such as a
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. Here 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
This table lists the data contained in a job history CSV file.
| Data Name | Data Type | Description |
|---|---|---|
| User | String | Owner of the task |
| Version | String | MATLAB version of the task, for example R2024a |
| Mode | String | Execution mode of the job associated with the task. Possible values are:
|
| Type | String | Type of the job associated with the task. Possible values are:
|
| Job | Integer | ID number of the job associated with the task |
| Task | Integer | ID number of the task |
| Attempt | Integer | Number of the task attempt |
| Start | Double | Start time of the task, given as the number of seconds that have elapsed since the epoch of January 1, 1970, 00:00:00 UTC |
| Duration | Double | Duration of the task, measured in seconds |
| State | String | Finished state of the task. Possible values are:
|
| Worker | String | Name of the worker that ran the task |
| Host | String | Host machine of the worker that ran the task |
You can use any program that can read CSV files to view, extract, and analyze data from the job history files.
