How to Use the Command 'sstat' (with examples)

‘sstat’ is a command-line tool provided by SLURM (Simple Linux Utility for Resource Management), which is an open-source workload manager. The ‘sstat’ command is specifically used for gathering and displaying information about running jobs within the SLURM workload management system. This tool serves as a means of tracking and analyzing the performance and usage of computing resources by active jobs, which can be highly valuable for users who need to monitor the real-time status of their jobs, optimize resource usage, and debug performance issues.

Use case 1: Display Status Information of a Comma-Separated List of Jobs

Code:

sstat --jobs=job_id

Motivation:

One of the most common needs for users within a SLURM-managed environment is to quickly check the status and other key metrics of their currently running jobs. This command allows users to specify one or more job IDs to retrieve concise information about them. This is essential for users who manage multiple jobs simultaneously and need a fast way to keep track of their progress and status without sifting through massive logs or outputs.

Explanation:

• sstat: This is the command being invoked to check the status of the jobs.
• --jobs=job_id: This option specifies which jobs you would like to check the status of. This can be a single job ID or a comma-separated list of multiple job IDs, allowing flexibility and scope tailored to your needs.

Example Output:

       JobID       User  MaxVMSize     AveCPU 
------------ ----------- ---------- ---------- 
 12345.batch     johndoe      2000M    00:10:23 
 12345.0        johndoe       1800M    00:09:15

This output provides key information such as the job ID, user, maximum virtual memory size, and average CPU time consumed by the specified jobs.

Use case 2: Display Job ID, Average CPU, and Average Virtual Memory Size with Pipes as Column Delimiters

Code:

sstat --parsable --jobs=job_id --format=JobID,AveCPU,AveVMSize

Motivation:

When dealing with data output that needs to be further processed or integrated into other systems, script-friendly formats are invaluable. This command outputs the status information with pipe delimiters, which makes it easier for automated systems to parse and process the data. This can be particularly helpful in automated report generation or data analysis scripts, where standard delimiters can reduce parsing errors and integration issues.

Explanation:

• sstat: As before, this is the command being used to gather the job status.
• --parsable: This flag configures the output to be easily parseable by using pipe (|) characters as the delimiters between columns.
• --jobs=job_id: Specifies the identifiers of the jobs for which information is being requested, supporting multiple entries as a comma-separated list.
• --format=JobID,AveCPU,AveVMSize: Determines the precise columns of data to be returned in the output, focusing here on the job ID, average CPU usage, and average virtual memory size to provide focused metrics.

Example Output:

12345|00:10:23|1900M
12346|00:09:45|1750M

Each line represents a job with its associated ID, average CPU time, and average virtual memory size, separated by pipes for easy further processing.

Use case 3: Display List of Available Fields

Code:

sstat --helpformat

Motivation:

Understanding what kind of data is available for jobs running under the SLURM workload manager is a crucial step in customizing the output to suit specific requirements. Calling sstat with the --helpformat option gives a list of all possible fields that can be included in the command’s output. This is particularly useful for users looking to tailor their information retrieval to specific needs, whether for monitoring a particular resource or integrating with other workflows.

Explanation:

• sstat: This is the main command used for querying job status.
• --helpformat: A special flag that outputs a list of all available data fields that can be requested from sstat. This is purely informational and does not require a job ID.

Example Output:

JobID, JobName, User, Nodes, MaxVMSize, AveCPU, State, ...

This output lists all the columns you can request when using sstat, helping you decide which metrics are most relevant for your current needs.

Conclusion:

The ‘sstat’ command in SLURM provides detailed and customizable insights into running jobs, facilitating effective monitoring and management of computing resources. Whether you need a quick overview, a script-friendly format for further processing, or awareness of available data fields, each use case empowers you to harness SLURM’s capabilities to better align with your operational requirements. By leveraging these powerful functionalities, SLURM users can make informed decisions and optimize the performance and efficiency of their job workflows.