PowerShell CLI - Use Cases - Manage the CLI Cache

Starting Situation

• The PowerShell CLI interacts with the JobScheduler Master to retrieve information about available objects such as jobs, job chains, orders etc.
• For environments with a large number of jobs, e.g. some 5000 jobs and more, repeatedly retrieving the available objects from the Master creates some overhead.
• The PowerShell CLI provides a caching mechanism to reduce this overhead. Job-related objects are retrieved just once and are stored in a cache that is used for subsequent operations.
• The cache is not applicable if up-to-date information is required.

Use Cases

When to use the cache

• The cache improves the speed of a number of operations. This applies in particular to pipelined operations.
  • Approx. increase in speed of 50% for single operations.
  • Mulitplied increase in speed when using pipelined operations:
    • Get-JobChain /some_folder/some_job_chain | Get-Job | Get-Task | Stop-Task
    • The pipelined operations force the JobScheduler Master to be accessed three times to retrieve the respective objects. Resolving objects by use of the cache improves speed tremendously.
• The cache is activated by the Get-Status and Show-Status cmdlets. Subsequent calls to these cmdlets update the cache.

• The cache is available for the following cmdlets:

  • Get-Job
  • Get-JobChain
  • Get-Order

  • Get-Version
• The Get-Task cmdlet by default does not make use of the cache. However, it can be used with the -UseCache switch to enforce cache usage.

When not to use the cache

• If up-to-date information is required then it is preferable
• Use of the cache can be deactivated with 
  • the User-Master cmdlet and the -NoCache switch;
  • the Get-Status cmdlet and the -NoCache switch.

• The Get-Task cmdlet by default does not make use of the cache.