Working with Queues

This topic describes how to work with job queues.

Queues consist of functionally related jobs that can be managed together as a group. Creating queues allows you to efficiently set priorities per job groups as opposed to single jobs which can be extremely important in complex systems executing a large number of asynchronous tasks.

Note:

When upgrading from a previous version, Zend Server will automatically assign existing jobs to the 'default' queue.

This procedure will describe how to create a new queue.

Instructions on how to complete a procedure

To add a new job queue:

  1. In the Zend Server UI, go to the Job Queue | Queues page.
  2. In the Action bar, click Add Queue.
    The Add Queue page is displayed.
  3. Configure the new job queue:
    • Queue Name - Name the new queue.
    • Priority - Set a priority for the queue: Low, Below Normal, Normal, Above Normal, High.

      How do queue priorities work?

      Zend Server will execute jobs according to the priority of the queue they are associated with. Within a queue, Zend Server will execute jobs according to the priority associated with a job.
      However, there are two exceptions to this rule:
      - Should Zend Server identify that the amount of jobs being executed exceeds the amount set in the queue's Max Concurrent Jobs setting (see below), the next queue in line is executed.
      - Should Zend Server identify a job pending execution that has exceeded the time set in the queue's Max Job Wait Time setting (see below), this job is scheduled for immediate execution.

    • Max Concurrent Jobs - Set the maximum amount queue jobs allowed to be executed at the same time.

      Note:

      The global value of max concurrent jobs is defined in the Job Queue Settings page. If you are working with an external service provider, make sure the value you enter does not exceed their requirements for concurrent requests.

    • Max Job Wait Time - Set the maximum amount of time queue jobs can wait before they are executed regardless queue priority.
    • Connection Timeout - Set the amount of time (in seconds) the Job Queue daemon tries to establish a connection with the back-end server.
    • HTTP Job Timeout - Set the time frame (in seconds) in which a URL-based queue job must be completed.
    • CLI Job Timeout - Set the time frame (in seconds) in which a CLI-based queue job must be completed, or set to Unlimited.
    • Job Retry Count - Set the number of retries for failed HTTP jobs.
    • Job Retry Timeout - Set the amount of time (in seconds) between retries for failed HTTP jobs.
  4. Click Add Queue.
    The new queue is added to the Queues list on the Queues page.

Note:

Queue settings can be edited at any time by clicking the Edit icon . The name of the Default queue cannot be edited.

This procedure will describe how to suspend or activate an existing queue. Suspending a queue puts all associated jobs on hold.

Instructions on how to complete a procedure

To suspend/activate a job queue:

  1. In the Zend Server UI, go to the Job Queue | Queues page.
  2. From the Queues list, select the queue you wish to suspend/activate.
  3. In the Action bar, select Suspend Selected / Activate Selected.
    The queue you selected is suspended/activated.

 

This procedure will describe how to assign a job to a queue. Once assigned, the job will be executed according to the prioritization associated with the queue and the queue settings.

Instructions on how to complete a procedure

To assign a job to a job queue:

  1. In the Zend Server UI, go to the Job Queue | Jobs page.
  2. In the Jobs list, click the Edit icon for the job you wish to assign.
    The Edit Recurring Job page is displayed.
  3. Select the Queue drop-down menu and select the queue you wish to assign the job to.
  4. Click Save.
    The job is assigned to the queue you selected and will be executed according to the queue settings.

 

This procedure will describe how to remove an existing queue. Removal of queues is only allowed if there are no pending jobs and if there are no recurring jobs that are set for that queue.

Instructions on how to complete a procedure

To remove a job queue:

  1. In the Zend Server UI, go to the Job Queue | Queues page.
  2. From the Queues list, select the queue you wish to remove.
  3. In the Action bar, select or hover over the queue you wish to remove, and in the Actions column on the right, click .
  4. When prompted, affirm your action by selecting the check-box in the dialog, and click Delete.
    The queue you selected is removed.

Note:

The Default queue cannot be removed.

This procedure will describe how to import or export queue data. This feature can be used when working in different environments or when sharing queue settings with other Zend Server users.

Instructions on how to complete a procedure

To export queues:

  1. In the Zend Server UI, go to the Job Queue | Queues page.
  2. In the action bar, click the Export button.
    Existing queue data is exported to a .zip file.]

To import queues:

  1. In the Zend Server UI, go to the Job Queue | Queues page.
  2. In the action bar, click the Import button.
    The Import Queues page is displayed.
  3. Select an exported .zip file containing queue data.
  4. Select the Delete current queues to remove all the existing queues in your system before the import operation is performed (The Default queue will be overridden by the imported Default queue).

    Note:

    If left unselected, existing queues that do not exist in the imported data will be left untouched.