Tasks

Introduction

The Pulp server uses Celery to handle requests that may take longer than a HTTP request timeout to execute. Many of the commands from the pulp-admin command line client will return messages along the lines of

Request accepted

check status of task e239ae4f-7fad-4004-bfb6-8e06f17d22ef with "pulp-admin tasks details"

This means the server’s REST API returned a 202 ACCEPTED response with the task information for the task that is handling the request.

This page details querying and managing these tasks.

Details

The pulp-admin command line client provides the tasks section and the details command to inspect the runtime details of a task, identified with the required --task-id=<id> flag.

$ pulp-admin tasks details --task-id e239ae4f-7fad-4004-bfb6-8e06f17d22ef
+----------------------------------------------------------------------+
                              Task Details
+----------------------------------------------------------------------+

Operations:
Resources:    orphans (content_unit)
State:        Successful
Start Time:   2012-12-09T03:26:51Z
Finish Time:  2012-12-09T03:26:51Z
Result:       N/A
Task Id:      e239ae4f-7fad-4004-bfb6-8e06f17d22ef
Progress:

In the output above there are several sections:

  • Operations: a list of operations that are being performed by this task

  • Resources: a list of resources that are being operated on

  • State: the state of the task, such as: Waiting, Running, Successful or Error

  • Start Time: the UTC time the task started

  • Finish Time: the UTC time the task finished

  • Result: the reported result of the task, if any

  • Task Id: a unique identifier for the task (as a UUID)

  • Progress: arbitrary progress information provided by the task, if any

Listing

To see all the tasks on the server at any given time, the pulp-admin command line client provides the tasks section and the list command.

It provides all the same information as the details command, but for every task that has been executed on the pulp server. The length of history depends on the settings described below.

In addition to tasks launched using pulp-admin or the API , reaper and monthly tasks appear in the list.

The reaper task is responsible for cleaning up the database on a regularly scheduled interval. The interval is configured with reaper_interval in [data_reaping] section of /etc/pulp/server.conf. The value can be whole or fraction of days. The length of time to keep documents for each collection is also configured in the same section. task_status_history, consumer_history, repo_sync_history, repo_publish_history, repo_group_publish_history, and task_result_history take values of whole or fraction of days to keep that type of history. This database cleanup is needed because these transactions can occur very frequently and as result the database can grow to an unreasonable size.

The monthly task is run every 30 days to clean up data referencing any repositories that no longer exist.

Purging

To purge the completed tasks on the server at any given time, the pulp-admin command line client provides the tasks section and the purge command.

By giving a --all flag, the tasks in successful, failed and skipped state will be purged.

By giving a --state flag, specific states can be passed as an argument and all the tasks belonging to these states will be purged. These states must be from the completed state list(except canceled) or the command will result in error message.

$ pulp-admin tasks purge
+----------------------------------------------------------------------+
                         Purge Completed Tasks
+----------------------------------------------------------------------+

Command: purge
Description: purge tasks in one or more completed states

Available Arguments:

  --all, -a   - if specified, all tasks in "successful, skipped and failed states
                will be purged
  --state, -s - comma-separated list of tasks states desired to be purged.
                Example: "successful,failed". Do not include spaces.

$ pulp-admin tasks purge --all
+----------------------------------------------------------------------+
                         Purge Completed Tasks
+----------------------------------------------------------------------+

Task purging is successfully initiated.

$ pulp-admin tasks purge -s successful,failed
+----------------------------------------------------------------------+
                         Purge Completed Tasks
+----------------------------------------------------------------------+

Task purging is successfully initiated.

$ pulp-admin tasks purge -s canceled
+----------------------------------------------------------------------+
                         Purge Completed Tasks
+----------------------------------------------------------------------+

Invalid task state passed to parameters list: canceled.

Canceling a Task

Tasks may be canceled before they are run (i.e. in the waiting state) or while they are running.

The pulp-admin command line client provides the tasks section and the cancel command to cancel a task identified by the required --task-id flag.

$ pulp-admin tasks cancel --task-id e0e0a250-eded-468f-9d97-0419a00b130f

$ pulp-admin tasks details --task-id e0e0a250-eded-468f-9d97-0419a00b130f
+----------------------------------------------------------------------+
                              Task Details
+----------------------------------------------------------------------+

Operations:   sync
Resources:    ff7-e6 (repository)
State:        Canceled
Start Time:   2012-12-09T04:28:10Z
Finish Time:  2012-12-09T04:29:09Z
Result:       N/A
Task Id:      e0e0a250-eded-468f-9d97-0419a00b130f
Progress:
  Yum Importer:
    Comps:
      State: NOT_STARTED
    Content:
      Details:
        Delta Rpm:
          Items Left:  0
          Items Total: 0
          Num Error:   0
          Num Success: 0
          Size Left:   0
          Size Total:  0
        File:
          Items Left:  0
          Items Total: 0
          Num Error:   0
          Num Success: 0
          Size Left:   0
          Size Total:  0
        Rpm:
          Items Left:  6
          Items Total: 37
          Num Error:   0
          Num Success: 31
          Size Left:   112429996
          Size Total:  149958122
        Tree File:
          Items Left:  0
          Items Total: 0
          Num Error:   0
          Num Success: 0
          Size Left:   0
          Size Total:  0
      Error Details:
      Items Left:    0
      Items Total:   37
      Num Error:     0
      Num Success:   31
      Size Left:     112429996
      Size Total:    149958122
      State:         CANCELED
    Errata:
      State: NOT_STARTED
    Metadata:
      State: FINISHED

Note

It is possible for tasks to complete or experience an error before the task cancellation request is processed. In these instances, the task’s final state might not be “canceled” even though a cancel was requested.