Scheduled Backups

Trove currently has no way to schedule backups of instances. This document proposes to implement scheduled backups by utilizing Mistral workflows.

Launchpad Blueprint: https://blueprints.launchpad.net/trove/+spec/scheduled-backup

Problem Description

Trove does not support scheduled backups.

Proposed Change

Scheduled backups will be supported by utilizing Mistral workflows [1]. The Trove python API will be extended to provide a Trove centric interface to Mistral workflows.

A Trove workbook will be loaded into Mistral to support calling the trove.backup_create python API via a schedule. Trove python API methods will be added to support scheduling backups and listing scheduled backups and their executions. Using these Trove commands a user will be able to manage backup schedules (create/delete/list, etc.) and view the executions of said schedules. Like is done with Nova flavors however, Trove will not actually execute any commands itself, just pass them down to Mistral. Any errors that occur will be visible when viewing the executions, however will be limited to whatever Mistral exposes.

All changes will be within the python-troveclient module with the exception of the workbook. This will be available in the Trove repo to (possibly) be loaded by the devstack plugin if Mistral is enabled.

See the Appendix for a sample Trove workbook.

Configuration

No configuration changes.

Database

No database changes.

Public API

No changes to the REST API.

Public API Security

No security impact.

Python API

Note: The referenced ‘cron pattern’ is the standard cron expression. [2]

def schedule_create(self, instance, pattern, name,
                    description=None, parent_id=None,
                    mistral_client=None):
    """Create a new schedule to backup the given instance.

    :param instance: instance to backup.
    :param pattern: cron pattern for schedule.
    :param name: name for backup.
    :param description: (optional).
    :param parent_id: base for incremental backup (optional).
    :returns: :class:`Backups`
    """

def schedule_list(self, instance, mistral_client=None):
    """Get a list of all backup schedules for an instance.

    :param: instance for which to list schedules.
    :rtype: list of :class:`Schedule`.
    """

def schedule_show(self, schedule, mistral_client=None):
    """Get details of a backup schedule.

    :param: schedule to show.
    :rtype: :class:`Schedule`.
    """

def schedule_delete(self, schedule, mistral_client=None):
    """Remove a given backup schedule.

    :param schedule: schedule to delete.
    """

def execution_list(self, schedule, mistral_client=None,
                   marker='', limit=None):
    """Get a list of all executions of a scheduled backup.

    :param: schedule for which to list executions.
    :rtype: list of :class:`ScheduleExecution`.
    """

def execution_delete(self, execution, mistral_client=None):
    """Remove a given schedule execution.

    :param execution: id of execution to remove.
    """

CLI (python-troveclient)

Load trove workbook

$ mistral workbook-create ~/mwj/mistral/trove.yaml

Create Schedule

$ trove schedule-create m "*/2 * * * *" myback
+---------------------+----------------------------------------------------------------------------------------------------------------+
| Property            | Value                                                                                                          |
+---------------------+----------------------------------------------------------------------------------------------------------------+
| created_at          | 2016-06-14 14:47:16.865731                                                                                     |
| id                  | fb149a29-be9b-49c1-a2f7-ca6c1213896f                                                                           |
| input               | {"instance": "5328f62a-d999-4be3-90bb-83cc6af4469c", "description": null, "parent_id": null, "name": "myback"} |
| instance            | 5328f62a-d999-4be3-90bb-83cc6af4469c                                                                           |
| name                | myback                                                                                                         |
| next_execution_time | 2016-06-14 07:48:00                                                                                            |
| parent_id           | None                                                                                                           |
| pattern             | */2 * * * *                                                                                                    |
+---------------------+----------------------------------------------------------------------------------------------------------------+

List Schedule

$ trove schedule-list m
+--------------------------------------+--------+-------------+---------------------+
| ID                                   | Name   | Pattern     | Next Execution Time |
+--------------------------------------+--------+-------------+---------------------+
| fb149a29-be9b-49c1-a2f7-ca6c1213896f | myback | */2 * * * * | 2016-06-14 07:50:00 |
+--------------------------------------+--------+-------------+---------------------+

Show Schedule

trove schedule-show fb149a29-be9b-49c1-a2f7-ca6c1213896f
+---------------------+----------------------------------------------------------------------------------------------------------------+
| Property            | Value                                                                                                          |
+---------------------+----------------------------------------------------------------------------------------------------------------+
| created_at          | 2016-06-14 14:47:16                                                                                            |
| id                  | fb149a29-be9b-49c1-a2f7-ca6c1213896f                                                                           |
| input               | {"instance": "5328f62a-d999-4be3-90bb-83cc6af4469c", "description": null, "parent_id": null, "name": "myback"} |
| instance            | 5328f62a-d999-4be3-90bb-83cc6af4469c                                                                           |
| name                | myback                                                                                                         |
| next_execution_time | 2016-06-14 07:52:00                                                                                            |
| parent_id           | None                                                                                                           |
| pattern             | */2 * * * *                                                                                                    |
| updated_at          | 2016-06-14 14:49:59                                                                                            |
+---------------------+----------------------------------------------------------------------------------------------------------------+

Delete Schedule

$ trove schedule-delete fb149a29-be9b-49c1-a2f7-ca6c1213896f

List Executions

trove execution-list fb149a29-be9b-49c1-a2f7-ca6c1213896f
+--------------------------------------+---------------------+---------+-------------------------------+
| ID                                   | Execution Time      | State   | Output                        |
+--------------------------------------+---------------------+---------+-------------------------------+
| 38ef2289-4330-4554-8574-4b5351f69713 | 2016-06-14 14:49:59 | SUCCESS | {"status": "Backup complete"} |
| 3713355a-b65e-44e0-ac43-150b863a6e6e | 2016-06-14 14:51:59 | SUCCESS | {"status": "Backup complete"} |
+--------------------------------------+---------------------+---------+-------------------------------+

Delete Executions

$ trove execution-delete 3713355a-b65e-44e0-ac43-150b863a6e6e

Internal API

No internal API changes.

Guest Agent

No guest changes.

Alternatives

The alternative would be for Trove to implement its own scheduling mechanism.

Dashboard Impact (UX)

An action will be added to the instance actions pulldown to show the scheduled backups for an instance. This will lead to a chain of panels for scheduled backups, details of a schedule, and executions of a schedule. The scheduled backups list will have an option to create a new schedule. The panels which list schedules and executions will have an action to delete the corresponding resource.

Implementation

Assignee(s)

Primary assignee:
6-morgan
Dashboard assignee:
duktesora

Milestones

Target Milestone for completion:
Newton

Work Items

  • already prototyped [3]
  • implement unit tests

Upgrade Implications

No upgrade implications.

Dependencies

n/a

Testing

If we add support in scenario tests (through the python API) that would mean we’d require Mistral to be installed. As such, no scenario tests will be created.

Documentation Impact

New python API methods and CLI commands would need to be documented.

Appendix

This is an idea of what the Trove workbook for Mistral would look like:

---
version: '2.0'

name: trove

description: Trove Workflows

workflows:

  backup_create:
    input: [instance, name, description, parent_id]
    output:
      status: <% $.message %>

    tasks:
      backup_create:
        action: trove.backups_create instance=<% $.instance %> name=<% $.name %> description=<% $.description %> parent_id=<% $.parent_id %>
        publish:
          message: <% 'Backup complete' %>