Consistency groups » History » Version 1
Victor Denisov, 03/11/2016 01:19 AM
| 1 | 1 | Victor Denisov | h1. Consistency Groups |
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| 3 | h3. Summary |
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| 4 | |||
| 5 | Consistency Groups could be useful for Data Protection (snapshots, backups) and Remote Replication (Mirroring). |
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| 6 | |||
| 7 | The Mirroring support will allow to setup mirroring of multiple volumes in the same consistency group (i.e. attaching multiple RBD images to the same journal to ensure consistent replay). |
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| 8 | |||
| 9 | There is already an interest to implement this functionality as a part Mirroring feature: |
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| 10 | http://tracker.ceph.com/issues/13295 |
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| 11 | |||
| 12 | The snapshot support will allow snapshots of multiple volumes in the same consistency group to be taken at the same point-in-time to ensure data consistency. |
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| 13 | |||
| 14 | h3. Owners |
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| 15 | |||
| 16 | * Victor Denisov (Mirantis) |
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| 17 | * Mykola Golub (Mirantis) |
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| 18 | |||
| 19 | h3. Interested Parties |
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| 20 | |||
| 21 | * Victor Denisov (Mirantis) |
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| 22 | * Mykola Golub (Mirantis) |
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| 23 | |||
| 24 | h3. Current Status |
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| 25 | |||
| 26 | Currently Mirroring feature is being implemented. Consistency groups is supposed to be implemented as a part of Mirroring. The snapshot support will allow snapshots of multiple volumes in the same consistency group to be take at the same point-in-time to ensure data consistency. |
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| 28 | h3. Detailed Description |
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| 29 | |||
| 30 | This feature will require to add a new entity - consistency group. |
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| 31 | You should be able to run the following operations on a consistency group: |
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| 32 | |||
| 33 | * Create a consistency group |
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| 34 | * Show a consistency group |
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| 35 | * List all available consistency groups |
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| 36 | * Add an image to a consistency group |
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| 37 | * Create a snapshot of all the members of a consistency group |
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| 38 | - Created snapshot of a consistency group only has references to snapshots that appear under the corresponding images |
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| 39 | * List all snapshots of a consistency group |
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| 40 | * Delete consistency group's snapshot |
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| 41 | * Modify consistency group (delete, add images to the consistency group) |
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| 42 | |||
| 43 | A consistency group is empty upon its creation. Images need to be created and added to it later. |
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| 44 | Not all operations have to be implemented at once. Many can be added later. |
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| 46 | h4. Openstack Cinder Integration |
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| 47 | |||
| 48 | The functionality should cover Cinder Driver API to make integration possible: |
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| 49 | |||
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| 51 | def create_consistencygroup(self, context, consistencygroup, volumes) |
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| 52 | def delete_consistencygroup(self, context, consistencygroup) |
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| 53 | def create_cgsnapshot(self, context, cgsnapshot) |
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| 54 | def delete_cgsnapshot(self, context, cgsnapshot) |
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| 55 | |||
| 56 | https://github.com/openstack/cinder-specs/blob/master/specs/juno/consistency-groups.rst |
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| 57 | |||
| 58 | h3. Work items |
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| 59 | |||
| 60 | h4. Coding tasks |
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| 61 | |||
| 62 | # Task 1 |
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| 63 | # Task 2 |
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| 64 | # Task 3 |
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| 65 | |||
| 66 | h4. Build / release tasks |
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| 67 | |||
| 68 | # Task 1 |
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| 69 | # Task 2 |
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| 70 | # Task 3 |
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| 71 | |||
| 72 | h4. Documentation tasks |
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| 73 | |||
| 74 | # Task 1 |
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| 75 | # Task 2 |
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| 76 | # Task 3 |
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| 77 | |||
| 78 | h4. Deprecation tasks |
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| 79 | |||
| 80 | # Task 1 |
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| 81 | # Task 2 |
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| 82 | # Task 3 |