PowerPoint Presentation

The status of ReplicationJohn Griffith - john.griffith@solidfire.comEd Balduf - ed.balduf@solidfire.com

Why are we building replication into Cinder?Whats it for? What does it buy me?Its a DR strategy for non-cloud applications.Backup (Kind of). Limited use cases today.Different vendors Different terminology for states. How does failover/failback work?Crawl-walk-runShould be aware of Availability Groups (future).

Use Cases ConsideredNEVER - 2 different vendor backends. Consider:2 backends, same cloud2 backends, different cloud2 backends, one not in a cloudReplication one to multiple backendsAutomated -vs- Non-Automated failoverSnapshot replication -vs - Continuous replication

How we got hereMissteps

Many voicesLack of agreed upon visionDifference in interpretationUnique characteristics that dont translate wellLack of testabilityRush at the end of release cycle

V1 lessons learnedLack of community involvementOnly worked for one vendorNot clearly understoodDocumentation was not up to standards

V2 Learning from our mistakesHeavy involvement from multiple vendorsReviews, reviews, reviewsDONT RUSH!!!We will sell no wine, before its time

How it works and what it does:Driver must report: replication_enabled = TrueIn its capabilities.

New config variable:replication_device = {device_target_id: ,managed_backend_name: ,Vendor Key1: ,Vendor Key2: ,}

(Note: No trailing comma allowed in replication_device KV pair list)

Example config file.[Solidfire1]volume_driver=cinder.volume.drivers.solidfire.SolidFireDriversan_ip=192.168.1.50san_login=adminsan_password=solidfirevolume_backend_name=SF1

[Solidfire2]volume_driver=cinder.volume.drivers.solidfire.SolidFireDriversan_ip=192.168.1.250san_login=adminsan_password=solidfirevolume_backend_name=SF2managed_replication_target=Truereplication_device = device_target_id: vendorSpecificID, \ managed_backend_name: SF1, \ mvip: 192.168.1.50, \ login: admin, \ password: solidfire

Volume-typesKeywords:

replication_enabled enabled replication, this way you can set it up and not do replicationreplication_type Async, syncreplication_count number of replicas

V1 semantics (NO LONGER USED)promotereenable

Current Terms and StatusTerms:enabled/disabledStatus:disabledinactiveactiveactive-stoppederrorTasks (Admin)replication enablereplication disablereplication failoverlist replication targets

Drivers in work (or done)SolidFirePure StorageHPIBMIn progress, NO review yetDellEMC (VNX)NTAP (pool level)

Demo