Renan DelValle

Posted September 10, 2018

0.21.0 Released

The latest Apache Aurora release, 0.21.0, is now available for download. Here are some highlights in this release:

  • Updated to Mesos 1.5.0.
  • Introduce ability for tasks to specify custom SLA requirements via the new SlaPolicy structs. There are 3 different SLA Policies that are currently supported - CountSlaPolicy, PercentageSlaPolicy and CoordinatorSlaPolicy. SLA policies based on count and percentage express the required number of RUNNING instances as either a count or percentage in addition to allowing the duration-window for which these requirements have to be satisfied. For applications that need more control over how SLA is determined, a custom SLA calculator can be configured a.k.a Coordinator. Any action that can affect SLA, will first check with the Coordinator before proceeding.

    IMPORTANT: The storage changes required for this feature will make scheduler snapshot backwards incompatible. Scheduler will be unable to read snapshot if rolled back to previous version. If rollback is absolutely necessary, perform the following steps:

    1. Stop all host maintenance requests via aurora_admin host_activate.
    2. Ensure a new snapshot is created by running aurora_admin scheduler_snapshot <cluster>
    3. Rollback to previous version

Note: The Coordinator interface required for the CoordinatorSlaPolicy is experimental at this juncture and is bound to change in the future. - Introduced ability for updates to be ‘SLA-aware’, or only update instances if it is within SLA, using the new sla_aware field in UpdateConfig. See the bullet point above for an explanation of custom SLA requirements.

NOTE: SLA-aware updates will use the desired config’s SLA, not the existing config.

Three additional scheduler options have been added to support this feature:

1. `max_update_action_batch_size (default: 300)`: the number of update actions to process in a
2. `sla_aware_kill_retry_min_delay (default: 1mins)`: the minimum amount of time to wait before
retrying an SLA-aware kill (using a truncated binary backoff).
3. `sla_aware_kill_retry_max_delay (default: 5mins)`: the maximum amount of time to wait before
retrying an SLA-aware kill (using a truncated binary backoff).

Deprecations and removals:

  • Deprecated the aurora_admin host_drain command used for maintenance. With this release the SLA computations are moved to the scheduler and it is no longer required for the client to compute SLAs and watch the drains. The scheduler persists any host maintenance request and performs SLA-aware drain of the tasks, before marking the host as DRAINED. So maintenance requests survive across scheduler fail-overs. Use the newly introduced aurora_admin sla_host_drain to skip the SLA computations on the admin client.
  • Removed resource fields (numCpus, ramMb, diskMb) from ResourceAggregate.

Full release notes are available in the release CHANGELOG.


Thanks to the 9 contributors who made Apache Aurora 0.21.0 possible:

  • Jing Chen
  • Renan DelValle
  • Stephan Erb
  • Jordan Ly
  • David McLaughlin
  • John Sirois
  • Sameer Parekh
  • Reza Motamedi
  • Ezequiel Torres Feyuk