[jira] [Comment Edited] (MESOS-7688) Improve master failover performance by reducing unnecessary agent retries.

["Ilya Pronin (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/MESOS-7688?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16059531#comment-16059531 ] 

Ilya Pronin edited comment on MESOS-7688 at 6/22/17 3:32 PM:
-------------------------------------------------------------

Attached a perf script ([^reregistration.perf.gz]) and a flamegraph ([^reregistration.svg]) for a 2 minute sample of 33k agents reregistration after master failover.


was (Author: ipronin):
Attached a perf script ([^reregistration.perf.gz]) and a flamegraph ([^reregistration.svg]) for a 2 minute sample of agents reregistration after master failover.

> Improve master failover performance by reducing unnecessary agent retries.
> --------------------------------------------------------------------------
>
>                 Key: MESOS-7688
>                 URL: https://issues.apache.org/jira/browse/MESOS-7688
>             Project: Mesos
>          Issue Type: Improvement
>          Components: agent, master
>            Reporter: Benjamin Mahler
>              Labels: scalability
>         Attachments: 1.2.0.png, reregistration.perf.gz, reregistration.svg
>
>
> Currently, during a failover the agents will (re-)register with the master. While the master is recovering, the master may drop messages from the agents, and so the agents must retry registration using a backoff mechanism. For large clusters, there can be a lot of overhead in processing unnecessary retries from the agents, given that these messages must be deserialized and contain all of the task / executor information many times over.
> In order to reduce this overhead, the idea is to avoid the need for agents to blindly retry (re-)registration with the master. Two approaches for this are:
> (1) Update the MasterInfo in ZK when the master is recovered. This is a bit of an abuse of MasterInfo unfortunately, but the idea is for agents to only (re-)register when they see that the master reaches a recovered state. Once recovered, the master will not drop messages, and therefore agents only need to retry when the connection breaks.
> (2) Have the master reply with a retry message when it's in the recovering state, so that agents get a clear signal that their messages were dropped. The agents only retry when the connection breaks or they get a retry message. This one is less optimal, because the master may have to process a lot of messages and send retries, but once the master is recovered, the master will process only a single (re-)registration from each agent. The number of (re-)registrations that occur while the master is recovering can be reduced to 1 in this approach if the master sends the retry message only after the master completes recovery.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)