[
https://issues.apache.org/jira/browse/TEZ-1867?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14254464#comment-14254464
]
Siddharth Seth commented on TEZ-1867:
-------------------------------------
>From a quick look at the patch.
- rename: SpeculatorDispatcher - this is more of an eventHandler ?
SpeculatorEventHandler instead of SpeculatorDispatcher
- public void register(Class<? extends Enum> eventType, EventHandler handler,
String dispatcherName) - Should this method be accepting a handler ? - in which
case it should likely be called registerOnNewHandler. Alternately it could just
accept a Dispatcher. That, I think is better for unit testing - so that
DrainDispatchers, as an example, could be passed in, if necessary.
- serviceStart / serviceStop iterate the list of dispatchers and stop them.
This fits into the CompositeServiceModel, where each Dispatcher adds it's child
dispatchers as services. The service model should take care of stopping /
starting services properly in that case.
bq. We should not be depending on any ordering in the processing of events
other than the sending order for the same entity. ie. if entity A sends events
(1 and then 2) to entity B then entity B should see the events in the same
order (1 and then 2). Events from other entities B or to other entities C
should not depend on ordering relative to other components. If we have such
cases then we should fix them as they come up after we move all event
processing off the central dispatcher. The design is expected to be decoupled
but the current single thread model may have led to inadvertent ordering
behavior. We should work our way out of this in 0.7.
We shouldn't. I'm sure we do though, in multiple places. This could be a very
destabilizing change - equivalent of making the entire processing threaded,
dealing with locks etc. I'd be wary of making this change for the core
processing unless we're gaining a lot from this ?
> Create new central dispatcher for Tez AM
> ----------------------------------------
>
> Key: TEZ-1867
> URL: https://issues.apache.org/jira/browse/TEZ-1867
> Project: Apache Tez
> Issue Type: Improvement
> Reporter: Bikas Saha
> Assignee: Bikas Saha
> Attachments: TEZ-1867.1.patch
>
>
> The dispatcher should be able to federate events across multiple event
> specific dispatchers for AM control plane scalability. Add dispatcher
> specific thread names for easier debugging.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
