GitHub user onurkaraman opened a pull request:
https://github.com/apache/kafka/pull/2816
KAFKA-5028: convert kafka controller to a single-threaded event queue model
The goal of this ticket is to improve controller maintainability by
simplifying the controller's concurrency semantics. The controller code has a
lot of shared state between several threads using several concurrency
primitives. This makes the code hard to reason about.
This ticket proposes we convert the controller to a single-threaded event
queue model. We add a new controller thread which processes events held in an
event queue. Note that this does not mean we get rid of all threads used by the
controller. We merely delegate all work that interacts with controller local
state to this single thread. With only a single thread accessing and modifying
the controller local state, we no longer need to worry about concurrent access,
which means we can get rid of the various concurrency primitives used
throughout the controller.
Performance is expected to match existing behavior since the bulk of the
existing controller work today already happens sequentially in the ZkClientâs
single ZkEventThread.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/onurkaraman/kafka KAFKA-5028
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/kafka/pull/2816.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #2816
----
commit d74cad8874f1a9dd2b781c3033921f562d4e7630
Author: Onur Karaman <okara...@linkedin.com>
Date: 2017-04-06T05:20:23Z
KAFKA-5028: convert kafka controller to a single-threaded event queue model
The goal of this ticket is to improve controller maintainability by
simplifying the controller's concurrency semantics. The controller code has a
lot of shared state between several threads using several concurrency
primitives. This makes the code hard to reason about.
This ticket proposes we convert the controller to a single-threaded event
queue model. We add a new controller thread which processes events held in an
event queue. Note that this does not mean we get rid of all threads used by the
controller. We merely delegate all work that interacts with controller local
state to this single thread. With only a single thread accessing and modifying
the controller local state, we no longer need to worry about concurrent access,
which means we can get rid of the various concurrency primitives used
throughout the controller.
Performance is expected to match existing behavior since the bulk of the
existing controller work today already happens sequentially in the ZkClientâs
single ZkEventThread.
----
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastruct...@apache.org or file a JIRA ticket
with INFRA.
---
