Implement a distributed pipeline executor #3119
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
dominiklohmann
force-pushed
the
topic/actor-executor
branch
2 times, most recently
from
038e154 to
9ed6b5c
Compare
dominiklohmann
force-pushed
the
topic/actor-executor
branch
from
9ed6b5c to
f67f483
Compare
jachris
approved these changes
May 4, 2023
tobim
reviewed
May 5, 2023
The function is no longer necessary in the current design, so we're removing it for now.
After a lot of experimenting and researching throughout the CAF code base, it turned out that the only reliable way to shut down a stream spanning actors in multiple processes is to send a sentinel value within the stream itself. Now, you may wonder, why don't the other approaches work? Here's why: 1. Make the stream own the execution nodes: This works wonderfully up to the point where an execution node is in a different process, and its reference count never goes to zero when the part of the stream hosted by that execution node goes down. 2. Close and flush the stream explicitly: This causes a race condition in the stream drivers finalize handler, which makes it impossible to send out further events from a stream stage to a stream sink after the stream has been closed. 3. Shut down the hosting execution node actor from within the stream: This causes another race condition where it the stream finalize handler may be called after the actor state was destroyed, causing address sanitizer to go boom. So yeah, in-stream sentinel values it is. Works wonderfully.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR changes
vast execto support executing parts of a pipeline remotely, and introduces the concept of an operator location, and theremoteandlocaloperator modifiers.The changes in this PR should have little user-visible effect, except for the new operator modifiers, but will allow future operators to run remotely and as such unblocks the development of many planned operators like
exportandimport.