Cherry pick #21643 to 21.2: Fix distributed requests cancellation with async_socket_for_remote=1#21783
Merged
robot-clickhouse merged 3 commits intobackport/21.2/21643from Mar 16, 2021
Conversation
Before this patch for distributed queries, that requires cancellation
(simple select from multiple shards with limit, i.e. `select * from
remote('127.{2,3}', system.numbers) limit 100`) it is very easy to
trigger the situation when remote shard is in the middle of sending Data
block while the initiator already send Cancel and expecting some new
packet, but it will receive not new packet, but part of the Data block
that was in the middle of sending before cancellation, and this will
lead to some various errors, like:
- Unknown packet X from server Y
- Unexpected packet from server Y
- and a lot more...
Fix this, by correctly waiting for the pending packet before
cancellation.
It is not very easy to write a test, since localhost is too fast.
Also note, that it is not possible to get these errors with hedged
requests (use_hedged_requests=1) since handle fibers correctly.
But it had been disabled by default for 21.3 in #21534, while
async_socket_for_remote is enabled by default.
Fix distributed requests cancellation with async_socket_for_remote=1
robot-clickhouse
added
do not test
…7e7e82e28b8dc20e18046eec3b0
robot-clickhouse
deleted the
cherrypick/21.2/0ffea300acb5d7e7e82e28b8dc20e18046eec3b0
branch
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Original pull-request #21643
This pull-request is a first step of an automated backporting.
It contains changes like after calling a local command
git cherry-pick.If you intend to continue backporting this changes, then resolve all conflicts if any.
Otherwise, if you do not want to backport them, then just close this pull-request.
The check results does not matter at this step - you can safely ignore them.
Also this pull-request will be merged automatically as it reaches the mergeable state, but you always can merge it manually.