gresockj opened a new pull request #5025:
URL: https://github.com/apache/nifi/pull/5025
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
#### Description of PR
Previously, when a cluster with at least 3 nodes offloaded the first node
(the one targeted by a Single Node load balanced queue), only the offloaded
node updated its list of partitions in the SocketLoadBalancedFlowFileQueue's
partitionQueue. If the offloaded node reconnected, its queue would list the
second node first, but all other nodes (including the second node) would still
have the first node listed first. Therefore, an infinite loop resulted where
the first node would be balancing its flowfiles to the second node, and the
second node would balance all of its flowfiles to the first node. The result
was that this particular queue would ignore backpressure and the following
processor would never be reached, at the same time.
All that said, this fix does the following to resolve the issue:
# Causes all non-offloading nodes to remove the offloading node from their
partitionQueues in SocketLoadBalancedFlowFileQueue, whenever the OFFLOADING
node state change is detected. This allows all other nodes to be in sync with
the first node's partitionQueue.
# Causes all non-offloading nodes (of which the previously offloaded node
will now be one) to add back a node to the partition queue upon CONNECTED node
state change. This allows the offloaded node to regain its place as the "first
node" in Single Node load balancing.
In order to streamline the review of the contribution we ask you
to ensure the following steps have been taken:
### For all changes:
- [x] Is there a JIRA ticket associated with this PR? Is it referenced
in the commit message?
- [x] Does your PR title start with **NIFI-XXXX** where XXXX is the JIRA
number you are trying to resolve? Pay particular attention to the hyphen "-"
character.
- [x] Has your PR been rebased against the latest commit within the target
branch (typically `main`)?
- [x] Is your initial contribution a single, squashed commit? _Additional
commits in response to PR reviewer feedback should be made on this branch and
pushed to allow change tracking. Do not `squash` or use `--force` when pushing
to allow for clean monitoring of changes._
### For code changes:
- [x] Have you ensured that the full suite of tests is executed via `mvn
-Pcontrib-check clean install` at the root `nifi` folder?
- [x] Have you written or updated unit tests to verify your changes?
- [x] Have you verified that the full build is successful on JDK 8?
- [x] Have you verified that the full build is successful on JDK 11?
- [ ] If adding new dependencies to the code, are these dependencies
licensed in a way that is compatible for inclusion under [ASF
2.0](http://www.apache.org/legal/resolved.html#category-a)?
- [ ] If applicable, have you updated the `LICENSE` file, including the main
`LICENSE` file under `nifi-assembly`?
- [ ] If applicable, have you updated the `NOTICE` file, including the main
`NOTICE` file found under `nifi-assembly`?
- [ ] If adding new Properties, have you added `.displayName` in addition to
.name (programmatic access) for each of the new properties?
### For documentation related changes:
- [ ] Have you ensured that format looks appropriate for the output in which
it is rendered?
### Note:
Please ensure that once the PR is submitted, you check GitHub Actions CI for
build issues and submit an update to your PR as soon as possible.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
