simonbence opened a new pull request #4349: URL: https://github.com/apache/nifi/pull/4349
[NIFI-7549](https://issues.apache.org/jira/browse/NIFI-7549) The PR contains my proposal of Hazelcast support for DistributedMapCacheClient. In general, I followed the patterns I found in the existing implementations, for the cases were not explicitly documented the behaviour follows them, mainly the ones were added with the feature itself (I considered them the most relevant and accurate implementations) As for the organisation of the implementation, I did split the feature into three "layers". The package structure follows this as well. In the bottom, there is the HazelcastCache, and the implementation. This layer is responsible to directly communicate with the Hazelcast (via a provided connection) and hide the details of the used data structure. The current implementation is based on IMap, but there is the possibility to change or extend this. Also, the map-like data structure's interface is heavily changed between Hazelcast 3.x and 4.x. In case if the support would be needed for older implementations, wrapping the logic could help to avoid sprawl of the changes. The layer above is the "cache manager" (HazelcastCacheManager). This is responsible to create the cache instances and maintain the connection. Currently there are two implementation: one which starts an embedded Hazelcast for easy usage and one which connects to a Hazelcast cluster running outside NiFi. The embedded provides a limited capability for configuration, but it could serve effectively as local cache. The "standalone" could joint to any non-enterprise Hazelcast. Note: I looked after how to connect with secured Hazelcast, but as I found it is part of the enterprise package. For now, it was not part of my intent to support that. This layer should hide all Hazelcast specific interface or implementation. The top layer is the actual DistributedMapCacheClient implementation. Depends on both the bottom ones, as the manager is needed for acquiring the cache which it works with. All the NiFi specific logic is within this. AtomicDistributedMapCacheClient methods are supported. The revision handling comes in with this is general for all the entries. A long-based version is attached to all the entries. Please share your thoughts on the proposal, I hope it would be useful for the community! _Enables X functionality; fixes bug NIFI-YYYY._ In order to streamline the review of the contribution we ask you to ensure the following steps have been taken: ### For all changes: - [ ] Is there a JIRA ticket associated with this PR? Is it referenced in the commit message? - [ ] 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. - [ ] Has your PR been rebased against the latest commit within the target branch (typically `master`)? - [ ] 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: - [ ] Have you ensured that the full suite of tests is executed via `mvn -Pcontrib-check clean install` at the root `nifi` folder? - [ ] Have you written or updated unit tests to verify your changes? - [ ] Have you verified that the full build is successful on JDK 8? - [ ] 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]
