hzh0425 opened a new pull request, #5807: URL: https://github.com/apache/rocketmq/pull/5807
**Make sure set the target branch to `develop`** ## What is the purpose of the change Support DLedger Controller snapshot In RocketMQ 5.0, the DLedger Controller component was introduced (RIP-44) to allow automatic master-slave switching. Briefly speaking, it is a strong consistent metadata center based on the DLedger (Raft), which stores metadata related to the Master/Slave selection. However, given the lack of snapshot capability from the DLedger, the DLedger Controller would face the following problems: 1. The DLedger Controller requires replaying the complete log from the store while restarting the node to restore its state. This might cost a considerable amount of time once the log size gets large. 2. The log will continue to expand over time and is likely to cause insufficient storage space in the end. Therefore, the DLedger Controller (or perhaps other future components which require DLedger (Raft) abilities) needs the snapshot capability from DLedger to enhance its space and time performance in certain aspects. This drives us to introduce this improvement. The links to our (GitHub id: tsunghanjacktsai, hzh0425, TheR1sing3un) proposal are given below (both Google Docs and Shimo Docs versions were provided to prevent someone cannot access the specific app): SHIMO: https://shimo.im/docs/WlArzngm9JhzY0A2 GOOGLE DOCS: https://docs.google.com/document/d/1jiKtv5WRDqlgZLGYK0oHuZww1r7KKrnTdRGf_eDIQy8/edit?usp=sharing ## Brief changelog Support DLedger Controller snapshot ## Verifying this change Follow this checklist to help us incorporate your contribution quickly and easily. Notice, `it would be helpful if you could finish the following 5 checklist(the last one is not necessary)before request the community to review your PR`. - [x] Make sure there is a [Github issue](https://github.com/apache/rocketmq/issues) filed for the change (usually before you start working on it). Trivial changes like typos do not require a Github issue. Your pull request should address just this issue, without pulling in other changes - one PR resolves one issue. - [x] Format the pull request title like `[ISSUE #123] Fix UnknownException when host config not exist`. Each commit in the pull request should have a meaningful subject line and body. - [x] Write a pull request description that is detailed enough to understand what the pull request does, how, and why. - [x] Write necessary unit-test(over 80% coverage) to verify your logic correction, more mock a little better when cross module dependency exist. If the new feature or significant change is committed, please remember to add integration-test in [test module](https://github.com/apache/rocketmq/tree/master/test). - [x] Run `mvn -B clean apache-rat:check findbugs:findbugs checkstyle:checkstyle` to make sure basic checks pass. Run `mvn clean install -DskipITs` to make sure unit-test pass. Run `mvn clean test-compile failsafe:integration-test` to make sure integration-test pass. - [ ] If this contribution is large, please file an [Apache Individual Contributor License Agreement](http://www.apache.org/licenses/#clas). -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
