saLeox opened a new pull request, #4374: URL: https://github.com/apache/zeppelin/pull/4374
### What is this PR for? When multi users perform some notebook/folder operation, like rename or move, some notebooks become not accessible from zeppelin page, while they are still existing on the HDFS, and only resort to restart Zeppelin daemon to solve the problem. In this PR, unit test is created to simulate the concurrent request scenario and reproduce the issue successfully, including the operations of saveNote, moveNote, moveFolder and removeNote. Accordingly, some changes are made to ensure thread safety of note manager operation, so that the note or folder info will not be lost, after which the unit test should get passed. ### What type of PR is it? Bug Fix ### Todos * [ ] - Task ### What is the Jira issue? * Open an issue on Jira https://issues.apache.org/jira/browse/ZEPPELIN-5744 ### How should this be tested? * Automated unit tests for the change is added. ### Questions: * Does the licenses files need to update? No * Is there breaking changes for older versions? No * Does this needs documentation? No -- 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: dev-unsubscr...@zeppelin.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org