fix TestRawZkClient unstableness

[kaisun2000]

Issues

• My PR addresses the following Helix issues and references them in the PR description:

Fix #1294

Description

• Here are some details about my PR, including screenshots of any UI changes:

ZkClient connect to ZooKeeper client first before monitor bean
initialization. If the monitor is not fully constructed, the
test would pass. Otherwise, as in github, it would not. Fix this
issue by properly construct the object.

Tests

• The following tests are written for this issue:

None

• The following is the result of the "mvn test" command on the appropriate module:

In Old connection New session
After session expiry sessionId= 72277739317428225
Shut down zookeeper at port 2127 in thread main
Starting ZK server at localhost:2358
[INFO] Tests run: 44, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 701.476 s - in TestSuite
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 44, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 11:47 min
[INFO] Finished at: 2020-08-19T18:11:02-07:00
[INFO] ------------------------------------------------------------------------
ksun-mn1:zookeeper-api ksun$ git status

Documentation (Optional)

• In case of new functionality, my PR adds documentation in the following wiki page:

(Link the GitHub wiki you added)

Commits

• My commits all reference appropriate Apache Helix GitHub issues in their subject lines. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters (not including Jira issue reference)
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

Code Quality

• My diff has been formatted using helix-style.xml
  (helix-style-intellij.xml if IntelliJ IDE is used)

[huizhilu]

I'll look into this more carefully about the race condition.

[jiajunwang]

I took a deeper look at the test logic. Since this might be the most important test in our code base, let's be careful to not lose any coverage.

For more details, we can discuss in next week's meeting.

[jiajunwang]

LGTM! Please address the last comment.

[kaisun2000]

This diff is approved. Please help to merge

ZkClient connects to ZooKeeper before monitor bean
initialization and registration. This causes race condition that fails
metrics test. Fix this issue by properly construct the object.

[jiajunwang]

@kaisun2000 Please run helix-core tests since the change impacts almost all logics.

[jiajunwang]

@kaisun2000 you can rerun the test job in Github UI. There is no need to touch code for a re-run.

[huizhilu]

I've triggered rerun the workflow.
FYI, @kaisun2000 This is a button for us to Re-run jobs.

[kaisun2000]

@jiajunwang, @pkuwm, as we looked, my github page does not have this UI button to re-run. Other than that, any other concerns? Or let us merge this in.

[huizhilu]

@jiajunwang, @pkuwm, as we looked, my github page does not have this UI button to re-run. Other than that, any other concerns? Or let us merge this in.

@kaisun2000 I've helped re-run all the jobs.

[kaisun2000]

@jiajunwang, removed the extra space to trigger run from my side. Please help to merge.