change default monitor window length from 1 hour to 1 min

[zhangmeng916]

Issues

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

Fixed #1259

Description

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

Helix default monitor window length was set as 1 hour for histogram metrics. The long time window leads to a high memory usage during runtime. This PR changes the default length from 1 hour to 1 min in order to reduce memory usage.

Tests

• The following is the result of the "mvn test" command on the appropriate module:
  helix-core:
  [INFO]
  [INFO] Results:
  [INFO]
  [ERROR] Failures:
  [ERROR] TestWagedRebalance.testChangeIdealState:303->validate:646 expected: but was:
  [INFO]
  [ERROR] Tests run: 1163, Failures: 1, Errors: 0, Skipped: 1
  [INFO]
  [INFO] ------------------------------------------------------------------------
  [INFO] BUILD FAILURE
  [INFO] ------------------------------------------------------------------------
  [INFO] Total time: 01:15 h
  [INFO] Finished at: 2020-08-12T15:13:28-07:00

helix-rest
[INFO] Tests run: 165, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 30.512 s - in TestSuite
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 165, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 34.307 s
[INFO] Finished at: 2020-08-12T15:29:08-07:00

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)

[zhangmeng916]

This PR is ready to merge, approved by @narendly
Final commit message:
Change default monitor window length from 1 hour to 1 min