Fix connection leakage in CustomRestClient

[huizhilu]

Issues

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

Fixes #1471

Description

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There is connection leakage in CustomRestClientImpl and causes timeout waiting for connection.

Fix this issue by consuming entity and releasing stream and connection.

Tests

• The following tests are written for this issue:

Manually reproduce the issue locally. After the fix, the issue is gone.

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

[INFO] Tests run: 170, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 100.208 s - in TestSuite
[INFO]
[INFO] Results:
[INFO]
[INFO] Tests run: 170, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  01:46 min
[INFO] Finished at: 2020-10-16T15:20:24-07:00
[INFO] ------------------------------------------------------------------------

Documentation (Optional)

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Commits

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  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

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[kaisun2000]

@pkuwm, yes, this should fix the issue I found which can be urgent. So without a unit test, it is fine for now.

Can you also add an issue to add a unit test?

[huizhilu]

@pkuwm, yes, this should fix the issue I found which can be urgent. So without a unit test, it is fine for now.

Can you also add an issue to add a unit test?

I actually thought about unit testing the connection leak and did an investigation on it. It is not easy. As long as we use it correctly, it is fine.
One way is, once we switch to use an instrumented http client, we can check the metrics in the unit test to test the connection leak.
Created a ticket: #1475 for tracking.

[huizhilu]

This PR is ready to be merged, approved by @kaisun2000

There is connection leakage in CustomRestClientImpl and causes timeout waiting for connection.
Fix this issue by consuming entity and releasing the content stream and connection.