[#1201] improvement: only invoking LOG.debug when LOG.isDebugEnabled() is true

[misselvexu]

What changes were proposed in this pull request?

Improve invoking LOG.debug when LOG.isDebugEnabled() is true .

Why are the changes needed?

Fix: #1201

Does this PR introduce any user-facing change?

(Please list the user-facing changes introduced by your change, including

1. Change in user-facing APIs.
2. Addition or removal of property keys.)

No.

How was this patch tested?

(Please test your changes, and provide instructions on how to test it:

1. If you add a feature or fix a bug, add a test to cover your changes.
2. If you fix a flaky test, repeat it for many times to prove it works.)

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 2.75229% with 106 lines in your changes missing coverage. Please review.

Project coverage is 54.67%. Comparing base (b4adaa5) to head (eb5b7eb).
Report is 503 commits behind head on master.

Files with missing lines	Patch %	Lines
...pache/spark/shuffle/writer/WriteBufferManager.java	0.00%	7 Missing and 3 partials ⚠️
...ffle/client/impl/grpc/ShuffleServerGrpcClient.java	0.00%	9 Missing ⚠️
...java/org/apache/hadoop/mapred/SortWriteBuffer.java	0.00%	6 Missing and 1 partial ⚠️
...torage/handler/impl/HadoopShuffleWriteHandler.java	0.00%	5 Missing and 2 partials ⚠️
...he/uniffle/coordinator/CoordinatorGrpcService.java	0.00%	6 Missing ⚠️
...le/storage/handler/impl/LocalFileWriteHandler.java	0.00%	4 Missing and 2 partials ⚠️
...ain/java/org/apache/tez/common/TezClassLoader.java	0.00%	5 Missing ⚠️
...pache/uniffle/server/ShuffleServerGrpcService.java	0.00%	5 Missing ⚠️
...he/uniffle/server/buffer/ShuffleBufferManager.java	0.00%	5 Missing ⚠️
...java/org/apache/uniffle/client/RestClientImpl.java	0.00%	4 Missing ⚠️
... and 15 more

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #1217      +/-   ##
============================================
+ Coverage     53.75%   54.67%   +0.92%     
- Complexity     2600     2611      +11     
============================================
  Files           392      372      -20     
  Lines         22486    20165    -2321     
  Branches       1887     1923      +36     
============================================
- Hits          12087    11026    -1061     
+ Misses         9689     8476    -1213     
+ Partials        710      663      -47     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[advancedxy]

And two meta questions:

1. do we have a way to enforce this? such as style check.
2. In java8, I believe we could use supplier to lazy logging message without the explicit check. Is it possible to upgrade the log4j version and leverages that. For example: https://stackoverflow.com/questions/47063232/lazy-evaluation-for-logging-in-java-8

[misselvexu]

And two meta questions:

1. do we have a way to enforce this? such as style check.
2. In java8, I believe we could use supplier to lazy logging message without the explicit check. Is it possible to upgrade the log4j version and leverages that. For example: https://stackoverflow.com/questions/47063232/lazy-evaluation-for-logging-in-java-8

Currently the project is using log4j-1.2.17 version, theoretically it is possible to use log4j2 to replace, as for whether it can be fully compatible with other components still need to be tested.

[roryqi]

LGTM, thanks @misselvexu