[SUPPORT] Spark driver memory overflows after using spark streaming for a long time

[hj2016]

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Describe the problem you faced

1. Use Kafka as the data source and use spark streamming to write to hudi. After about 10 days of execution, the spark dirver memory overflows.
2. Dump spark dirver memory found that the memory of spark dirver is set to 4g, while the memory of HoodieLogFormatWriter object is occupied by more than 3g.
   

3.Analyzing the source code of HoodieLogFormatWriter, HoodieLogFormatWriter object will be constructed every time the metadata is submitted by commit. As spark streamming submits more and more batches, it leads to the accumulation of HoodieLogFormatWriter objects. GC does not seem to be able to perform garbage collection.

To Reproduce

Steps to reproduce the behavior:

Expected behavior

A clear and concise description of what you expected to happen.

Environment Description

• Hudi version :0.5.2

• Spark version :2.4.0

• Hive version :2.1.1

• Hadoop version :3.0.0

• Storage (HDFS/S3/GCS..) :hdfs

• Running on Docker? (yes/no) :no

Additional context

Question 1: Has the problem been fixed in the higher version?
Question 2: The HoodieLogFormatWriter object internally refers to a global object, which causes gc to fail to reclaim the object. I feel that setting the object to null after the HoodieLogFormatWriter object executes the close method can fix the problem. Does this have any other impact?

Stacktrace

[bvaradar]

I made a quick PR to fix this issue in master - #2217
@hj2016 : Can you try this and see if this solves the memory leak ?

[hj2016]

@bvaradar Ok, let me verify.

[hj2016]

I tried to run the spark task for several hours, the HoodieLogFormatWriter object problem was solved, but I found a new problem. Many Hbase ShutdownHook objects cannot be released. Need to removeShutDownHook thread。

[bvaradar]

Thanks @hj2016 . I have updated the PR to fix this issue as well. Can you please check ?

[hj2016]

@bvaradar The spark dirver memory is no problem, but spark execute memory has the same problem。

[hj2016]

Supplement: HoodieLogFileReader object may also have the same problem。

[bvaradar]

@hj2016 : Apologies. I missed seeing your comment. I have update the PR to take care of this. Can you kindly try. I will go ahead and merge the PR to master once the unit-test passes.

[hj2016]

@bvaradar You missed the DiskBasedMap object.

[hj2016]

@bvaradar I tried to modify it and tested it in version 0.5.2, no problem

[vinothchandar]

@bvaradar may be I jumped the gun and merged the PR? :( . Feel free to do a follow on

[bvaradar]

No worries @vinothchandar .

@hj2016 : Opened a new PR #2249 Also identified one more place where this could happen and did the similar fix.

[ygordefraga]

@vinothchandar @bvaradar Hey guys, just to help you. I have the same problem when executing a streaming writing into a hudi table for a while.

Any updates about the solution? Affected versions? I use 0.5.3 currently.

[bvaradar]

The fixes are available in 0.7.0 which is in the process of getting released. The release branch will be cut in couple of days (https://lists.apache.org/thread.html/r3473e0aea28a2ffb050a650a09f93b8fabdcef0d456d71afba6c2694%40%3Cdev.hudi.apache.org%3E)

Balaji.V

[wxplovecc]

@bvaradar I have the same problem in 0.9.0 release

[danny0405]

@wxplovecc I have fired a fix here #3951
please verify if it can solve your problem.