Memory leak in MessageChannelPartitionHandler when polling the database

[a-del-devision]

Memory leak in MessageChannelPartitionHandler when polling the database

[hpoettker]

Thanks for the very well written bug report. I think your description and analysis are absolutely on point, and the example files are very concise and useful. Very much appreciated!

I've opened a PR to resolve the issue: #4599

With this fix, your reproducer runs successfully even with -Xmx32m.

[fmbenhassine]

@a-del-devision Thank you for reporting this issue in details and for providing a minimal complete example!

In fact, there is no need to hold a reference to the entire object graph of each completed worker step in memory until the partition step is completed. The change in #4599 removes the intermediate result that holds these references, which fixes the memory leak.

I will plan that fix for the upcoming patch releases 5.1.2 and 5.0.6.