Add flag to disable kinesis-mock persistence

[dfangl]

Motivation

With recent kinesis performance tests, we have seen a significant performance degradation up to an out-of-memory error of kinesis-mock, especially when pushing over 50 entries with the maximum payload of 1024KB to a stream.
This behavior is way worse when the persistence is enabled when starting kinesis-mock. For now, to fix it for users not needing persistence, we need a flag to disable it.

In the future, we need to spend some work on increasing the performance and memory usage of the persistence of our kinesis implementation.

Changes

• Add flag to disable the persistence mechanism for kinesis, which is currently active regardless of cloud pods or persistence being used on the localstack level.

[github-actions]

S3 Image Test Results (AMD64 / ARM64)

    2 files  ±0      2 suites  ±0   3m 14s ⏱️ ±0s
381 tests ±0  331 ✔️ ±0    50 💤 ±0  0 ❌ ±0 
762 runs  ±0  662 ✔️ ±0  100 💤 ±0  0 ❌ ±0 

Results for commit 3644427. ± Comparison against base commit a77e4f8.

[thrau]

that's a great catch! why not just use if config.PERSISTENCE though?

[dfangl]

Because then cloud pods will not work anymore for kinesis, I think. For usual payload sizes currently persistence is not a problem, but for bigger ones it becomes one, so I felt like a separate variable to disable it made more sense.

[coveralls]

coverage: 84.02% (-0.01%) from 84.031%
when pulling 3644427 on add-kinesis-persistence-flag
into a77e4f8 on master.

[github-actions]

LocalStack Community integration with Pro

       2 files  ±0         2 suites  ±0   1h 11m 56s ⏱️ +18s
2 405 tests ±0  2 177 ✔️ ±0  228 💤 ±0  0 ❌ ±0 
2 406 runs  ±0  2 177 ✔️ ±0  229 💤 ±0  0 ❌ ±0 

Results for commit 3644427. ± Comparison against base commit a77e4f8.

[giograno]

Correct, pods won't work if we don't start kinesis already with the correct env variables for persistence (there won't be any assets to persist). It would be very handy to have a sort of dump command to be called ad-hoc in kinesis mock 🤔