HPCC-31171 Encrypt on worker threads rather than UDP send thread

[richardkchapman]

Type of change:

• This change is a bug fix (non-breaking change which fixes an issue).
• This change is a new feature (non-breaking change which adds functionality).
• This change improves the code (refactor or other change that does not change the functionality)
• This change fixes warnings (the fix does not alter the functionality or the generated code)
• This change is a breaking change (fix or feature that will cause existing behavior to change).
• This change alters the query API (existing queries will have to be recompiled)

Checklist:

• My code follows the code style of this project.
  • My code does not create any new warnings from compiler, build system, or lint.
• The commit message is properly formatted and free of typos.
  • The commit message title makes sense in a changelog, by itself.
  • The commit is signed.
• My change requires a change to the documentation.
  • I have updated the documentation accordingly, or...
  • I have created a JIRA ticket to update the documentation.
  • Any new interfaces or exported functions are appropriately commented.
• I have read the CONTRIBUTORS document.
• The change has been fully tested:
  • I have added tests to cover my changes.
  • All new and existing tests passed.
  • I have checked that this change does not introduce memory leaks.
  • I have used Valgrind or similar tools to check for potential issues.
• I have given due consideration to all of the following potential concerns:
  • Scalability
  • Performance
  • Security
  • Thread-safety
  • Cloud-compatibility
  • Premature optimization
  • Existing deployed queries will not be broken
  • This change fixes the problem, not just the symptom
  • The target branch of this pull request is appropriate for such a change.
• There are no similar instances of the same problem that should be addressed
  • I have addressed them here
  • I have raised JIRA issues to address them separately
• This is a user interface / front-end modification
  • I have tested my changes in multiple modern browsers
  • The component(s) render as expected

Smoketest:

• Send notifications about my Pull Request position in Smoketest queue.
• Test my draft Pull Request.

Testing:

Using udpsim

[github-actions]

https://track.hpccsystems.com/browse/HPCC-31171
Jira updated

[ghalliday]

Change looks good.
It is hard to know which way to default the option. I suspect on a lightly loaded system this may reduce performance slightly - because aes encryption will no longer be executed in parallel with the code to walk the indexes. On a heavily loaded system I suspect it will help because once the udp transport layer becomes the bottleneck, anything that speeds up the rate packets are sent is likely to help.

[mckellyln]

I think it makes sense, looks good to merge.

[richardkchapman]

On a lightly loaded system, there will be other worker threads available for walking the indexes when the AES encryption is happening. I would have thought

[ghalliday]

I think it is a good idea. My concern is changing the way it works on a point release. I wonder about defaulting it to remain the same for 9.4.x, but encourage business units to test enabling the option and look its effect on performance.

@richardkchapman @mckellyln

What are your votes for merging this?

[mckellyln]

We could merge it, but leave default as-is and do some testing and change default in a future release ?
I would learn towards defaulting it on (the new method) and if there is some noticeable diff in the near term then we can disable via config.

[richardkchapman]

Feels like a smaller change than many others that have gone into the 9.4 series. I don't really mind either way but if we choose to default off in 9.4.x then we need to also release a change to change the default in master, or else it will become yet another unused option...

(Also, if we change the default at a major release rather than a minor one, it will be much harder for us to spot any negative impact - not that I think a negative impact is likely)