[LL-HLS] Mega-task

[master312]

To make life easier, this is an issue containing list of all recent LL-HLS related tasks.

Should be reviewed and merged in order listed here.

1. Low Latency HLS (ll-hls) sometimes overrides segments of other streams in high-concurrency scenarions [0.5 days] [done]

• ISSUE LINK: [BUG] Low Latency HLS (ll-hls) sometimes overrides segments of other streams in high-concurrency scenarions #7503
• PR: https://github.com/ant-media/Paid-Plugins/pull/6

2. Plugin stability and misc bugfixes [3 days] [done]

• ISSUE LINK: Additional Low Latency HLS issues (ll-hls) #7510
• PR: https://github.com/ant-media/Paid-Plugins/pull/7
• TODO: Maybe update documentation with discoveries made here?

3.0. Caching, fault handling and error recovery

• Work done: File caching, Runner management system, health-checks and recovery mechanism, misc bugfixes.
• TODO: Final code review, fix tests
• PR Coming soon
  !THOSE HAVE BEEN DROPPED! IN FAVOR OF STEP BELOW!

3.1. Major refactoring [2 weeks]

• Work done:
• • Major Refactor of plugin structure
• • Custom playlist parsing and manipulation engine for better control
• • Improved runner management
• • UDP proxy between ffmpeg and mediastreamsegmenter, to handle socket-poisioning cases
• • Various health-check and recovery systems
• • Playlist combining and index offset system to make recovery seamless from the player side
• • New common file-watcher for improved stability performance
• • Various new settings in configuration
• • ll-hls-muxer new ffmpeg settings for improved stability and latency
• • Various minor tun-ups and bugfixes, to many to list.
• • Extensive testing
• Time split: 1 week for research and experimentation (while working on previous crossed out step 3); 1 week for actual refactor and implementation of this.
• PR - Community: A small change to support ll-hls plugin refactor. #7550
• PR - Enterprise: https://gitlab.com/Ant-Media/Ant-Media-Enterprise/-/merge_requests/873
• PR - Plugin: https://github.com/ant-media/Paid-Plugins/pull/10
• TODO: Documentation

4. LL-HLS cluster support [2.5 days]

• ISSUE LINK: LL-HLS Not Working in Cluster Mode  #6901
• PR - Community: Fix/ll hls cluster play2 #7492
• PR - Enterprise: https://gitlab.com/Ant-Media/Ant-Media-Enterprise/-/merge_requests/864
• PR - Plugin: https://github.com/ant-media/Paid-Plugins/pull/5
• NOTE: Community and Enterprise PR's can be merged any time. BUT Plugins PR will need more work that can be done only when other PR's above are merged.
• TODO: Update plugin source to work with new ll-hls refactors.