consistent lz4 compression

[719media]

Expected behaviour

Able to use redis with lz4 compression across servers and get consistent results

Actual behaviour

Different results based on whether or not server is running amazon linux 2 or amazon linux 2023

I'm seeing this behaviour on

• OS: Amazon linux 2 and 2023
• Redis: 7.0.7
• PHP: 8.2
• phpredis: 7.0.1

Steps to reproduce, backtrace or example script

On Amazon Linux 2 (lz4 v1.7.5), I will store a key zAdd('test', 1, 'joslin-wins-the-battle-at-the-berries');

Using redis-cli, I can see that the value is stored as 2%\x00\x00\x00\xf0\x16joslin-wins-the-battle-at-the-berries

On Amazon Linux 2023 (lz4 v1.9.4), I will store a key zAdd('test', 1, 'joslin-wins-the-battle-at-the-berries');

Using redis-cli, I can see that the value is stored as 2%\x00\x00\x00\xf2\njoslin-wins-the-battle-at\x0e\x00`erries

I imagine the reason here is something to do with the option "use system lz4", but I'm not familiar with the implications of all of these options as they are not documented. I would help by "documenting", but I'm ignorant on the inner workings here.

Seems like the lz4 version being different leads to this issue, just wondering what the standard practice here is, and also when (if ever) you'd set "use system lz4" to false during redis install?