EC performance

[Lucas12138]

Hi community,

We changed our replication type from Ratis One to EC RS-6-3-1024k.
We did some performance benchmarking and saw for downloading a 1TB file,
Ratis One took around 1500s and EC RS-6-3-1024k took around 4000s.
We are wondering is this mush of the performance difference is expected?

Also, we're curious if XOR-2-1-1024k might have better or worse performance?

Besides, I saw that "Enabling ISA-L allows significantly improve EC performance." For the performance here, is it more about uploading speed, downloading speed or storage usage?

Thanks!

[kerneltime]

@Lucas12138 if you used Ratis One, there is only a single copy created and that will be faster than reading multiple erasure coded shards. For diving deeper into why the erasure coded copy takes longer, I would recommend to start dashboard-ing metrics and providing more details about the setup, commands used and configuration.