Not your complete problem, but you've got two SSDs (disk 1 & 2) and a spinner (parity)
Reads are going to be fast, but writes will be slow. The docker image and appdata are effectively read and written to constantly, so the write penalty will be huge. You're going to be better off setting up the SSDs as a cache pool (trim isn't supported in the array). This will significantly increase your speed / response (orders of magnitude)
You've got tons of "invalid opcodes" being logged. Could be simple program errors, but also could be bad memory. Run memtest for at least a couple of passes.