Connection open + one select + close takes about 30 ms about mysql

[kelunik]

Please try opening a single connection instead of creating a new pool and closing it each time. I expect it to be a bit slower, but we should investigate what makes it that much slower.

[mvorisek]

FYI, without a pool ($db = yield \Amp\Mysql\connect(\Amp\Mysql\ConnectionConfig::fromString(...));) it is a little faster, but still very slow. I run is several times and I cannot get under 20s / 1000 iters.

[kelunik]

I think this is probably mainly caused by PDO using the old mysql_native_password, while amphp/mysql supports the newer caching_sha2_password pluggable authentication. caching_sha2_password however, comes with quite some cost, because the client needs to fetch the server's public key and computed openssl_public_encrypt (which takes about 13% in my benchmark).

[kelunik]

@mvorisek Turns out there was a bug in the caching_sha2_password implementation, which made it always to a full authentication roundtrip instead of using the fast auth flow.

I'm at 3s for 1000 iterations now instead of 7s with a local mysql docker container.

[mvorisek]

@kelunik nice finding, thank you ❤️