performance: find a way to stream the body into the parser

[syphar]

with ~150 lines of logs we "only" get around 2k RPS, with an empty body we get 50k RPS for the web-server component.

I'm not sure if this is possible with axum, but it would be good if we wouldn't need to convert the body to a byte buffer in the web handler.

So either pass the body to the background task and buffer it there, or even convert the parser into a streaming parser.

[syphar]

-- wrk.lua 
wrk.method = "POST"
wrk.body = [[
473 <131>1 2023-02-20T07:16:58+00:00 host app postgres.2595527 - [DATABASE] [10-1]  sql_error_code = 28000 time_ms = "2023-02-20 07:16:58.219 UTC" pid="2105602" proc_start_time="2023-02-20 07:16:58 UTC" session_id="63f31e6a.202102" vtid="2/2324671" tid="0" log_line="2" database="postgres" connection_source="110.87.46.194(52440)" user="postgres" application_name="[unknown]" FATAL:  no pg_hba.conf entry for host "110.87.46.194", user "postgres", database "postgres", SSL off
]]

wrk.headers["logplex-drain-token"] = "logplex_token"

then run wrk http://localhost:3000 -s wrk.lua -t24 -c24 -d30s

[syphar]

just did a short test that reads the body in the async task, this directly doesn't help.

Probably we need to combine this with the BodyStream extractor

[syphar]

BodyStream also doesn't make it faster, the reason has to be somewhere else.

[syphar]

( there is also a chance that wrk is slow?)