Multiple HTTP sockets with map-socket: the second HTTP socket is very slow

[mmartinello]

I am making some tests on uWSGI 2.0.25.1 with multiple HTTP sockets and map-socket in order to avoid socket busyness due to healthchecks from HAProxy.

I enabled 2 HTTP sockets and 4 processes, and I mapped 3 processes for the first socket (for application) and the 4th process for the second socket (for monitoring and healthchecks):

http-socket = :8000
http-socket = :8001
map-socket=0:1,2,3
map-socket=1:4
processes = 4

As a result, the first socket on the port 8000 works and is fast as it should be:

root@154dc56d3a27:/opt/app# time http -h 127.0.0.1:8000
HTTP/1.1 200 OK
Connection: Keep-Alive
Content-Length: 174
Content-Type: text/html; charset=utf-8
Cross-Origin-Opener-Policy: same-origin
Referrer-Policy: same-origin
Vary: Authorization, Cookie, origin
X-Content-Type-Options: nosniff
X-Frame-Options: DENY

real	0m0.158s
user	0m0.108s
sys	0m0.040s

If I try to connect to the second socket (port 8001), the connection hangs and the socket seems not to serving anything:

root@154dc56d3a27:/opt/app# time http -h 127.0.0.1:8001
[...] No response [...]
^C

real	0m10.855s
user	0m0.133s
sys	0m0.012s

This is my uwsgi.ini file:

[uwsgi]
strict = true
master = true
enable-threads = true
vacuum = true
single-interpreter = true
die-on-term = true
need-app = true
lazy-apps = false
no-defer-accept = true
py-call-osafterfork = true
thunder-lock = true

# Avoid errors on aborted client connections
ignore-sigpipe = true
ignore-write-errors = true
disable-write-exception = true


disable-logging = true
log-5xx = true
log-date = %%Y-%%m-%%d %%H:%%M:%%S
logformat-strftime

log-format = [pid: %(pid)|app: -|req: -/-] %(addr) (%(user)) {%(vars) vars in %(pktsize) bytes} [%(ctime)] %(method) %(uri) => generated %(rsize) bytes in %(msecs) msecs (%(proto) %(status)) %(headers) headers in %(hsize) bytes (%(switches) switches on core %(core))
logger = file:/var/log/uwsgi/logger.log
req-logger = file:/var/log/uwsgi/req-logger.log

harakiri = 3600

max-requests = 1000
max-worker-lifetime = 3600
reload-on-rss = 2048
worker-reload-mercy = 60

#processes = 2

cheaper-algo = busyness
cheaper = 1
cheaper-initial = 1
cheaper-overload = 1
cheaper-step = 1

cheaper-busyness-multiplier = 30
cheaper-busyness-min = 20
cheaper-busyness-max = 70
cheaper-busyness-backlog-alert = 64
cheaper-busyness-backlog-step = 2


#http-socket = :8000

http-timeout = 120
http-connect-timeout = 120
http-enable-proxy-protocol = 1
http-auto-chunked = true
http-keepalive = 1
add-header = Connection: Keep-Alive

chdir = .
wsgi-file = /opt/app/wsgi.py

gid = app
uid = app

pidfile = /tmp/project-master.pid


route = ^/info* donotlog:

stats = :1785
stats-http = true

http-socket = :8000
http-socket = :8001
map-socket=0:1,2,3
map-socket=1:4
processes = 4

Could you help me to understand where I'm wrong, please?