Logstash hangs (CLOSE_WAIT)

[manunc]

Hello,

Logstash version 7.3.2-1 on CentOS 7.6.1810

Since several days I noticed that Logstash is frozen every 24h.
When I check the server I found a lot of CLOSE_WAIT (131).

Nothing in the logstash-plain.log relevant and even no error logs displayed

...
tcp6 322 0 127.0.0.1:52001 127.0.0.1:33758 CLOSE_WAIT 0 0 -
tcp6 322 0 127.0.0.1:52001 127.0.0.1:42042 CLOSE_WAIT 0 0 -
tcp6 322 0 127.0.0.1:52001 127.0.0.1:41674 CLOSE_WAIT 0 0 -
tcp6 622 0 127.0.0.1:52001 127.0.0.1:35762 CLOSE_WAIT 0 0 -
...

My configuration is the following:
NGINX listening on port 443 (SSL) forwarding request to logstash on port 52001 (SSL) using http-input-plugin:

input {
http {
host => "0.0.0.0"
port => 52001
ssl => true
ssl_certificate_authorities => ["/var/element/elk/certs/cert4.pem"]
ssl_certificate => "/var/element/elk/certs/fullchain4.pem"
ssl_key => "/var/element/elk/certs/privkey4.pem"
ssl_verify_mode => "peer"
tags => ["opt","lorawan"]
}
}

Any idea or clues to debug this?

The only things to do for the moment is to restart logstash

[manunc]

Hello,

Any help?
The situation appears again today.
Is it possible to turn something in debug mode?

Br

[manunc]

I found the root cause of my issue without for the moment found the solution but every 24 hours I got too many CLOSE_WAIT due to an input syslog plugin not used so I removed it for the moment.
If it can help someone