# Nginx Error: Address already in use

**URL:** <https://discourse.openondemand.org/t/nginx-error-address-already-in-use/1238>\
**Category:** Get Help\
**Tags:** question\
**Created:** [December 3, 2020, 9:48pm UTC](https://discourse.openondemand.org/t/nginx-error-address-already-in-use/1238 "2020-12-03T21:48:40Z")\
**Posts on this page:** 1\
**Showing post:** 7

<div class="post-metadata">

**Author:** ![jeff.ohrstrom](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.openondemand.org/jeff.ohrstrom/32/136_2.png) [@jeff.ohrstrom](https://discourse.openondemand.org/u/jeff.ohrstrom)\
**Post date:** [January 14, 2021, 6:08pm UTC](https://discourse.openondemand.org/t/nginx-error-address-already-in-use/1238/7 "2021-01-14T18:08:54Z")

</div>

here’s my best guess as to what’s happening: The first `nginx` starts and crashes, but doesn’t release the socket file or zombies.

(1) I would try to find out what the process is still using it. `lsof` will give you this. See if that process is still running or what’s going on with that.

```auto
[jeff@518bd97864ee /]$ lsof /var/run/ondemand-nginx/jeff/passenger.sock 
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
nginx 379 jeff 6u unix 0x00000000ff78144c 0t0 2523864 /var/run/ondemand-nginx/jeff/passenger.sock type=STREAM

```

(2) I would also check if there are coredumps in `/var/lib/systemd/coredump` or if there are any messages in `journalctl` related to crashes.

(3) I would do a spot check on ulimits. You could be hitting some limit. Specifically max # of files or processes.

```auto
[johrstrom ~()] 🐰 ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 63375
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 4096
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited

```

(4) After all that, we could employ strace to dig into what it’s doing (and failing to do)  
Here’s a simple nginx wrapper that you could reconfigure the `nginx_bin` configuration of your `/etc/ood/config/nginx_stage.yml` file.

(you could parse out a user name from the `-c /var/lib/ondemand-nginx/config/puns/<USER>.conf` option if you like to specify a new filename. I put the `$(date +%s)` here to get unqiue files, given your going to get 1 that we’re intersted in - the very first - and the others will throw the error in the message you’ve given there about the address being already in use).

```auto
#!/bin/bash

/bin/strace -o /tmp/nginx_strace_$(date +%s).out /opt/ood/ondemand/root/usr/sbin/nginx $@

```

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_[View the full topic](https://discourse.openondemand.org/t/nginx-error-address-already-in-use/1238)._