Identifying "Writing" connections in status stub

[Peter Booth]

Vlad,

I'd suggest beginning by seeing whether or not this is real. If you create a cron job that invokes netstat -ant every hour, then summarize the connections and either view them manually or write them into an influxdb and graph with grafana you will see whether or not the #tcp connections really is growing and, if so, which connections are growing.

That would seem like a useful first step.

Peter 

Sent from my iPhone

> On Jul 26, 2017, at 6:15 AM, Vlad K. <nginx-ml at acheronmedia.hr> wrote:
> 
> 
> Hello list,
> 
> I'm graphing information from the nginx status page, and have noticed something odd. The "Writing" connections are flat over time, not correlated to the Active/Reading/Waiting connections and are steadily increasing over time. Example for the past week:
> 
> https://pasteboard.co/GCHKB3B.png
> 
> Where it drops, is where I've restarted (not reloaded) the service, and starts growing up after a short while. This server FreeBSD but I've noticed it also in Debian.
> 
> Is there a way to find out which connections are these, which remote IPs they are so I can track them with netstat or sockstat? This looks to me like connection FD or something has been leaking. If this is a bug, I'm not sure what to report.
> 
> I've also noticed, from time to time, connections lingering for long time in "CLOSED" state (as reported by netstat), googling for which seems to suggest a bug in application, where it doesn't release the FD after the remote has closed.
> 
> 
> Thanks.
> 
> 
> -- 
> Vlad K.
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