Understanding Traffic Top

[Nick Dunkin <Ni...@vecima.com>]

HI,

We’ve recently started using traffic_top to monitor our ATS instances, but we are having trouble understanding some of the metrics.

For example Curr Conn/Active Conn, who’s values seem to be significantly higher (by an order of magnitude) than a tool like netstat, on the same server, would suggest.

[A screenshot of a computer  Description automatically generated with medium confidence]

And, the value for New Conn here is also confusing.  What does 0.5 represent?

So, my questions are:

  *   Is traffic_top a commonly used and reliable tool in the ATS community?, and if it is
  *   Why do the readings for Curr Conn/Active Conn seems to not correlate with a tool like netstat?

Maybe we’re holding it wrong?!?

Many thanks,

Nick

Nick Dunkin
Director, Software Architecture
Manager – Architecture and New Product Introduction
o:  +1 678.258.4071
e: nick.dunkin@vecima.com<ma...@vecima.com>

[cidimage001.png@01D6CC8C.6FC5A580]

RE: Understanding Traffic Top

[Alan Carroll <am...@network-geographics.com>]

What does your netstat look like? IIRC connections counts both inbound and outbound connections.

From: Nick Dunkin <Ni...@vecima.com>
Sent: Thursday, December 1, 2022 8:30 AM
To: users@trafficserver.apache.org
Subject: Understanding Traffic Top

HI,

We've recently started using traffic_top to monitor our ATS instances, but we are having trouble understanding some of the metrics.

For example Curr Conn/Active Conn, who's values seem to be significantly higher (by an order of magnitude) than a tool like netstat, on the same server, would suggest.

[A screenshot of a computer  Description automatically generated with medium confidence]

And, the value for New Conn here is also confusing.  What does 0.5 represent?

So, my questions are:

  *   Is traffic_top a commonly used and reliable tool in the ATS community?, and if it is
  *   Why do the readings for Curr Conn/Active Conn seems to not correlate with a tool like netstat?

Maybe we're holding it wrong?!?

Many thanks,

Nick

Nick Dunkin
Director, Software Architecture
Manager - Architecture and New Product Introduction
o:  +1 678.258.4071
e: nick.dunkin@vecima.com<ma...@vecima.com>

[cidimage001.png@01D6CC8C.6FC5A580]

Re: Understanding Traffic Top

[Bryan Call <bc...@apache.org>]

Curr Conn (current connections) is the number of socket connections connected to the server.  Active Con (active connections) should be number of connection that are handling requests.  New Conn (new connections) is how may new connections per second the server is accepting.

All of the stats traffic_top uses comes from the metrics in ATS.   They can also be fetched using traffic_ctl metric match .

What does your ss -s show you in the server?  What version of ATS are you running?

-Bryan

> On Dec 1, 2022, at 6:29 AM, Nick Dunkin <Ni...@vecima.com> wrote:
> 
> HI,
>  
> We’ve recently started using traffic_top to monitor our ATS instances, but we are having trouble understanding some of the metrics.
>  
> For example Curr Conn/Active Conn, who’s values seem to be significantly higher (by an order of magnitude) than a tool like netstat, on the same server, would suggest.
>  
> <image002.png>
>  
> And, the value for New Conn here is also confusing.  What does 0.5 represent?
>  
> So, my questions are:
> Is traffic_top a commonly used and reliable tool in the ATS community?, and if it is
> Why do the readings for Curr Conn/Active Conn seems to not correlate with a tool like netstat?
>  
> Maybe we’re holding it wrong?!?
>  
> Many thanks,
>  
> Nick
>  
> Nick Dunkin
> Director, Software Architecture
> Manager – Architecture and New Product Introduction 
> o:  +1 678.258.4071
> e: nick.dunkin@vecima.com <ma...@vecima.com>
>  
> <image001.png>