[Orca-users] Re: TCP attempt fail rate

[Blair Zajac]

Martin Jenner wrote:
> 
> Hello
> 
> I work for a large ISP and one of our customers is using your ORCA tool
> to moinot performance of the servers we manage for them.
> 
> They've raised an issue about the "TCP attempt fail rate" levels that
> ORCA is recording.
> 
> Can you tell me exectly what this is measuring so I can address the
> issue?

Hi,

[cc'ing Orca Users mailing list.]

Good question.  My page

http://www.orcaware.com/orca/docs/orcallator.html#TCP_attempt_fail_rate

specifically the section at

http://www.orcaware.com/orca/docs/orcallator.html#TCP_attempt_fail_rate

doesn't describe a whole lot.


Looking at the SE source code which gets this from the kernel
(RICHPse/include/mib.se)

uint  tcpAttemptFails;  // # of dir. SYN-SENT/RCVD->CLOSED/LISTEN { tcp 7 }

Does anybody know exactly what this measures?  It looks like it's the
number of active connections the host is attempting to set up that fail
per second.

> is this recording some system parameters actually on the machine or

Yes.

> would it be recording data from some remote machine trying to connect?

No, it doesn't appear so.

Best,
Blair

-- 
Blair Zajac <blair at orcaware.com>
Web and OS performance plots - http://www.orcaware.com/orca/

> 
> Any data would be gratefully received.
> 
> Best Regards
> 
> Martin Jenner
> Internet Support Group
> NTL