Re: [Devmon] if_err stats

[Buchan M. <bg...@st...>]

On Tuesday, 24 January 2012 13:26:01 Mario Valetti wrote:
> Hi,
> 
> When selecting 'network device | <if_err>' column, the resultant table
> shows total interface errors since the device start / reset.

Can you provide the name of the template you are using for the device in 
question (if it is a standard, unmodified template), or the template itself 
you are using (if not standard unmodified)?

> I'm
> only interested in checking if errors occured within the previous 24 or
> 48hrs (for example).

The transforms file on most of the if_err tests includes:

# Get bit speed delta (so we dont have to provide custom delta limit)
ifInOps         : DELTA         : {ifInOctets}
ifOutOps        : DELTA         : {ifOutOctets}
# Convert our octets delta into bits per second
ifInBps         : MATH          : {ifInOps} x 8
ifOutBps        : MATH          : {ifOutOps} x 8
# Do delta transform on all error counters
ifInEps         : DELTA         : {ifInErrors}
ifOutEps        : DELTA         : {ifOutErrors}
# Perform error to traffic percentage calculations
ifInErrPct      : MATH          : ({ifInEps} / {ifInBps}) x 100
ifOutErrPct     : MATH          : ({ifOutEps} / {ifOutBps}) x 100
# Create an alias in a bracketed box, or nothing if alias is blank
ifAliasBox      : REGSUB        : {ifAlias} /(\S+.*)/ [$1]/

And the thresholds:
# Create thresholds for all the error rate counters
# oid name      : color         : limit : Error message

ifInErrPct      : yellow        : 5     : {ifName}{ifAliasBox} - High input 
error rate ({ifInErrPct}%)
ifInErrPct      : red           : 10    : {ifName}{ifAliasBox} - Very high 
input error rate ({ifInErrPct}%)
ifOutErrPct     : yellow        : 5     : {ifName}{ifAliasBox} - High output 
error rate ({ifOutErrPct}%)
ifOutErrPct     : red           : 10    : {ifName}{ifAliasBox} - Very high 
output error rate ({ifOutErrPct}%)


So, all alarming is for Error packets per second / Bits per second (so, 
unfortunately, not a real percentage) averaged over the poll period.

It may instead be better to make it 'Error packets per second' / ('Unicast 
pps' + 'Multicast pps' + 'Broadcast pps') to give a real percentage.

However, your assertion that the table holds the total errors since counter 
reset is false (at least for most if_err tests).

Feel free to send a patch ...

> I know the if_err graphs are available under the "trends" column, but is it
> possible to view this period for errors directly in the table within the
> if_err column check?

You can get the graphs on the if_err page as well by adding e.g. '--
multigraphs=disk,if_load,if_err,temp' to CGI_SVC_OPTS in hobbitcgi.cfg or 
equivalent.


Regards,
Buchan