RRD::Threshold - Check for thresholds exceeding values in RRD files data
This Perl module is capable of extracting some RRD information and to detect if the current value of a datasource is exeeding some thresholds using different algorithms and the help of past values of the same or other datasource.
The constructor takes no arguments.
($value, $bool) = boundaries($rrdfile, $ds, min => $min, max => $max)
This threshold takes too optional values, a minimum and a maximum value. If the data source strays outside of this interval, it returns false.
The path to the RRD file
The name of the data source
If current value is lower than this argument, the function returns false.
If current value is greater than this argument, the function returns false.
Throws:
If min is greater than max
on RRDs library error
if fetched value is Not a Number
if the given datasource can't be found in the RRD file
($value, $bool) = exact($rrdfile, $ds, $exact)
This threshold allows you to monitor a datasource for an exact match. This is useful in cases where an enumerated (or boolean) SNMP object instruments a condition where a transition to a specific state requires attention. For example, a datasource might return either true(1) or false(2), depending on whether or not a power supply has failed.
If the current value is different than this argument, the function will return false.
if exact argument isn't given
($value, $bool) = relation($rrdfile, $ds, $threshold, %args, cmp_rrdfile => $cmp_rrdfile, cmp_ds => $cmp_ds, cmp_timp => $cmp_time);
A relation threshold considers the difference between two data sources (possibly from different RRD files), or alternatively, the difference between two temporally distinct values for the same data source. The difference can be expressed as absolute value, or as a percentage of the second data source (comparison) value. This difference is compared to a threshold argument with either the greater than (>) or lesser than (<) operator. The criteria fails when the expression (<absolute or relative difference> <either greater-than or less-than> <threshold>) evaluates to false.
The path of the base RRD file.
The name of the base data source. The data source must belong to the $rrdfile.
The threshold number, optionally preceded by the greater than (>) or less than (<) symbol, and optionally followed by the symbol percent (%). If omitted, greater than is used by default and the expression, difference > threshold, is evaluated. "<10%", ">1000", "50%", and "500" are all examples of valid thresholds.
The path of the comparison RRD file. This argument is optional and if omitted the first RRD file is also taken as the comparison target.
The name of the comparison data source. This data source must belong to the comparison RRD file. This argument is optional and if omitted the first data source name is also taken as the comparison data source name. If the value is a number, the value is considered as a fix value and is taked for the comparison
The temporal offset to go back in the RRD file that is being fetched from for comparison from the current value. Note that a data source value must exist in the RRD file for that exact offset. If This argument is optional and if omitted, it is set to 0.
on argument error
($value, $bool) = quotient($rrdfile, $ds, $threshold, %args, cmp_rrdfile => $cmp_rrdfile, cmp_ds => $cmp_ds, cmp_timp => $cmp_time);
Quotient thresholds are similar to relation thresholds, except that they consider the quotient of two data sources, or alternatively, the same data source at two different time points. For a quotient monitor threshold, the value of the first data source is computed as a percentage of the second data source value (such as 10 (first datasource) is 50% of 20 (second datasource)). This percentage is then compared to a threshold argument with either the greater than (>) or less than (<) operator. The criteria fails when the expression (<percentage> <either greater-than or less-than> <threshold>) evaluates to false.
The threshold number, optionally preceded by the greater than (>) or less than (<) symbol and followed by the symbol percent (%). If omitted, greater than is used by default and the expression, difference > threshold, is evaluated. "<10%" and "50%" are examples of valid thresholds.
The name of the comparison data source. This data source must belong to the comparison RRD file. This argument is optional and if omitted the monitor threshold data source name is also taken as the comparison data source name. If the value is a number, the value is taken as-is to do the comparison.
($value, $bool) = hunt($rrdfile, $ds, $roll, cmp_rrdfile => $cmp_rrdfile, cmp_ds => $cmp_ds)
The hunt threshold is designed for the situation where the data source serves as an overflow for another data source; that is, if one data source (the parent) is at or near capacity, then traffic will begin to appear on this (the monitored) data source. One application of hunt monitor thresholds is to identify premature rollover in a set of modem banks configured to hunt from one to the next. Specifically, the criteria of the hunt monitor threshold fails if the value of the monitored data source is non-zero and the current value of the parent data source falls below a specified capacity threshold.
The threshold of the parent data source. Generally this should be slightly less than the maximum capacity of the target.
The path of the parent RRD file. This argument is optional and if omitted the base RRD file is also taken as the parent.
The name of the parent data source. This data source must belong to the parent RRD file. This argument is optional and if omitted the base data source name is also take as the comparison data source name.
if roll argument isn't given
Aberrant Behavior Detection failure detection.
not yet implemented
Olivier Poitrey <rs@rhapsodyk.net>
RRD::Threshold, checks for thresholds exceeding values in RRD files data. Copyright (C) 2004 Olivier Poitrey
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
RRDs, rrdgraph, RRD::Query, Error
1 POD Error
The following errors were encountered while parsing the POD:
Non-ASCII character seen before =encoding in 'source. One'. Assuming CP1252
To install RRD::Query, copy and paste the appropriate command in to your terminal.
cpanm
cpanm RRD::Query
CPAN shell
perl -MCPAN -e shell install RRD::Query
For more information on module installation, please visit the detailed CPAN module installation guide.