Chapter 10. Data Queries

Field

Description

query >oid_num_indexes

An OID that can be queried to determine the total number of available

indexes. If specified, this will be used to determine when to automatically

recache this SNMP query when it is attached to a device.

query >index_order

As of version 0.8.6, Cacti will attempt to find the best field to index off of

based on whether each row in the query is unique and non null. If specified,

Cacti will perform this check on the fields listed here in the order specified.

Only input fields can be specified and multiple fields should be delimited

with a comma.

query >index_order_type

For sorting purposes, specify whether the index is numeric or alphanumeric.

numeric

: The indexes in this SNMP query are to be sorted numerically (ie.

1,2,3,10,20,31)

alphabetic

: The indexes in this SNMP query are to be sorted alphabetically

(1,10,2,20,3,31).

query >index_title_format

Specify the title format to use when representing an index to the user. Any

input field name can be used as a variable if enclosed in pipes (|). The

variable

|chosen_order_field|

will be substituted with the field chosen

by Cacti to index off of (see index_order above).

query >fields

Each field contained within the SNMP query must be defined under this tag.

query >fields >ifIndex

Each defined field in the SNMP query must have a unique name given to it.

Do not use spaces or any non alphanumeric characters, this name must be

identifiable within Cacti.

query >fields >ifIndex >name

Here you can specify a "friendly name" for the field. This name will be used

by Cacti to help the user identify this field.

query >fields >ifIndex >method

Tell Cacti how you want it to gather SNMP information for this field.

get

: The 'get' method obtains a list of indexes and does an snmpget for each

index of the OID specified for this field.

walk

: The 'walk' method does a walk of the OID specified for this field. Both

methods will return the same values, even though the 'walk' method is typi 

cally more efficient.

query >fields >ifIndex >source

When Cacti obtains a list for this field, you need to tell it how to derive its

value for each row.

value

: The 'value' option simply returns the result of the snmpget for each

row.

OID/REGEXP:(regexp_match)

: The 'OID/REGEXP:(regexp_match)' can

be used when you need to use a POSIX based regular expression to derive

the value from the OID. The most common example of this is to retreive the

IP address of an interface, and can be seen in the 'interface.xml' file.

VALUE/REGEXP:(regexp_match)

: The 'OID/REGEXP:(regexp_match)'

option can be used to parse the value based on a regular expression, return 

ing the first match.

index

: Simply use the value of the index for this row as the value. If the in 

dex is being parsed from the OID using the oid_index_parse field, you must

specify

index

here.

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