From aff2b94c1747e16e1a550f09a0b16f6c3cbf63e4 Mon Sep 17 00:00:00 2001 From: Florian Forster Date: Sat, 1 Sep 2007 21:44:59 +0200 Subject: [PATCH] collectd-snmp(5): Update the documentation. --- src/collectd-snmp.pod | 49 ++++++++++++++++++++++++++++++++++--------------- 1 file changed, 34 insertions(+), 15 deletions(-) diff --git a/src/collectd-snmp.pod b/src/collectd-snmp.pod index 22d6e37c..0f7e3a4e 100644 --- a/src/collectd-snmp.pod +++ b/src/collectd-snmp.pod @@ -56,6 +56,10 @@ internal format and dispatches them. Depending on the write plugins you have loaded they may be written to disk or submitted to another instance or whatever you configured. +Because querying a host via SNMP may produce a timeout multiple threads are +used to query hosts in parallel. Depending on the number of hosts between one +and ten threads are used. + =head1 CONFIGURATION Since the aim of the C is to provide a generic interface to SNMP, @@ -81,15 +85,35 @@ defined. =item B I Define if this is a single list of values or a table of values. The difference -is that when querying a list of values from SNMP that data is going to be -dispatched as one value-list to the daemon (i.Ee. one RRD file will be -created). If the correcponding data-set needs more than one value (has more -than one data-source) you will still need to configure more than one B -(see below). - -If B
is set to I then the plugin will search the entire subtree -and dispatch all values it can find. This is handy for the typical SNMP -tables, such as the interface table (C). +is the following: + +When B
is set to B, the OIDs given to B (see below) are +queried using the C SNMP command (see L) and transmitted to +collectd. B value list is dispatched and, eventually, one file will be +written. + +When B
is set to B, the OIDs given to B (see below) are +queried using the C SNMP command until the subtree is left. After all +the lists (think: all columns of the table) have been read B values +sets will be dispatches and, eventually, several files will be written. If you +configure a B (see above) which needs more than one data source (for +example C which needs C and C) you will need to specify more +than one (two, in the example case) OIDs with the B option. This has +nothing to do with the B
setting. + +For example, if you want to query the number of users on a system, you can use +C. This is one value and belongs to one +value list, therefore B
must be set to B. Please note that, in +this case, you have to include the sequence number (zero in this case) in the +OID. + +Counter example: If you want to query the interface table provided by the +C, e.Eg. the bytes transmitted. There are potentially many +interfaces, so you will want to set B
to B. Because the +C type needs two values, received and transmitted bytes, you need to +specify two OIDs in the B setting, in this case likely +C and C. But, this is because of +the B setting, not the B
setting. Since the semantic of B and B depends on this setting you need to set it before setting them. Doing vice verse will result in undefined @@ -98,7 +122,7 @@ behavior. =item B I Sets the type-instance of the values that are dispatched. The meaning of this -setting depends on wether B
is set to I or I: +setting depends on whether B
is set to I or I: If B
is set to I, I is interpreted as an SNMP-prefix that will return a list of strings. Those strings are then used as the actual @@ -170,11 +194,6 @@ wise to select a reasonable value once and never change it. =back -=head1 BUGS - -All configured hosts are queried sequencially, so timeouts may cause gaps in -graphs. - =head1 SEE ALSO L, -- 2.11.0