
[[ref-daemon-config-files-collectd]]
= Collectd
:description: Learn about collectd, which collects performance data to persist node metric data over time in OpenNMS {page-component-title}.

Collects xref:operation:deep-dive/performance-data-collection/introduction.adoc[performance management] data to persist node metric data over time.

.Collectd configuration file overview
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|===
| File
| Description
| Reload Event
| Restart Required

| collectd-configuration.xml
| This file defines which collections are being collected and assigned to which nodes. +
Restart is required in case new collectors are created or removed. +
The reload event loads changed configuration parameters of existing collectors but will not load new collectors.
| yes
| yes

| datacollection-config.xml
| Schema for SNMP data collection imports. +
SNMP data collection is managed in the database via *Admin -> Manage SNMP Data Collection Config*; this file is read only at first-boot migration if present.
| no
| no

| datacollection/*.xml
| Datacollection groups for SNMP. +
SNMP data collection is managed in the database via *Admin -> Manage SNMP Data Collection Config*; these files are read only at first-boot migration if present.
| no
| no

| jdbc-datacollection-config.xml
| Defines JDBC data collections.
Attributes are retrieved using SQL queries.
| no
| yes

| jmx-datacollection-config.xml
| Defines data collections via JMX.
| no
| yes

| jmx-datacollection-config.d/*.xml
| Defines data collections via JMX.
| no
| yes

| http-datacollection-config.xml
| Defines HTTP data collections.
Attributes are extracted from the HTTP responses using a regular expression.
| no
| yes

| prometheus-datacollection-config.xml
| Defines data collections via Prometheus Exporter.
| no
| yes

| prometheus-datacollection.d/*.xml
| Defines data collections via Prometheus Exporter.
| no
| yes

| snmp-config.xml
| Defines per-host security settings for SNMP communication.
| no
| no

| wsman-config.xml
| Defines per-host security settings for WSMAN communication.
| no
| no

| wsman-datacollection-config.xml
| Defines data collections via WSMAN.
| no
| yes

| wsman-datacollection.d/*.xml
| Files in this folder must be specified as an include directive in `wsman-datacollection-config.xml`.
| no
| yes

| xml-datacollection-config.xml
| Defines data collections that can be extracted from XML or JSON documents.
| no
| yes

| xml-datacollection/*.xml
| Files in this folder must be specified as an include directive in `xml-datacollection-config.xml`.
| no
| yes
|===

.Collectd log file overview
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|===
| File
| Description

| collectd.log
| Logs relating to collector server events.

| instrumentation.log
| Collection statistics used to populate the xref:operation:deep-dive/admin/logging/log-reader.adoc[Instrumentation Log Reader].
|===
