syslog-ng Open Source Edition 3.16 - Administration Guide

graphite: Sending metrics to Graphite

The graphite() destination can send metrics to a Graphite server to store numeric time-series data. There are many ways to feed the Graphite template function with name value pairs. The syslog-ng OSE CSV and PatternDB parsers (for details, see Using pattern parsers) can parse log messages and generate name value pairs based on message content. The CSV parser (for details, see Parsing messages with comma-separated and similar values) can be used for logs which have a constant field based structure, like the Apache web server access logs. The patterndb parser can parse information and can extract important fields from free form log messages, as long as patterns describing the log messages are available. Another way is to send JSON-based log messages (for details, see The JSON parser) to syslog-ng OSE, like running a simple shell script collecting metrics and running it from cron regularly.

To see an example of how the graphite() destination is used to collect statistics coming from syslog-ng, see the blog post Collecting syslog-ng statistics to Graphite.

graphite(payload());

destination d_graphite { graphite(payload("--key monitor.*")); };

graphite() destination options

The graphite() destination has the following options:

hook-commands()

Description: This option makes it possible to execute external programs when the relevant driver is initialized or torn down. The hook-commands() can be used with all source and destination drivers with the exception of the usertty() and internal() drivers.

Using the hook-commands() when syslog-ng OSE starts or stops

To execute an external program when syslog-ng OSE starts or stops, use the following options:

Using the hook-commands() when syslog-ng OSE reloads

To execute an external program when the syslog-ng OSE configuration is initiated or torn down, for example, on startup/shutdown or during a syslog-ng OSE reload, use the following options:

source {
   network(transport(udp)
	hook-commands(
          startup("iptables -I LOGCHAIN 1 -p udp --dport 514 -j ACCEPT")
          shutdown("iptables -D LOGCHAIN 1")
        )
     );
};

empty string

Sending logs to Graylog

graylog2(): Sending logs to Graylog

You can use the graylog2() destination and a Graylog Extended Log Format (GELF) template to send syslog messages to Graylog.

You can forward simple name-value pairs where the name starts with a dot or underscore. If names of your name-value pairs include dots other than the first character, you should use JSON formatting directly instead of the GELF template and send logs to a raw TCP port in Graylog, which can then extract fields from nested JSON.

graylog2();

graylog() destination options

The graylog2() destination has the following options:

hook-commands()

Description: This option makes it possible to execute external programs when the relevant driver is initialized or torn down. The hook-commands() can be used with all source and destination drivers with the exception of the usertty() and internal() drivers.

Using the hook-commands() when syslog-ng OSE starts or stops

To execute an external program when syslog-ng OSE starts or stops, use the following options:

Using the hook-commands() when syslog-ng OSE reloads

To execute an external program when the syslog-ng OSE configuration is initiated or torn down, for example, on startup/shutdown or during a syslog-ng OSE reload, use the following options:

source {
   network(transport(udp)
	hook-commands(
          startup("iptables -I LOGCHAIN 1 -p udp --dport 514 -j ACCEPT")
          shutdown("iptables -D LOGCHAIN 1")
        )
     );
};