NAME

SYNOPSIS

syslog-ng.conf

DESCRIPTION

The application is a flexible and highly scalable system logging application. Typically, syslog-ng is used to manage log messages and implement centralized logging, where the aim is to collect the log messages of several devices on a single, central log server. The different devices - called syslog-ng clients - all run syslog-ng, and collect the log messages from the various applications, files, and other sources. The clients send all important log messages to the remote syslog-ng server, where the server sorts and stores them.

BASIC CONCEPTS OF

Log messages enter syslog-ng in one of the defined sources, and are sent to one or more destinations.

Sources and destinations are independent objects, log paths define what syslog-ng does with a message, connecting the sources to the destinations. A log path consists of one or more sources and one or more destinations: messages arriving from a source are sent to every destination listed in the log path. A log path defined in syslog-ng is called a log statement.

Optionally, log paths can include filters. Filters are rules that select only certain messages, for example, selecting only messages sent by a specific application. If a log path includes filters, syslog-ng sends only the messages satisfying the filter rules to the destinations set in the log path.

Other optional elements that can appear in log statements are parsers and rewriting rules. Parsers segment messages into different fields to help processing the messages, while rewrite rules modify the messages by adding, replacing, or removing parts of the messages.

CONFIGURING SYSLOG-NG

type-of-the-object identifier-of-the-object {<parameters>};

source s_internal { internal(); };

log { source(s_internal); destination(d_file); };

option(parameter1, parameter2); option2(parameter1, parameter2);

source s_tail { file("/var/log/apache/access.log"
    follow-freq(1) flags(no-parse, validate-utf8)); };

source s_demo_stream1 {
        unix-stream("<path-to-socket>" max-connections(10) group(log)); };
source s_demo_stream2 {
        unix-stream("<path-to-socket>" group(log) max-connections(10)); };

options { use-dns(no); };

# Comment: This is a stream source
source s_demo_stream {
        unix-stream("<path-to-socket>" max-connections(10) group(log)); };

The syntax of log statements is as follows:

log {
    source(s1); source(s2); ...
    optional_element(filter1|parser1|rewrite1);
    optional_element(filter2|parser2|rewrite2);
    ...
    destination(d1); destination(d2); ...
    flags(flag1[, flag2...]);
};

The following log statement sends all messages arriving to the localhost to a remote server.

source s_localhost { network(ip(127.0.0.1) port(1999)); };
destination d_tcp { network("10.1.2.3" port(1999) localport(999)); };
log { source(s_localhost); destination(d_tcp); };

The syslog-ng application has a number of global options governing DNS usage, the timestamp format used, and other general points. Each option may have parameters, similarly to driver specifications. To set global options, add an option statement to the syslog-ng configuration file using the following syntax:

options { option1(params); option2(params); ... };

Example 2. Using global options

To disable domain name resolving, add the following line to the syslog-ng configuration file:

options { use-dns(no); };

The sources, destinations, and filters available in syslog-ng are listed below. For details, see The syslog-ng Administrator Guide.

Table 1. Source drivers available in syslog-ng

Table 2. Destination drivers available in syslog-ng

Table 3. Filter functions available in

FILES

/usr/local/etc/syslog-ng.conf

SEE ALSO

AUTHOR

COPYRIGHT

NOTES

1.

The Administrator Guide

2.

the official syslog-ng website

3.

Hadoop Distributed File System (HDFS)

4.

Apache Kafka

5.

Loggly

6.

Logmatic.io

7.

MongoDB

8.

The 3.36 Administrator Guide

9.

syslog-ng mailing list

10.

syslog-ng blogs