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syslog-ng Open Source Edition 3.16 - Administration Guide

Preface Introduction to syslog-ng The concepts of syslog-ng Installing syslog-ng The syslog-ng OSE quick-start guide The syslog-ng OSE configuration file source: Read, receive, and collect log messages
How sources work default-network-drivers: Receive and parse common syslog messages internal: Collecting internal messages file: Collecting messages from text files wildcard-file: Collecting messages from multiple text files network: Collecting messages using the RFC3164 protocol (network() driver) nodejs: Receiving JSON messages from nodejs applications mbox: Converting local e-mail messages to log messages osquery: Collect and parse osquery result logs pipe: Collecting messages from named pipes pacct: Collecting process accounting logs on Linux program: Receiving messages from external applications snmptrap: Read Net-SNMP traps sun-streams: Collecting messages on Sun Solaris syslog: Collecting messages using the IETF syslog protocol (syslog() driver) system: Collecting the system-specific log messages of a platform systemd-journal: Collecting messages from the systemd-journal system log storage systemd-syslog: Collecting systemd messages using a socket tcp, tcp6, udp, udp6: Collecting messages from remote hosts using the BSD syslog protocol— OBSOLETE unix-stream, unix-dgram: Collecting messages from UNIX domain sockets stdin: Collecting messages from the standard input stream
destination: Forward, send, and store log messages
amqp: Publishing messages using AMQP elasticsearch: Sending messages directly to Elasticsearch version 1.x elasticsearch2: Sending logs directly to Elasticsearch and Kibana 2.0 or higher file: Storing messages in plain-text files graphite: Sending metrics to Graphite Sending logs to Graylog hdfs: Storing messages on the Hadoop Distributed File System (HDFS) Posting messages over HTTP http: Posting messages over HTTP without Java kafka: Publishing messages to Apache Kafka loggly: Using Loggly logmatic: Using Logmatic.io mongodb: Storing messages in a MongoDB database network: Sending messages to a remote log server using the RFC3164 protocol (network() driver) osquery: Sending log messages to osquery's syslog table pipe: Sending messages to named pipes program: Sending messages to external applications pseudofile() redis: Storing name-value pairs in Redis riemann: Monitoring your data with Riemann smtp: Generating SMTP messages (e-mail) from logs Splunk: Sending log messages to Splunk sql: Storing messages in an SQL database stomp: Publishing messages using STOMP syslog: Sending messages to a remote logserver using the IETF-syslog protocol syslog-ng: Forwarding messages and tags to another syslog-ng node tcp, tcp6, udp, udp6: Sending messages to a remote log server using the legacy BSD-syslog protocol (tcp(), udp() drivers) Telegram: Sending messages to Telegram unix-stream, unix-dgram: Sending messages to UNIX domain sockets usertty: Sending messages to a user terminal: usertty() destination Write your own custom destination in Java or Python
log: Filter and route log messages using log paths, flags, and filters Global options of syslog-ng OSE TLS-encrypted message transfer template and rewrite: Format, modify, and manipulate log messages parser: Parse and segment structured messages db-parser: Process message content with a pattern database (patterndb) Correlating log messages Enriching log messages with external data Statistics of syslog-ng Multithreading and scaling in syslog-ng OSE Troubleshooting syslog-ng Best practices and examples The syslog-ng manual pages Third-party contributions Creative Commons Attribution Non-commercial No Derivatives (by-nc-nd) License About us

Configuring log rotation

The syslog-ng OSE application does not rotate logs by itself. To use syslog-ng OSE for log rotation, consider the following approaches:

Use logrotate together with syslog-ng OSE:

  • Ideal for workstations or when processing fewer logs.

  • It is included in most distributions by default.

  • Less scripting is required, only logrotate has to be configured correctly.

  • Requires frequent restart (syslog-ng OSE must be reloaded/restarted when the files are rotated). After rotating the log files, reload syslog-ng OSE using the syslog-ng-ctl reload command, or use another method to send a SIGHUP to syslog-ng OSE.

  • The statistics collected by syslog-ng OSE, and the correlation information gathered with Pattern Database is lost with each restart.

Separate incoming logs based on time, host or other information:

  • Ideal for central log servers, where regular restart of syslog-ng OSE is unfavorable.

  • Requires shell scripts or cron jobs to remove old logs.

  • It can be done by using macros in the destination name (in the filename, directory name, or the database table name). (For details on using macros, see Templates and macros.)

Example: File destination for log rotation

This sample file destination configuration stores incoming logs in files that are named based on the current year, month and day, and places these files in directories that are named based on the hostname:

destination d_sorted {
    file(
        "/var/log/remote/${HOST}/${YEAR}_${MONTH}_${DAY}.log"
        create-dirs(yes)
    );
};

This sample logstore destination configuration stores incoming logs in logstores that are named based on the current year, month and day, and places these logstores in directories that are named based on the hostname:

destination d_logstore {
    logstore(
        "/var/log/remote/${HOST}/${YEAR}_${MONTH}_${DAY}.lgs"
        compress(9)
        create-dirs(yes)
    );
};
Example: Command for cron for log rotation

This sample command for cron removes files older than two weeks from the /var/log/remote directory:

find /var/log/remote/ -daystart -mtime +14 -type f -exec rm {} \;

The syslog-ng manual pages

This chapter collects the manual pages of syslog-ng OSE and other related applications that are usually distributed and packaged together with the syslog-ng Open Source Edition application.

Manual pages

This chapter collects the manual pages of syslog-ng OSE and other related applications that are usually distributed and packaged together with the syslog-ng Open Source Edition application.

dqtool.1

Table of Contents

dqtool — Display the contents of a disk-buffer file created with syslog-ng Open Source Edition

Name

dqtool — Display the contents of a disk-buffer file created with syslog-ng Open Source Edition

Synopsis

dqtool [command] [options]

Description

NOTE: The dqtool application is distributed with the syslog-ng Open Source Edition system logging application, and is usually part of the syslog-ng package. The latest version of the syslog-ng application is available at the syslog-ng page.

This manual page is only an abstract, for the complete documentation of syslog-ng, see the syslog-ng Documentation page.

The dqtool application is a utility that can be used to display and format the messages stored in a disk-buffer file.

The cat command

cat [options] [file]

Use the cat command to display the log messages stored in the disk-buffer (also called disk-queue) file, and also information from the header of the disk queue file. The messages are printed to the standard output (stdout), so it is possible to use grep and other tools to find particular log messages, e.g., dqtool cat /var/log/messages.lgs |grep 192.168.1.1.

The cat command has the following options:

--debug or -d

Print diagnostic and debugging messages to stderr.

--help or -h

Display a brief help message.

--template=<template> or -t

Format the messages using the specified template.

--verbose or -v

Print verbose messages to stderr.

--version or -V

Display version information.

Example:

./dqtool cat ../var/syslog-ng-00000.qf

The output looks like:

Disk-buffer state loaded; filename='../var/syslog-ng-00000.qf', qout_length='65', qbacklog_length='0', qoverflow_length='9205', qdisk_length='0'
Mar  3 10:52:05 tristram localprg[1234]: seq: 0000011630, runid: 1267609923, stamp: 2010-03-03T10:52:05 PADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADD
Mar  3 10:52:05 tristram localprg[1234]: seq: 0000011631, runid: 1267609923, stamp: 2010-03-03T10:52:05 PADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADDPADD

Files

/opt/syslog-ng/bin/dqtool

See also

syslog-ng.conf(5)

syslog-ng(8)

Note

For the detailed documentation of syslog-ng OSE see the syslog-ng Documentation page

If you experience any problems or need help with syslog-ng, visit the syslog-ng mailing list.

For news and notifications about of syslog-ng, visit the syslog-ng blogs.

Author

This manual page was written by the Balabit Documentation Team <documentation@balabit.com>.

Copyright

The authors grant permission to copy, distribute and/or modify this manual page under the terms of the GNU General Public License Version 2 or newer (GPL v2+).

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