multiline

Milestone: 3

The multiline codec will collapse multiline messages and merge them into a single event.

The original goal of this codec was to allow joining of multiline messages from files into a single event. For example, joining Java exception and stacktrace messages into a single event.

The config looks like this:

input {
  stdin {
    codec => multiline {
      pattern => "pattern, a regexp"
      negate => "true" or "false"
      what => "previous" or "next"
    }
  }
}

The pattern should match what you believe to be an indicator that the field is part of a multi-line event.

The what must be “previous” or “next” and indicates the relation to the multi-line event.

The negate can be “true” or “false” (defaults to “false”). If “true”, a message not matching the pattern will constitute a match of the multiline filter and the what will be applied. (vice-versa is also true)

For example, Java stack traces are multiline and usually have the message starting at the far-left, with each subsequent line indented. Do this:

input {
  stdin {
    codec => multiline {
      pattern => "^\s"
      what => "previous"
    }
  }
}

This says that any line starting with whitespace belongs to the previous line.

Another example is to merge lines not starting with a date up to the previous line..

input {
  file {
    path => "/var/log/someapp.log"
    codec => multiline {
      # Grok pattern names are valid! :)
      pattern => "^%{TIMESTAMP_ISO8601} "
      negate => true
      what => previous
    }
  }
}

This says that any line not starting with a timestamp should be merged with the previous line.

One more common example is C line continuations (backslash). Here’s how to do that:

filter {
  multiline {
    type => "somefiletype"
    pattern => "\\$"
    what => "next"
  }
}

This says that any line ending with a backslash should be combined with the following line.

Synopsis

This is what it might look like in your config file:
# with an input plugin:
# you can also use this codec with an output.
input { 
  file {
    codec => multiline {
      charset => ... # string, one of ["ASCII-8BIT", "Big5", "Big5-HKSCS", "Big5-UAO", "CP949", "Emacs-Mule", "EUC-JP", "EUC-KR", "EUC-TW", "GB18030", "GBK", "ISO-8859-1", "ISO-8859-2", "ISO-8859-3", "ISO-8859-4", "ISO-8859-5", "ISO-8859-6", "ISO-8859-7", "ISO-8859-8", "ISO-8859-9", "ISO-8859-10", "ISO-8859-11", "ISO-8859-13", "ISO-8859-14", "ISO-8859-15", "ISO-8859-16", "KOI8-R", "KOI8-U", "Shift_JIS", "US-ASCII", "UTF-8", "UTF-16BE", "UTF-16LE", "UTF-32BE", "UTF-32LE", "Windows-1251", "GB2312", "IBM437", "IBM737", "IBM775", "CP850", "IBM852", "CP852", "IBM855", "CP855", "IBM857", "IBM860", "IBM861", "IBM862", "IBM863", "IBM864", "IBM865", "IBM866", "IBM869", "Windows-1258", "GB1988", "macCentEuro", "macCroatian", "macCyrillic", "macGreek", "macIceland", "macRoman", "macRomania", "macThai", "macTurkish", "macUkraine", "CP950", "CP951", "stateless-ISO-2022-JP", "eucJP-ms", "CP51932", "GB12345", "ISO-2022-JP", "ISO-2022-JP-2", "CP50220", "CP50221", "Windows-1252", "Windows-1250", "Windows-1256", "Windows-1253", "Windows-1255", "Windows-1254", "TIS-620", "Windows-874", "Windows-1257", "Windows-31J", "MacJapanese", "UTF-7", "UTF8-MAC", "UTF-16", "UTF-32", "UTF8-DoCoMo", "SJIS-DoCoMo", "UTF8-KDDI", "SJIS-KDDI", "ISO-2022-JP-KDDI", "stateless-ISO-2022-JP-KDDI", "UTF8-SoftBank", "SJIS-SoftBank", "BINARY", "CP437", "CP737", "CP775", "IBM850", "CP857", "CP860", "CP861", "CP862", "CP863", "CP864", "CP865", "CP866", "CP869", "CP1258", "Big5-HKSCS:2008", "eucJP", "euc-jp-ms", "eucKR", "eucTW", "EUC-CN", "eucCN", "CP936", "ISO2022-JP", "ISO2022-JP2", "ISO8859-1", "CP1252", "ISO8859-2", "CP1250", "ISO8859-3", "ISO8859-4", "ISO8859-5", "ISO8859-6", "CP1256", "ISO8859-7", "CP1253", "ISO8859-8", "CP1255", "ISO8859-9", "CP1254", "ISO8859-10", "ISO8859-11", "CP874", "ISO8859-13", "CP1257", "ISO8859-14", "ISO8859-15", "ISO8859-16", "CP878", "CP932", "csWindows31J", "SJIS", "PCK", "MacJapan", "ASCII", "ANSI_X3.4-1968", "646", "CP65000", "CP65001", "UTF-8-MAC", "UTF-8-HFS", "UCS-2BE", "UCS-4BE", "UCS-4LE", "CP1251", "external", "locale"] (optional), default: "UTF-8"
      multiline_tag => ... # string (optional), default: "multiline"
      negate => ... # boolean (optional), default: false
      pattern => ... # string (required)
      patterns_dir => ... # array (optional), default: []
      what => ... # string, one of ["previous", "next"] (required)
    }
  }
}

Details

charset

  • Value can be any of: "ASCII-8BIT", "Big5", "Big5-HKSCS", "Big5-UAO", "CP949", "Emacs-Mule", "EUC-JP", "EUC-KR", "EUC-TW", "GB18030", "GBK", "ISO-8859-1", "ISO-8859-2", "ISO-8859-3", "ISO-8859-4", "ISO-8859-5", "ISO-8859-6", "ISO-8859-7", "ISO-8859-8", "ISO-8859-9", "ISO-8859-10", "ISO-8859-11", "ISO-8859-13", "ISO-8859-14", "ISO-8859-15", "ISO-8859-16", "KOI8-R", "KOI8-U", "Shift_JIS", "US-ASCII", "UTF-8", "UTF-16BE", "UTF-16LE", "UTF-32BE", "UTF-32LE", "Windows-1251", "GB2312", "IBM437", "IBM737", "IBM775", "CP850", "IBM852", "CP852", "IBM855", "CP855", "IBM857", "IBM860", "IBM861", "IBM862", "IBM863", "IBM864", "IBM865", "IBM866", "IBM869", "Windows-1258", "GB1988", "macCentEuro", "macCroatian", "macCyrillic", "macGreek", "macIceland", "macRoman", "macRomania", "macThai", "macTurkish", "macUkraine", "CP950", "CP951", "stateless-ISO-2022-JP", "eucJP-ms", "CP51932", "GB12345", "ISO-2022-JP", "ISO-2022-JP-2", "CP50220", "CP50221", "Windows-1252", "Windows-1250", "Windows-1256", "Windows-1253", "Windows-1255", "Windows-1254", "TIS-620", "Windows-874", "Windows-1257", "Windows-31J", "MacJapanese", "UTF-7", "UTF8-MAC", "UTF-16", "UTF-32", "UTF8-DoCoMo", "SJIS-DoCoMo", "UTF8-KDDI", "SJIS-KDDI", "ISO-2022-JP-KDDI", "stateless-ISO-2022-JP-KDDI", "UTF8-SoftBank", "SJIS-SoftBank", "BINARY", "CP437", "CP737", "CP775", "IBM850", "CP857", "CP860", "CP861", "CP862", "CP863", "CP864", "CP865", "CP866", "CP869", "CP1258", "Big5-HKSCS:2008", "eucJP", "euc-jp-ms", "eucKR", "eucTW", "EUC-CN", "eucCN", "CP936", "ISO2022-JP", "ISO2022-JP2", "ISO8859-1", "CP1252", "ISO8859-2", "CP1250", "ISO8859-3", "ISO8859-4", "ISO8859-5", "ISO8859-6", "CP1256", "ISO8859-7", "CP1253", "ISO8859-8", "CP1255", "ISO8859-9", "CP1254", "ISO8859-10", "ISO8859-11", "CP874", "ISO8859-13", "CP1257", "ISO8859-14", "ISO8859-15", "ISO8859-16", "CP878", "CP932", "csWindows31J", "SJIS", "PCK", "MacJapan", "ASCII", "ANSI_X3.4-1968", "646", "CP65000", "CP65001", "UTF-8-MAC", "UTF-8-HFS", "UCS-2BE", "UCS-4BE", "UCS-4LE", "CP1251", "external", "locale"
  • Default value is "UTF-8"

The character encoding used in this input. Examples include “UTF-8” and “cp1252”

This setting is useful if your log files are in Latin-1 (aka cp1252) or in another character set other than UTF-8.

This only affects “plain” format logs since JSON is UTF-8 already.

multiline_tag

  • Value type is string
  • Default value is "multiline"

Tag multiline events with a given tag. This tag will only be added to events that actually have multiple lines in them.

negate

  • Value type is boolean
  • Default value is false

Negate the regexp pattern (‘if not matched’).

pattern (required setting)

  • Value type is string
  • There is no default value for this setting.

The regular expression to match.

patterns_dir

  • Value type is array
  • Default value is []

Logstash ships by default with a bunch of patterns, so you don’t necessarily need to define this yourself unless you are adding additional patterns.

Pattern files are plain text with format:

NAME PATTERN

For example:

NUMBER \d+

what (required setting)

  • Value can be any of: "previous", "next"
  • There is no default value for this setting.

If the pattern matched, does event belong to the next or previous event?


This is documentation from lib/logstash/codecs/multiline.rb