:plugin: multiline
:type: codec

///////////////////////////////////////////
START - GENERATED VARIABLES, DO NOT EDIT!
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:version: %VERSION%
:release_date: %RELEASE_DATE%
:changelog_url: %CHANGELOG_URL%
:include_path: ../../../../logstash/docs/include
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END - GENERATED VARIABLES, DO NOT EDIT!
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[id="plugins-{type}s-{plugin}"]

=== Multiline codec plugin

include::{include_path}/plugin_header.asciidoc[]

==== Description

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

IMPORTANT: If you are using a Logstash input plugin that supports multiple
hosts, such as the {logstash-ref}/plugins-inputs-beats.html[beats input plugin], you should not use
the multiline codec to handle multiline events. Doing so may result in the
mixing of streams and corrupted event data. In this situation, you need to
handle multiline events before sending the event data to Logstash. 

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:
[source,ruby]
    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:
[source,ruby]
    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..
[source,ruby]
    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:
[source,ruby]
    input {
      stdin {
        codec => multiline {
          pattern => "\\$"
          what => "next"
        }
      }
    }

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


[id="plugins-{type}s-{plugin}-options"]
==== Multiline Codec Configuration Options

[cols="<,<,<",options="header",]
|=======================================================================
|Setting |Input type|Required
| <<plugins-{type}s-{plugin}-auto_flush_interval>> |<<number,number>>|No
| <<plugins-{type}s-{plugin}-charset>> |<<string,string>>, one of `["ASCII-8BIT", "UTF-8", "US-ASCII", "Big5", "Big5-HKSCS", "Big5-UAO", "CP949", "Emacs-Mule", "EUC-JP", "EUC-KR", "EUC-TW", "GB2312", "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", "UTF-16BE", "UTF-16LE", "UTF-32BE", "UTF-32LE", "Windows-31J", "Windows-1250", "Windows-1251", "Windows-1252", "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", "IBM037", "stateless-ISO-2022-JP", "eucJP-ms", "CP51932", "EUC-JIS-2004", "GB12345", "ISO-2022-JP", "ISO-2022-JP-2", "CP50220", "CP50221", "Windows-1256", "Windows-1253", "Windows-1255", "Windows-1254", "TIS-620", "Windows-874", "Windows-1257", "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", "ebcdic-cp-us", "eucJP", "euc-jp-ms", "EUC-JISX0213", "eucKR", "eucTW", "EUC-CN", "eucCN", "CP936", "ISO2022-JP", "ISO2022-JP2", "ISO8859-1", "ISO8859-2", "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", "MacJapan", "ASCII", "ANSI_X3.4-1968", "646", "CP65000", "CP65001", "UTF-8-MAC", "UTF-8-HFS", "UCS-2BE", "UCS-4BE", "UCS-4LE", "CP932", "csWindows31J", "SJIS", "PCK", "CP1250", "CP1251", "CP1252", "external", "locale"]`|No
| <<plugins-{type}s-{plugin}-max_bytes>> |<<bytes,bytes>>|No
| <<plugins-{type}s-{plugin}-max_lines>> |<<number,number>>|No
| <<plugins-{type}s-{plugin}-multiline_tag>> |<<string,string>>|No
| <<plugins-{type}s-{plugin}-negate>> |<<boolean,boolean>>|No
| <<plugins-{type}s-{plugin}-pattern>> |<<string,string>>|Yes
| <<plugins-{type}s-{plugin}-patterns_dir>> |<<array,array>>|No
| <<plugins-{type}s-{plugin}-what>> |<<string,string>>, one of `["previous", "next"]`|Yes
|=======================================================================

&nbsp;

[id="plugins-{type}s-{plugin}-auto_flush_interval"]
===== `auto_flush_interval` 

  * Value type is <<number,number>>
  * There is no default value for this setting.

The accumulation of multiple lines will be converted to an event when either a
matching new line is seen or there has been no new data appended for this many
seconds. No default.  If unset, no auto_flush. Units: seconds

[id="plugins-{type}s-{plugin}-charset"]
===== `charset` 

  * Value can be any of: `ASCII-8BIT`, `UTF-8`, `US-ASCII`, `Big5`, `Big5-HKSCS`, `Big5-UAO`, `CP949`, `Emacs-Mule`, `EUC-JP`, `EUC-KR`, `EUC-TW`, `GB2312`, `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`, `UTF-16BE`, `UTF-16LE`, `UTF-32BE`, `UTF-32LE`, `Windows-31J`, `Windows-1250`, `Windows-1251`, `Windows-1252`, `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`, `IBM037`, `stateless-ISO-2022-JP`, `eucJP-ms`, `CP51932`, `EUC-JIS-2004`, `GB12345`, `ISO-2022-JP`, `ISO-2022-JP-2`, `CP50220`, `CP50221`, `Windows-1256`, `Windows-1253`, `Windows-1255`, `Windows-1254`, `TIS-620`, `Windows-874`, `Windows-1257`, `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`, `ebcdic-cp-us`, `eucJP`, `euc-jp-ms`, `EUC-JISX0213`, `eucKR`, `eucTW`, `EUC-CN`, `eucCN`, `CP936`, `ISO2022-JP`, `ISO2022-JP2`, `ISO8859-1`, `ISO8859-2`, `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`, `MacJapan`, `ASCII`, `ANSI_X3.4-1968`, `646`, `CP65000`, `CP65001`, `UTF-8-MAC`, `UTF-8-HFS`, `UCS-2BE`, `UCS-4BE`, `UCS-4LE`, `CP932`, `csWindows31J`, `SJIS`, `PCK`, `CP1250`, `CP1251`, `CP1252`, `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.

[id="plugins-{type}s-{plugin}-max_bytes"]
===== `max_bytes` 

  * Value type is <<bytes,bytes>>
  * Default value is `"10 MiB"`

The accumulation of events can make logstash exit with an out of memory error
if event boundaries are not correctly defined. This settings make sure to flush
multiline events after reaching a number of bytes, it is used in combination
max_lines.

[id="plugins-{type}s-{plugin}-max_lines"]
===== `max_lines` 

  * Value type is <<number,number>>
  * Default value is `500`

The accumulation of events can make logstash exit with an out of memory error
if event boundaries are not correctly defined. This settings make sure to flush
multiline events after reaching a number of lines, it is used in combination
max_bytes.

[id="plugins-{type}s-{plugin}-multiline_tag"]
===== `multiline_tag` 

  * Value type is <<string,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.

[id="plugins-{type}s-{plugin}-negate"]
===== `negate` 

  * Value type is <<boolean,boolean>>
  * Default value is `false`

Negate the regexp pattern ('if not matched').

[id="plugins-{type}s-{plugin}-pattern"]
===== `pattern` 

  * This is a required setting.
  * Value type is <<string,string>>
  * There is no default value for this setting.

The regular expression to match.

[id="plugins-{type}s-{plugin}-patterns_dir"]
===== `patterns_dir` 

  * Value type is <<array,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:
[source,ruby]
    NAME PATTERN

For example:
[source,ruby]
    NUMBER \d+

[id="plugins-{type}s-{plugin}-what"]
===== `what` 

  * This is a 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?


