Fluentd

Overview
Setup instructions
Multiline logs

Fluentd is a data collector, which unifies the data collection and consumption. This integration allows you to use Fluentd to send logs to your Logz.io account.

Fluentd will fetch all existing logs, as it is not able to ignore older logs.

Configure Fluentd

Before you begin, you’ll need: Ruby and ruby-dev 2.1 or higher

Install Fluentd and the Logz.io plugin

gem install fluentd fluent-plugin-logzio

Set up Fluentd

fluentd --setup ./fluent

Add an input plugin

Add a required input plugin to the configuration file. You can find the list of available input plugins here.

An example input plugin looks as follows:

<source>
  @type tail
  path /var/log/httpd-access.log
  pos_file /var/log/td-agent/httpd-access.log.pos
  tag apache.access
  <parse>
    @type apache2
  </parse>
</source>

Configure Fluentd with Logz.io output

Add this code block to your Fluent configuration file (fluent.conf by default).

See the configuration parameters below the code block.👇

<match **>
  @type logzio_buffered
  endpoint_url https://<<LISTENER-HOST>>:8071?token=<<LOG-SHIPPING-TOKEN>>&type=my_type
  output_include_time true
  output_include_tags true
  http_idle_timeout 10
  <buffer>
      @type memory
      flush_thread_count 4
      flush_interval 3s
      chunk_limit_size 16m
      queue_limit_length 4096
  </buffer>
</match>

Parameters

Parameter	Description
endpoint_url	A url composed of your Logz.io region’s listener URL, account token, and log type. Replace `<<LISTENER-HOST>>` with the host for your region. For example, `listener.logz.io` if your account is hosted on AWS US East, or `listener-nl.logz.io` if hosted on Azure West Europe. Replace `<<LOG-SHIPPING-TOKEN>>` with the token of the account you want to ship to.
output_include_time	To add a timestamp to your logs when they’re processed, `true` (recommended). Otherwise, `false`.
output_include_tags	To add the `fluentd` tag to logs, `true`. Otherwise, `false`. If `true`, use in combination with `output_tags_fieldname`.
output_tags_fieldname	If `output_include_tags` is `true`, sets output tag’s field name. The default is `fluentd_tag`
http_idle_timeout	Time, in seconds, that the HTTP connection will stay open without traffic before timing out.
retry_count	Counter of the times to resend failed bulks. The default is `4`.
retry_sleep	Interval in seconds to sleep initially between retries, exponential step-off. The default is `2s`.
bulk_limit	Limit to the size of the Logz.io upload bulk. Defaults to 1000000 bytes, leaving about 24kB for overhead.
bulk_limit_warning_limit	Limit to the size of the Logz.io warning message when a record exceeds bulk_limit to prevent a recursion when Fluent warnings are sent to the Logz.io output. The default is `nil` (no truncation).
proxy_uri	Your proxy uri. The default is `nil`. For example: “my.ip:12345”.
proxy_cert	Your proxy cert. The default is `nil`.
gzip	Defines if the plugin needs to ship the logs in gzip compression. The default is `false`.

Run Fluentd

fluentd -c ./fluent/fluent.conf -vv

Check Logz.io for your logs

Give your logs some time to get from your system to ours, and then open Kibana.

If you still don’t see your logs, see log shipping troubleshooting.

Fluentd can receive and concatenate multiline logs. To do this, you need to add a parser and concatenation plugin to your Fluentd configuration.

Add multiline parser to your input plugin

Multiline parsing only works with in_tail plugins. Refer to the Fluentd documentation for more on this.

Add the following code block to your in_tail plugin:

<parse>
  @type multiline
  format_firstline /^<<YOUR-REGEX-PATTERN>>/
</parse>

Replace <<YOUR-REGEX-PATTERN>> with the definition of your Regex pattern. You can use regex101 to define it.

The indentation of the parse plugin must be one level under the tail function as in the example below:

<source>
  @type tail
  path /var/log/httpd-access.log
  pos_file /var/log/td-agent/httpd-access.log.pos
  tag apache.access
	<parse>
	  @type multiline
	  format_firstline /\d{4}-\d{1,2}-\d{1,2}/
	  format1 /^(?<time>\d{4}-\d{1,2}-\d{1,2} \d{1,2}:\d{1,2}:\d{1,2}) \[(?<thread>.*)\] (?<level>[^\s]+)(?<message>.*)/
	</parse>
</source>