NATS

The nats output plugin, allows to flush your records into a NATS Server end point. The following instructions assumes that you have a fully operational NATS Server in place.

In order to flush records, the nats plugin requires to know two parameters:

parameter description default
host IP address or hostname of the NATS Server 127.0.0.1
port TCP port of the target NATS Server 4222

In order to override the default configuration values, the plugin uses the optional Fluent Bit network address format, e.g:

  1. nats://host:port

Running

Fluent Bit only requires to know that it needs to use the nats output plugin, if no extra information is given, it will use the default values specified in the above table.

  1. $ bin/fluent-bit -i cpu -o nats -V -f 5
  2. Fluent-Bit v0.7.0
  3. Copyright (C) Treasure Data
  5. [2016/03/04 10:17:33] [ info] Configuration
  6. flush time     : 5 seconds
  7. input plugins  : cpu
  8. collectors     :
  9. [2016/03/04 10:17:33] [ info] starting engine
  10. cpu[all] all=3.250000 user=2.500000 system=0.750000
  11. cpu[i=0] all=3.000000 user=1.000000 system=2.000000
  12. cpu[i=1] all=3.000000 user=2.000000 system=1.000000
  13. cpu[i=2] all=2.000000 user=2.000000 system=0.000000
  14. cpu[i=3] all=6.000000 user=5.000000 system=1.000000
  15. [2016/03/04 10:17:33] [debug] [in_cpu] CPU 3.25%
  16. ...

As described above, the target service and storage point can be changed, e.g:

Data format

For every set of records flushed to a NATS Server, Fluent Bit uses the following JSON format:

  1. [
  2.   [UNIX_TIMESTAMP, JSON_MAP_1],
  3.   [UNIX_TIMESTAMP, JSON_MAP_2],
  4.   [UNIX_TIMESTAMP, JSON_MAP_N],
  5. ]

Each record is an individual entity represented in a JSON array that contains a UNIX_TIMESTAMP and a JSON map with a set of key/values. A summarized output of the CPU input plugin will looks as this:

  1. [
  2.   [1457108504,{"tag":"fluentbit","cpu_p":1.500000,"user_p":1,"system_p":0.500000}],
  3.   [1457108505,{"tag":"fluentbit","cpu_p":4.500000,"user_p":3,"system_p":1.500000}],
  4.   [1457108506,{"tag":"fluentbit","cpu_p":6.500000,"user_p":4.500000,"system_p":2}]
  5. ]