Sensu extension for sending metrics with graphite data-format to InfluxDB. For more arbitrary event-type data, check out sensu-influxdb-proxy-extension instead.
For each sensu-event it receives, it will transform each line of data into a InfluxDB datapoint, containing optional tags defined on the sensu client. It will buffer up points until it reaches the configured length or maximum age (see buffer_size and buffer_max_age), and then post the data directly to the InfluxDB REST-API using the line protocol.
Example line of graphite data-format ([metric_path] [value] [timestamp]\n):
key_a 6996 1435216969
will be transformed into the following data-point (line protocol)...
key_a[,<sensu_client_tags>] value=6996 1435216969\n...
-
Add the sensu-influxdb-extension.rb to the sensu extensions folder (/etc/sensu/extensions)
-
Create your InfluxDB configuration for Sensu (or copy and edit influxdb-extension.json.tmpl) inside the sensu config folder (/etc/sensu/conf.d).
Example of a minimal configuration file
{
"influxdb-extension": {
"hostname": "influxdb.mydomain.tld",
"database": "metrics",
}
}
| variable | default value |
|---|---|
| hostname | none (required) |
| port | 8086 |
| database | none (required) |
| buffer_size | 100 (lines) |
| buffer_max_age | 10 (seconds) |
| ssl | false |
| precision | s (*) |
| retention_policy | none |
| username | none |
| password | none |
(*) s = seconds. Other valid options are n, u, ms, m, h. See influxdb docs for more details
- Add the extension to your sensu-handler configuration
"handlers": {
"metrics": {
"type": "set",
"handlers": [ "influxdb-extension" ]
}
...
}
- Configure your metric/check-definitions to use this handler
"checks": {
"metric_cpu": {
"type": "metric",
"command": "/etc/sensu/plugins/metrics/cpu-usage.rb",
"handlers": [ "metrics" ],
...
}
- Restart your sensu-server and sensu-client(s)
If you follow the sensu-server log (/var/log/sensu/sensu-server.log) you should see the following output if all is working correctly:
{"timestamp":"2015-06-21T13:37:04.256753+0200","level":"info","message":"influxdb-extension:
Successfully initialized config: hostname: ....
#tags (optional)
If you want to tag your InfluxDB measurements (great for querying, as tags are indexed), you can define this on the sensu-client as well as on the checks definition.
Example sensu-client definition:
{
"client": {
"name": "app_env_hostname",
"address": "my-app-in-env.domain.tld",
"subscriptions": [],
"tags": {
"environment": "dev",
"application": "myapp",
"hostname": "my-app-in-env.domain.tld"
}
}
}
Example check definition:
{
"checks": {
"metric_cpu": {
"command": "/opt/sensu/embedded/bin/ruby /path/to/script.rb",
"interval": 20,
"standalone": true,
"type": "metric",
"handlers": [
"metrics"
],
"tags": {
"mytag": "xyz"
}
}
}
}
... will turn into the following tags for that point: ,environment=dev,application=myapp,hostname=my-app-in-env.domain.tld,mytag=xyz
If both the client and the check tags have the same key, the one defined on the check will overwrite/win the merge.
#performance
The extension will buffer up points until it reaches the configured buffer_size length or buffer_max_age, and then post all the points in the buffer to InfluxDB. Depending on your load, you will want to tune these configurations to match your environment.
Example: If you set the buffer_size to 1000, and you have a event-frequency of 100 per second, it will give you about a ten second lag before the data is available through the InfluxDB query API.
buffer_size / event-frequency = latency
However, if you set the buffer_max_age to 5 seconds, it will flush the buffer each time it exeeds this limit.
I recommend testing different buffer_sizes and buffer_max_ages depending on your environment and requirements.