Pulse

Pulse is a stat collecting and publishing service. It serves historical stats over an http api while live stats are sent to mist for live updates.

Usage

Simply running pulse -s will start pulse with the default config options.
pulse -h or pulse --help will show more detailed usage and config options:

Usage:
  pulse [flags]

Flags:
  -a, --aggregate-interval int         Interval at which stats are aggregated (default 15)
  -b, --beat-interval int              Heartbeat frequency (seconds) (default 30)
  -c, --config-file string             Config file location for server
  -C, --cors-allow string              Sets the 'Access-Control-Allow-Origin' header (default "*")
  -H, --http-listen-address string     Http listen address (default "127.0.0.1:8080")
  -i, --influx-address string          InfluxDB server address (default "http://127.0.0.1:8086")
  -I, --insecure                       Run insecure (default true)
  -k, --kapacitor-address string       Kapacitor server address (http://127.0.0.1:9092)
  -l, --log-level string               Level at which to log (default "INFO")
  -m, --mist-address string            Mist server address
  -M, --mist-token string              Mist server token
  -p, --poll-interval int              Interval to request stats from clients (default 60)
  -r, --retention int                  Number of weeks to store aggregated stats (default 1)
  -s, --server                         Run as server
  -S, --server-listen-address string   Server listen address (default "127.0.0.1:3000")
  -t, --token string                   Security token (recommend placing in config file) (default "secret")
  -v, --version                        Print version info and exit

Config File Options:

{
  "server": true,
  "server-listen-address": "127.0.0.1:3000",
  "http-listen-address": "127.0.0.1:8080",
  "influx-address": "http://127.0.0.1:8086",
  "kapacitor-address": "http://127.0.0.1:9092",
  "insecure": true,
  "mist-address": "",
  "mist-token": "",
  "log-level": "info",
  "cors-allow": "*",
  "token": "secret",
  "poll-interval": 60,
  "aggregate-interval": 15,
  "beat-interval": 30,
  "retention": 12
}

API

Route	Description	Output
GET /keys	Returns list of stats being recorded	string array
GET /tags	Returns list of filterable tags	string array
GET /latest/{stat}*	Returns latest stat (averages if multiple filters applied)	json stat object
GET /hourly/{stat}**	Returns hourly averages for stat	json array of stat objects
GET /daily/{stat}**	Returns average for stat at the same daily time	string map

ALERTS (requires "kapacitor-address" to be configured)

Route	Description	Payload	Output
POST /alerts	Add a kapacitor alert	json alert object	json alert object
PUT /alerts	Update a kapacitor alert	json alert object	json alert object
DELETE /alerts/{alert}	Delete a kapacitor alert	nil	success message

*: reserved query parameters is 'verb', all others act as filters
**: reserved query parameters are 'backfill', 'verb', 'start', and 'stop', all others act as filters

note: The API requires a token to be passed for authentication by default and is configurable at server start (--token). The token is passed in as a custom header: X-AUTH-TOKEN.

For examples, see the api's readme.

Data Types

Stat Object

json:

{
  "time": 1465419600,
  "value": 0.75
}

Fields:

• time: Unix epoch timestamp of stat
• value: Numeric value of stat

Alert Object

json:

{
  "tags": {"host":"abc"},
  "metric": "cpu_used",
  "level": "crit",
  "threshold": 80,
  "duration": "30s",
  "post": "http://127.0.0.1/alert"
}

Fields:

• tags: Populates the WHERE
• metric: Stat to track
• level: Alert level (info, warn, crit)
• threshold: Limit that alert is triggered at
• duration: How far back to average (5m)
• post: Api to hit when alert is triggered

Relay

A pulse relay is a service that connects to pulse and advertises stats that are available for collection. A relay implementation is available in the pulse project and can be embedded in other projects.

For an example, look in the README for relay.

TCP pulse api

The TCP api used to communicate between the pulse server and a relay is simple and is designed to be human readable and debuggable. It is newline delimited.

Command	Description	Response
id {id}	Must be the first command to be run, identifies the client to the server	ok
add {name}	Exposes a stat that can be collected by the server	ok
remove {name}	Removes a stat previously exposed to the server	ok

TCP relay api

Command	Description	Response
get {tag,tag2}	Request a list of stats corrosponding to the list of tags passed in	got {tag:value}
flush	Clear all current values from the stat collectors	ok
override {duration} {tag:interval}	for duration seconds, bump the collection interval from the default to interval for each tag:interval	ok

Notes

• If an override is specified for a stat, and a new machine comes online and connects, that override is NOT honored.
• Pulse server does not actively connect to servers to have stats pushed to it, rather, it waits for stat collecting machines to connect and then requests certain stats on specific intervals.

Contributing

Contributions to the pulse project are welcome and encouraged. Pulse is a Nanobox project and contributions should follow the Nanobox Contribution Process & Guidelines.

TODO

Licence

Mozilla Public License Version 2.0