zag

zag

Zag-Web serves the graphing frontend.

Setup

Start the server:

require('zag')(
{ host:        "address:port"
, db:          "postgres://postgres:1234@localhost/postgres"
, env:         "dev" or "prod"
, daemons:    ["address:port", ...]
, defaultPath: "/graph/your_favorite_metric"
, backend:     require('zag-backend-pg')
// This directory needs to be readable and writable by the process.
, public:      "/tmp/metrics-public"
}).on("error", function(err) {
  // An error occurred.
}).on("ready", function() {
  // The server is listening.
})

Features

• Press ? for keyboard shortcuts.
• Graphs
  • To zoom a graph, click and drag vertically or horizontally.
  • To revert the zoom, double-click the graph.
  • To pan a graph, shift click and drag.
  • To monitor a live graph, select an interval from the "minutes" row of the range picker.
• Tree
  • Clicking on a triangle expands/collapses the keys.
  • Shift-clicking on a triangle graphs all of the key's children.
  • Shift-click on a leaf to overlay it on the current graph.
• Tags
  • Each "tag" has a timestamp, a label, and a category. The category determines the tag color.
  • Use the admin.js script to create and manage tag categories.
  • To create a tag manually, right-click a graph's X axis.
  • To edit an existing tag, left-click it's tick mark on the X axis.
• There is an API CLI in web/bin/admin.js.

HTTP API

Metrics

GET /api/metrics/:mkey

Get historical (not live) metrics data for a :mkey.

Querystring

• start - Integer timestamp, required
• end - Integer timestamp, required
• delta - Integer milliseconds. The downsample interval (e.g. 60000, 300000, ...) optional. Defaults to 1 minute (60000).

Response: 200

The response JSON will depending on whether the data is a histogram, counter, heat map, etc.

Histogram:

[ { "ts":    Integer
  , "count": Number
  , "mean":  Number
  , "p10":   Number
  , ...
  } or { "ts": Integer, "empty": true }
, ...
]

Counter:

[ { "ts":    Integer
  , "count": Number
  } or { "ts": Integer, "empty": true }
, ...
]

Heat map: (buckets are sorted)

[ [timestamp, bucketA, frequencyA, bucketB, frequencyB, ...]
, ...
]

---

Keys

GET /api/keys

Get a sorted list of the top-level metrics keys.

Response: 200

[ { "key":         String
  , "hasChildren": Boolean
  , "type":       "histogram" | "counter" | "none"
  }
, ...
]

"none" is the type of the key A when data is sent to A>B, because there is no actual metrics data associated with it.

GET /api/keys/:parents

Get the children of 1 or more parent metrics keys.

:parents is a comma-separated list of metrics keys to look up.

Response: 200

Returns lists of the child keys keyed by their parents.

{ "parentkey1":
  [ { "key":         String
    , "hasChildren": Boolean
    , "type":       "histogram" | "counter" | "none"
    }
  , ...
  ]
, ...
}

DELETE /api/keys/:mkey

Delete a metrics key and all of its children. The associated metrics data is not deleted.

Response: 204

GET /api/filter

Get a list of metrics keys matching a query.

Querystring

• q - String, the query. required
• limit - Integer, max results optional

Response: 200

[ { "key":         String
  , "hasChildren": Boolean
  , "type":       "histogram" | "counter" | "none"
  }
, ...
]

GET /api/allkeys

Get a sorted list of all metrics keys (recursive).

Response: 200

[ "key1"
, "key2"
, "key2|bar"
, "key2|foo"
, "key3"
, ...
]

---

Tags

GET /api/tags

Get a list of tags in a time range, sorted by ts.

Querystring

• begin - Integer timestamp, required
• end - Integer timestamp, required

Response: 200

[ { "id":    String, unique tag identifier
  , "ts":    Integer, position timestamp
  , "label": String
  , "color": String, hex e.g. "#f00"
  }
, ...
]

POST /api/tags

Create a tag.

Querystring

• ts - Integer timestamp, required
• color - String hex color, required
• label - String tag label, required
• id - String, optional. If id isn't passed, it will be assigned.

Response: 204

DELETE /api/tags/:id

Delete a tag by :id.

Response: 204

Tag types

GET /api/tagtypes

List all tag types.

Response: 200

[ { "color": String
  , "name":  String
  , "id":    String
  }
, ...
]

POST /api/tagtypes

Create a tag type.

Querystring

• color - String, e.g. "#ff0000" required
• name - String, a short description of the category required

Response: 204

DELETE /api/tagtypes/:id

Delete a tag type by :id. The tag type's ID can by found via GET /api/tagtypes.

Response: 204

---

Dashboards

GET /api/dashboards

Get a sorted list of all dashboard IDs.

Response: 200

[ "dashboard1"
, "dashboard1>subdashboard"
, "dashboard2"
, ...
]

GET /api/dashboards/:id

Get a dashboard by :id.

Response: 200

{ "id": String :id
, "graphs":
  { "<graph id 1>":
    { "id":      "<graph id 1>"
    , "key":     [String metrics key]
    , "title"     String, optional
    , "subkey"    String, optional
    , "renderer"  String, optional
    , "histkeys" [String], optional
    }
  , ...
  }
}

POST /api/dashboards/:id

Replace the dashboard. The post data should be {"graphs": {all the graphs}}.

Response: 204

PATCH /api/dashboards/:id

To rename a dashboard, the request body should be {"id": "<new id>"}.

To edit a dashboard's graphs, the request body should be {"graphs": {updated graphs by graph id}}. Graphs that are not included will be left unchanged, not removed.

Response: 204

DELETE /api/dashboards/:id

Delete the dashboard by :id.

Response: 204