influent

:ocean:

InfluxDB javascript driver

Overview

This is a InfluxDB driver for Javascript apps. It could work both in Node or browser¹.

Install

For node.js/iojs usage:

$ npm install --save influent

For usage in browser:

bower install --save influent

Usage

var influent = require('influent');

influent
    .createHttpClient({
        server: [
            {
                protocol: "http",
                host:     "localhost",
                port:     8086
            }
        ],
        username: "gobwas",
        password: "xxxx",
        
        database: "mydb"
    })
    .then(function(client) {
        client
            .query("show databases")
            .then(function(result) {
                // ...
            });

        // super simple point
        client.write({ key: "myseries", value: 10 });
            
        // more explicit point
        client
            .write({
                key: "myseries",
                tags: {
                    some_tag: "sweet"
                },
                fields: {
                    some_field: 10
                },
                timestamp: Date.now()
            })
            .then(function() {
                // ...
            });
    });

Type System

According to InfluxDB@0.9 docs there are four data types:

Field values may be stored as float64, int64, boolean, or string. All subsequent field values must match the type of the first point written to given measurement.

• float64 values are the default numerical type. 1 is a float, 1i is an integer;
• int64 value must have a trailing i. The field bikes_present=15i stores an integer and the field bikes_present=15 stores a float;
• boolean values are t, T, true, True, or TRUE for TRUE, and f, F, false, False, or FALSE for FALSE;
• string values for field values must be double-quoted. Double-quotes contained within the string must be escaped. All other characters are supported without escaping.

There is a little bit problem with Javascript numbers, cause it could be both integer or float. So to solve it there is the influent.Value abstraction for you:

var influent = require("influent");

// client creation somewhere

client
    .write({
        key: "myseries",
        tags: {
            some_tag: "sweet"
        },
        fields: {
            // this will be written as 10i, and saved as int64 10 into InfluxDB
            i_field: new influent.I64(10),
            
            // implicit way to write values
            // note that all implicit field numbers are casted to the influxdb's float64
            
            f_field: 10,       // is equal to new influent.F64(10)
            s_field: "string"  // is equal to new influent.Str("string")
            b_field: true      // is equal to new influent.Bool(true)
        },
        timestamp: Date.now()
    });

Usage without decorator

When you call influent.createAnyClient you get a decorated client, that allows you to pass simple object literals to write and query. This, of course, get some performance overhead and unnecessary object casting and type checks.

You could use this way, to be more explicit:

    // create client
    var client = new HttpClient({
        username: "gobwas",
        password: "xxxx"
    });
    
    // use line serializer
    client.injectSerializer(new LineSerializer());
    
    // use http client (this is for node, XhrHttp is for browser)
    client.injectHttp(new NodeHttp());
    
    // use stub elector, that always elects first host
    client.injectElector(new StubElector([ host ]));

    // create batch of points
    var batch = new Batch({ database: "mydb" });
    batch.add((new Measurement("key")).addField("value", 1))
    
    // send batch
    client.write(batch).then(...);
    
    // create query object
    var query = new Query("select * from key", { database: "mydb" });
    
    // eval query
    client.query(query).then(...);
    

API

influent.createHttpClient(config: Object) -> Promise[influent.DecoratorClient[influent.HttpClient]]

Creates influent.DecoratorClient instance, with influent.HttpClient inside. This method makes client.ping(), to sure that connection is OK.

The config should have structure like this:

{
    // required
    // --------
    
    server: {
        protocol: string
        host:     string
        port:     number
    }
    // or
    server: [ serverA... serverN ]
    
    username: string
    password: string
    
    // optional
    // --------
    
    database: string
    
    // write options
    precision:   enum[n, u, ms, s, m, h]
    consistency: enum[one, quorum, all, any]
    rp:          string
    max_batch:   number
    
    // query options
    epoch:      enum[n, u, ms, s, m, h]
    chunk_size: number
}

influent.createUdpClient(config: Object) -> Promise[influent.DecoratorClient[influent.UdpClient]]

Default factory for creating udp client. Creates influent.DecoratorClient instance, with influent.UdpClient inside.

The config should have structure like:

{
    // required
    // --------
    
    server: {
        protocol: string
        host:     string
        port:     number
    }
    // or
    server: [ serverA... serverN ]
    
    // optional
    // --------
    
    // write options
    precision:   enum[n, u, ms, s, m, h] // unsupported yet
    max_batch:   number
    safe_limit:  number   
}

Class: influent.Batch

new influent.Batch([options: Object])

Where options could be:

{
    database:    string
    precision:   enum[n, u, ms, s, m, h]
    consistency: enum[one, quorum, all, any]
    rp:          string
}

batch.add(m: influent.Measurement)

batch.options() -> Object

batch.measurements() -> Array[Measurement]

Class: influent.Query

new influent.Query(command: string[, options: Object])

Where options could be:

{
    database:   string
    epoch:      enum[n, u, ms, s, m, h]
    chunk_size: number
}

query.command() -> string

query.options() -> Object

Class: influent.Client

Abstract class of InfluxDB client. Has several abstract methods:

new influent.Client([options: Object])

client.ping() -> Promise[Object{ info: influent.Info, host: influent.Host }]

Pings host.

client.query(query: influent.Query) -> Promise[Object]

Asks for data.

client.write(batch: influent.Batch) -> Promise[]

Writes measurements.

Class: influent.NetClient

Abstract ancessor of influent.Client. Has several injector methods:

client.injectElector(elector: influent.Elector)

client.injectSerializer(serializer: influent.Serializer)

Class: influent.HttpClient

Implementation of influent.NetClient for http usage.

new influent.HttpClient(options: Object)

Where options could be like:

{
    // required
    // --------
    
    username:   string,
    password:   string,
}

httpClient.query(query: influent.Query) -> Promise[Object]

httpClient.write(batch: influent.Batch) -> Promise[]

httpClient.injectHttp(http: hurl.Http)

Injector of http service, that is implementation of abstract hurl.Http class. hurl is just npm dependency.

Class: influent.UdpClient

Implementation of influent.NetClient for udp usage.

new influent.UdpClient(options: Object)

Where options could be like:

{
    // optional
    // --------

    safe_limit: number
}

udpClient.query(query: influent.Query) -> Promise[Object]

This method returns rejected Promise, cause there is no ability to fetch some data through udp from InfluxDB.

udpClient.write(batch: influent.Batch) -> Promise[]

httpClient.injectUdp(http: influent.Udp)

Injector of udp service.

Class: influent.DecoratorClient[T: influent.Client]

Wrapper around influent.Client for better usability purposes.

new DecoratorClient([options: Object])

If options are present, the could contain these optional fields:

database: string
    
// write options
precision:   enum[n, u, ms, s, m, h]
consistency: enum[one, quorum, all, any]
rp:          string
max_batch:   number

// query options
epoch:      enum[n, u, ms, s, m, h]
chunk_size: number

decoratorClient.write(data: influent.Batch | Object | influent.Measurement | Array[Object | influent.Measurement][, options: Object]) -> Promise[]

When measurement is Object, it should have structure like:

{
    // required
    key: string,
    
    // one of or both `value` or non-empty `fields` should be present
    value: string | number | boolean | influent.Type,
    fields: {
        fieldName: string | number | boolean | influent.Type
    },
    
    // optional
    tags: {
        tagName: string
    },
    
    // optional
    timestamp: number | string | Date
}

decoratorClient.injectClient(client: influent.Client)

Class: influent.Elector

Represents strategy of electing host to send request.

new influent.Elector(hosts: Array[influent.Host][, options])

elector.getHost() -> Promise[Host]

Class: influent.RoundRobinElector

Round robin strategy of host election.

Class: influent.BaseElector

Base strategy of election. Uses influent.Ping to check health.

new influent.BaseElector(hosts: Array[influent.Host][, options])

Where options:

{
    period: number
}

baseElector.injectPing(ping: influent.Ping)

Class: influent.Ping

Represents strategy of checking host health.

new influent.Ping([, options])

ping.pong() -> Promise[]

Class: influent.HttpPing

Checks health via http request.

new influent.HttpPing([, options])

Where options:

{
    timeout: number
}

httpPing.injectHttp(http: hurl.Http)

Class: influent.CmdPing

Checks health via exec ping ....

new influent.CmdPing([, options])

Where options:

{
    timeout: number,
    count:   number
}

Class: influent.LineSerializer

Line protocol implementation of influent.Serializer.

Class: influent.Type

Class: influent.I64

new influent.I64(data: number)

Class: influent.F64

new influent.F64(data: number)

Class: influent.Bool

new influent.Bool(data: boolean)

Class: influent.Str

new influent.Str(data: string)

Class: influent.Measurement

new influent.Measurement(key: string)

measurement.addTag(key: string, value: string)

measurement.addField(key: string, value: influent.Value)

measurement.setTimestamp(timestamp: string)

Sets timestamp to the measurement. Using numeric string, cause it make sense on a big numbers with precision in nanoseconds.

Class: influent.Host

new influent.Host(protocol: string, host: string, port: number)

host.toString() -> String

Class: influent.Info

Represents client.ping() meta information.

new influent.Info()

Notes

¹: Browser version is about 41KB minified, and 13KB gzipped. There are no polyfills in bundle for old browsers! Be sure, that you have at least these global objects and object methods:

• Promise;
• Object.keys;
• Array.forEach;
• XMLHttpRequest.

Some Node.js specific classes are excluded from the influent API browser build.

Compatibility

InfluxDB	Influent
<0.9.3	^0.2.3
>0.9.3	^0.3.0

License

MIT © Sergey Kamardin