InfluxDB.Client.Flux 4.18.0

InfluxDB.Client.Flux

The reference C# library for the InfluxDB 1.7+ /api/v2/query REST API using the Flux language.

Documentation

This section contains links to the client library documentation.

• Product documentation, Getting Started
• Examples
• API Reference
• Changelog

How To Use

Create client

The FluxClientFactory creates an instance of a FluxClient client that can be customized with FluxConnectionOptions.

FluxConnectionOptions parameters:

• url - the url to connect to InfluxDB
• okHttpClient - custom HTTP client to use for communications with InfluxDB (optional)
• username - name of your InfluxDB user (optional)
• password - password of your InfluxDB user (optional)
• authentication - type of authentication (optional). There are two options for authenticating: Basic Authentication and the URL query parameters (default).

// client creation
var options = new FluxConnectionOptions("http://127.0.0.1:8086");

using var client = new FluxClient(options);

client.QueryAsync(...)
...

Authenticate requests

URL query parameters

// client creation
var options = new FluxConnectionOptions("http://127.0.0.1:8086", "my-user", "my-password".ToCharArray());

using var client = new FluxClient(options);

client.QueryAsync(...)
...

Basic authentication

// client creation
var options = new FluxConnectionOptions("http://127.0.0.1:8086", "my-user", "my-password".ToCharArray(),
    FluxConnectionOptions.AuthenticationType.BasicAuthentication);

using var client = new FluxClient(options);

client.QueryAsync(...)
...

Query using the Flux language

The library supports an asynchronous queries.

The asynchronous query API allows streaming of FluxRecords with the possibility of implementing custom error handling and OnComplete callback notification.

A CancellationToken object is used for aborting a query while processing.

A query example:

string fluxQuery = "from(bucket: \"telegraf\")\n" +
    " |> filter(fn: (r) => (r[\"_measurement\"] == \"cpu\" AND r[\"_field\"] == \"usage_system\"))" +
    " |> range(start: -1d)" +
    " |> sample(n: 5, pos: 1)";
    
var source = new CancellationTokenSource();

fluxClient.QueryAsync(fluxQuery, record =>
            {
                // process the flux query records
                Console.WriteLine(record.GetTime() + ": " + record.GetValue());
                
                if (some condition) 
                {
                    // abort processing
                    source.Cancel();
                }
            },
            (error) =>
            {
                // error handling while processing result
                Console.WriteLine($"Error occured: {error}");
            }, 
            () =>
            {
                // on complete
                Console.WriteLine("Query completed");
            }, source.Token).ConfigureAwait(false).GetAwaiter().GetResult();

Raw query response

It is possible to parse a result line-by-line using the QueryRaw method.

void QueryRawAsync(string query, Action<string> onResponse, string dialect = null, Action<Exception> onError = null, Action onComplete = null, CancellationToken cancellationToken = default);

Advanced Usage

Check the server status and version

Server availability can be checked using the FluxClient.PingAsync() endpoint. Server version can be obtained using FluxClient.VersionAsync().

Log HTTP Request and Response

The Requests and Responses can be logged by changing the LogLevel. LogLevel values are None, Basic, Headers, Body. Note that applying the Body LogLevel will disable chunking while streaming and will load the whole response into memory.

client.SetLogLevel(LogLevel.Body)

Version

The latest package for .NET CLI:

dotnet add package InfluxDB.Client.Flux

Or when using with Package Manager:

Install-Package InfluxDB.Client.Flux