Azure Data Explorer

Description

Azure Data Explorer (Kusto) can be used as the backing implementation for Flex time-series operations. Your application code should depend on IFlexTimeSeriesStore, while Flex provides the provider bridge and wiring.

Important concepts

• IFlexTimeSeriesStore is the contract: app code writes and queries time-series data via a shared interface.

• Write + query patterns: generated handlers typically call WriteAsync<TPoint>(point), and generated queries use GetLatestAsync<TPoint>(seriesId) / QueryAsync<TPoint>(seriesId, start, end).

• Provider bridge: the Azure Data Explorer implementation is exposed via an IFlexTimeSeriesStoreBridge internally, but most consumers only need IFlexTimeSeriesStore.

Configuration in DI

Add the provider in your DI composition root (commonly in EndPoints/...CommonConfigs/OtherApplicationServicesConfig.cs or wherever you centralize registrations).

// using Sumeru.Flex; // IFlexTimeSeriesStore

public static class OtherApplicationServicesConfig
{
	public static IServiceCollection AddOtherApplicationServices(
		this IServiceCollection services,
		IConfiguration configuration)
	{
		// Registers Azure Data Explorer as the IFlexTimeSeriesStore bridge.
		// Flex auto-wires generated Queries/Handlers that *use* IFlexTimeSeriesStore.
		services.AddFlexAzureDataExplorerTimeSeriesStore(configuration);

		return services;
	}
}

appsettings.json

Configuration is read from FlexBase:DataStores:TimeSeries:AzureDataExplorer.

{
  "FlexBase": {
	"DataStores": {
	  "TimeSeries": {
		"AzureDataExplorer": {
		  "ClusterUri": "https://yourcluster.region.kusto.windows.net",
		  "Database": "your-database",
		  "ClientId": null,
		  "ClientSecret": null,
		  "TenantId": null
		}
	  }
	}
  }
}

Examples (template-based)

These examples mirror the generated Query and PostBusHandler templates. You do not register these types manually—Flex discovers and wires generated Queries/Handlers automatically.

Write a data point (PostBusHandler)

using Microsoft.Extensions.Logging;
using Sumeru.Flex;
using System;
using System.Threading.Tasks;

namespace {YourApplication}.Handlers.TimeSeries;

public partial class WriteTelemetryPointHandler : IAmFlexCommandHandler<WriteTelemetryPointCommand>
{
	protected string EventCondition = "";

	protected readonly ILogger<WriteTelemetryPointHandler> _logger;
	protected readonly IFlexHost _flexHost;
	protected readonly IFlexTimeSeriesStore _timeSeriesStore;

	protected TelemetryPoint? _model;
	protected FlexAppContextBridge? _flexAppContext;

	public WriteTelemetryPointHandler(
		ILogger<WriteTelemetryPointHandler> logger,
		IFlexHost flexHost,
		IFlexTimeSeriesStore timeSeriesStore)
	{
		_logger = logger;
		_flexHost = flexHost;
		_timeSeriesStore = timeSeriesStore;
	}

	public virtual async Task Execute(WriteTelemetryPointCommand cmd, IFlexServiceBusContext serviceBusContext)
	{
		_logger.LogDebug("Starting Write for {EntityType}", nameof(TelemetryPoint));
		_flexAppContext = cmd.Dto.GetAppContext();  //do not remove this line

		_model = _flexHost.GetDomainModel<TelemetryPoint>().Create(cmd);
		await _timeSeriesStore.WriteAsync<TelemetryPoint>(_model);

		await this.Fire(EventCondition, serviceBusContext);
	}
}

public class TelemetryPoint
{
	public string SeriesId { get; set; }
	public DateTime Timestamp { get; set; }
}

Get the latest point (Query)

using Microsoft.Extensions.Logging;
using Sumeru.Flex;
using System.Threading.Tasks;

namespace {YourApplication}.Queries.TimeSeries;

public class TelemetryGetLatest : FlexiQueryBridgeAsync<TelemetryPointDto>
{
	protected readonly ILogger<TelemetryGetLatest> _logger;
	protected readonly IFlexHost _flexHost;
	protected readonly IFlexTimeSeriesStore _timeSeriesStore;
	protected TelemetryGetLatestParams _params;
	protected FlexAppContextBridge _flexAppContext;

	public TelemetryGetLatest(ILogger<TelemetryGetLatest> logger, IFlexHost flexHost, IFlexTimeSeriesStore timeSeriesStore)
	{
		_logger = logger;
		_flexHost = flexHost;
		_timeSeriesStore = timeSeriesStore;
	}

	public virtual TelemetryGetLatest AssignParameters(TelemetryGetLatestParams @params)
	{
		_params = @params;
		return this;
	}

	public virtual async Task<TelemetryPointDto?> Fetch()
	{
		_flexAppContext = _params.GetAppContext();
		var latest = await _timeSeriesStore.GetLatestAsync<TelemetryPoint>(_params.SeriesId);
		// TODO: map TelemetryPoint -> TelemetryPointDto
		return latest as TelemetryPointDto;
	}
}

public class TelemetryGetLatestParams : DtoBridge
{
	public string SeriesId { get; set; }
}

Azure Data Explorer considerations

• ClusterUri and Database are required for cluster mode.

• If you need custom authentication behavior (managed identity vs app registration), handle it via environment/Azure identity configuration or by overriding the generated bridge in your application.