Breaking Changes: Application Insights 2.x → 3.x

July 29, 2026 · View on GitHub

This document outlines the breaking changes when migrating from Application Insights SDK 2.x to 3.x (Shimmed version using OpenTelemetry).

IMPORTANT: Mixing 2.x and 3.x packages is not supported. All Application Insights packages in your application must be upgraded to 3.x together.

Architecture Overview

Version 3.x represents a fundamental architectural shift:

  • 2.x: Custom telemetry pipeline with processors, initializers, channels, and modules
  • 3.x: Built on OpenTelemetry with Azure Monitor Exporter as the backend

The 3.x version maintains most public APIs for backward compatibility but uses OpenTelemetry and Azure Monitor Exporter internally.

Released Packages in 3.0.0-beta1

The following packages are part of the shimmed 3.x release:

  1. Microsoft.ApplicationInsights (Core SDK)
  2. Microsoft.ApplicationInsights.AspNetCore (ASP.NET Core integration)
  3. Microsoft.ApplicationInsights.WorkerService (Worker Service integration)
  4. Microsoft.ApplicationInsights.NLogTarget (NLog integration)
  5. Microsoft.ApplicationInsights.Web (Classic ASP.NET integration)

1. Microsoft.ApplicationInsights (Core SDK)

Connection String Breaking Change

3.x will throw an exception if a connection string is not provided. For test scenarios, one could supply a dummy string like: InstrumentationKey=00000000-0000-0000-0000-000000000000.

TelemetryClient Breaking Changes

3.x no longer writes span events to the Debug console, and therefore Visual Studio's Events section of the Diagnostics Tools window no longer displays spans as events.

Removed APIs

Constructor

  • Parameterless constructor removed
    • 2.x: TelemetryClient() - Used TelemetryConfiguration.Active (obsolete)
    • 3.x: Removed - Must use TelemetryClient(TelemetryConfiguration)

Property

  • InstrumentationKey property setter removed
    • 2.x: public string InstrumentationKey { get; set; }
    • 3.x: Property completely removed from public API
    • Migration: Use TelemetryConfiguration.ConnectionString instead

Methods

  • PageView tracking removed entirely
    • TrackPageView(string name)
    • TrackPageView(PageViewTelemetry telemetry)
    • TrackEvent or TrackRequest can be used in lieu of TrackPageView in dotnet components.

Methods with Changed Signatures

TrackEvent

  • 2.x: TrackEvent(string eventName, IDictionary<string, string> properties, IDictionary<string, double> metrics)
  • 3.x: TrackEvent(string eventName, IDictionary<string, string> properties) Metrics parameter removed

TrackAvailability

  • 2.x: TrackAvailability(string name, DateTimeOffset timeStamp, TimeSpan duration, string runLocation, bool success, string message, IDictionary<string, string> properties, IDictionary<string, double> metrics)
  • 3.x: TrackAvailability(string name, DateTimeOffset timeStamp, TimeSpan duration, string runLocation, bool success, string message, IDictionary<string, string> properties) Metrics parameter removed

TrackException

  • 2.x: TrackException(Exception exception, IDictionary<string, string> properties, IDictionary<string, double> metrics)
  • 3.x: TrackException(Exception exception, IDictionary<string, string> properties) Metrics parameter removed

TrackDependency (Obsolete Overload)

  • 2.x: TrackDependency(string dependencyName, string data, DateTimeOffset startTime, TimeSpan duration, bool success) [Obsolete]
  • 3.x: Overload removed entirely

Recommendation for metrics: Track metrics separately via TrackMetric().

GetMetric Overloads

All GetMetric overloads have been simplified:

  • MetricConfiguration parameter removed from all overloads
  • MetricAggregationScope parameter removed from all overloads Metrics configuration and aggregation is now internally managed by OpenTelemetry meters.

Examples:

  • 2.x: GetMetric(MetricIdentifier metricIdentifier, MetricConfiguration metricConfiguration, MetricAggregationScope aggregationScope)

  • 3.x: GetMetric(MetricIdentifier metricIdentifier)

  • 2.x: GetMetric(string metricId, string dimension1Name, MetricConfiguration metricConfiguration, MetricAggregationScope aggregationScope)

  • 3.x: GetMetric(string metricId, string dimension1Name)

This applies to all dimension combinations (1D, 2D, 3D, 4D).

Metric Name and Namespace Conventions

In 3.x, Application Insights uses OpenTelemetry internally to emit metrics. As a result, the name parameter in TrackMetric and the metricId / metricNamespace parameters in GetMetric and MetricIdentifier must now adhere to the OpenTelemetry Instrument Name Syntax:

  • Must not be null or empty.
  • Must be case-insensitive, ASCII strings.
  • The first character must be an alphabetic character (A-Z or a-z).
  • Subsequent characters must be alphanumeric (A-Z, a-z, 0-9), _, ., -, or /.
  • Maximum length of 255 characters.

This applies to:

  • TrackMetric(string name, double value, ...) — the name parameter
  • GetMetric(string metricId, ...) — the metricId parameter
  • MetricIdentifier(string metricNamespace, string metricId, ...) — both metricNamespace and metricId parameters

Methods with changed internal implementation

  • Track(ITelemetry telemetry) - Still exists with [EditorBrowsable(EditorBrowsableState.Never)] attribute. In 3.x, it routes to specific Track methods (TrackRequest, TrackDependency, etc.) instead of using the telemetry processor pipeline.
  • StartOperation<T> and StopOperation<T> - Extension methods in TelemetryClientExtensions now use OpenTelemetry Activities instead of the legacy correlation system.

TelemetryConfiguration Breaking Changes

Removed APIs

Properties

  • TelemetryConfiguration.Active: Initialize via TelemetryConfiguration.CreateDefault() instead
  • InstrumentationKey - Replaced by ConnectionString
  • TelemetryInitializers - See detailed migration information here
  • TelemetryProcessors - See detailed migration information here
  • TelemetryProcessorChainBuilder - See detailed migration information here
  • TelemetryChannel - See detailed migration information here
  • ApplicationIdProvider - See detailed migration information here.
  • EndpointContainer - In 3.x, the connection string is parsed to determine where to send telemetry.
  • ExperimentalFeatures - No longer needed
  • TelemetrySinks - See detailed migration information here
  • DefaultTelemetrySink - See detailed migration information here

Constructors

  • TelemetryConfiguration(string instrumentationKey)
  • TelemetryConfiguration(string instrumentationKey, ITelemetryChannel channel) Migration note: TelemetryConfiguration.CreateDefault is the recommended way to initialize.

Methods

  • CreateFromConfiguration(string config) - Static method that created a TelemetryConfiguration from XML configuration string. Use CreateDefault() and set properties directly.

Methods with changed Behavior

  • CreateDefault() returns an internal static configuration instead of a new TelemetryConfiguration()

New APIs Added in 3.x

  • SamplingRatio (float?) - Gets or sets the sampling ratio for traces (0.0 to 1.0). A value of 1.0 means all telemetry is sent.
  • TracesPerSecond (double?) - Gets or sets the number of traces per second for rate-limited sampling (default sampling mode).
  • StorageDirectory (string) - Gets or sets the directory for offline telemetry storage.
  • DisableOfflineStorage (bool?) - Gets or sets whether offline storage is disabled.
  • EnableLiveMetrics (bool?) - Gets or sets whether Live Metrics is enabled.
  • EnableTraceBasedLogsSampler (bool?) - Gets or sets whether trace-based log sampling is enabled.
  • ConfigureOpenTelemetryBuilder(Action<IOpenTelemetryBuilder> configure) - Allows extending OpenTelemetry configuration
  • SetAzureTokenCredential(TokenCredential tokenCredential) - Call this method to enable Azure Active Directory (AAD) authentication for Application Insights ingestion

TelemetryContext Breaking Changes

Several TelemetryContext sub-context properties have been made internal, and some previously public properties have been removed.

Important

Context properties set on TelemetryClient.Context are applied to all traces and logs (TrackRequest, TrackDependency, TrackTrace, TrackEvent, TrackException, TrackAvailability). Metrics are not enriched with context properties.

TelemetryContext Properties Removed

  • InstrumentationKey - Removed. Use TelemetryConfiguration.ConnectionString instead.
  • Flags - Removed from public API as there isn't equivalent configuration in the underlying exporter.
  • Properties (obsolete) - Was obsoleted in 2.x in favor of GlobalProperties.
  • TryGetRawObject() / StoreRawObject() - Removed. These methods were used to pass raw objects between collectors and initializers, which no longer exist.

Sub-Context Properties Made Internal

The following properties on sub-context classes have been made internal:

  • Device.OemName — Now internal. The Application Insights ingestion service does not surface this field in workspace-based resources.
  • Session.IsFirst — Now internal. The Application Insights ingestion service does not surface this field in workspace-based resources.
  • Operation.Id — Now internal. Correlation IDs are managed automatically by OpenTelemetry.
  • Operation.ParentId — Now internal. Correlation IDs are managed automatically by OpenTelemetry.
  • Operation.CorrelationVector — Now internal. No longer needed due to shift to OpenTelemetry correlation.

Properties Retained (Public)

All sub-context classes remain public. The following properties remain public and can be set on TelemetryClient.Context (applies to all non-metric telemetry) or on individual telemetry items:

  • Cloud (RoleName, RoleInstance)
  • Component (Version)
  • User (Id, AuthenticatedUserId, AccountId, UserAgent)
  • Operation (Name, SyntheticSource)
  • Location (Ip)
  • Session (Id)
  • Device (Type, Id, OperatingSystem, Model)
  • GlobalProperties

See detailed migration guidance here

2. Microsoft.ApplicationInsights.AspNetCore

Extension Methods Removed

From IServiceCollection

  • AddApplicationInsightsTelemetry(string instrumentationKey) - Obsolete overload removed
  • AddApplicationInsightsKubernetesEnricher() - Kubernetes enrichment removed; there is a resource detector for enriching telemetry that is implemented internally.

From IApplicationBuilder

  • UseApplicationInsightsRequestTelemetry() - Obsolete middleware removed
  • UseApplicationInsightsExceptionTelemetry() - Obsolete middleware removed

From IWebHostBuilder

  • UseApplicationInsights() - All overloads removed (were obsolete in 2.x)

From Shared Extensions

  • AddApplicationInsightsTelemetryProcessor<T>() - See more detailed migration guidance here
  • AddApplicationInsightsTelemetryProcessor(Type telemetryProcessorType) - See more detailed migration guidance here
  • ConfigureTelemetryModule<T>(Action<T> configModule) - Module configuration without options (was already obsolete in 2.x)
  • ConfigureTelemetryModule<T>(Action<T, ApplicationInsightsServiceOptions> configModule) - Use one of the retained methods or set options via appsettings.json.
  • AddApplicationInsightsSettings(bool? developerMode, string endpointAddress, string instrumentationKey) - Was already obsolete in 2.x
  • AddApplicationInsightsSettings(string connectionString, bool? developerMode, string endpointAddress, string instrumentationKey) - Use one of the retained methods or set options via appsettings.json. The connection string specifies endpoints and batching of telemetry is internally managed by the underlying exporter. However, TelemetryClient.Flush() can still be used.

Extension Methods Retained

The following extension methods remain with identical signatures:

  • AddApplicationInsightsTelemetry()
  • AddApplicationInsightsTelemetry(IConfiguration configuration)
  • AddApplicationInsightsTelemetry(Action<ApplicationInsightsServiceOptions> configureOptions)
  • AddApplicationInsightsTelemetry(ApplicationInsightsServiceOptions options)

Classes/Components Removed

Entire Classes

  • ExceptionTrackingMiddleware - Middleware class removed, was already obsolete
  • HostingDiagnosticListener - this was previously internal
  • Resources - Previously public APIs now set to internal. These were autogenerated APIs not directly used by customers in 2.x.
    • Resources.Culture (get/set)
    • Resources.JavaScriptAuthSnippet (get)
    • Resources.JavaScriptSnippet (get)
    • Resources.ResourceManager (get)

TelemetryInitializers Removed (All 7)

  • AspNetCoreEnvironmentTelemetryInitializer
  • AzureAppServiceRoleNameFromHostNameHeaderInitializer
  • ClientIpHeaderTelemetryInitializer
  • DomainNameRoleInstanceTelemetryInitializer
  • HttpDependenciesParsingTelemetryInitializer
  • OperationNameTelemetryInitializer
  • WebSessionTelemetryInitializer
  • TelemetryInitializerBase

Please see detailed migration guidance here

Telemetry Modules Removed

The following ITelemetryModule implementations were previously registered via AddApplicationInsightsTelemetry() in 2.x. In 3.x, their functionality is either handled internally or removed:

  • RequestTrackingTelemetryModule — Request tracking is now handled internally via OpenTelemetry ASP.NET Core instrumentation. Configurable via EnableRequestTrackingTelemetryModule.
  • DiagnosticsTelemetryModule — Removed. Self-diagnostics and heartbeat are internally implemented in 3.x.
  • AppServicesHeartbeatTelemetryModule — Removed. 3.x internally uses a resource detector to emit resource attributes.
  • AzureInstanceMetadataTelemetryModule — Removed. 3.x internally uses a resource detector to emit resource attributes.
  • PerformanceCollectorModule — Performance counter collection is now internally managed. Configurable via EnablePerformanceCounterCollectionModule.
  • QuickPulseTelemetryModule — Live Metrics is now internally managed. Configurable via EnableQuickPulseMetricStream.
  • DependencyTrackingTelemetryModule — Dependency tracking is now handled internally via OpenTelemetry instrumentation. Configurable via EnableDependencyTrackingTelemetryModule.
  • EventCounterCollectionModule — Discontinued. There is no direct replacement.

The ConfigureTelemetryModule<T>() extension method has also been removed. Use ApplicationInsightsServiceOptions properties or appsettings.json to configure the retained toggles listed above.

ApplicationInsightsServiceOptions Changes

Properties Removed

  • InstrumentationKey - Obsolete property removed (use ConnectionString)
  • DeveloperMode - Batching of telemetry is now internally managed by the underlying exporter, with no equivalent toggle. However, TelemetryClient.Flush() can still be used in testing scenarios to flush telemetry.
  • EndpointAddress - No longer needed (ConnectionString contains endpoint information)
  • TelemetryInitializers - See detailed migration guidance here
  • EnableHeartbeat - Heartbeat configuration removed as the 3.x internally maintains its own heartbeating mechanism.
  • RequestCollectionOptions - See detailed migration guidance here
  • DependencyCollectionOptions - See detailed migration guidance here
  • EnableAdaptiveSampling - Removed in favor of our internal rate limited sampler, which is now the default sampling behavior.
  • EnableDebugLogger - Removed as internal self diagnostics accomplishes the same goal. Instructions to enable here.

Properties Retained

  • ConnectionString - Primary configuration method
  • ApplicationVersion
  • AddAutoCollectedMetricExtractor
  • EnableQuickPulseMetricStream
  • EnableAuthenticationTrackingJavaScript - JavaScript auth tracking config
  • EnableDependencyTrackingTelemetryModule - Dependency tracking toggle
  • EnablePerformanceCounterCollectionModule - Performance counter toggle
  • EnableRequestTrackingTelemetryModule - Request tracking toggle

New Properties Added in 3.x

  • Credential (Azure.Core.TokenCredential) - Enables Azure Active Directory (AAD) authentication
  • TracesPerSecond (double?) - Gets or sets the number of traces per second for rate-limited sampling (default sampling mode). Replaces EnableAdaptiveSampling.
  • SamplingRatio (float?) - Gets or sets the sampling ratio for traces (0.0 to 1.0). A value of 1.0 means all telemetry is sent.
  • EnableTraceBasedLogsSampler (bool?) - Gets or sets whether trace-based log sampling is enabled (default: true). When enabled, logs are sampled based on the sampling decision of the associated trace.

Please see our migration guide for detailed guidance on sampling.

JavaScriptSnippet Constructor Change

2.x:

public JavaScriptSnippet(
    TelemetryConfiguration telemetryConfiguration,
    IOptions<ApplicationInsightsServiceOptions> serviceOptions,
    IHttpContextAccessor httpContextAccessor,
    JavaScriptEncoder encoder = null)

3.x:

public JavaScriptSnippet(
    TelemetryConfiguration telemetryConfiguration,
    IOptions<ApplicationInsightsServiceOptions> serviceOptions,
    IHttpContextAccessor httpContextAccessor = null,  // Now optional
    JavaScriptEncoder encoder = null)

3. Microsoft.ApplicationInsights.WorkerService

Extension Methods Removed

  • AddApplicationInsightsTelemetryWorkerService(string instrumentationKey) - Instrumentation key overload removed (was obsolete in 2.x)

Extension Methods Retained

The following extension methods remain with identical signatures:

  • AddApplicationInsightsTelemetryWorkerService()
  • AddApplicationInsightsTelemetryWorkerService(IConfiguration configuration)
  • AddApplicationInsightsTelemetryWorkerService(Action<ApplicationInsightsServiceOptions> configureOptions)
  • AddApplicationInsightsTelemetryWorkerService(ApplicationInsightsServiceOptions options)

Telemetry Modules Removed

The following ITelemetryModule implementations were previously registered via AddApplicationInsightsTelemetryWorkerService() in 2.x. In 3.x, their functionality is either handled internally or removed:

  • DiagnosticsTelemetryModule — Removed. Self-diagnostics and heartbeat are internally implemented in 3.x.
  • AppServicesHeartbeatTelemetryModule — Removed. 3.x internally uses a resource detector to emit resource attributes.
  • AzureInstanceMetadataTelemetryModule — Removed. 3.x internally uses a resource detector to emit resource attributes.
  • PerformanceCollectorModule — Performance counter collection is now internally managed. Configurable via EnablePerformanceCounterCollectionModule.
  • QuickPulseTelemetryModule — Live Metrics is now internally managed. Configurable via EnableQuickPulseMetricStream.
  • DependencyTrackingTelemetryModule — Dependency tracking is now handled internally via OpenTelemetry instrumentation. Configurable via EnableDependencyTrackingTelemetryModule.
  • EventCounterCollectionModule — Discontinued. There is no direct replacement.

The ConfigureTelemetryModule<T>() extension method has also been removed. Use ApplicationInsightsServiceOptions properties or appsettings.json to configure the retained toggles listed above.

ApplicationInsightsServiceOptions Changes

Properties Removed

  • InstrumentationKey - Obsolete property removed (use ConnectionString)
  • EnableEventCounterCollectionModule - EventCounter module configuration removed. There is no intended replacement.
  • EnableAppServicesHeartbeatTelemetryModule - 3.x internally calls a resource detector that emits resource attributes to an internal resource metric.
  • EnableAzureInstanceMetadataTelemetryModule - 3.x internally calls a resource detector that emits resource attributes to an internal resource metric.
  • EnableHeartbeat - 3.x internally emits a heartbeat metric by default.
  • EnableDiagnosticsTelemetryModule - Removed in favor of self diagnostics and internally implemented heartbeat.
  • DeveloperMode - Batching of telemetry is now internally managed by the underlying exporter, with no equivalent toggle. However, TelemetryClient.Flush() can still be used in testing scenarios to flush telemetry.
  • EndpointAddress - No longer configurable (ConnectionString contains endpoints)
  • DependencyCollectionOptions - See detailed migration guidance here
  • EnableAdaptiveSampling - Removed in favor of our internal rate limited sampler, which is now the default sampling mechanism.
  • EnableDebugLogger - Removed in favor of self diagnostics. Learn how to enable here.

Properties Retained

  • ConnectionString
  • ApplicationVersion
  • EnableDependencyTrackingTelemetryModule - Enabled by default
  • EnablePerformanceCounterCollectionModule - Enabled by default
  • EnableQuickPulseMetricStream - Live metrics collection is enabled by default
  • AddAutoCollectedMetricExtractor - Standard metrics collection is enabled by default.

New Properties Added in 3.x

  • Credential (Azure.Core.TokenCredential) - Enables Azure Active Directory (AAD) authentication
  • TracesPerSecond (double?) - Gets or sets the number of traces per second for rate-limited sampling (default sampling mode). Replaces EnableAdaptiveSampling.
  • SamplingRatio (float?) - Gets or sets the sampling ratio for traces (0.0 to 1.0). A value of 1.0 means all telemetry is sent.
  • EnableTraceBasedLogsSampler (bool?) - Gets or sets whether trace-based log sampling is enabled (default: true). When enabled, logs are sampled based on the sampling decision of the associated trace.

Please see our migration guide for detailed guidance on sampling.

4. Microsoft.ApplicationInsights.NLogTarget

API Changes

Property Removed

  • InstrumentationKey property (string)
    • 2.x: public string InstrumentationKey { get; set; }
    • 3.x: Completely removed
    • Migration: Use ConnectionString property instead

New Property Added in 3.x

  • Credential (Azure.Core.TokenCredential) - Enables Azure Active Directory (AAD) authentication for Application Insights

Configuration Breaking Changes

Migration Required: Users MUST update their NLog configuration:

2.x Configuration:

<target type="ApplicationInsightsTarget" InstrumentationKey="xxx" />

3.x Configuration:

<target type="ApplicationInsightsTarget" ConnectionString="InstrumentationKey=xxx;IngestionEndpoint=https://..." />

Target Framework Changes

  • 2.x: net452, netstandard2.0
  • 3.x: net462, net8.0
  • Breaking: Minimum .NET Framework version raised from 4.5.2 → 4.6.2
  • Breaking: netstandard2.0 replaced with net8.0

Migration Checklist

Critical Actions Required:

  1. Replace InstrumentationKey with ConnectionString in NLog configuration
  2. Ensure connection string is always provided (no longer optional)
  3. Update minimum .NET Framework from 4.5.2 to 4.6.2 if using .NET Framework

5. Microsoft.ApplicationInsights.Web (Classic ASP.NET)

Telemetry Modules REMOVED

The following modules have been removed:

  • RequestTrackingTelemetryModule - This is replaced by an internal ActivityFilterProcessor and is configurable via <EnabledRequestTrackingTelemetryModule>
  • ExceptionTrackingTelemetryModule - Exception tracking is automatically included via OpenTelemetry instrumentation. No action needed from customer side.
  • AspNetDiagnosticTelemetryModule - OpenTelemtry's ASPNET instrumentation is automatically enabled in 3.x

Note that the applicationinsights.config configuration for and its sub-settings have been removed in favor of alternatives above.

Telemetry Initializers REMOVED

All public TelemetryInitializers from 2.x are REMOVED from the public API in 3.x. Please refer to the migration guidance for the list previous initalizers and their replacements.

Base Classes REMOVED

  • WebTelemetryInitializerBase
  • WebTelemetryModuleBase OpenTelemetry Processors are meant to provide extensibility. See more detailed guidance in migration documentation.

Extension Methods Changes

  • HttpContextExtension class removed from public API: The intended replacement is for customers to register a custom activity processor via TelemetryConfiguration.ConfigureOpenTelemetryBuilder().
  • HttpContextBaseExtension: was previously marked obsolete, now completely removed.

See migration guidance for how to create a custom activity processor and register it.

Configuration Model Changes

2.x Configuration (applicationinsights.config):

<ApplicationInsights>
  <InstrumentationKey>your-key-here</InstrumentationKey>

  <TelemetryInitializers>
    <Add Type="Microsoft.ApplicationInsights.Web.WebTestTelemetryInitializer, Microsoft.AI.Web" />
    <Add Type="Microsoft.ApplicationInsights.Web.SyntheticUserAgentTelemetryInitializer, Microsoft.AI.Web">
      <Filters>search|spider|crawl|Bot|Monitor|AlwaysOn</Filters>
    </Add>
    <Add Type="Microsoft.ApplicationInsights.Web.ClientIpHeaderTelemetryInitializer, Microsoft.AI.Web" />
    <!-- ... 7 more initializers ... -->
  </TelemetryInitializers>

  <TelemetryModules>
    <Add Type="Microsoft.ApplicationInsights.Web.RequestTrackingTelemetryModule, Microsoft.AI.Web">
      <Handlers>...</Handlers>
    </Add>
    <Add Type="Microsoft.ApplicationInsights.Web.ExceptionTrackingTelemetryModule, Microsoft.AI.Web" />
    <Add Type="Microsoft.ApplicationInsights.Web.AspNetDiagnosticTelemetryModule, Microsoft.AI.Web" />
  </TelemetryModules>
</ApplicationInsights>

3.x Configuration (applicationinsights.config):

<ApplicationInsights>
  <ConnectionString>InstrumentationKey=your-key;IngestionEndpoint=https://...</ConnectionString>
  <DisableTelemetry>false</DisableTelemetry>
  <ApplicationVersion>1.0.0</ApplicationVersion>
  <SamplingRatio>1.0</SamplingRatio>
  <TracesPerSecond>5</TracesPerSecond>
  <StorageDirectory>C:\Logs</StorageDirectory>
  <DisableOfflineStorage>false</DisableOfflineStorage>
  <EnableQuickPulseMetricStream>true</EnableQuickPulseMetricStream>
  <EnableTraceBasedLogsSampler>false</EnableTraceBasedLogsSampler>
  <EnablePerformanceCounterCollectionModule>true</EnablePerformanceCounterCollectionModule>
  <AddAutoCollectedMetricExtractor>true</AddAutoCollectedMetricExtractor>
  <EnableDependencyTrackingTelemetryModule>true</EnableDependencyTrackingTelemetryModule>
  <EnableRequestTrackingTelemetryModule>true</EnableRequestTrackingTelemetryModule>
</ApplicationInsights>

Summary of config changes:

  • <TelemetryInitializers> section no longer supported
  • <TelemetryModules> section no longer supported
  • <InstrumentationKey> replaced with <ConnectionString>
  • Multiple new configuration elements supported (see example above)
  • ASPNET & exception telemetry modules are now autoconfigured to use OpenTelemetry instrumentation.

Target Framework Changes

  • 2.x: net452 (Targets .NET Framework 4.5.2)
  • 3.x: net462 (Targets .NET Framework 4.6.2)
  • Breaking: Minimum framework version raised from 4.5.2 → 4.6.2