Tracking Selectors

Select tracking id from header or message body with stable selectors.

Header Selector

Example: header:X-Correlation-Id. Selector helper APIs expose direct TrackingFieldSelector construction, Parse/TryParse, and string formatting helpers.

Body Selector

Examples: json:$.trackingId or json:$trackingId with optional MessagePayloadType for typed parsing. JSON property lookup is case-insensitive. Invalid selector expressions use the same helper error contract across SDKs.

Destination GatherByField

Optional selector using the same syntax as TrackingField; enables grouped correlation summaries and percentile trend charts.

Endpoint Base Fields

TrafficEndpointDefinition supports AutoGenerateTrackingIdWhenMissing, PollInterval, MessageHeaders, MessagePayload, MessagePayloadType, JsonSettings, JsonConvertSettings, and ContentType. PollInterval must be a positive value when explicitly configured. These apply across endpoint adapters.

Feature Usage Samples

How to use snippets for Tracking Selectors.

Switch between C#, Java, Python, TypeScript, and JavaScript to see the native SDK shape for this sample.

Licensing note: every runnable sample requires a valid runner key via WithRunnerKey("...") or config key LoadStrike:RunnerKey.

Tracking Selectors

var source = new HttpEndpointDefinition
{
    Name = "http-source",
    Mode = TrafficEndpointMode.Produce,
    TrackingField = TrackingFieldSelector.Parse("header:X-Correlation-Id"),
    Url = "https://orders.example.com/api/orders",
    Method = "POST",
    MessagePayload = new { orderId = 1001 }
};

var destination = new KafkaEndpointDefinition
{
    Name = "kafka-destination",
    Mode = TrafficEndpointMode.Consume,
    TrackingField = TrackingFieldSelector.Parse("header:X-Correlation-Id"),
    BootstrapServers = "localhost:9092",
    Topic = "orders.completed",
    ConsumerGroupId = "orders-tests"
};

var tracking = new CrossPlatformTrackingConfiguration
{
    Source = source,
    Destination = destination,
    RunMode = TrackingRunMode.GenerateAndCorrelate,
    CorrelationTimeout = TimeSpan.FromSeconds(30)
};

import com.loadstrike.runtime.CrossPlatformTrackingConfiguration;
import com.loadstrike.runtime.HttpEndpointDefinition;
import com.loadstrike.runtime.KafkaEndpointDefinition;
import com.loadstrike.runtime.LoadStrikeCorrelation.TrackingFieldSelector;
import com.loadstrike.runtime.LoadStrikeTransports;

var source = new HttpEndpointDefinition();
source.name = "http-source";
source.mode = LoadStrikeTransports.TrafficEndpointMode.Produce;
source.trackingField = TrackingFieldSelector.parse("header:X-Correlation-Id");
source.url = "https://orders.example.com/api/orders";
source.method = "POST";
source.messagePayload = java.util.Map.of("orderId", 1001);

var destination = new KafkaEndpointDefinition();
destination.name = "kafka-destination";
destination.mode = LoadStrikeTransports.TrafficEndpointMode.Consume;
destination.trackingField = TrackingFieldSelector.parse("header:X-Correlation-Id");
destination.bootstrapServers = "localhost:9092";
destination.topic = "orders.completed";
destination.consumerGroupId = "orders-tests";

var tracking = new CrossPlatformTrackingConfiguration();
tracking.source = source;
tracking.destination = destination;
tracking.runMode = LoadStrikeTransports.TrackingRunMode.GenerateAndCorrelate;
tracking.correlationTimeoutSeconds = 30d;

from loadstrike_sdk import (
    CrossPlatformScenarioConfigurator,
    LoadStrikeScenario,
    LoadStrikeSimulation,
)

tracking = {
    "RunMode": "GenerateAndCorrelate",
    "CorrelationTimeoutSeconds": 30,
    "Source": {
        "Kind": "Http",
        "Name": "http-source",
        "Mode": "Produce",
        "TrackingField": "header:X-Correlation-Id",
        "Url": "https://orders.example.com/api/orders",
        "Method": "POST",
        "MessagePayload": {"orderId": 1001},
    },
    "Destination": {
        "Kind": "Kafka",
        "Name": "kafka-destination",
        "Mode": "Consume",
        "TrackingField": "header:X-Correlation-Id",
        "BootstrapServers": "localhost:9092",
        "Topic": "orders.completed",
        "ConsumerGroupId": "orders-tests",
    },
}

scenario = (
    CrossPlatformScenarioConfigurator.Configure(
        LoadStrikeScenario.empty("orders-http-to-kafka"),
        tracking,
    )
    .with_load_simulations(LoadStrikeSimulation.iterations_for_constant(1, 1))
)

import {
  CrossPlatformScenarioConfigurator,
  LoadStrikeScenario,
  LoadStrikeSimulation,
  TrackingFieldSelector
} from "@loadstrike/loadstrike-sdk";

const tracking = {
  RunMode: "GenerateAndCorrelate",
  CorrelationTimeoutSeconds: 30,
  Source: {
    Kind: "Http",
    Name: "http-source",
    Mode: "Produce",
    TrackingField: new TrackingFieldSelector("Header", "X-Correlation-Id"),
    Url: "https://orders.example.com/api/orders",
    Method: "POST",
    MessagePayload: { orderId: 1001 }
  },
  Destination: {
    Kind: "Kafka",
    Name: "kafka-destination",
    Mode: "Consume",
    TrackingField: new TrackingFieldSelector("Header", "X-Correlation-Id"),
    BootstrapServers: "localhost:9092",
    Topic: "orders.completed",
    ConsumerGroupId: "orders-tests"
  }
};

const scenario = CrossPlatformScenarioConfigurator
  .Configure(LoadStrikeScenario.empty("orders-http-to-kafka"), tracking)
  .withLoadSimulations(LoadStrikeSimulation.iterationsForConstant(1, 1));

const {
  CrossPlatformScenarioConfigurator,
  LoadStrikeScenario,
  LoadStrikeSimulation,
  TrackingFieldSelector
} = require("@loadstrike/loadstrike-sdk");

const tracking = {
  RunMode: "GenerateAndCorrelate",
  CorrelationTimeoutSeconds: 30,
  Source: {
    Kind: "Http",
    Name: "http-source",
    Mode: "Produce",
    TrackingField: new TrackingFieldSelector("Header", "X-Correlation-Id"),
    Url: "https://orders.example.com/api/orders",
    Method: "POST",
    MessagePayload: { orderId: 1001 }
  },
  Destination: {
    Kind: "Kafka",
    Name: "kafka-destination",
    Mode: "Consume",
    TrackingField: new TrackingFieldSelector("Header", "X-Correlation-Id"),
    BootstrapServers: "localhost:9092",
    Topic: "orders.completed",
    ConsumerGroupId: "orders-tests"
  }
};

const scenario = CrossPlatformScenarioConfigurator
  .Configure(LoadStrikeScenario.empty("orders-http-to-kafka"), tracking)
  .withLoadSimulations(LoadStrikeSimulation.iterationsForConstant(1, 1));

Selector Formats

header:<name>

Extract the tracking value from a header using the supplied header name.

json:$.<path>

Extract the tracking value from a JSON body using a dotted JSON path expression.

json:$<path>

Use the same JSON extraction contract in the compact dollar-prefixed form.

TrackingFieldSelector(...)

Construct the selector directly in code when you want explicit location and path values instead of parsing a string.