revision based on pr feedback, critical requirement oversight was that legacy metrics was never released and thus does not need continued support, it can be replaced wholesale.

Author: chrishagglund-ship-it

CHANGELOG.md

@@ -6,17 +6,18 @@ All notable changes to this project will be documented in this file.
 
 ### Added
 
-- Canonical metrics mode: opt-in harmonized metric surface via `WORKER_CANONICAL_METRICS=true` — [details](conductor-client-metrics/README.md#detailed-technical-notes--unreleased)
-- Automatic metrics wiring: `ConductorClient.Builder.withMetricsCollector(...)` installs the HTTP interceptor and auto-registers listeners on `TaskClient` and `WorkflowClient` (automatic in canonical mode; opt-in via `setAutoWiringEnabled(true)` for legacy)
+- Standardized Prometheus metrics: `PrometheusMetricsCollector` now emits the harmonized cross-SDK metric surface — [details](conductor-client-metrics/README.md)
+- Automatic metrics wiring: `ConductorClient.Builder.withMetricsCollector(...)` installs the HTTP interceptor and auto-registers listeners on `TaskClient`, `WorkflowClient`, and `TaskRunnerConfigurer`
+- HTTP API client metrics via OkHttp interceptor (`http_api_client_request_seconds`, `task_result_size_bytes`, `workflow_input_size_bytes`)
+- Event-driven metrics architecture with `EventDispatcher` and typed event POJOs
 
 ### Changed
 
-- Legacy metrics emit unchanged by default; no env var required
+- `PrometheusMetricsCollector` metric names updated to the harmonized cross-SDK catalog (e.g. `task_poll_total`, `task_execute_time_seconds`)
 - `micrometer-registry-prometheus` is now a transitive (`api`) dependency
 
 ### Deprecated
 
-- `PrometheusMetricsCollector` — use `MetricsCollectorFactory.create()` or `MetricsBundle.create()`
 - `TaskClient.ack(String, String)` — use `ack(String taskType, String taskId, String workerId)`
 
 ## [4.0.0] - 2024-10-09

INTERCEPTOR.md

@@ -240,31 +240,19 @@ public class ListenerRegister {
 }
 ```
 
-### 4. MetricsCollectorFactory / LegacyPrometheusMetricsCollector / CanonicalPrometheusMetricsCollector
+### 4. PrometheusMetricsCollector
 
 **Location**: `conductor-client-metrics/src/main/java/com/netflix/conductor/client/metrics/prometheus/`
 
 Reference implementation of `MetricsCollector` using Micrometer Prometheus.
 
 **Features**:
 - Exposes HTTP endpoint for Prometheus scraping (default: `localhost:9991/metrics`)
-- Selects either the legacy or canonical Prometheus collector at startup
 - Records worker, task client, and workflow client metrics through the event listener system
 - Records HTTP API client metrics through an OkHttp interceptor
 - Keeps the metrics backend separated from task and workflow business logic
 
-For setup instructions, environment-variable selection, the complete legacy and canonical metric catalogs, and migration guidance, see [`conductor-client-metrics/README.md`](conductor-client-metrics/README.md).
-
-### Compatibility: `PrometheusMetricsCollector`
-
-`com.netflix.conductor.client.metrics.prometheus.PrometheusMetricsCollector` is retained as a deprecated alias for `LegacyPrometheusMetricsCollector`. Existing 4.0.x code that does:
-
-```java
-PrometheusMetricsCollector metricsCollector = new PrometheusMetricsCollector();
-metricsCollector.startServer(9991, "/metrics");
-```
-
-continues to compile and emit the same six legacy meter names (`poll_started`, `poll_success`, `poll_failure`, `task_execution_started`, `task_execution_completed`, `task_execution_failure`) byte-for-byte. The shim deliberately delegates to `LegacyPrometheusMetricsCollector`, **not** to `MetricsCollectorFactory.create()`, so an upgrader who already has `WORKER_CANONICAL_METRICS=true` in their environment is not silently flipped to the canonical surface. New code should use `MetricsCollectorFactory.create()` (or `MetricsBundle.create()`) to opt into env-var-driven selection.
+For the complete metric catalog and setup instructions, see [`conductor-client-metrics/README.md`](conductor-client-metrics/README.md).
 
 ## Event Lifecycle
 
@@ -352,16 +340,17 @@ import com.netflix.conductor.client.automator.TaskRunnerConfigurer;
 import com.netflix.conductor.client.http.ConductorClient;
 import com.netflix.conductor.client.http.TaskClient;
 import com.netflix.conductor.client.http.WorkflowClient;
-import com.netflix.conductor.client.metrics.prometheus.MetricsBundle;
+import com.netflix.conductor.client.metrics.prometheus.PrometheusMetricsCollector;
 
-// 1. Create and start metrics (factory-selected collector + Prometheus scrape server)
-MetricsBundle bundle = MetricsBundle.create(); // port 9991, /metrics
+// 1. Create and start metrics
+PrometheusMetricsCollector metricsCollector = new PrometheusMetricsCollector();
+metricsCollector.startServer(); // port 9991, /metrics
 
 // 2. Create ConductorClient — withMetricsCollector installs the HTTP interceptor
 //    and enables automatic listener registration on downstream clients
 ConductorClient client = ConductorClient.builder()
     .basePath("http://conductor-server:8080/api")
-    .withMetricsCollector(bundle.getCollector())
+    .withMetricsCollector(metricsCollector)
     .build();
 
 // 3. Downstream clients auto-register as listeners
@@ -376,13 +365,13 @@ TaskRunnerConfigurer configurer = new TaskRunnerConfigurer.Builder(taskClient, w
 configurer.init();
 ```
 
-For fine-grained control over which listeners are registered, use `withHttpMetrics` instead of `withMetricsCollector`. This installs only the HTTP interceptor and leaves all listener registration to you. See the [Manual Wiring](conductor-client-metrics/README.md#manual-wiring) section in the metrics README.
+For fine-grained control over which listeners are registered, create the `ConductorClient` without `withMetricsCollector` and register listeners explicitly. See the [Manual Wiring](conductor-client-metrics/README.md#manual-wiring) section in the metrics README.
 
 ### Custom Metrics Endpoint
 
 ```java
 // Start Prometheus server on custom port and endpoint
-AbstractPrometheusMetricsCollector metricsCollector = MetricsCollectorFactory.create();
+PrometheusMetricsCollector metricsCollector = new PrometheusMetricsCollector();
 metricsCollector.startServer(8080, "/custom-metrics");
 ```
 
@@ -858,7 +847,7 @@ public class CloudWatchMetricsCollector implements MetricsCollector {
 
 ```java
 // Create multiple collectors
-AbstractPrometheusMetricsCollector prometheus = MetricsCollectorFactory.create();
+PrometheusMetricsCollector prometheus = new PrometheusMetricsCollector();
 prometheus.startServer(9991, "/metrics");
 
 DatadogMetricsCollector datadog = new DatadogMetricsCollector(
@@ -1219,8 +1208,7 @@ import com.netflix.conductor.client.http.TaskClient;
 import com.netflix.conductor.client.http.ConductorClient;
 import com.netflix.conductor.client.automator.TaskRunnerConfigurer;
 import com.netflix.conductor.client.worker.Worker;
-import com.netflix.conductor.client.metrics.prometheus.MetricsCollectorFactory;
-import com.netflix.conductor.client.metrics.prometheus.AbstractPrometheusMetricsCollector;
+import com.netflix.conductor.client.metrics.prometheus.PrometheusMetricsCollector;
 import java.util.List;
 
 public class ConductorMonitoringSetup {
@@ -1239,7 +1227,7 @@ public class ConductorMonitoringSetup {
         );
 
         // 3. Setup Prometheus metrics
-        AbstractPrometheusMetricsCollector prometheus = MetricsCollectorFactory.create();
+        PrometheusMetricsCollector prometheus = new PrometheusMetricsCollector();
         prometheus.startServer(9991, "/metrics");
 
         // 4. Setup custom monitoring

README.md

@@ -303,24 +303,32 @@ Enable Prometheus metrics collection for monitoring workers:
 ```groovy
 // Using conductor-client-metrics module
 dependencies {
-    implementation 'org.conductoross:conductor-client-metrics:4.0.1'
+    implementation 'org.conductoross:conductor-client-metrics:5.1.0'
 }
 ```
 
 ```java
-import com.netflix.conductor.client.metrics.prometheus.MetricsCollectorFactory;
+import com.netflix.conductor.client.metrics.prometheus.PrometheusMetricsCollector;
+
+PrometheusMetricsCollector metricsCollector = new PrometheusMetricsCollector();
+metricsCollector.startServer(); // http://localhost:9991/metrics
+
+ConductorClient client = ConductorClient.builder()
+    .basePath("...")
+    .withMetricsCollector(metricsCollector)
+    .build();
+
+TaskClient taskClient = new TaskClient(client);
+WorkflowClient workflowClient = new WorkflowClient(client);
 
 TaskRunnerConfigurer configurer = new TaskRunnerConfigurer.Builder(taskClient, workers)
     .withThreadCount(10)
-    .withMetricsCollector(MetricsCollectorFactory.create())
     .build();
 ```
 
-`MetricsCollectorFactory.create()` uses the legacy Java SDK metric names by default. Set `WORKER_CANONICAL_METRICS=true` to opt in to the canonical cross-SDK metric names.
-
-> Migrating from 4.0.x? `PrometheusMetricsCollector` still works — it is now a deprecated alias for `LegacyPrometheusMetricsCollector` and emits the same six legacy meter names byte-for-byte. New code should use `MetricsCollectorFactory.create()` (or `MetricsBundle.create()`) so it can opt into canonical metrics via `WORKER_CANONICAL_METRICS=true`.
+When a `MetricsCollector` is attached to the `ConductorClient`, downstream clients (`TaskClient`, `WorkflowClient`, `TaskRunnerConfigurer`) automatically register themselves as event listeners.
 
-See [conductor-client-metrics/README.md](conductor-client-metrics/README.md) for setup details, the complete legacy and canonical metric catalogs, and migration guidance.
+See [conductor-client-metrics/README.md](conductor-client-metrics/README.md) for the complete metric catalog and setup details.
 
 ## Workflows