Renamed queue_name attrbute of running_client_size to be in line with other metrics

doc/telemetry.md

@@ -0,0 +1,34 @@
+# Telemetry in Taskmanager
+
+The TaskManager application is equipped with OpenTelemetry capabilities.
+That means that it supports the use of an OpenTelemetry java agent, even though it is not manually instrumented.
+
+## Traces
+
+When using the OpenTelemetry java agent, use of the RabbitMQ library within TaskManager should ensure that spans are created on task pickup/delivery.
+Taskmanager will try to keep traces per task intact as much as possible, for instance when switching threads.
+Taskmanager does not explicitly defines spans itself currently, it relies on the automatic spans created when using the java agent.
+
+## Metrics
+
+The TaskManager defines a few custom metrics for OpenTelemetry to capture.
+These metrics are all defined with the `nl.aerius.TaskManager` instrumentation scope.
+
+| metric name                             | type      | description                                                          |
+|-----------------------------------------|-----------|----------------------------------------------------------------------|
+| `aer.taskmanager.worker_size`<sup>1</sup>           | gauge     | The number of workers that are configured according to Taskmanager.  |
+| `aer.taskmanager.current_worker_size`<sup>1</sup>   | gauge     | The number of workers that are current in Taskmanager.               |
+| `aer.taskmanager.running_worker_size`<sup>1</sup>   | gauge     | The number of workers that are occupied in Taskmanager.              |
+| `aer.taskmanager.running_client_size`<sup>2</sup>   | gauge     | The number of workers that are occupied for a specific client queue. |
+| `aer.taskmanager.dispatched`<sup>1</sup>            | histogram | The number of tasks dispatched.                                      |
+| `aer.taskmanager.dispatched.wait`<sup>1</sup>       | histogram | The average wait time of tasks dispatched.                           |
+| `aer.taskmanager.dispatched.queue`<sup>2</sup>      | histogram | The number of tasks dispatched per client queue.                     |
+| `aer.taskmanager.dispatched.queue.wait`<sup>2</sup> | histogram | The average wait time of tasks dispatched per client queue.          |
+| `aer.taskmanager.work.load`<sup>1</sup>             | gauge     | Percentage of workers used in the timeframe (1 minute).              |
+
+The workers have different attributes to distinguish specific metrics.
+* <sup>1</sup> have attribute `worker_type`.
+* <sup>2</sup> have attribute `worker_type` and `queue_name`.
+
+`worker_type` is the type of worker, e.g. `ops`.
+`queue_name` is the originating queue the task initially was put on, e.g. `...calculator_ui_small`.

source/taskmanager/src/main/java/nl/aerius/taskmanager/scheduler/priorityqueue/PriorityQueueMap.java

@@ -71,7 +71,10 @@ public void incrementOnWorker(final TaskRecord taskRecord) {
   }
 
   public int onWorkerTotal(final String queueName) {
-    return tasksOnWorkersPerQueue.entrySet().stream().filter(e -> keyMapper.queueName(e.getKey()).equals(queueName)).mapToInt(e -> e.getValue().get()).sum();
+    return tasksOnWorkersPerQueue.entrySet().stream()
+        .filter(e -> keyMapper.queueName(e.getKey()).equals(queueName))
+        .mapToInt(e -> e.getValue().get())
+        .sum();
   }
 
   public int onWorker(final TaskRecord taskRecord) {

source/taskmanager/src/main/java/nl/aerius/taskmanager/scheduler/priorityqueue/PriorityTaskSchedulerMetrics.java

@@ -20,8 +20,6 @@
 import java.util.Map;
 import java.util.function.IntSupplier;
 
-import io.opentelemetry.api.common.AttributeKey;
-import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.metrics.ObservableDoubleGauge;
 
 import nl.aerius.taskmanager.metrics.OpenTelemetryMetrics;
@@ -47,7 +45,8 @@ public void addMetric(final IntSupplier countSupplier, final String workerQueueN
     metrics.put(clientQueueName, OpenTelemetryMetrics.METER
         .gaugeBuilder(METRIC_PREFIX)
         .setDescription(DESCRIPTION)
-        .buildWithCallback(result -> result.record(countSupplier.getAsInt(), workerDefaultAttributes(workerQueueName, clientQueueName))));
+        .buildWithCallback(
+            result -> result.record(countSupplier.getAsInt(), OpenTelemetryMetrics.queueAttributes(workerQueueName, clientQueueName))));
   }
 
   /**
@@ -60,11 +59,4 @@ public void removeMetric(final String clienQueueName) {
       metrics.remove(clienQueueName).close();
     }
   }
-
-  private static Attributes workerDefaultAttributes(final String workerQueueName, final String clientQueueName) {
-    return Attributes.builder()
-        .put(AttributeKey.stringKey("worker_type"), workerQueueName)
-        .put(AttributeKey.stringKey("client_queue_name"), clientQueueName)
-        .build();
-  }
 }