rename 'jvm.buffer.memory.usage' metric to 'jvm.buffer.memory.used'

Author: SylvainJuge

instrumentation/runtime-telemetry/runtime-telemetry-java17/library/README.md

@@ -37,7 +37,7 @@ default, and the telemetry each produces:
 
 | JfrFeature                | Default Enabled | Metrics                                                                                                           |
 |---------------------------|-----------------|-------------------------------------------------------------------------------------------------------------------|
-| BUFFER_METRICS            | `false`         | `jvm.buffer.count`, `jvm.buffer.memory.limit`, `jvm.buffer.memory.usage`                                          |
+| BUFFER_METRICS            | `false`         | `jvm.buffer.count`, `jvm.buffer.memory.limit`, `jvm.buffer.memory.used`                                           |
 | CLASS_LOAD_METRICS        | `false`         | `jvm.class.count`, `jvm.class.loaded`, `jvm.class.unloaded`                                                       |
 | CONTEXT_SWITCH_METRICS    | `true`          | `jvm.cpu.context_switch`                                                                                          |
 | CPU_COUNT_METRICS         | `true`          | `jvm.cpu.limit`                                                                                                   |

instrumentation/runtime-telemetry/runtime-telemetry-java17/library/src/main/java/io/opentelemetry/instrumentation/runtimemetrics/java17/internal/buffer/DirectBufferStatisticsHandler.java

@@ -22,7 +22,7 @@
  * any time.
  */
 public final class DirectBufferStatisticsHandler implements RecordedEventHandler {
-  private static final String METRIC_NAME_USAGE = "jvm.buffer.memory.usage";
+  private static final String METRIC_NAME_USAGE = "jvm.buffer.memory.used";
   private static final String METRIC_NAME_LIMIT = "jvm.buffer.memory.limit";
   private static final String METRIC_NAME_COUNT = "jvm.buffer.count";
   private static final String METRIC_DESCRIPTION_USAGE = "Measure of memory used by buffers.";

instrumentation/runtime-telemetry/runtime-telemetry-java17/library/src/test/java/io/opentelemetry/instrumentation/runtimemetrics/java17/BufferMetricTest.java

@@ -72,7 +72,7 @@ void shouldHaveJfrLoadedClassesCountEvents() {
                                     }))),
         metric ->
             metric
-                .hasName("jvm.buffer.memory.usage")
+                .hasName("jvm.buffer.memory.used")
                 .hasDescription("Measure of memory used by buffers.")
                 .hasUnit(BYTES)
                 .hasLongSumSatisfying(

instrumentation/runtime-telemetry/runtime-telemetry-java8/library/src/main/java/io/opentelemetry/instrumentation/runtimemetrics/java8/internal/ExperimentalBufferPools.java

@@ -45,7 +45,7 @@ static List<AutoCloseable> registerObservers(
     Meter meter = JmxRuntimeMetricsUtil.getMeter(openTelemetry);
     observables.add(
         meter
-            .upDownCounterBuilder("jvm.buffer.memory.usage")
+            .upDownCounterBuilder("jvm.buffer.memory.used")
             .setDescription("Measure of memory used by buffers.")
             .setUnit("By")
             .buildWithCallback(callback(bufferBeans, BufferPoolMXBean::getMemoryUsed)));

instrumentation/runtime-telemetry/runtime-telemetry-java8/library/src/test/java/io/opentelemetry/instrumentation/runtimemetrics/java8/internal/ExperimentalBufferPoolsTest.java

@@ -56,7 +56,7 @@ void registerObservers() {
 
     testing.waitAndAssertMetrics(
         "io.opentelemetry.runtime-telemetry-java8",
-        "jvm.buffer.memory.usage",
+        "jvm.buffer.memory.used",
         metrics ->
             metrics.anySatisfy(
                 metricData ->