Corrects the bufferUsage metric by making it equal to the difference …

…between the bufferCapacity and the available permits in the semaphore. Adds a new capacityUsed metric which tracks the actual capacity used by the semaphore which blocks. Resolves #3936. (#3937) Signed-off-by: David Venable <[email protected]>
opensearch-project · Jan 10, 2024 · d61b0c5 · d61b0c5
1 parent fbc6fab
commit d61b0c5
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Showing 3 changed files with 13 additions and 14 deletions.
diff --git a/data-prepper-api/src/main/java/org/opensearch/dataprepper/model/buffer/AbstractBuffer.java b/data-prepper-api/src/main/java/org/opensearch/dataprepper/model/buffer/AbstractBuffer.java
@@ -35,7 +35,7 @@ public abstract class AbstractBuffer<T extends Record<?>> implements Buffer<T> {
     private final Timer readTimer;
     private final Timer checkpointTimer;
 
-    public AbstractBuffer(final PluginSetting pluginSetting) {
+    AbstractBuffer(final PluginSetting pluginSetting) {
         this(PluginMetrics.fromPluginSetting(pluginSetting), pluginSetting.getPipelineName());
     }
 

diff --git a/...rc/main/java/org/opensearch/dataprepper/plugins/buffer/blockingbuffer/BlockingBuffer.java b/...rc/main/java/org/opensearch/dataprepper/plugins/buffer/blockingbuffer/BlockingBuffer.java
@@ -5,15 +5,15 @@
 
 package org.opensearch.dataprepper.plugins.buffer.blockingbuffer;
 
+import com.google.common.base.Stopwatch;
+import org.opensearch.dataprepper.metrics.PluginMetrics;
 import org.opensearch.dataprepper.model.CheckpointState;
 import org.opensearch.dataprepper.model.annotations.DataPrepperPlugin;
 import org.opensearch.dataprepper.model.buffer.AbstractBuffer;
 import org.opensearch.dataprepper.model.buffer.Buffer;
 import org.opensearch.dataprepper.model.buffer.SizeOverflowException;
 import org.opensearch.dataprepper.model.configuration.PluginSetting;
 import org.opensearch.dataprepper.model.record.Record;
-import com.google.common.base.Stopwatch;
-import com.google.common.util.concurrent.AtomicDouble;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -50,9 +50,9 @@ public class BlockingBuffer<T extends Record<?>> extends AbstractBuffer<T> {
     private static final String ATTRIBUTE_BATCH_SIZE = "batch_size";
     private static final String BLOCKING_BUFFER = "BlockingBuffer";
     private static final String BUFFER_USAGE_METRIC = "bufferUsage";
+    public static final String CAPACITY_USED_METRIC = "capacityUsed";
     private final int bufferCapacity;
     private final int batchSize;
-    private final AtomicDouble bufferUsage;
     private final BlockingQueue<T> blockingQueue;
     private final String pipelineName;
 
@@ -67,12 +67,16 @@ public class BlockingBuffer<T extends Record<?>> extends AbstractBuffer<T> {
      */
     public BlockingBuffer(final int bufferCapacity, final int batchSize, final String pipelineName) {
         super(BLOCKING_BUFFER, pipelineName);
-        bufferUsage = pluginMetrics.gauge(BUFFER_USAGE_METRIC, new AtomicDouble());
         this.bufferCapacity = bufferCapacity;
         this.batchSize = batchSize;
         this.blockingQueue = new LinkedBlockingQueue<>(bufferCapacity);
         this.capacitySemaphore = new Semaphore(bufferCapacity);
         this.pipelineName = pipelineName;
+
+        PluginMetrics pluginMetrics = PluginMetrics.fromNames(BLOCKING_BUFFER, pipelineName);
+
+        pluginMetrics.gauge(CAPACITY_USED_METRIC, capacitySemaphore, capacity -> bufferCapacity - capacity.availablePermits());
+        pluginMetrics.gauge(BUFFER_USAGE_METRIC, capacitySemaphore, capacity -> ((double) bufferCapacity - capacity.availablePermits()) / bufferCapacity * 100);
     }
 
     /**
@@ -196,15 +200,6 @@ public static PluginSetting getDefaultPluginSettings() {
         return new PluginSetting(PLUGIN_NAME, settings);
     }
 
-    @Override
-    public void postProcess(final Long recordsInBuffer) {
-        // adding bounds to address race conditions and reporting negative buffer usage
-        final Double nonNegativeTotalRecords = recordsInBuffer.doubleValue() < 0 ? 0 : recordsInBuffer.doubleValue();
-        final Double boundedTotalRecords = nonNegativeTotalRecords > bufferCapacity ? bufferCapacity : nonNegativeTotalRecords;
-        final Double usage = boundedTotalRecords / bufferCapacity * 100;
-        bufferUsage.set(usage);
-    }
-
     @Override
     public void doCheckpoint(final CheckpointState checkpointState) {
         final int numCheckedRecords = checkpointState.getNumRecordsToBeChecked();

diff --git a/...st/java/org/opensearch/dataprepper/plugins/buffer/blockingbuffer/BlockingBufferTests.java b/...st/java/org/opensearch/dataprepper/plugins/buffer/blockingbuffer/BlockingBufferTests.java
@@ -217,6 +217,8 @@ public void testBatchRead(final int readTimeout) throws Exception {
             assertThat(record.getData(), equalTo("TEST" + i));
             i++;
         }
+        verifyBufferUsageMetric(38.46153846153847);
+        blockingBuffer.checkpoint(partialReadResult.getValue());
         verifyBufferUsageMetric(15.384615384615385);
         final Map.Entry<Collection<Record<String>>, CheckpointState> finalReadResult = blockingBuffer.read(readTimeout);
         final Collection<Record<String>> finalBatch = finalReadResult.getKey();
@@ -227,6 +229,8 @@ public void testBatchRead(final int readTimeout) throws Exception {
             assertThat(record.getData(), equalTo("TEST" + i));
             i++;
         }
+        verifyBufferUsageMetric(15.384615384615385);
+        blockingBuffer.checkpoint(finalReadResult.getValue());
         verifyBufferUsageMetric(0.0);
     }