IGNITE-28085 Add the EvictionsStarted metric to DataStorageMetricsImpl

modules/core/src/main/java/org/apache/ignite/internal/processors/cache/persistence/DataStorageMetricsImpl.java

@@ -17,6 +17,7 @@
 package org.apache.ignite.internal.processors.cache.persistence;
 
 import java.util.Collection;
+import java.util.function.BooleanSupplier;
 import org.apache.ignite.DataRegionMetrics;
 import org.apache.ignite.internal.pagemem.wal.IgniteWriteAheadLogManager;
 import org.apache.ignite.internal.pagemem.wal.record.CheckpointRecord;
@@ -173,6 +174,9 @@ public class DataStorageMetricsImpl {
     /** Total size of the compressed segments in bytes. */
     private final LongAdderMetric walCompressedBytes;
 
+    /** Supplier for the eviction-started flag. */
+    private volatile BooleanSupplier evictionsStartedSupplier = () -> false;
+
     /**
      * @param mmgr Metrics manager.
      * @param metricsEnabled Metrics enabled flag.
@@ -372,6 +376,12 @@ public DataStorageMetricsImpl(
             "Used checkpoint buffer size in bytes.");
 
         mreg.register("CheckpointBufferSize", this::checkpointBufferSize, "Checkpoint buffer size in bytes.");
+
+        mreg.register(
+            "EvictionsStarted",
+            this::evictionsStarted,
+            "True if page eviction was triggered due to data region memory pressure."
+        );
     }
 
     /** @return Current number of WAL segments in the WAL archive. */
@@ -810,4 +820,14 @@ public void onWalSegmentCompressed(long size) {
 
         walCompressedBytes.add(size);
     }
+
+    /** @param supplier Supplier for the eviction-started flag. */
+    public void setEvictionsStartedSupplier(BooleanSupplier supplier) {
+        evictionsStartedSupplier = (supplier == null) ? () -> false : supplier;
+    }
+
+    /** @return {@code true} if page eviction was triggered due to data region memory pressure. */
+    private boolean evictionsStarted() {
+        return evictionsStartedSupplier.getAsBoolean();
+    }
 }

modules/core/src/main/java/org/apache/ignite/internal/processors/cache/persistence/IgniteCacheDatabaseSharedManager.java

@@ -198,6 +198,8 @@ public IgniteCacheDatabaseSharedManager(GridKernalContext ctx) {
                 DFLT_SUB_INTERVALS
             );
         }
+
+        dsMetrics.setEvictionsStartedSupplier(this::evictionsStarted);
     }
 
     /** {@inheritDoc} */
@@ -1660,4 +1662,12 @@ private void checkRegionWarmUpConfiguration(
     public void onWalTruncated(WALPointer highBound) throws IgniteCheckedException {
         // No-op.
     }
+
+    /**
+     * @return Value of the {@link IgniteCacheDatabaseSharedManager#firstEvictWarn} flag, where {@code true} indicates
+     * that the eviction process has started.
+     */
+    public boolean evictionsStarted() {
+        return firstEvictWarn;
+    }
 }

modules/core/src/test/java/org/apache/ignite/internal/processors/cache/persistence/IgniteDataStorageMetricsSelfTest.java

@@ -52,6 +52,7 @@
 import org.apache.ignite.internal.processors.cache.persistence.wal.FileDescriptor;
 import org.apache.ignite.internal.processors.cache.persistence.wal.FileWriteAheadLogManager;
 import org.apache.ignite.internal.processors.metric.impl.AtomicLongMetric;
+import org.apache.ignite.internal.processors.metric.impl.BooleanGauge;
 import org.apache.ignite.internal.processors.metric.impl.LongAdderMetric;
 import org.apache.ignite.internal.processors.metric.impl.LongGauge;
 import org.apache.ignite.internal.util.tostring.GridToStringInclude;
@@ -63,14 +64,17 @@
 import org.apache.ignite.spi.metric.HistogramMetric;
 import org.apache.ignite.spi.metric.LongMetric;
 import org.apache.ignite.testframework.ListeningTestLogger;
+import org.apache.ignite.testframework.LogListener;
 import org.apache.ignite.testframework.junits.common.GridCommonAbstractTest;
 import org.junit.Test;
 
 import static java.util.Collections.emptyList;
+import static org.apache.commons.lang3.StringUtils.repeat;
 import static org.apache.ignite.cache.CacheAtomicityMode.ATOMIC;
 import static org.apache.ignite.cache.CacheMode.PARTITIONED;
 import static org.apache.ignite.cache.CacheWriteSynchronizationMode.FULL_SYNC;
 import static org.apache.ignite.cluster.ClusterState.ACTIVE;
+import static org.apache.ignite.configuration.DataPageEvictionMode.RANDOM_LRU;
 import static org.apache.ignite.internal.processors.cache.CacheGroupMetricsImpl.CACHE_GROUP_METRICS_PREFIX;
 import static org.apache.ignite.internal.processors.cache.persistence.DataStorageMetricsImpl.DATASTORAGE_METRIC_PREFIX;
 import static org.apache.ignite.internal.processors.cache.persistence.wal.serializer.RecordV1Serializer.HEADER_RECORD_SIZE;
@@ -137,7 +141,8 @@ public class IgniteDataStorageMetricsSelfTest extends GridCommonAbstractTest {
                     .setMaxSize(maxRegionSize)
                     .setPersistenceEnabled(false)
                     .setMetricsEnabled(true)
-                    .setName(NO_PERSISTENCE))
+                    .setName(NO_PERSISTENCE)
+                    .setPageEvictionMode(RANDOM_LRU))
             .setWalMode(WALMode.LOG_ONLY)
             .setMetricsEnabled(true);
 
@@ -505,6 +510,37 @@ public void testWalTotalSizeWithArchiveTurnedOff() throws Exception {
         checkWalArchiveAndTotalSize(n, false);
     }
 
+    /** Verifies that the 'EvictionsStarted' metric becomes {@code true} after page eviction is triggered. */
+    @Test
+    public void testEvicstionsStartedMetric() throws Exception {
+        IgniteEx ignite = startGrid(0);
+
+        ignite.cluster().state(ClusterState.ACTIVE);
+
+        String msg = "Page-based evictions started. Consider increasing 'maxSize' on Data Region configuration";
+
+        LogListener lsnr = LogListener.matches(msg).build();
+
+        listeningLog.registerListener(lsnr);
+
+        IgniteCache<Object, Object> cacheNp = ignite.cache("cache-np");
+
+        String big = repeat('X', 256 * 1024);
+
+        for (int i = 0; i < 1_000_000 && !lsnr.check(); i++)
+            cacheNp.put(i, new Person("first-" + i + "-" + big, "last-" + i + "-" + big));
+
+        assertTrue(lsnr.check());
+
+        MetricRegistry metrics = ignite.context().metric().registry(DATASTORAGE_METRIC_PREFIX);
+        assertNotNull(metrics);
+
+        BooleanGauge evictStarted = metrics.findMetric("EvictionsStarted");
+        assertNotNull(evictStarted);
+
+        assertTrue(evictStarted.value());
+    }
+
     /**
      * Populates a cache w/32 KB of data.
      *