feat(metrics): add block transaction count and SR set change monitoring

common/src/main/java/org/tron/common/prometheus/MetricKeys.java

@@ -14,6 +14,7 @@ public static class Counter {
     public static final String TXS = "tron:txs";
     public static final String MINER = "tron:miner";
     public static final String BLOCK_FORK = "tron:block_fork";
+    public static final String SR_SET_CHANGE = "tron:sr_set_change";
     public static final String P2P_ERROR = "tron:p2p_error";
     public static final String P2P_DISCONNECT = "tron:p2p_disconnect";
     public static final String INTERNAL_SERVICE_FAIL = "tron:internal_service_fail";
@@ -62,6 +63,7 @@ public static class Histogram {
     public static final String MESSAGE_PROCESS_LATENCY = "tron:message_process_latency_seconds";
     public static final String BLOCK_FETCH_LATENCY = "tron:block_fetch_latency_seconds";
     public static final String BLOCK_RECEIVE_DELAY = "tron:block_receive_delay_seconds";
+    public static final String BLOCK_TRANSACTION_COUNT = "tron:block_transaction_count";
 
     private Histogram() {
       throw new IllegalStateException("Histogram");

common/src/main/java/org/tron/common/prometheus/MetricLabels.java

@@ -31,6 +31,8 @@ public static class Counter {
     public static final String TXS_FAIL_SIG = "sig";
     public static final String TXS_FAIL_TAPOS = "tapos";
     public static final String TXS_FAIL_DUP = "dup";
+    public static final String SR_ADD = "add";
+    public static final String SR_REMOVE = "remove";
 
     private Counter() {
       throw new IllegalStateException("Counter");

common/src/main/java/org/tron/common/prometheus/MetricsCounter.java

@@ -14,6 +14,7 @@ class MetricsCounter {
     init(MetricKeys.Counter.TXS, "tron  txs  info .", "type", "detail");
     init(MetricKeys.Counter.MINER, "tron  miner info .", "miner", "type");
     init(MetricKeys.Counter.BLOCK_FORK, "tron  block fork info .", "type");
+    init(MetricKeys.Counter.SR_SET_CHANGE, "tron sr set change .", "action", "witness");
     init(MetricKeys.Counter.P2P_ERROR, "tron p2p error  info .", "type");
     init(MetricKeys.Counter.P2P_DISCONNECT, "tron p2p disconnect .", "type");
     init(MetricKeys.Counter.INTERNAL_SERVICE_FAIL, "internal Service fail.",

common/src/main/java/org/tron/common/prometheus/MetricsHistogram.java

@@ -9,6 +9,7 @@
 public class MetricsHistogram {
 
   private static final Map<String, Histogram> container = new ConcurrentHashMap<>();
+  private static final String MINER_LABEL = "miner";
 
   static {
     init(MetricKeys.Histogram.INTERNAL_SERVICE_LATENCY, "Internal Service latency.",
@@ -20,7 +21,7 @@ public class MetricsHistogram {
     init(MetricKeys.Histogram.JSONRPC_SERVICE_LATENCY, "JsonRpc Service latency.",
         "method");
     init(MetricKeys.Histogram.MINER_LATENCY, "miner latency.",
-        "miner");
+        MINER_LABEL);
     init(MetricKeys.Histogram.PING_PONG_LATENCY, "node  ping pong  latency.");
     init(MetricKeys.Histogram.VERIFY_SIGN_LATENCY, "verify sign latency for trx , block.",
         "type");
@@ -36,7 +37,7 @@ public class MetricsHistogram {
     init(MetricKeys.Histogram.PROCESS_TRANSACTION_LATENCY, "process transaction latency.",
         "type", "contract");
     init(MetricKeys.Histogram.MINER_DELAY, "miner delay time, actualTime - planTime.",
-        "miner");
+        MINER_LABEL);
     init(MetricKeys.Histogram.UDP_BYTES, "udp_bytes traffic.",
         "type");
     init(MetricKeys.Histogram.TCP_BYTES, "tcp_bytes traffic.",
@@ -48,6 +49,11 @@ public class MetricsHistogram {
     init(MetricKeys.Histogram.BLOCK_FETCH_LATENCY, "fetch block latency.");
     init(MetricKeys.Histogram.BLOCK_RECEIVE_DELAY,
         "receive block delay time, receiveTime - blockTime.");
+
+    init(MetricKeys.Histogram.BLOCK_TRANSACTION_COUNT,
+        "Distribution of transaction counts per block.",
+        new double[]{0, 10, 50, 100, 200, 500, 1000, 2000, 5000, 10000},
+        MINER_LABEL);
   }
 
   private MetricsHistogram() {
@@ -62,6 +68,17 @@ private static void init(String name, String help, String... labels) {
         .register());
   }
 
+  private static void init(String name, String help, double[] buckets, String... labels) {
+    Histogram.Builder builder = Histogram.build()
+        .name(name)
+        .help(help)
+        .labelNames(labels);
+    if (buckets != null && buckets.length > 0) {
+      builder.buckets(buckets);
+    }
+    container.put(name, builder.register());
+  }
+
   static Histogram.Timer startTimer(String key, String... labels) {
     if (Metrics.enabled()) {
       Histogram histogram = container.get(key);

framework/src/main/java/org/tron/core/metrics/blockchain/BlockChainMetricManager.java

@@ -3,10 +3,13 @@
 import com.codahale.metrics.Counter;
 import com.google.protobuf.ByteString;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.SortedMap;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Collectors;
 import lombok.Getter;
 import lombok.Setter;
 import org.bouncycastle.util.encoders.Hex;
@@ -42,6 +45,9 @@ public class BlockChainMetricManager {
   private long failProcessBlockNum = 0;
   @Setter
   private String failProcessBlockReason = "";
+  private final Set<String> lastActiveWitnesses = ConcurrentHashMap.newKeySet();
+  // To control SR set change metric update logic, -1 means not initialized
+  private long lastNextMaintenanceTime = -1;
 
   public BlockChainInfo getBlockChainInfo() {
     BlockChainInfo blockChainInfo = new BlockChainInfo();
@@ -169,6 +175,46 @@ public void applyBlock(BlockCapsule block) {
       Metrics.counterInc(MetricKeys.Counter.TXS, block.getTransactions().size(),
           MetricLabels.Counter.TXS_SUCCESS, MetricLabels.Counter.TXS_SUCCESS);
     }
+    // Record transaction count distribution for all blocks (including empty blocks)
+    int txCount = block.getTransactions().size();
+    Metrics.histogramObserve(MetricKeys.Histogram.BLOCK_TRANSACTION_COUNT, txCount,
+        StringUtil.encode58Check(address));
+
+    // SR set change detection
+    long nextMaintenanceTime = dbManager.getDynamicPropertiesStore().getNextMaintenanceTime();
+    if (lastNextMaintenanceTime == -1) {
+      lastNextMaintenanceTime = nextMaintenanceTime;
+      lastActiveWitnesses.addAll(chainBaseManager.getWitnessScheduleStore().getActiveWitnesses()
+          .stream().map(w -> Hex.toHexString(w.toByteArray())).collect(Collectors.toSet()));
+    } else if (nextMaintenanceTime != lastNextMaintenanceTime) {
+      Set<String> currentWitnesses = chainBaseManager.getWitnessScheduleStore().getActiveWitnesses()
+          .stream()
+          .map(w -> Hex.toHexString(w.toByteArray()))
+          .collect(Collectors.toSet());
+      recordSrSetChange(currentWitnesses);
+      lastNextMaintenanceTime = nextMaintenanceTime;
+    }
+  }
+
+  private void recordSrSetChange(Set<String> currentWitnesses) {
+    Set<String> added = new HashSet<>(currentWitnesses);
+    added.removeAll(lastActiveWitnesses);
+
+    Set<String> removed = new HashSet<>(lastActiveWitnesses);
+    removed.removeAll(currentWitnesses);
+
+    for (String address : added) {
+      Metrics.counterInc(MetricKeys.Counter.SR_SET_CHANGE, 1,
+          MetricLabels.Counter.SR_ADD, StringUtil.encode58Check(Hex.decode(address)));
+    }
+    for (String address : removed) {
+      Metrics.counterInc(MetricKeys.Counter.SR_SET_CHANGE, 1,
+          MetricLabels.Counter.SR_REMOVE, StringUtil.encode58Check(Hex.decode(address)));
+    }
+    if (!added.isEmpty() || !removed.isEmpty()) {
+      lastActiveWitnesses.clear();
+      lastActiveWitnesses.addAll(currentWitnesses);
+    }
   }
 
   private List<WitnessInfo> getSrList() {

framework/src/test/java/org/tron/core/metrics/prometheus/PrometheusApiServiceTest.java

@@ -7,6 +7,7 @@
 import java.time.ZoneId;
 import java.time.ZonedDateTime;
 import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
@@ -25,6 +26,7 @@
 import org.tron.common.utils.ByteArray;
 import org.tron.common.utils.PublicMethod;
 import org.tron.common.utils.Sha256Hash;
+import org.tron.common.utils.StringUtil;
 import org.tron.common.utils.Utils;
 import org.tron.consensus.dpos.DposSlot;
 import org.tron.core.ChainBaseManager;
@@ -38,6 +40,9 @@
 
 @Slf4j(topic = "metric")
 public class PrometheusApiServiceTest extends BaseTest {
+
+  private static final String MINER_LABEL = "miner";
+
   static LocalDateTime localDateTime = LocalDateTime.now();
   @Resource
   private DposSlot dposSlot;
@@ -65,7 +70,7 @@ protected static void initParameter(CommonParameter parameter) {
     parameter.setMetricsPrometheusEnable(true);
   }
 
-  protected void check() throws Exception {
+  protected void check(byte[] address, Map<ByteString, String> witnessAndAccount) throws Exception {
     Double memoryBytes = CollectorRegistry.defaultRegistry.getSampleValue(
         "system_total_physical_memory_bytes");
     Assert.assertNotNull(memoryBytes);
@@ -80,6 +85,56 @@ protected void check() throws Exception {
         new String[] {"sync"}, new String[] {"false"});
     Assert.assertNotNull(pushBlock);
     Assert.assertEquals(pushBlock.intValue(), blocks + 1);
+
+    String minerBase58 = StringUtil.encode58Check(address);
+    // Query histogram bucket le="0.0" for empty blocks
+    Double emptyBlock = CollectorRegistry.defaultRegistry.getSampleValue(
+        "tron:block_transaction_count_bucket",
+        new String[] {MINER_LABEL, "le"}, new String[] {minerBase58, "0.0"});
+
+    Assert.assertNotNull("Empty block bucket should exist for miner: " + minerBase58, emptyBlock);
+    Assert.assertEquals("Should have 1 empty block", 1, emptyBlock.intValue());
+
+    // Check SR_REMOVE for initial address (removed when addTestWitnessAndAccount() is called)
+    Double srRemoveCount = CollectorRegistry.defaultRegistry.getSampleValue(
+        "tron:sr_set_change_total",
+        new String[] {"action", "witness"},
+        new String[] {MetricLabels.Counter.SR_REMOVE, minerBase58}
+    );
+    Assert.assertNotNull(srRemoveCount);
+    Assert.assertEquals(1, srRemoveCount.intValue());
+
+    // Check SR_ADD and empty blocks for each new witness in witnessAndAccount
+    // (excluding initial address)
+    ByteString addressByteString = ByteString.copyFrom(address);
+    double totalNewWitnessEmptyBlocks = 0;
+    for (ByteString witnessAddress : witnessAndAccount.keySet()) {
+      if (witnessAddress.equals(addressByteString)) {
+        continue; // Skip initial address
+      }
+      String witnessBase58 = StringUtil.encode58Check(witnessAddress.toByteArray());
+
+      // Check SR_ADD
+      Double srAddCount = CollectorRegistry.defaultRegistry.getSampleValue(
+          "tron:sr_set_change_total",
+          new String[] {"action", "witness"},
+          new String[] {MetricLabels.Counter.SR_ADD, witnessBase58}
+      );
+      Assert.assertNotNull("SR_ADD should be recorded for witness: " + witnessBase58,
+          srAddCount);
+      Assert.assertEquals("Each new witness should have 1 SR_ADD record", 1,
+          srAddCount.intValue());
+
+      // Collect empty blocks count from histogram bucket
+      Double witnessEmptyBlock = CollectorRegistry.defaultRegistry.getSampleValue(
+          "tron:block_transaction_count_bucket",
+          new String[] {MINER_LABEL, "le"}, new String[] {witnessBase58, "0.0"});
+      Assert.assertNotNull("Empty block bucket should exist for witness: " + witnessBase58,
+          witnessEmptyBlock);
+      totalNewWitnessEmptyBlocks += witnessEmptyBlock;
+    }
+    Assert.assertEquals(blocks, (int)totalNewWitnessEmptyBlocks);
+
     Double errorLogs = CollectorRegistry.defaultRegistry.getSampleValue(
         "tron:error_info_total", new String[] {"net"}, new String[] {MetricLabels.UNDEFINED});
     Assert.assertNull(errorLogs);
@@ -130,10 +185,23 @@ public void testMetric() throws Exception {
 
     Map<ByteString, String> witnessAndAccount = addTestWitnessAndAccount();
     witnessAndAccount.put(ByteString.copyFrom(address), key);
+
+    // Explicitly update WitnessScheduleStore to remove initial address,
+    // triggering SR_REMOVE metric
+    List<ByteString> newActiveWitnesses = new ArrayList<>(witnessAndAccount.keySet());
+    newActiveWitnesses.remove(ByteString.copyFrom(address));
+    chainBaseManager.getWitnessScheduleStore().saveActiveWitnesses(newActiveWitnesses);
+
+    // Update nextMaintenanceTime to trigger SR set change detection
+    long nextMaintenanceTime = 
+        chainBaseManager.getDynamicPropertiesStore().getNextMaintenanceTime();
+    chainBaseManager.getDynamicPropertiesStore().updateNextMaintenanceTime(
+        nextMaintenanceTime + 3600_000L);
+
     for (int i = 0; i < blocks; i++) {
       generateBlock(witnessAndAccount);
     }
-    check();
+    check(address, witnessAndAccount);
   }
 
   private Map<ByteString, String> addTestWitnessAndAccount() {