Named thread.It is useful when debugging.

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/boot/DefaultNamedThreadFactory.java

+/*
+ * Copyright 2017, OpenSkywalking Organization All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Project repository: https://github.com/OpenSkywalking/skywalking
+ */
+package org.skywalking.apm.agent.core.boot;
+
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * @author zhangkewei
+ */
+public class DefaultNamedThreadFactory implements ThreadFactory {
+    private static final AtomicInteger BOOT_SERVICE_SEQ = new AtomicInteger(0);
+    private final AtomicInteger threadSeq = new AtomicInteger(0);
+    private final String namePrefix;
+    public DefaultNamedThreadFactory(String name) {
+        namePrefix = "SkywalkingAgent-" + BOOT_SERVICE_SEQ.incrementAndGet() + "-" + name + "-";
+    }
+    @Override
+    public Thread newThread(Runnable r) {
+        Thread t = new Thread();
+        t.setName(namePrefix + threadSeq.getAndIncrement());
+        t.setDaemon(true);
+        return t;
+    }
+}

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/jvm/JVMService.java

@@ -25,6 +25,7 @@ import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import org.skywalking.apm.agent.core.boot.BootService;
+import org.skywalking.apm.agent.core.boot.DefaultNamedThreadFactory;
 import org.skywalking.apm.agent.core.boot.ServiceManager;
 import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.conf.RemoteDownstreamConfig;
@@ -57,7 +58,6 @@ public class JVMService implements BootService, Runnable {
     private volatile ScheduledFuture<?> collectMetricFuture;
     private volatile ScheduledFuture<?> sendMetricFuture;
     private Sender sender;
-
     @Override
     public void beforeBoot() throws Throwable {
         queue = new LinkedBlockingQueue(Config.Jvm.BUFFER_SIZE);
@@ -68,10 +68,10 @@ public class JVMService implements BootService, Runnable {
     @Override
     public void boot() throws Throwable {
         collectMetricFuture = Executors
-            .newSingleThreadScheduledExecutor()
+            .newSingleThreadScheduledExecutor(new DefaultNamedThreadFactory("JVMService-produce"))
             .scheduleAtFixedRate(this, 0, 1, TimeUnit.SECONDS);
         sendMetricFuture = Executors
-            .newSingleThreadScheduledExecutor()
+            .newSingleThreadScheduledExecutor(new DefaultNamedThreadFactory("JVMService-consume"))
             .scheduleAtFixedRate(sender, 0, 1, TimeUnit.SECONDS);
     }
 

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/remote/AppAndServiceRegisterClient.java

@@ -24,6 +24,7 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import org.skywalking.apm.agent.core.boot.BootService;
+import org.skywalking.apm.agent.core.boot.DefaultNamedThreadFactory;
 import org.skywalking.apm.agent.core.boot.ServiceManager;
 import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.conf.RemoteDownstreamConfig;
@@ -89,7 +90,7 @@ public class AppAndServiceRegisterClient implements BootService, GRPCChannelList
     @Override
     public void boot() throws Throwable {
         applicationRegisterFuture = Executors
-            .newSingleThreadScheduledExecutor()
+            .newSingleThreadScheduledExecutor(new DefaultNamedThreadFactory("AppAndServiceRegisterClient"))
             .scheduleAtFixedRate(this, 0, Config.Collector.APP_AND_SERVICE_REGISTER_CHECK_INTERVAL, TimeUnit.SECONDS);
     }
 

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/remote/CollectorDiscoveryService.java

@@ -22,6 +22,7 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import org.skywalking.apm.agent.core.boot.BootService;
+import org.skywalking.apm.agent.core.boot.DefaultNamedThreadFactory;
 import org.skywalking.apm.agent.core.conf.Config;
 
 /**
@@ -39,7 +40,7 @@ public class CollectorDiscoveryService implements BootService {
 
     @Override
     public void boot() throws Throwable {
-        future = Executors.newSingleThreadScheduledExecutor()
+        future = Executors.newSingleThreadScheduledExecutor(new DefaultNamedThreadFactory("CollectorDiscoveryService"))
             .scheduleAtFixedRate(new DiscoveryRestServiceClient(), 0,
                 Config.Collector.DISCOVERY_CHECK_INTERVAL, TimeUnit.SECONDS);
     }

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/remote/GRPCChannelManager.java

@@ -32,6 +32,7 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import org.skywalking.apm.agent.core.boot.BootService;
+import org.skywalking.apm.agent.core.boot.DefaultNamedThreadFactory;
 import org.skywalking.apm.agent.core.conf.RemoteDownstreamConfig;
 import org.skywalking.apm.logging.ILog;
 import org.skywalking.apm.logging.LogManager;
@@ -58,7 +59,7 @@ public class GRPCChannelManager implements BootService, Runnable {
     @Override
     public void boot() throws Throwable {
         connectCheckFuture = Executors
-            .newSingleThreadScheduledExecutor()
+            .newSingleThreadScheduledExecutor(new DefaultNamedThreadFactory("GRPCChannelManager"))
             .scheduleAtFixedRate(this, 0, GRPC_CHANNEL_CHECK_INTERVAL, TimeUnit.SECONDS);
     }
 

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/sampling/SamplingService.java

@@ -24,6 +24,7 @@ import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import org.skywalking.apm.agent.core.boot.BootService;
+import org.skywalking.apm.agent.core.boot.DefaultNamedThreadFactory;
 import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 import org.skywalking.apm.logging.ILog;
@@ -63,7 +64,7 @@ public class SamplingService implements BootService {
             on = true;
             this.resetSamplingFactor();
             ScheduledExecutorService service = Executors
-                .newSingleThreadScheduledExecutor();
+                .newSingleThreadScheduledExecutor(new DefaultNamedThreadFactory("SamplingService"));
             scheduledFuture = service.scheduleAtFixedRate(new Runnable() {
                 @Override
                 public void run() {