Add health checks

pom.xml

@@ -84,6 +84,10 @@
             <groupId>io.smallrye.reactive</groupId>
             <artifactId>smallrye-mutiny-vertx-web-client</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-smallrye-health</artifactId>
+        </dependency>
 
         <!-- Test -->
         <dependency>

src/main/java/org/commonjava/util/gateway/metrics/health/HeapHealthCheck.java

@@ -0,0 +1,24 @@
+package org.commonjava.util.gateway.metrics.health;
+
+import org.commonjava.util.gateway.metrics.honeycomb.JvmRootSpanFields;
+import org.eclipse.microprofile.health.HealthCheck;
+import org.eclipse.microprofile.health.HealthCheckResponse;
+import org.eclipse.microprofile.health.Liveness;
+
+import javax.enterprise.context.ApplicationScoped;
+import java.util.Map;
+import java.util.Optional;
+
+import static org.eclipse.microprofile.health.HealthCheckResponse.State.UP;
+
+@Liveness
+@ApplicationScoped
+public class HeapHealthCheck
+                implements HealthCheck
+{
+    @Override
+    public HealthCheckResponse call()
+    {
+        return new HealthCheckResponse( "heap", UP, Optional.of( JvmRootSpanFields.getInstance().getHeapInfo() ) );
+    }
+}

src/main/java/org/commonjava/util/gateway/metrics/health/ThreadsHealthCheck.java

@@ -0,0 +1,24 @@
+package org.commonjava.util.gateway.metrics.health;
+
+import org.commonjava.util.gateway.metrics.honeycomb.JvmRootSpanFields;
+import org.eclipse.microprofile.health.HealthCheck;
+import org.eclipse.microprofile.health.HealthCheckResponse;
+import org.eclipse.microprofile.health.Liveness;
+
+import javax.enterprise.context.ApplicationScoped;
+import java.util.Optional;
+
+import static org.eclipse.microprofile.health.HealthCheckResponse.State.UP;
+
+@Liveness
+@ApplicationScoped
+public class ThreadsHealthCheck
+                implements HealthCheck
+{
+    @Override
+    public HealthCheckResponse call()
+    {
+        return new HealthCheckResponse( "threads", UP,
+                                        Optional.of( JvmRootSpanFields.getInstance().getThreadsInfo() ) );
+    }
+}

src/main/java/org/commonjava/util/gateway/metrics/honeycomb/JvmRootSpanFields.java

@@ -2,6 +2,9 @@
 
 import org.commonjava.o11yphant.honeycomb.RootSpanFields;
 
+import java.lang.management.ManagementFactory;
+import java.lang.management.ThreadInfo;
+import java.lang.management.ThreadMXBean;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -10,19 +13,62 @@ public class JvmRootSpanFields
 {
     private final static long MB = 1024 * 1024;
 
+    private static final JvmRootSpanFields INSTANCE = new JvmRootSpanFields();
+
+    public static JvmRootSpanFields getInstance()
+    {
+        return INSTANCE;
+    }
+
     private final Runtime rt = Runtime.getRuntime();
 
+    private final ThreadMXBean mxBean = ManagementFactory.getThreadMXBean();
+
+    private JvmRootSpanFields()
+    {
+    }
+
     @Override
     public Map<String, Object> get()
+    {
+        Map<String, Object> ret = new HashMap<>();
+        getHeapInfo().forEach( ( k, v ) -> ret.put( "heap_" + k, v ) );
+        getThreadsInfo().forEach( ( k, v ) -> ret.put( "threads_" + k, v ) );
+        return ret;
+    }
+
+    public Map<String, Object> getHeapInfo()
     {
         long total = rt.totalMemory();
         long free = rt.freeMemory();
         long used = total - free;
 
         Map<String, Object> ret = new HashMap<>();
-        ret.put( "heap_total_mb", total / MB );
-        ret.put( "heap_free_mb", free / MB );
-        ret.put( "heap_used_mb", used / MB );
+        ret.put( "total_mb", total / MB );
+        ret.put( "free_mb", free / MB );
+        ret.put( "used_mb", used / MB );
+        return ret;
+    }
+
+    public Map<String, Object> getThreadsInfo()
+    {
+        Map<String, Object> ret = new HashMap<>();
+        ThreadInfo[] threads = mxBean.getThreadInfo( mxBean.getAllThreadIds() );
+
+        for ( ThreadInfo info : threads )
+        {
+            String state = info.getThreadState().toString().toLowerCase();
+            Long count = (Long) ret.get( state );
+            if ( count == null )
+            {
+                count = 1L;
+            }
+            else
+            {
+                count += 1;
+            }
+            ret.put( state, count );
+        }
         return ret;
     }
 }

src/main/java/org/commonjava/util/gateway/metrics/honeycomb/ProxyHoneycombManager.java

@@ -32,7 +32,7 @@ public ProxyHoneycombManager( ProxyHoneycombConfiguration honeycombConfiguration
     public void init()
     {
         super.init();
-        registerRootSpanFields( new JvmRootSpanFields() );
+        registerRootSpanFields( JvmRootSpanFields.getInstance() );
     }
 
     public void addFields( long elapse, HttpServerRequest request, Object item, Throwable err )