Add the handle to overload connection (#10783)

* add the handle to overload connection * fast return
alibaba · Jul 17, 2023 · 318892d · 318892d
1 parent 3374cf4
commit 318892d
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Showing 2 changed files with 57 additions and 1 deletion.
diff --git a/core/src/main/java/com/alibaba/nacos/core/remote/ConnectionManager.java b/core/src/main/java/com/alibaba/nacos/core/remote/ConnectionManager.java
@@ -263,8 +263,9 @@ public void loadCount(int loadClient, String redirectAddress) {
      *
      * @param connectionId    connection id of client.
      * @param redirectAddress server address to redirect.
+     * @return whether remove connection.
      */
-    public void loadSingle(String connectionId, String redirectAddress) {
+    public boolean loadSingle(String connectionId, String redirectAddress) {
         Connection connection = getConnection(connectionId);
 
         if (connection != null) {
@@ -281,9 +282,11 @@ public void loadSingle(String connectionId, String redirectAddress) {
                     unregister(connectionId);
                 } catch (Exception e) {
                     LOGGER.error("error occurs when expel connection, connectionId: {} ", connectionId, e);
+                    return false;
                 }
             }
         }
+        return true;
 
     }
 

diff --git a/core/src/main/java/com/alibaba/nacos/core/remote/NacosRuntimeConnectionEjector.java b/core/src/main/java/com/alibaba/nacos/core/remote/NacosRuntimeConnectionEjector.java
@@ -48,6 +48,16 @@ public NacosRuntimeConnectionEjector() {
      * eject connections on runtime.
      */
     public void doEject() {
+        // remove out dated connection
+        ejectOutdatedConnection();
+        // remove overload connection
+        ejectOverLimitConnection();
+    }
+
+    /**
+     * eject the outdated connection.
+     */
+    private void ejectOutdatedConnection() {
         try {
 
             Loggers.CONNECTION.info("Connection check task start");
@@ -137,6 +147,49 @@ public void onException(Throwable e) {
             Loggers.CONNECTION.error("Error occurs during connection check... ", e);
         }
     }
+
+    /**
+     * eject the over limit connection.
+     */
+    private void ejectOverLimitConnection() {
+        // if not count set, then give up
+        if (getLoadClient() > 0) {
+            try {
+                Loggers.CONNECTION.info("Connection overLimit check task start, loadCount={}, redirectAddress={}",
+                        getLoadClient(), getRedirectAddress());
+                // check count
+                int currentConnectionCount = connectionManager.getCurrentConnectionCount();
+                int ejectingCount = currentConnectionCount - getLoadClient();
+                // if overload
+                if (ejectingCount > 0) {
+                    // we may modify the connection map when connection reset
+                    // avoid concurrent modified exception, create new set for ids snapshot
+                    Set<String> ids = new HashSet<>(connectionManager.connections.keySet());
+                    for (String id : ids) {
+                        if (ejectingCount > 0) {
+                            // check sdk
+                            Connection connection = connectionManager.getConnection(id);
+                            if (connection != null && connection.getMetaInfo().isSdkSource()) {
+                                if (connectionManager.loadSingle(id, redirectAddress)) {
+                                    ejectingCount--;
+                                }
+                            }
+                        } else {
+                            // reach the count
+                            break;
+                        }
+                    }
+                }
+                Loggers.CONNECTION.info("Connection overLimit task end, current loadCount={}, has ejected loadCont={}",
+                        connectionManager.getCurrentConnectionCount(), getLoadClient() - ejectingCount);
+            } catch (Throwable e) {
+                Loggers.CONNECTION.error("Error occurs during connection overLimit... ", e);
+            }
+            // reset
+            setRedirectAddress(null);
+            setLoadClient(-1);
+        }
+    }
 
     @Override
     public String getName() {