[Fix][Master] Fix Potential danger in the event of a worker failover

dolphinscheduler-master/src/main/java/org/apache/dolphinscheduler/server/master/registry/MasterRegistryClient.java

@@ -131,17 +131,20 @@ public void removeMasterNodePath(String path, RegistryNodeType nodeType, boolean
     public void removeWorkerNodePath(String path, RegistryNodeType nodeType, boolean failover) {
         log.info("{} node deleted : {}", nodeType, path);
         try {
-            String serverHost = null;
-            if (!StringUtils.isEmpty(path)) {
-                serverHost = registryClient.getHostByEventDataPath(path);
-                if (StringUtils.isEmpty(serverHost)) {
-                    log.error("server down error: unknown path: {}", path);
-                    return;
-                }
-                if (!registryClient.exists(path)) {
-                    log.info("path: {} not exists", path);
-                }
+            if (StringUtils.isEmpty(path)) {
+                log.error("server down error: node empty path: {}, nodeType:{}", path, nodeType);
+                return;
             }
+
+            String serverHost = registryClient.getHostByEventDataPath(path);
+            if (StringUtils.isEmpty(serverHost)) {
+                log.error("server down error: unknown path: {}", path);
+                return;
+            }
+            if (!registryClient.exists(path)) {
+                log.info("path: {} not exists", path);
+            }
+
             // failover server
             if (failover) {
                 failoverService.failoverServerWhenDown(serverHost, nodeType);

dolphinscheduler-master/src/test/java/org/apache/dolphinscheduler/server/master/registry/MasterRegistryClientTest.java

@@ -103,4 +103,10 @@ public void removeNodePathTest() {
         // Cannot mock static methods
         masterRegistryClient.removeWorkerNodePath("/path", RegistryNodeType.WORKER, true);
     }
+
+    @Test
+    public void removeWorkNodePathTest() {
+        masterRegistryClient.removeWorkerNodePath("", RegistryNodeType.WORKER, true);
+        masterRegistryClient.removeWorkerNodePath(null, RegistryNodeType.WORKER, true);
+    }
 }