diff --git a/flink-cdc-connect/flink-cdc-source-connectors/flink-cdc-base/src/main/java/org/apache/flink/cdc/connectors/base/relational/connection/JdbcConnectionPools.java b/flink-cdc-connect/flink-cdc-source-connectors/flink-cdc-base/src/main/java/org/apache/flink/cdc/connectors/base/relational/connection/JdbcConnectionPools.java
index 64a2a7288b0..625cb8db9ff 100644
--- a/flink-cdc-connect/flink-cdc-source-connectors/flink-cdc-base/src/main/java/org/apache/flink/cdc/connectors/base/relational/connection/JdbcConnectionPools.java
+++ b/flink-cdc-connect/flink-cdc-source-connectors/flink-cdc-base/src/main/java/org/apache/flink/cdc/connectors/base/relational/connection/JdbcConnectionPools.java
@@ -86,12 +86,10 @@ public String getJdbcUrl(
     }
 
     public void clear() throws IOException {
-        if (instance != null) {
-            synchronized (instance.pools) {
-                instance.pools.values().stream().forEach(HikariDataSource::close);
-                instance.pools.clear();
-                POOL_FACTORY_MAP.clear();
-            }
+        synchronized (pools) {
+            pools.values().stream().forEach(HikariDataSource::close);
+            pools.clear();
+            POOL_FACTORY_MAP.clear();
         }
     }
 }
diff --git a/flink-cdc-connect/flink-cdc-source-connectors/flink-connector-mysql-cdc/src/main/java/org/apache/flink/cdc/connectors/mysql/source/connection/JdbcConnectionPools.java b/flink-cdc-connect/flink-cdc-source-connectors/flink-connector-mysql-cdc/src/main/java/org/apache/flink/cdc/connectors/mysql/source/connection/JdbcConnectionPools.java
index c6404bf0e02..9505a559ad0 100644
--- a/flink-cdc-connect/flink-cdc-source-connectors/flink-connector-mysql-cdc/src/main/java/org/apache/flink/cdc/connectors/mysql/source/connection/JdbcConnectionPools.java
+++ b/flink-cdc-connect/flink-cdc-source-connectors/flink-connector-mysql-cdc/src/main/java/org/apache/flink/cdc/connectors/mysql/source/connection/JdbcConnectionPools.java
@@ -53,10 +53,10 @@ public HikariDataSource getOrCreateConnectionPool(
         }
     }
 
-    public synchronized void clear() throws IOException {
-        synchronized (INSTANCE.pools) {
-            INSTANCE.pools.values().stream().forEach(HikariDataSource::close);
-            INSTANCE.pools.clear();
+    public void clear() throws IOException {
+        synchronized (pools) {
+            pools.values().stream().forEach(HikariDataSource::close);
+            pools.clear();
         }
     }
 }