[mysql-cdc] Fix race condition between split and coordinator thread that async exception might not be caught

flink-connector-mysql-cdc/src/main/java/com/ververica/cdc/connectors/mysql/source/assigners/MySqlSnapshotSplitAssigner.java

@@ -276,9 +276,9 @@ public class MySqlSnapshotSplitAssigner implements MySqlSplitAssigner {
 
     @Override
     public Optional<MySqlSplit> getNext() {
-        checkSplitterErrors();
         waitTableDiscoveryReady();
         synchronized (lock) {
+            checkSplitterErrors();
             if (!remainingSplits.isEmpty()) {
                 // return remaining splits firstly
                 Iterator<MySqlSchemalessSnapshotSplit> iterator = remainingSplits.iterator();
@@ -496,7 +496,8 @@ public class MySqlSnapshotSplitAssigner implements MySqlSplitAssigner {
 
     private void splitChunksForRemainingTables() {
         try {
-            // restore from a checkpoint and start to split the table from the previous checkpoint
+            // restore from a checkpoint and start to split the table from the previous
+            // checkpoint
             if (chunkSplitter.hasNextChunk()) {
                 LOG.info(
                         "Start splitting remaining chunks for table {}",
@@ -509,13 +510,13 @@ public class MySqlSnapshotSplitAssigner implements MySqlSplitAssigner {
                 splitTable(nextTable);
             }
         } catch (Throwable e) {
-            if (uncaughtSplitterException == null) {
-                uncaughtSplitterException = e;
-            } else {
-                uncaughtSplitterException.addSuppressed(e);
-            }
-            // Release the potential waiting getNext() call
             synchronized (lock) {
+                if (uncaughtSplitterException == null) {
+                    uncaughtSplitterException = e;
+                } else {
+                    uncaughtSplitterException.addSuppressed(e);
+                }
+                // Release the potential waiting getNext() call
                 lock.notify();
             }
         }