diff --git a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/DorisSource.java b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/DorisSource.java
index 6faed87df..1b05453ad 100644
--- a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/DorisSource.java
+++ b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/DorisSource.java
@@ -125,6 +125,7 @@ public SplitEnumerator<DorisSourceSplit, PendingSplitsCheckpoint> restoreEnumera
             SplitEnumeratorContext<DorisSourceSplit> context, PendingSplitsCheckpoint checkpoint)
             throws Exception {
         Collection<DorisSourceSplit> splits = checkpoint.getSplits();
+        LOG.info("Restore splits from checkpoint, size {}, splits {}", splits.size(), splits);
         DorisSplitAssigner splitAssigner = new SimpleSplitAssigner(splits);
         return new DorisSourceEnumerator(context, splitAssigner);
     }
diff --git a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/assigners/SimpleSplitAssigner.java b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/assigners/SimpleSplitAssigner.java
index ee96f6873..7948244ca 100644
--- a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/assigners/SimpleSplitAssigner.java
+++ b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/assigners/SimpleSplitAssigner.java
@@ -52,6 +52,7 @@ public void addSplits(Collection<DorisSourceSplit> splits) {
 
     @Override
     public PendingSplitsCheckpoint snapshotState(long checkpointId) {
+        LOG.info("Snapshot splits {} for checkpoint {}", splits, checkpointId);
         return new PendingSplitsCheckpoint(splits);
     }
 
diff --git a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/enumerator/DorisSourceEnumerator.java b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/enumerator/DorisSourceEnumerator.java
index 65fcc6fa7..be93f39dc 100644
--- a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/enumerator/DorisSourceEnumerator.java
+++ b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/enumerator/DorisSourceEnumerator.java
@@ -85,7 +85,7 @@ public void addSplitsBack(List<DorisSourceSplit> splits, int subtaskId) {
 
     @Override
     public void addReader(int subtaskId) {
-        // do nothing
+        LOG.info("add reader: {}", subtaskId);
     }
 
     @Override
diff --git a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/reader/DorisSourceReader.java b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/reader/DorisSourceReader.java
index 7e2a72087..dce23ee20 100644
--- a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/reader/DorisSourceReader.java
+++ b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/reader/DorisSourceReader.java
@@ -27,6 +27,8 @@
 import org.apache.doris.flink.cfg.DorisReadOptions;
 import org.apache.doris.flink.source.split.DorisSourceSplit;
 import org.apache.doris.flink.source.split.DorisSourceSplitState;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.List;
 import java.util.Map;
@@ -36,6 +38,8 @@ public class DorisSourceReader<T>
         extends SingleThreadMultiplexSourceReaderBase<
                 List, T, DorisSourceSplit, DorisSourceSplitState> {
 
+    private static final Logger LOG = LoggerFactory.getLogger(DorisSourceReader.class);
+
     public DorisSourceReader(
             DorisOptions options,
             DorisReadOptions readOptions,
@@ -64,6 +68,7 @@ protected void onSplitFinished(Map<String, DorisSourceSplitState> finishedSplitI
 
     @Override
     protected DorisSourceSplitState initializedState(DorisSourceSplit split) {
+        LOG.info("Initialized reader state for split: {}", split);
         return new DorisSourceSplitState(split);
     }
 
diff --git a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/reader/DorisSourceSplitReader.java b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/reader/DorisSourceSplitReader.java
index c9ed6f9ce..39187f87c 100644
--- a/flink-doris-connector/src/main/java/org/apache/doris/flink/source/reader/DorisSourceSplitReader.java
+++ b/flink-doris-connector/src/main/java/org/apache/doris/flink/source/reader/DorisSourceSplitReader.java
@@ -74,12 +74,22 @@ private void checkSplitOrStartNext() throws IOException, DorisException {
             throw new IOException("Cannot fetch from another split - no split remaining");
         }
         currentSplitId = nextSplit.splitId();
+        LOG.info("Fetch a new split {}", nextSplit);
         valueReader =
                 ValueReader.createReader(
                         nextSplit.getPartitionDefinition(), options, readOptions, LOG);
     }
 
     private DorisSplitRecords finishSplit() {
+        if (valueReader != null) {
+            try {
+                valueReader.close();
+            } catch (Exception e) {
+                LOG.warn("Error while closing value reader: {}", e.getMessage());
+            }
+            valueReader = null;
+        }
+
         final DorisSplitRecords finishRecords = DorisSplitRecords.finishedSplit(currentSplitId);
         currentSplitId = null;
         return finishRecords;
@@ -87,7 +97,7 @@ private DorisSplitRecords finishSplit() {
 
     @Override
     public void handleSplitsChanges(SplitsChange<DorisSourceSplit> splitsChange) {
-        LOG.debug("Handling split change {}", splitsChange);
+        LOG.info("Handling split change {}", splitsChange);
         splits.addAll(splitsChange.splits());
     }