(gravitino) branch main updated: [#8382]Improvement(IcebergHiveCachedClientPool): prevent NPE in IcebergHiveCachedClientPool when closing multiple instances (#8455)

[yuqi4733]

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yuqi4733 pushed a commit to branch main
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The following commit(s) were added to refs/heads/main by this push:
     new 36024acd06 [#8382]Improvement(IcebergHiveCachedClientPool): prevent 
NPE in IcebergHiveCachedClientPool when closing multiple instances (#8455)
36024acd06 is described below

commit 36024acd06c179a7c6029383b1f065edbd78d6f7
Author: Sambhavi Pandey <48976443+pandeysam...@users.noreply.github.com>
AuthorDate: Sun Sep 7 17:43:38 2025 +0530

    [#8382]Improvement(IcebergHiveCachedClientPool): prevent NPE in 
IcebergHiveCachedClientPool when closing multiple instances (#8455)
    
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    ### What changes were proposed in this pull request?
    Add a null check before shutting down scheduledExecutorService in close
    method.
    
    
    ### Why are the changes needed?
    clientPoolCache is a static field, meaning it is shared across all
    instances of IcebergHiveCachedClientPool.
    Only the first instance that calls init() will initialize both
    clientPoolCache and scheduledExecutorService.
    Any subsequent instances will find clientPoolCache already initialized,
    so they will not initialize scheduledExecutorService (it remains null
    for those instances).When we create multiple instances of
    IcebergHiveCachedClientPool, only the first instance will have a
    non-null scheduledExecutorService.The other instances will have
    scheduledExecutorService as null.
    When we call close() on all instances, each will attempt to call
    scheduledExecutorService.shutdownNow()
    For instances where scheduledExecutorService is null, this results in a
    NullPointerException.
    
    Fix: (#8382 )
    
    ### Does this PR introduce _any_ user-facing change?
    No
    
    ### How was this patch tested?
    unit testing
---
 .../iceberg/common/utils/IcebergHiveCachedClientPool.java  |  2 +-
 .../common/utils/TestIcebergHiveCachedClientPool.java      | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git 
a/iceberg/iceberg-common/src/main/java/org/apache/gravitino/iceberg/common/utils/IcebergHiveCachedClientPool.java
 
b/iceberg/iceberg-common/src/main/java/org/apache/gravitino/iceberg/common/utils/IcebergHiveCachedClientPool.java
index 06a8c32aab..9c15639d1d 100644
--- 
a/iceberg/iceberg-common/src/main/java/org/apache/gravitino/iceberg/common/utils/IcebergHiveCachedClientPool.java
+++ 
b/iceberg/iceberg-common/src/main/java/org/apache/gravitino/iceberg/common/utils/IcebergHiveCachedClientPool.java
@@ -261,6 +261,6 @@ public class IcebergHiveCachedClientPool
   public void close() throws IOException {
     clientPoolCache.asMap().forEach((key, value) -> value.close());
     clientPoolCache.invalidateAll();
-    scheduledExecutorService.shutdownNow();
+    if (scheduledExecutorService != null) 
scheduledExecutorService.shutdownNow();
   }
 }
diff --git 
a/iceberg/iceberg-common/src/test/java/org/apache/gravitino/iceberg/common/utils/TestIcebergHiveCachedClientPool.java
 
b/iceberg/iceberg-common/src/test/java/org/apache/gravitino/iceberg/common/utils/TestIcebergHiveCachedClientPool.java
index 1f69d69db4..4a5ef88543 100644
--- 
a/iceberg/iceberg-common/src/test/java/org/apache/gravitino/iceberg/common/utils/TestIcebergHiveCachedClientPool.java
+++ 
b/iceberg/iceberg-common/src/test/java/org/apache/gravitino/iceberg/common/utils/TestIcebergHiveCachedClientPool.java
@@ -99,4 +99,18 @@ public class TestIcebergHiveCachedClientPool {
                 () -> IcebergHiveCachedClientPool.extractKey("ugi", 
configuration));
     Assertions.assertNotEquals(key9, key10);
   }
+
+  @Test
+  void testCloseMultipleInstances() throws IOException {
+    Configuration configuration = new Configuration();
+    Map<String, String> properties = Maps.newHashMap();
+    IcebergHiveCachedClientPool pool1 = new 
IcebergHiveCachedClientPool(configuration, properties);
+    IcebergHiveCachedClientPool pool2 = new 
IcebergHiveCachedClientPool(configuration, properties);
+
+    Assertions.assertDoesNotThrow(
+        () -> {
+          pool1.close();
+          pool2.close();
+        });
+  }
 }