DATAREDIS-1104 - Suppress connection close failures when unbinding a connection.

We now no longer propagate exceptions that happen during connection disposal but instead we log them on DEBUG level to avoid exception masking.

src/main/java/org/springframework/data/redis/core/RedisConnectionUtils.java

@@ -24,8 +24,10 @@ import org.aopalliance.intercept.MethodInterceptor;
 import org.aopalliance.intercept.MethodInvocation;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
+
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.cglib.proxy.MethodProxy;
+import org.springframework.dao.DataAccessException;
 import org.springframework.data.redis.connection.RedisConnection;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
 import org.springframework.lang.Nullable;
@@ -236,12 +238,8 @@ public abstract class RedisConnectionUtils {
 					log.debug("Leaving bound Redis Connection attached.");
 				}
 			}
-
 		} else {
-			if (log.isDebugEnabled()) {
-				log.debug("Closing Redis Connection.");
-			}
-			conn.close();
+			doCloseConnection(conn);
 		}
 	}
 
@@ -264,11 +262,7 @@ public abstract class RedisConnectionUtils {
 				log.debug("Redis Connection will be closed when outer transaction finished.");
 			}
 		} else {
-			if (log.isDebugEnabled()) {
-				log.debug("Closing bound connection.");
-			}
-			RedisConnection connection = connHolder.getConnection();
-			connection.close();
+			doCloseConnection(connHolder.getConnection());
 		}
 	}
 
@@ -290,6 +284,21 @@ public abstract class RedisConnectionUtils {
 		return (connHolder != null && conn == connHolder.getConnection());
 	}
 
+	private static void doCloseConnection(RedisConnection connection) {
+
+		if (log.isDebugEnabled()) {
+			log.debug("Closing Redis Connection.");
+		}
+
+		try {
+			connection.close();
+		} catch (DataAccessException ex) {
+			log.debug("Could not close Redis Connection", ex);
+		} catch (Throwable ex) {
+			log.debug("Unexpected exception on closing Redis Connection", ex);
+		}
+	}
+
 	/**
 	 * A {@link TransactionSynchronizationAdapter} that makes sure that the associated RedisConnection is released after
 	 * the transaction completes.
@@ -326,7 +335,7 @@ public abstract class RedisConnectionUtils {
 				}
 
 				connHolder.setTransactionSyncronisationActive(false);
-				connection.close();
+				doCloseConnection(connection);
 				TransactionSynchronizationManager.unbindResource(factory);
 			}
 		}
@@ -370,7 +379,7 @@ public abstract class RedisConnectionUtils {
 			} finally {
 				// properly close the unbound connection after executing command
 				if (!connection.isClosed()) {
-					connection.close();
+					doCloseConnection(connection);
 				}
 			}
 		}

src/test/java/org/springframework/data/redis/core/RedisConnectionUtilsUnitTests.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.redis.core;
+
+import static org.mockito.Mockito.*;
+
+import org.junit.Test;
+
+import org.springframework.data.redis.connection.RedisConnection;
+import org.springframework.data.redis.connection.RedisConnectionFactory;
+
+/**
+ * Unit tests for {@link RedisConnectionUtils}.
+ *
+ * @author Mark Paluch
+ */
+public class RedisConnectionUtilsUnitTests {
+
+	@Test // DATAREDIS-1104
+	public void shouldSilentlyCloseRedisConnection() {
+
+		RedisConnection connectionMock = mock(RedisConnection.class);
+		RedisConnectionFactory factoryMock = mock(RedisConnectionFactory.class);
+
+		doThrow(new IllegalStateException()).when(connectionMock).close();
+
+		RedisConnectionUtils.releaseConnection(connectionMock, factoryMock, false);
+
+		verify(connectionMock).close();
+	}
+}