Added configuration option to destroy UCP pool

jdbc-ucp/src/main/java/io/micronaut/configuration/jdbc/ucp/DatasourceConfiguration.java

@@ -178,6 +178,11 @@ public String getValidationQuery() {
         return calculatedSettings.getValidationQuery();
     }
 
+    /**
+     * Sets the validation query.
+     *
+     * @param validationQuery The validation query
+     */
     public void setValidationQuery(String validationQuery) {
         try {
             delegate.setSQLForValidateConnection(validationQuery);

jdbc-ucp/src/main/java/io/micronaut/configuration/jdbc/ucp/OracleUcpConfiguration.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2017-2025 original 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 io.micronaut.configuration.jdbc.ucp;
+
+import io.micronaut.context.annotation.ConfigurationProperties;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.core.annotation.Nullable;
+
+import static io.micronaut.configuration.jdbc.ucp.OracleUcpConfiguration.PREFIX;
+
+/**
+ * Configuration properties for Oracle Universal Connection Pooling (UCP).
+ *
+ * @param destroyOnReload Flag indicating whether to destroy connections on reload
+ */
+@ConfigurationProperties(PREFIX)
+@Requires(property = PREFIX)
+public record OracleUcpConfiguration(@Nullable Boolean destroyOnReload) {
+
+    /** Prefix used for configuration properties. */
+    static final String PREFIX = "oracle.ucp";
+}

jdbc-ucp/src/main/java/io/micronaut/configuration/jdbc/ucp/OracleUcpConfigurator.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2017-2025 original 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 io.micronaut.configuration.jdbc.ucp;
+
+import io.micronaut.context.annotation.Context;
+import io.micronaut.context.annotation.Requires;
+import io.micronaut.core.annotation.Internal;
+import io.micronaut.core.annotation.Nullable;
+import jakarta.annotation.PostConstruct;
+import oracle.ucp.jdbc.PoolDataSource;
+
+/** Oracle UCP configuration setting some {@code oracle.ucp} system properties. */
+@Context
+@Internal
+@Requires(classes = PoolDataSource.class)
+@Requires(beans = OracleUcpConfiguration.class)
+public class OracleUcpConfigurator {
+
+    private static final String UCP_DESTROY_ON_RELOAD = "oracle.ucp.destroyOnReload";
+
+    /**
+     * Initializes the Oracle UCP (Universal Connection Pooling) configuration.
+     *
+     * <p>If the {@code oracle.ucp.destroyOnReload} system property is not set or is empty, this method
+     * sets it based on the value of the {@link OracleUcpConfiguration#destroyOnReload()} field.
+     * This property determines whether the connection pool should be destroyed when the application
+     * is reloaded.
+     *
+     * <p>This initialization helps prevent duplicate connection pool errors that may occur during
+     * application reloading.
+     *
+     * @param oracleUcpConfiguration The Oracle UCP configuration
+     */
+    @PostConstruct
+    public void initUcp(@Nullable OracleUcpConfiguration oracleUcpConfiguration) {
+        if (oracleUcpConfiguration != null && oracleUcpConfiguration.destroyOnReload() != null) {
+            final String ucpDestroyOnReloadProperty = System.getProperty(UCP_DESTROY_ON_RELOAD);
+            if (ucpDestroyOnReloadProperty == null || ucpDestroyOnReloadProperty.isBlank()) {
+                // This is to deal with a duplicate connection pool error of:
+                // "oracle.ucp.UniversalConnectionPoolException: Universal Connection Pool already
+                // exists in the Universal Connection Pool Manager. Universal Connection Pool cannot
+                // be added to the Universal Connection Pool Manager"
+                // This magic flag is used by oracle.ucp.util.Util.isDestroyOnReloadEnabled, which
+                // defaults it to false.
+                // When true the oracle.ucp.jdbc.PoolDataSourceImpl.createUniversalConnectionPool()
+                // will destroy the connection pool if it is still around.
+                System.setProperty(
+                    UCP_DESTROY_ON_RELOAD,
+                    String.valueOf(oracleUcpConfiguration.destroyOnReload()));
+            }
+        }
+    }
+}

src/main/docs/guide/jdbc/jdbc-connection-pools.adoc

@@ -48,7 +48,9 @@ datasources:
     maxPoolSize: 10
 ----
 
-The Oracle UCP is managed by the link:https://docs.oracle.com/en/database/oracle/oracle-database/21/jjuar/oracle/ucp/admin/UniversalConnectionPoolManager.html[UniversalConnectionPoolManager]. The manager can be disabled byt setting `ucp-manager.enabled` to `false`. Additionally you can enable the link:https://docs.oracle.com/en/database/oracle/oracle-database/21/jjucp/jmx-based-management.html[JMX-Based Management] by setting the `ucp-manager.jmx.enabled` to `true` and providing the `ojdbc8dms.jar` and `dms.jar` dependencies.
+The Oracle UCP is managed by the link:https://docs.oracle.com/en/database/oracle/oracle-database/21/jjuar/oracle/ucp/admin/UniversalConnectionPoolManager.html[UniversalConnectionPoolManager]. The manager can be disabled byt setting `ucp-manager.enabled` to `false`. Additionally, you can enable the link:https://docs.oracle.com/en/database/oracle/oracle-database/21/jjucp/jmx-based-management.html[JMX-Based Management] by setting the `ucp-manager.jmx.enabled` to `true` and providing the `ojdbc8dms.jar` and `dms.jar` dependencies.
+
+In case when exception `Universal Connection Pool already exists in the Universal Connection Pool Manager` is thrown, there is `oracle.ucp.destroyOnReload` configuration that can be set to `true` to avoid this error. In that case, when creating new connection pool, if there is the one with the same name the old one will be destroyed first.
 
 For a list of other properties able to be configured, simply refer to the implementation that is being used. All setter methods are candidates for configuration.
 

tests/jdbc-ucp-tests/jdbc-ucp-oracle/src/test/java/example/jdbc/ucp/sync/OracleApp.java

@@ -23,6 +23,7 @@
 @Property(name = "datasources.default.db-type", value = "oracle")
 @Property(name = "datasources.default.connection-factory-class-name", value = "oracle.jdbc.pool.OracleDataSource")
 @Property(name = "test-resources.containers.oracle.startup-timeout", value = "600s")
+@Property(name = "oracle.ucp.destroyOnReload", value = "true")
 public class OracleApp extends AbstractApp {
 }