architjainjain commented on code in PR #6501: URL: https://github.com/apache/hive/pull/6501#discussion_r3712678667
########## ql/src/java/org/apache/hadoop/hive/ql/exec/tez/monitoring/yarnqueue/NoOpQueueMetricsCollector.java: ########## @@ -0,0 +1,51 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 + * + * http://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.apache.hadoop.hive.ql.exec.tez.monitoring.yarnqueue; +/** + * Null Object implementation of {@link QueueMetricsCollector}. + * Used when queue metrics collection is disabled. Provides safe no-op behavior + * so that callers don't need null checks. + * + * Thread-safe singleton following the Null Object pattern. Review Comment: done ########## ql/src/java/org/apache/hadoop/hive/ql/exec/tez/monitoring/yarnqueue/NoOpQueueMetricsCollector.java: ########## @@ -0,0 +1,51 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 + * + * http://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.apache.hadoop.hive.ql.exec.tez.monitoring.yarnqueue; +/** + * Null Object implementation of {@link QueueMetricsCollector}. + * Used when queue metrics collection is disabled. Provides safe no-op behavior + * so that callers don't need null checks. + * + * Thread-safe singleton following the Null Object pattern. + */ +public final class NoOpQueueMetricsCollector implements QueueMetricsCollector { + /** Singleton instance - thread-safe via static initialization. */ + public static final NoOpQueueMetricsCollector INSTANCE = new NoOpQueueMetricsCollector(); + // Private constructor prevents instantiation Review Comment: done ########## ql/src/java/org/apache/hadoop/hive/ql/exec/tez/monitoring/yarnqueue/NoOpQueueMetricsCollector.java: ########## @@ -0,0 +1,51 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 + * + * http://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.apache.hadoop.hive.ql.exec.tez.monitoring.yarnqueue; +/** + * Null Object implementation of {@link QueueMetricsCollector}. + * Used when queue metrics collection is disabled. Provides safe no-op behavior + * so that callers don't need null checks. + * + * Thread-safe singleton following the Null Object pattern. + */ +public final class NoOpQueueMetricsCollector implements QueueMetricsCollector { + /** Singleton instance - thread-safe via static initialization. */ + public static final NoOpQueueMetricsCollector INSTANCE = new NoOpQueueMetricsCollector(); + // Private constructor prevents instantiation + private NoOpQueueMetricsCollector() { + } + @Override + public QueueMetricsSnapshot getLatestSnapshot() { + // No metrics available when collection is disabled + return null; + } + @Override + public String getQueueName() { + // Return empty string instead of null to avoid NPEs + return ""; + } + @Override + public void shutdown() { + // No-op: nothing to shut down + } + @Override + public boolean isEnabled() { + // Metrics collection is disabled for no-op collector + return false; + } Review Comment: done -- This is an automated message from the Apache Git Service. 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