| /* |
| * 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.drill.exec.work.foreman.rm; |
| |
| import org.apache.drill.exec.proto.UserBitShared.QueryId; |
| |
| /** |
| * Interface which defines a queue implementation for query queues. |
| * Implementations can queue locally, queue distributed, or do |
| * nothing at all. |
| * <p> |
| * A queue can report itself as enabled or disabled. When enabled, |
| * all queries must obtain a lease prior to starting execution. The |
| * lease must be released at the completion of execution. |
| */ |
| |
| public interface QueryQueue { |
| |
| /** |
| * The opaque lease returned once a query is admitted |
| * for execution. |
| */ |
| |
| public interface QueueLease { |
| long queryMemoryPerNode(); |
| |
| /** |
| * Release a query lease obtained from {@link #enqueue(QueryId, double)}. |
| * Should be called by the per-query resource manager. |
| */ |
| |
| void release(); |
| |
| String queueName(); |
| }; |
| |
| /** |
| * Exception thrown if a query exceeds the configured wait time |
| * in the query queue. |
| */ |
| |
| @SuppressWarnings("serial") |
| public class QueueTimeoutException extends Exception { |
| |
| private final QueryId queryId; |
| private final String queueName; |
| private final int timeoutMs; |
| |
| public QueueTimeoutException(QueryId queryId, String queueName, int timeoutMs) { |
| super( String.format( |
| "Query timed out of the %s queue after %,d ms. (%d seconds)", |
| queueName, timeoutMs, (int) Math.round(timeoutMs/1000.0) )); |
| this.queryId = queryId; |
| this.queueName = queueName; |
| this.timeoutMs = timeoutMs; |
| } |
| |
| public QueryId queryId() { return queryId; } |
| public String queueName() { return queueName; } |
| public int timeoutMs() { return timeoutMs; } |
| } |
| |
| /** |
| * Exception thrown for all non-timeout error conditions. |
| */ |
| |
| @SuppressWarnings("serial") |
| public class QueryQueueException extends Exception { |
| QueryQueueException(String msg, Exception e) { |
| super(msg, e); |
| } |
| } |
| |
| void setMemoryPerNode(long memoryPerNode); |
| |
| /** |
| * Return the amount of memory per node when creating a EXPLAIN |
| * query plan. Plans to be executed should get the query memory from |
| * the lease, as the lease may adjust the default amount on a per-query |
| * basis. This means that the memory used to execute the query may |
| * differ from the amount shown in an EXPLAIN plan. |
| * |
| * @return assumed memory per node, in bytes, to use when creating |
| * an EXPLAIN plan |
| */ |
| |
| long defaultQueryMemoryPerNode(double cost); |
| |
| /** |
| * Optional floor on the amount of memory assigned per operator. |
| * This ensures that operators receive a certain amount, separate from |
| * any memory slicing. This can oversubscribe node memory if used |
| * incorrectly. |
| * |
| * @return minimum per-operator memory, in bytes |
| */ |
| |
| long minimumOperatorMemory(); |
| |
| /** |
| * Determine if the queue is enabled. |
| * @return true if the query is enabled, false otherwise. |
| */ |
| |
| boolean enabled(); |
| |
| /** |
| * Queue a query. The method returns only when the query is admitted for |
| * execution. As a result, the calling thread may block up to the configured |
| * wait time. |
| * @param queryId the query ID |
| * @param cost the cost of the query used for cost-based queueing |
| * @return the query lease which must be passed to {@code #release(QueueLease)} |
| * upon query completion |
| * @throws QueueTimeoutException if the query times out waiting to be |
| * admitted. |
| * @throws QueryQueueException for any other error condition. |
| */ |
| |
| QueueLease enqueue(QueryId queryId, double cost) throws QueueTimeoutException, QueryQueueException; |
| |
| void close(); |
| } |