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/*
* Copyright 2012-2020 Aerospike, Inc.
*
* Portions may be licensed to Aerospike, Inc. under one or more contributor
* license agreements WHICH ARE COMPATIBLE WITH THE APACHE LICENSE, VERSION 2.0.
*
* 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 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 com.aerospike.client.policy;
/**
* Container object for policy attributes used in query operations.
*/
public class QueryPolicy extends Policy {
/**
* Approximate number of records to return to client. This number is divided by the
* number of nodes involved in the query. The actual number of records returned
* may be less than maxRecords if node record counts are small and unbalanced across
* nodes.
*
* maxRecords is supported on server versions >= 4.9 for scans only. maxRecords
* exists here because query methods will convert into a scan when the query
* filter is null. maxRecords is ignored when the query contains a filter.
*
* Default: 0 (do not limit record count)
*/
public long maxRecords;
/**
* Maximum number of concurrent requests to server nodes at any point in time.
* If there are 16 nodes in the cluster and maxConcurrentNodes is 8, then queries
* will be made to 8 nodes in parallel. When a query completes, a new query will
* be issued until all 16 nodes have been queried.
*
* Default: 0 (issue requests to all server nodes in parallel)
*/
public int maxConcurrentNodes;
/**
* Number of records to place in queue before blocking.
* Records received from multiple server nodes will be placed in a queue.
* A separate thread consumes these records in parallel.
* If the queue is full, the producer threads will block until records are consumed.
*
* Default: 5000
*/
public int recordQueueSize = 5000;
/**
* Should bin data be retrieved. If false, only record digests (and user keys
* if stored on the server) are retrieved.
*
* Default: true
*/
public boolean includeBinData = true;
/**
* Terminate query if cluster is in migration state.
* Only used for server versions < 4.9.
*
* Default: false
*/
public boolean failOnClusterChange;
/**
* Copy query policy from another query policy.
*/
public QueryPolicy(QueryPolicy other) {
super(other);
this.maxRecords = other.maxRecords;
this.maxConcurrentNodes = other.maxConcurrentNodes;
this.recordQueueSize = other.recordQueueSize;
this.includeBinData = other.includeBinData;
this.failOnClusterChange = other.failOnClusterChange;
}
/**
* Default constructor.
*
* Set maxRetries for non-aggregation queries with a null filter on
* server versions >= 4.9. All other queries are not retried.
*
* The latest servers support retries on individual data partitions.
* This feature is useful when a cluster is migrating and partition(s)
* are missed or incomplete on the first query (with null filter) attempt.
*
* If the first query attempt misses 2 of 4096 partitions, then only
* those 2 partitions are retried in the next query attempt from the
* last key digest received for each respective partition. A higher
* default maxRetries is used because it's wasteful to invalidate
* all query results because a single partition was missed.
*/
public QueryPolicy() {
super.maxRetries = 5;
}
}