1 2 /** 3 * Copyright (C) 2018-present MongoDB, Inc. 4 * 5 * This program is free software: you can redistribute it and/or modify 6 * it under the terms of the Server Side Public License, version 1, 7 * as published by MongoDB, Inc. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * Server Side Public License for more details. 13 * 14 * You should have received a copy of the Server Side Public License 15 * along with this program. If not, see 16 * <http://www.mongodb.com/licensing/server-side-public-license>. 17 * 18 * As a special exception, the copyright holders give permission to link the 19 * code of portions of this program with the OpenSSL library under certain 20 * conditions as described in each individual source file and distribute 21 * linked combinations including the program with the OpenSSL library. You 22 * must comply with the Server Side Public License in all respects for 23 * all of the code used other than as permitted herein. If you modify file(s) 24 * with this exception, you may extend this exception to your version of the 25 * file(s), but you are not obligated to do so. If you do not wish to do so, 26 * delete this exception statement from your version. If you delete this 27 * exception statement from all source files in the program, then also delete 28 * it in the license file. 29 */ 30 31 #pragma once 32 33 #include <boost/optional.hpp> 34 #include <string> 35 #include <vector> 36 37 #include "mongo/s/catalog/type_chunk.h" 38 #include "mongo/s/chunk_version.h" 39 #include "mongo/s/client/shard.h" 40 41 namespace mongo { 42 43 class NamespaceString; 44 class OperationContext; 45 class ShardKeyPattern; 46 class ShardRegistry; 47 template <typename T> 48 class StatusWith; 49 50 /** 51 * Set of functions used to introspect and manipulate the state of individual shards. 52 */ 53 namespace shardutil { 54 55 /** 56 * Executes the listDatabases command against the specified shard and obtains the total data 57 * size across all databases in bytes (essentially, the totalSize field). 58 * 59 * Returns OK with the total size or an error. Known errors are: 60 * ShardNotFound if shard by that id is not available on the registry 61 * NoSuchKey if the total shard size could not be retrieved 62 */ 63 StatusWith<long long> retrieveTotalShardSize(OperationContext* opCtx, const ShardId& shardId); 64 65 /** 66 * Ask the specified shard to figure out the split points for a given chunk. 67 * 68 * shardId The shard id to query. 69 * nss Namespace, which owns the chunk. 70 * shardKeyPattern The shard key which corresponds to this sharded namespace. 71 * chunkRange Bounds of the chunk to be split. 72 * chunkSize Chunk size to target in bytes. 73 * maxObjs Limits the number of objects in each chunk. Zero means max, unspecified means use the 74 * server default. 75 */ 76 StatusWith<std::vector<BSONObj>> selectChunkSplitPoints(OperationContext* opCtx, 77 const ShardId& shardId, 78 const NamespaceString& nss, 79 const ShardKeyPattern& shardKeyPattern, 80 const ChunkRange& chunkRange, 81 long long chunkSizeBytes, 82 boost::optional<int> maxObjs); 83 84 /** 85 * Asks the specified shard to split the chunk described by min/maxKey into the respective split 86 * points. If split was successful and the shard indicated that one of the resulting chunks should 87 * be moved off the currently owning shard, the return value will contain the bounds of this chunk. 88 * 89 * shardId The shard, which currently owns the chunk. 90 * nss Namespace, which owns the chunk. 91 * shardKeyPattern The shard key which corresponds to this sharded namespace. 92 * collectionVersion The expected collection version when doing the split. 93 * chunkRange Bounds of the chunk to be split. 94 * splitPoints The set of points at which the chunk should be split. 95 */ 96 StatusWith<boost::optional<ChunkRange>> splitChunkAtMultiplePoints( 97 OperationContext* opCtx, 98 const ShardId& shardId, 99 const NamespaceString& nss, 100 const ShardKeyPattern& shardKeyPattern, 101 ChunkVersion collectionVersion, 102 const ChunkRange& chunkRange, 103 const std::vector<BSONObj>& splitPoints); 104 105 } // namespace shardutil 106 } // namespace mongo 107