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/**
* Copyright (C) 2012 10gen Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects
* for all of the code used other than as permitted herein. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you do not
* wish to do so, delete this exception statement from your version. If you
* delete this exception statement from all source files in the program,
* then also delete it in the license file.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kSharding
#include "mongo/platform/basic.h"
#include "mongo/db/s/collection_metadata.h"
#include "mongo/bson/simple_bsonobj_comparator.h"
#include "mongo/bson/util/builder.h"
#include "mongo/s/catalog/type_chunk.h"
#include "mongo/stdx/memory.h"
#include "mongo/util/log.h"
#include "mongo/util/mongoutils/str.h"
namespace mongo {
using std::unique_ptr;
using std::make_pair;
using std::string;
using std::vector;
using str::stream;
CollectionMetadata::CollectionMetadata() = default;
CollectionMetadata::CollectionMetadata(const BSONObj& keyPattern, ChunkVersion collectionVersion)
: _collVersion(collectionVersion),
_shardVersion(ChunkVersion(0, 0, collectionVersion.epoch())),
_keyPattern(keyPattern.getOwned()) {}
CollectionMetadata::~CollectionMetadata() = default;
std::unique_ptr<CollectionMetadata> CollectionMetadata::cloneMigrate(
const ChunkType& chunk, const ChunkVersion& newCollectionVersion) const {
invariant(newCollectionVersion.epoch() == _collVersion.epoch());
invariant(newCollectionVersion > _collVersion);
invariant(rangeMapContains(_chunksMap, chunk.getMin(), chunk.getMax()));
unique_ptr<CollectionMetadata> metadata(stdx::make_unique<CollectionMetadata>());
metadata->_keyPattern = _keyPattern.getOwned();
metadata->fillKeyPatternFields();
metadata->_pendingMap = _pendingMap;
metadata->_chunksMap = _chunksMap;
metadata->_chunksMap.erase(chunk.getMin());
metadata->_shardVersion =
(metadata->_chunksMap.empty() ? ChunkVersion(0, 0, newCollectionVersion.epoch())
: newCollectionVersion);
metadata->_collVersion = newCollectionVersion;
metadata->fillRanges();
invariant(metadata->isValid());
return metadata;
}
unique_ptr<CollectionMetadata> CollectionMetadata::clonePlusChunk(
const BSONObj& minKey, const BSONObj& maxKey, const ChunkVersion& newShardVersion) const {
invariant(newShardVersion.epoch() == _shardVersion.epoch());
invariant(newShardVersion.isSet());
invariant(minKey.woCompare(maxKey) < 0);
invariant(!rangeMapOverlaps(_chunksMap, minKey, maxKey));
unique_ptr<CollectionMetadata> metadata(stdx::make_unique<CollectionMetadata>());
metadata->_keyPattern = _keyPattern.getOwned();
metadata->fillKeyPatternFields();
metadata->_pendingMap = _pendingMap;
metadata->_chunksMap = _chunksMap;
metadata->_chunksMap.insert(make_pair(minKey.getOwned(), maxKey.getOwned()));
metadata->_shardVersion = newShardVersion;
metadata->_collVersion = newShardVersion > _collVersion ? newShardVersion : _collVersion;
metadata->fillRanges();
invariant(metadata->isValid());
return metadata;
}
std::unique_ptr<CollectionMetadata> CollectionMetadata::cloneMinusPending(
const ChunkType& chunk) const {
invariant(rangeMapContains(_pendingMap, chunk.getMin(), chunk.getMax()));
unique_ptr<CollectionMetadata> metadata(stdx::make_unique<CollectionMetadata>());
metadata->_keyPattern = _keyPattern.getOwned();
metadata->fillKeyPatternFields();
metadata->_pendingMap = _pendingMap;
metadata->_pendingMap.erase(chunk.getMin());
metadata->_chunksMap = _chunksMap;
metadata->_rangesMap = _rangesMap;
metadata->_shardVersion = _shardVersion;
metadata->_collVersion = _collVersion;
invariant(metadata->isValid());
return metadata;
}
std::unique_ptr<CollectionMetadata> CollectionMetadata::clonePlusPending(
const ChunkType& chunk) const {
invariant(!rangeMapOverlaps(_chunksMap, chunk.getMin(), chunk.getMax()));
unique_ptr<CollectionMetadata> metadata(stdx::make_unique<CollectionMetadata>());
metadata->_keyPattern = _keyPattern.getOwned();
metadata->fillKeyPatternFields();
metadata->_pendingMap = _pendingMap;
metadata->_chunksMap = _chunksMap;
metadata->_rangesMap = _rangesMap;
metadata->_shardVersion = _shardVersion;
metadata->_collVersion = _collVersion;
// If there are any pending chunks on the interval to be added this is ok, since pending
// chunks aren't officially tracked yet and something may have changed on servers we do not
// see yet.
// We remove any chunks we overlap, the remote request starting a chunk migration must have
// been authoritative.
if (rangeMapOverlaps(_pendingMap, chunk.getMin(), chunk.getMax())) {
RangeVector pendingOverlap;
getRangeMapOverlap(_pendingMap, chunk.getMin(), chunk.getMax(), &pendingOverlap);
warning() << "new pending chunk " << rangeToString(chunk.getMin(), chunk.getMax())
<< " overlaps existing pending chunks " << overlapToString(pendingOverlap)
<< ", a migration may not have completed";
for (RangeVector::iterator it = pendingOverlap.begin(); it != pendingOverlap.end(); ++it) {
metadata->_pendingMap.erase(it->first);
}
}
metadata->_pendingMap.insert(make_pair(chunk.getMin(), chunk.getMax()));
invariant(metadata->isValid());
return metadata;
}
StatusWith<std::unique_ptr<CollectionMetadata>> CollectionMetadata::cloneSplit(
const BSONObj& minKey,
const BSONObj& maxKey,
const std::vector<BSONObj>& splitKeys,
const ChunkVersion& newShardVersion) const {
invariant(newShardVersion.epoch() == _shardVersion.epoch());
invariant(newShardVersion > _shardVersion);
// The version required in both resulting chunks could be simply an increment in the
// minor portion of the current version. However, we are enforcing uniqueness over the
// attributes <ns, version> of the configdb collection 'chunks'. So in practice, a
// migrate somewhere may force this split to pick up a version that has the major
// portion higher than the one that this shard has been using.
//
// TODO drop the uniqueness constraint and tighten the check below so that only the
// minor portion of version changes
// Check that we have the exact chunk that will be subtracted.
if (!rangeMapContains(_chunksMap, minKey, maxKey)) {
stream errMsg;
errMsg << "cannot split chunk " << rangeToString(minKey, maxKey)
<< ", this shard does not contain the chunk";
if (rangeMapOverlaps(_chunksMap, minKey, maxKey)) {
RangeVector overlap;
getRangeMapOverlap(_chunksMap, minKey, maxKey, &overlap);
errMsg << " and it overlaps " << overlapToString(overlap);
}
return {ErrorCodes::IllegalOperation, errMsg};
}
unique_ptr<CollectionMetadata> metadata(stdx::make_unique<CollectionMetadata>());
metadata->_keyPattern = _keyPattern.getOwned();
metadata->fillKeyPatternFields();
metadata->_pendingMap = _pendingMap;
metadata->_chunksMap = _chunksMap;
metadata->_shardVersion = newShardVersion; // will increment 2nd, 3rd,... chunks below
BSONObj startKey = minKey;
for (const auto& split : splitKeys) {
// Check that the split key is valid
if (!rangeContains(minKey, maxKey, split)) {
return {ErrorCodes::IllegalOperation,
stream() << "Cannot split chunk " << rangeToString(minKey, maxKey) << " at key "
<< split};
}
// Check that the split keys are in order
if (split.woCompare(startKey) <= 0) {
// The split keys came in out of order, this probably indicates a bug, so fail the
// operation. Re-iterate splitKeys to build a useful error message including the array
// of splitKeys in the order received.
str::stream errMsg;
errMsg << "Invalid input to splitChunk, split keys must be in order, got: [";
for (auto it2 = splitKeys.cbegin(); it2 != splitKeys.cend(); ++it2) {
if (it2 != splitKeys.begin()) {
errMsg << ", ";
}
errMsg << it2->toString();
}
errMsg << "]";
return {ErrorCodes::IllegalOperation, errMsg};
}
metadata->_chunksMap[startKey] = split.getOwned();
metadata->_chunksMap.insert(make_pair(split.getOwned(), maxKey.getOwned()));
metadata->_shardVersion.incMinor();
startKey = split;
}
metadata->_collVersion =
metadata->_shardVersion > _collVersion ? metadata->_shardVersion : _collVersion;
metadata->fillRanges();
invariant(metadata->isValid());
return std::move(metadata);
}
StatusWith<std::unique_ptr<CollectionMetadata>> CollectionMetadata::cloneMerge(
const BSONObj& minKey, const BSONObj& maxKey, const ChunkVersion& newShardVersion) const {
invariant(newShardVersion.epoch() == _shardVersion.epoch());
invariant(newShardVersion > _shardVersion);
RangeVector overlap;
getRangeMapOverlap(_chunksMap, minKey, maxKey, &overlap);
if (overlap.empty() || overlap.size() == 1) {
return {ErrorCodes::IllegalOperation,
stream() << "cannot merge range " << rangeToString(minKey, maxKey)
<< (overlap.empty() ? ", no chunks found in this range"
: ", only one chunk found in this range")};
}
bool validStartEnd = true;
bool validNoHoles = true;
if (overlap.begin()->first.woCompare(minKey) != 0) {
// First chunk doesn't start with minKey
validStartEnd = false;
} else if (overlap.rbegin()->second.woCompare(maxKey) != 0) {
// Last chunk doesn't end with maxKey
validStartEnd = false;
} else {
// Check that there are no holes
BSONObj prevMaxKey = minKey;
for (RangeVector::iterator it = overlap.begin(); it != overlap.end(); ++it) {
if (it->first.woCompare(prevMaxKey) != 0) {
validNoHoles = false;
break;
}
prevMaxKey = it->second;
}
}
if (!validStartEnd || !validNoHoles) {
return {ErrorCodes::IllegalOperation,
stream() << "cannot merge range " << rangeToString(minKey, maxKey)
<< ", overlapping chunks "
<< overlapToString(overlap)
<< (!validStartEnd ? " do not have the same min and max key"
: " are not all adjacent")};
}
unique_ptr<CollectionMetadata> metadata(stdx::make_unique<CollectionMetadata>());
metadata->_keyPattern = _keyPattern.getOwned();
metadata->fillKeyPatternFields();
metadata->_pendingMap = _pendingMap;
metadata->_chunksMap = _chunksMap;
metadata->_rangesMap = _rangesMap;
metadata->_shardVersion = newShardVersion;
metadata->_collVersion = newShardVersion > _collVersion ? newShardVersion : this->_collVersion;
for (RangeVector::iterator it = overlap.begin(); it != overlap.end(); ++it) {
metadata->_chunksMap.erase(it->first);
}
metadata->_chunksMap.insert(make_pair(minKey, maxKey));
invariant(metadata->isValid());
return std::move(metadata);
}
bool CollectionMetadata::keyBelongsToMe(const BSONObj& key) const {
// For now, collections don't move. So if the collection is not sharded, assume
// the document with the given key can be accessed.
if (_keyPattern.isEmpty()) {
return true;
}
if (_rangesMap.size() <= 0) {
return false;
}
RangeMap::const_iterator it = _rangesMap.upper_bound(key);
if (it != _rangesMap.begin())
it--;
bool good = rangeContains(it->first, it->second, key);
#if 0
// DISABLED because of SERVER-11175 - huge amount of logging
// Logs if the point doesn't belong here.
if ( !good ) {
log() << "bad: " << key << " " << it->first << " " << key.woCompare( it->first ) << " "
<< key.woCompare( it->second );
for ( RangeMap::const_iterator i = _rangesMap.begin(); i != _rangesMap.end(); ++i ) {
log() << "\t" << i->first << "\t" << i->second << "\t";
}
}
#endif
return good;
}
bool CollectionMetadata::keyIsPending(const BSONObj& key) const {
// If we aren't sharded, then the key is never pending (though it belongs-to-me)
if (_keyPattern.isEmpty()) {
return false;
}
if (_pendingMap.size() <= 0) {
return false;
}
RangeMap::const_iterator it = _pendingMap.upper_bound(key);
if (it != _pendingMap.begin())
it--;
bool isPending = rangeContains(it->first, it->second, key);
return isPending;
}
bool CollectionMetadata::getNextChunk(const BSONObj& lookupKey, ChunkType* chunk) const {
RangeMap::const_iterator upperChunkIt = _chunksMap.upper_bound(lookupKey);
RangeMap::const_iterator lowerChunkIt = upperChunkIt;
if (upperChunkIt != _chunksMap.begin()) {
--lowerChunkIt;
} else {
lowerChunkIt = _chunksMap.end();
}
if (lowerChunkIt != _chunksMap.end() && lowerChunkIt->second.woCompare(lookupKey) > 0) {
chunk->setMin(lowerChunkIt->first);
chunk->setMax(lowerChunkIt->second);
return true;
}
if (upperChunkIt != _chunksMap.end()) {
chunk->setMin(upperChunkIt->first);
chunk->setMax(upperChunkIt->second);
return true;
}
return false;
}
bool CollectionMetadata::getDifferentChunk(const BSONObj& chunkMinKey,
ChunkType* differentChunk) const {
RangeMap::const_iterator upperChunkIt = _chunksMap.end();
RangeMap::const_iterator lowerChunkIt = _chunksMap.begin();
while (lowerChunkIt != upperChunkIt) {
if (lowerChunkIt->first.woCompare(chunkMinKey) != 0) {
differentChunk->setMin(lowerChunkIt->first);
differentChunk->setMax(lowerChunkIt->second);
return true;
}
++lowerChunkIt;
}
return false;
}
void CollectionMetadata::toBSONBasic(BSONObjBuilder& bb) const {
_collVersion.addToBSON(bb, "collVersion");
_shardVersion.addToBSON(bb, "shardVersion");
bb.append("keyPattern", _keyPattern);
}
void CollectionMetadata::toBSONChunks(BSONArrayBuilder& bb) const {
if (_chunksMap.empty())
return;
for (RangeMap::const_iterator it = _chunksMap.begin(); it != _chunksMap.end(); ++it) {
BSONArrayBuilder chunkBB(bb.subarrayStart());
chunkBB.append(it->first);
chunkBB.append(it->second);
chunkBB.done();
}
}
void CollectionMetadata::toBSONPending(BSONArrayBuilder& bb) const {
if (_pendingMap.empty())
return;
for (RangeMap::const_iterator it = _pendingMap.begin(); it != _pendingMap.end(); ++it) {
BSONArrayBuilder pendingBB(bb.subarrayStart());
pendingBB.append(it->first);
pendingBB.append(it->second);
pendingBB.done();
}
}
string CollectionMetadata::toStringBasic() const {
return stream() << "collection version: " << _collVersion.toString()
<< ", shard version: " << _shardVersion.toString();
}
bool CollectionMetadata::getNextOrphanRange(const BSONObj& origLookupKey, KeyRange* range) const {
if (_keyPattern.isEmpty())
return false;
BSONObj lookupKey = origLookupKey;
BSONObj maxKey = getMaxKey(); // so we don't keep rebuilding
while (lookupKey.woCompare(maxKey) < 0) {
RangeMap::const_iterator lowerChunkIt = _chunksMap.end();
RangeMap::const_iterator upperChunkIt = _chunksMap.end();
if (!_chunksMap.empty()) {
upperChunkIt = _chunksMap.upper_bound(lookupKey);
lowerChunkIt = upperChunkIt;
if (upperChunkIt != _chunksMap.begin())
--lowerChunkIt;
else
lowerChunkIt = _chunksMap.end();
}
// If we overlap, continue after the overlap
// TODO: Could optimize slightly by finding next non-contiguous chunk
if (lowerChunkIt != _chunksMap.end() && lowerChunkIt->second.woCompare(lookupKey) > 0) {
lookupKey = lowerChunkIt->second;
continue;
}
RangeMap::const_iterator lowerPendingIt = _pendingMap.end();
RangeMap::const_iterator upperPendingIt = _pendingMap.end();
if (!_pendingMap.empty()) {
upperPendingIt = _pendingMap.upper_bound(lookupKey);
lowerPendingIt = upperPendingIt;
if (upperPendingIt != _pendingMap.begin())
--lowerPendingIt;
else
lowerPendingIt = _pendingMap.end();
}
// If we overlap, continue after the overlap
// TODO: Could optimize slightly by finding next non-contiguous chunk
if (lowerPendingIt != _pendingMap.end() &&
lowerPendingIt->second.woCompare(lookupKey) > 0) {
lookupKey = lowerPendingIt->second;
continue;
}
//
// We know that the lookup key is not covered by a chunk or pending range, and where the
// previous chunk and pending chunks are. Now we fill in the bounds as the closest
// bounds of the surrounding ranges in both maps.
//
range->keyPattern = _keyPattern;
range->minKey = getMinKey();
range->maxKey = maxKey;
if (lowerChunkIt != _chunksMap.end() && lowerChunkIt->second.woCompare(range->minKey) > 0) {
range->minKey = lowerChunkIt->second;
}
if (upperChunkIt != _chunksMap.end() && upperChunkIt->first.woCompare(range->maxKey) < 0) {
range->maxKey = upperChunkIt->first;
}
if (lowerPendingIt != _pendingMap.end() &&
lowerPendingIt->second.woCompare(range->minKey) > 0) {
range->minKey = lowerPendingIt->second;
}
if (upperPendingIt != _pendingMap.end() &&
upperPendingIt->first.woCompare(range->maxKey) < 0) {
range->maxKey = upperPendingIt->first;
}
return true;
}
return false;
}
BSONObj CollectionMetadata::getMinKey() const {
BSONObjIterator it(_keyPattern);
BSONObjBuilder minKeyB;
while (it.more())
minKeyB << it.next().fieldName() << MINKEY;
return minKeyB.obj();
}
BSONObj CollectionMetadata::getMaxKey() const {
BSONObjIterator it(_keyPattern);
BSONObjBuilder maxKeyB;
while (it.more())
maxKeyB << it.next().fieldName() << MAXKEY;
return maxKeyB.obj();
}
bool CollectionMetadata::isValid() const {
if (_shardVersion > _collVersion)
return false;
if (_collVersion.majorVersion() == 0)
return false;
if (_collVersion.epoch() != _shardVersion.epoch())
return false;
if (_shardVersion.majorVersion() > 0) {
// Must be chunks
if (_rangesMap.size() == 0 || _chunksMap.size() == 0)
return false;
} else {
// No chunks
if (_shardVersion.minorVersion() > 0)
return false;
if (_rangesMap.size() > 0 || _chunksMap.size() > 0)
return false;
}
return true;
}
bool CollectionMetadata::isValidKey(const BSONObj& key) const {
BSONObjIterator it(_keyPattern);
while (it.more()) {
BSONElement next = it.next();
if (!key.hasField(next.fieldName()))
return false;
}
return key.nFields() == _keyPattern.nFields();
}
void CollectionMetadata::fillRanges() {
if (_chunksMap.empty())
return;
// Load the chunk information, coallesceing their ranges. The version for this shard
// would be the highest version for any of the chunks.
RangeMap::const_iterator it = _chunksMap.begin();
BSONObj min, max;
while (it != _chunksMap.end()) {
BSONObj currMin = it->first;
BSONObj currMax = it->second;
++it;
// coalesce the chunk's bounds in ranges if they are adjacent chunks
if (min.isEmpty()) {
min = currMin;
max = currMax;
continue;
}
if (SimpleBSONObjComparator::kInstance.evaluate(max == currMin)) {
max = currMax;
continue;
}
_rangesMap.insert(make_pair(min, max));
min = currMin;
max = currMax;
}
dassert(!min.isEmpty());
_rangesMap.insert(make_pair(min, max));
}
void CollectionMetadata::fillKeyPatternFields() {
// Parse the shard keys into the states 'keys' and 'keySet' members.
BSONObjIterator patternIter = _keyPattern.begin();
while (patternIter.more()) {
BSONElement current = patternIter.next();
_keyFields.mutableVector().push_back(new FieldRef);
FieldRef* const newFieldRef = _keyFields.mutableVector().back();
newFieldRef->parse(current.fieldNameStringData());
}
}
} // namespace mongo
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