/
resharding_coordinator_service.cpp
1559 lines (1365 loc) · 74.4 KB
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resharding_coordinator_service.cpp
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/**
* Copyright (C) 2020-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* 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 Server Side 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_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kResharding
#include "mongo/platform/basic.h"
#include "mongo/db/s/resharding/resharding_coordinator_service.h"
#include "mongo/db/auth/authorization_session_impl.h"
#include "mongo/db/dbdirectclient.h"
#include "mongo/db/logical_session_cache.h"
#include "mongo/db/ops/write_ops.h"
#include "mongo/db/repl/primary_only_service.h"
#include "mongo/db/s/config/initial_split_policy.h"
#include "mongo/db/s/config/sharding_catalog_manager.h"
#include "mongo/db/s/resharding/resharding_coordinator_commit_monitor.h"
#include "mongo/db/s/resharding/resharding_metrics.h"
#include "mongo/db/s/resharding/resharding_server_parameters_gen.h"
#include "mongo/db/s/resharding_util.h"
#include "mongo/db/s/sharding_logging.h"
#include "mongo/db/s/sharding_util.h"
#include "mongo/db/storage/duplicate_key_error_info.h"
#include "mongo/db/vector_clock.h"
#include "mongo/logv2/log.h"
#include "mongo/rpc/get_status_from_command_result.h"
#include "mongo/s/catalog/type_chunk.h"
#include "mongo/s/grid.h"
#include "mongo/s/request_types/flush_resharding_state_change_gen.h"
#include "mongo/s/shard_id.h"
#include "mongo/s/write_ops/batched_command_response.h"
#include "mongo/util/fail_point.h"
#include "mongo/util/future_util.h"
#include "mongo/util/string_map.h"
#include "mongo/util/uuid.h"
namespace mongo {
namespace {
using namespace fmt::literals;
MONGO_FAIL_POINT_DEFINE(reshardingPauseCoordinatorBeforeCloning);
MONGO_FAIL_POINT_DEFINE(reshardingPauseCoordinatorInSteadyState);
MONGO_FAIL_POINT_DEFINE(reshardingPauseCoordinatorBeforeDecisionPersisted);
MONGO_FAIL_POINT_DEFINE(reshardingPauseCoordinatorBeforeCompletion);
MONGO_FAIL_POINT_DEFINE(reshardingPauseCoordinatorBeforeStartingErrorFlow);
MONGO_FAIL_POINT_DEFINE(reshardingPauseCoordinatorBeforePersistingStateTransition);
MONGO_FAIL_POINT_DEFINE(reshardingCoordinatorCanEnterCriticalImplicitly);
const std::string kReshardingCoordinatorActiveIndexName = "ReshardingCoordinatorActiveIndex";
const Backoff kExponentialBackoff(Seconds(1), Milliseconds::max());
bool shouldStopAttemptingToCreateIndex(Status status, const CancellationToken& token) {
return status.isOK() || token.isCanceled();
}
void assertNumDocsModifiedMatchesExpected(const BatchedCommandRequest& request,
const BSONObj& response,
int expected) {
auto numDocsModified = response.getIntField("n");
uassert(5030401,
str::stream() << "Expected to match " << expected << " docs, but only matched "
<< numDocsModified << " for write request " << request.toString(),
expected == numDocsModified);
}
void appendShardEntriesToSetBuilder(const ReshardingCoordinatorDocument& coordinatorDoc,
BSONObjBuilder& setBuilder) {
BSONArrayBuilder donorShards(
setBuilder.subarrayStart(ReshardingCoordinatorDocument::kDonorShardsFieldName));
for (const auto& donorShard : coordinatorDoc.getDonorShards()) {
donorShards.append(donorShard.toBSON());
}
donorShards.doneFast();
BSONArrayBuilder recipientShards(
setBuilder.subarrayStart(ReshardingCoordinatorDocument::kRecipientShardsFieldName));
for (const auto& recipientShard : coordinatorDoc.getRecipientShards()) {
recipientShards.append(recipientShard.toBSON());
}
recipientShards.doneFast();
}
void unsetInitializingFields(BSONObjBuilder& updateBuilder) {
BSONObjBuilder unsetBuilder(updateBuilder.subobjStart("$unset"));
unsetBuilder.append(ReshardingCoordinatorDocument::kPresetReshardedChunksFieldName, "");
unsetBuilder.append(ReshardingCoordinatorDocument::kZonesFieldName, "");
unsetBuilder.doneFast();
}
void writeToCoordinatorStateNss(OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
TxnNumber txnNumber) {
BatchedCommandRequest request([&] {
auto nextState = coordinatorDoc.getState();
switch (nextState) {
case CoordinatorStateEnum::kInitializing:
// Insert the new coordinator document.
return BatchedCommandRequest::buildInsertOp(
NamespaceString::kConfigReshardingOperationsNamespace,
std::vector<BSONObj>{coordinatorDoc.toBSON()});
case CoordinatorStateEnum::kDone:
// Remove the coordinator document.
return BatchedCommandRequest::buildDeleteOp(
NamespaceString::kConfigReshardingOperationsNamespace,
BSON("_id" << coordinatorDoc.getReshardingUUID()), // query
false // multi
);
default: {
// Partially update the coordinator document.
BSONObjBuilder updateBuilder;
{
BSONObjBuilder setBuilder(updateBuilder.subobjStart("$set"));
// Always update the state field.
setBuilder.append(ReshardingCoordinatorDocument::kStateFieldName,
CoordinatorState_serializer(coordinatorDoc.getState()));
if (auto cloneTimestamp = coordinatorDoc.getCloneTimestamp()) {
// If the cloneTimestamp exists, include it in the update.
setBuilder.append(ReshardingCoordinatorDocument::kCloneTimestampFieldName,
*cloneTimestamp);
}
if (auto abortReason = coordinatorDoc.getAbortReason()) {
// If the abortReason exists, include it in the update.
setBuilder.append(ReshardingCoordinatorDocument::kAbortReasonFieldName,
*abortReason);
}
if (auto approxBytesToCopy = coordinatorDoc.getApproxBytesToCopy()) {
// If the approxBytesToCopy exists, include it in the update.
setBuilder.append(
ReshardingCoordinatorDocument::kApproxBytesToCopyFieldName,
*approxBytesToCopy);
}
if (auto approxDocumentsToCopy = coordinatorDoc.getApproxDocumentsToCopy()) {
// If the approxDocumentsToCopy exists, include it in the update.
setBuilder.append(
ReshardingCoordinatorDocument::kApproxDocumentsToCopyFieldName,
*approxDocumentsToCopy);
}
if (nextState == CoordinatorStateEnum::kPreparingToDonate) {
appendShardEntriesToSetBuilder(coordinatorDoc, setBuilder);
setBuilder.doneFast();
unsetInitializingFields(updateBuilder);
}
}
return BatchedCommandRequest::buildUpdateOp(
NamespaceString::kConfigReshardingOperationsNamespace,
BSON("_id" << coordinatorDoc.getReshardingUUID()),
updateBuilder.obj(),
false, // upsert
false // multi
);
}
}
}());
auto expectedNumModified = (request.getBatchType() == BatchedCommandRequest::BatchType_Insert)
? boost::none
: boost::make_optional(1);
auto res = ShardingCatalogManager::get(opCtx)->writeToConfigDocumentInTxn(
opCtx, NamespaceString::kConfigReshardingOperationsNamespace, request, txnNumber);
if (expectedNumModified) {
assertNumDocsModifiedMatchesExpected(request, res, *expectedNumModified);
}
}
/**
* Creates reshardingFields.recipientFields for the resharding operation. Note: these should not
* change once the operation has begun.
*/
TypeCollectionRecipientFields constructRecipientFields(
const ReshardingCoordinatorDocument& coordinatorDoc) {
std::vector<DonorShardFetchTimestamp> donorShards;
for (const auto& donor : coordinatorDoc.getDonorShards()) {
DonorShardFetchTimestamp donorFetchTimestamp(donor.getId());
donorFetchTimestamp.setMinFetchTimestamp(donor.getMutableState().getMinFetchTimestamp());
donorShards.push_back(std::move(donorFetchTimestamp));
}
TypeCollectionRecipientFields recipientFields(
std::move(donorShards),
coordinatorDoc.getSourceUUID(),
coordinatorDoc.getSourceNss(),
resharding::gReshardingMinimumOperationDurationMillis.load());
emplaceCloneTimestampIfExists(recipientFields, coordinatorDoc.getCloneTimestamp());
emplaceApproxBytesToCopyIfExists(recipientFields,
coordinatorDoc.getReshardingApproxCopySizeStruct());
return recipientFields;
}
BSONObj createReshardingFieldsUpdateForOriginalNss(
OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
boost::optional<OID> newCollectionEpoch,
boost::optional<Timestamp> newCollectionTimestamp) {
auto nextState = coordinatorDoc.getState();
switch (nextState) {
case CoordinatorStateEnum::kInitializing: {
// Append 'reshardingFields' to the config.collections entry for the original nss
TypeCollectionReshardingFields originalEntryReshardingFields(
coordinatorDoc.getReshardingUUID());
originalEntryReshardingFields.setState(coordinatorDoc.getState());
return BSON("$set" << BSON(CollectionType::kReshardingFieldsFieldName
<< originalEntryReshardingFields.toBSON()
<< CollectionType::kUpdatedAtFieldName
<< opCtx->getServiceContext()->getPreciseClockSource()->now()
<< CollectionType::kAllowMigrationsFieldName << false));
}
case CoordinatorStateEnum::kPreparingToDonate: {
TypeCollectionDonorFields donorFields(
coordinatorDoc.getTempReshardingNss(),
coordinatorDoc.getReshardingKey(),
extractShardIdsFromParticipantEntries(coordinatorDoc.getRecipientShards()));
BSONObjBuilder updateBuilder;
{
BSONObjBuilder setBuilder(updateBuilder.subobjStart("$set"));
{
setBuilder.append(CollectionType::kReshardingFieldsFieldName + "." +
TypeCollectionReshardingFields::kStateFieldName,
CoordinatorState_serializer(nextState));
setBuilder.append(CollectionType::kReshardingFieldsFieldName + "." +
TypeCollectionReshardingFields::kDonorFieldsFieldName,
donorFields.toBSON());
setBuilder.append(CollectionType::kUpdatedAtFieldName,
opCtx->getServiceContext()->getPreciseClockSource()->now());
}
}
return updateBuilder.obj();
}
case CoordinatorStateEnum::kDecisionPersisted: {
// Update the config.collections entry for the original nss to reflect
// the new sharded collection. Set 'uuid' to the reshardingUUID, 'key' to the new shard
// key, 'lastmodEpoch' to newCollectionEpoch, and 'timestamp' to
// newCollectionTimestamp (if newCollectionTimestamp has a value; i.e. when the
// gShardingFullDDLSupportTimestampedVersion feature flag is enabled). Also update the
// 'state' field and add the 'recipientFields' to the 'reshardingFields' section.
auto recipientFields = constructRecipientFields(coordinatorDoc);
BSONObj setFields =
BSON("uuid" << coordinatorDoc.getReshardingUUID() << "key"
<< coordinatorDoc.getReshardingKey().toBSON() << "lastmodEpoch"
<< newCollectionEpoch.get() << "lastmod"
<< opCtx->getServiceContext()->getPreciseClockSource()->now()
<< "reshardingFields.state"
<< CoordinatorState_serializer(coordinatorDoc.getState()).toString()
<< "reshardingFields.recipientFields" << recipientFields.toBSON());
if (newCollectionTimestamp.has_value()) {
setFields = setFields.addFields(BSON("timestamp" << newCollectionTimestamp.get()));
}
return BSON("$set" << setFields);
}
case mongo::CoordinatorStateEnum::kDone:
// Remove 'reshardingFields' from the config.collections entry
return BSON(
"$unset" << BSON(CollectionType::kReshardingFieldsFieldName
<< "" << CollectionType::kAllowMigrationsFieldName << "")
<< "$set"
<< BSON(CollectionType::kUpdatedAtFieldName
<< opCtx->getServiceContext()->getPreciseClockSource()->now()));
default: {
// Update the 'state' field, and 'abortReason' field if it exists, in the
// 'reshardingFields' section.
BSONObjBuilder updateBuilder;
{
BSONObjBuilder setBuilder(updateBuilder.subobjStart("$set"));
setBuilder.append("reshardingFields.state",
CoordinatorState_serializer(nextState).toString());
setBuilder.append("lastmod",
opCtx->getServiceContext()->getPreciseClockSource()->now());
if (auto abortReason = coordinatorDoc.getAbortReason()) {
// If the abortReason exists, include it in the update.
setBuilder.append("reshardingFields.abortReason", *abortReason);
}
}
return updateBuilder.obj();
}
}
}
void updateConfigCollectionsForOriginalNss(OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
boost::optional<OID> newCollectionEpoch,
boost::optional<Timestamp> newCollectionTimestamp,
TxnNumber txnNumber) {
auto writeOp = createReshardingFieldsUpdateForOriginalNss(
opCtx, coordinatorDoc, newCollectionEpoch, newCollectionTimestamp);
auto request = BatchedCommandRequest::buildUpdateOp(
CollectionType::ConfigNS,
BSON(CollectionType::kNssFieldName << coordinatorDoc.getSourceNss().ns()), // query
writeOp,
false, // upsert
false // multi
);
auto res = ShardingCatalogManager::get(opCtx)->writeToConfigDocumentInTxn(
opCtx, CollectionType::ConfigNS, request, txnNumber);
assertNumDocsModifiedMatchesExpected(request, res, 1 /* expected */);
}
void writeToConfigCollectionsForTempNss(OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
boost::optional<ChunkVersion> chunkVersion,
boost::optional<const BSONObj&> collation,
TxnNumber txnNumber) {
BatchedCommandRequest request([&] {
auto nextState = coordinatorDoc.getState();
switch (nextState) {
case CoordinatorStateEnum::kPreparingToDonate: {
// Insert new entry for the temporary nss into config.collections
auto collType = resharding::createTempReshardingCollectionType(
opCtx, coordinatorDoc, chunkVersion.get(), collation.get());
return BatchedCommandRequest::buildInsertOp(
CollectionType::ConfigNS, std::vector<BSONObj>{collType.toBSON()});
}
case CoordinatorStateEnum::kCloning: {
// Update the 'state', 'donorShards', 'approxCopySize', and 'cloneTimestamp' fields
// in the 'reshardingFields.recipient' section
BSONArrayBuilder donorShardsBuilder;
for (const auto& donor : coordinatorDoc.getDonorShards()) {
DonorShardFetchTimestamp donorShardFetchTimestamp(donor.getId());
donorShardFetchTimestamp.setMinFetchTimestamp(
donor.getMutableState().getMinFetchTimestamp());
donorShardsBuilder.append(donorShardFetchTimestamp.toBSON());
}
return BatchedCommandRequest::buildUpdateOp(
CollectionType::ConfigNS,
BSON(CollectionType::kNssFieldName
<< coordinatorDoc.getTempReshardingNss().ns()),
BSON("$set" << BSON(
"reshardingFields.state"
<< CoordinatorState_serializer(nextState).toString()
<< "reshardingFields.recipientFields.approxDocumentsToCopy"
<< coordinatorDoc.getApproxDocumentsToCopy().get()
<< "reshardingFields.recipientFields.approxBytesToCopy"
<< coordinatorDoc.getApproxBytesToCopy().get()
<< "reshardingFields.recipientFields.cloneTimestamp"
<< coordinatorDoc.getCloneTimestamp().get()
<< "reshardingFields.recipientFields.donorShards"
<< donorShardsBuilder.arr() << "lastmod"
<< opCtx->getServiceContext()->getPreciseClockSource()->now())),
false, // upsert
false // multi
);
}
case CoordinatorStateEnum::kDecisionPersisted:
// Remove the entry for the temporary nss
return BatchedCommandRequest::buildDeleteOp(
CollectionType::ConfigNS,
BSON(CollectionType::kNssFieldName
<< coordinatorDoc.getTempReshardingNss().ns()),
false // multi
);
default: {
// Update the 'state' field, and 'abortReason' field if it exists, in the
// 'reshardingFields' section.
BSONObjBuilder updateBuilder;
{
BSONObjBuilder setBuilder(updateBuilder.subobjStart("$set"));
setBuilder.append("reshardingFields.state",
CoordinatorState_serializer(nextState).toString());
setBuilder.append("lastmod",
opCtx->getServiceContext()->getPreciseClockSource()->now());
if (auto abortReason = coordinatorDoc.getAbortReason()) {
setBuilder.append("reshardingFields.abortReason", *abortReason);
}
}
return BatchedCommandRequest::buildUpdateOp(
CollectionType::ConfigNS,
BSON(CollectionType::kNssFieldName
<< coordinatorDoc.getTempReshardingNss().ns()),
updateBuilder.obj(),
true, // upsert
false // multi
);
}
}
}());
auto expectedNumModified = (request.getBatchType() == BatchedCommandRequest::BatchType_Insert)
? boost::none
: boost::make_optional(1);
auto res = ShardingCatalogManager::get(opCtx)->writeToConfigDocumentInTxn(
opCtx, CollectionType::ConfigNS, request, txnNumber);
if (expectedNumModified) {
assertNumDocsModifiedMatchesExpected(request, res, *expectedNumModified);
}
}
void insertChunkAndTagDocsForTempNss(OperationContext* opCtx,
std::vector<ChunkType> initialChunks,
std::vector<BSONObj> newZones,
TxnNumber txnNumber) {
// Insert new initial chunk documents for temp nss
std::vector<BSONObj> initialChunksBSON(initialChunks.size());
std::transform(initialChunks.begin(),
initialChunks.end(),
initialChunksBSON.begin(),
[](ChunkType chunk) { return chunk.toConfigBSON(); });
ShardingCatalogManager::get(opCtx)->insertConfigDocumentsInTxn(
opCtx, ChunkType::ConfigNS, std::move(initialChunksBSON), txnNumber);
ShardingCatalogManager::get(opCtx)->insertConfigDocumentsInTxn(
opCtx, TagsType::ConfigNS, newZones, txnNumber);
}
void removeChunkAndTagsDocsForOriginalNss(OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
boost::optional<Timestamp> newCollectionTimestamp,
TxnNumber txnNumber) {
// Remove all chunk documents for the original nss. We do not know how many chunk docs currently
// exist, so cannot pass a value for expectedNumModified
const auto chunksQuery = [&]() {
if (newCollectionTimestamp) {
return BSON(ChunkType::collectionUUID() << coordinatorDoc.getSourceUUID());
} else {
return BSON(ChunkType::ns(coordinatorDoc.getSourceNss().ns()));
}
}();
ShardingCatalogManager::get(opCtx)->writeToConfigDocumentInTxn(
opCtx,
ChunkType::ConfigNS,
BatchedCommandRequest::buildDeleteOp(ChunkType::ConfigNS,
chunksQuery,
true // multi
),
txnNumber);
// Remove all tag documents for the original nss. We do not know how many tag docs currently
// exist, so cannot pass a value for expectedNumModified
ShardingCatalogManager::get(opCtx)->writeToConfigDocumentInTxn(
opCtx,
TagsType::ConfigNS,
BatchedCommandRequest::buildDeleteOp(
TagsType::ConfigNS,
BSON(ChunkType::ns(coordinatorDoc.getSourceNss().ns())), // query
true // multi
),
txnNumber);
}
void updateChunkAndTagsDocsForTempNss(OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
OID newCollectionEpoch,
boost::optional<Timestamp> newCollectionTimestamp,
TxnNumber txnNumber) {
// Update all chunk documents that currently have 'ns' as the temporary collection namespace
// such that 'ns' is now the original collection namespace and 'lastmodEpoch' is
// newCollectionEpoch.
const auto chunksQuery = [&]() {
if (newCollectionTimestamp) {
return BSON(ChunkType::collectionUUID() << coordinatorDoc.getReshardingUUID());
} else {
return BSON(ChunkType::ns(coordinatorDoc.getTempReshardingNss().ns()));
}
}();
const auto chunksUpdate = [&]() {
if (newCollectionTimestamp) {
return BSON("$set" << BSON(ChunkType::epoch << newCollectionEpoch
<< ChunkType::timestamp
<< *newCollectionTimestamp));
} else {
return BSON("$set" << BSON(ChunkType::ns << coordinatorDoc.getSourceNss().ns()
<< ChunkType::epoch << newCollectionEpoch));
}
}();
auto chunksRequest = BatchedCommandRequest::buildUpdateOp(ChunkType::ConfigNS,
chunksQuery, // query
chunksUpdate, // update
false, // upsert
true // multi
);
auto chunksRes = ShardingCatalogManager::get(opCtx)->writeToConfigDocumentInTxn(
opCtx, ChunkType::ConfigNS, chunksRequest, txnNumber);
auto tagsRequest = BatchedCommandRequest::buildUpdateOp(
TagsType::ConfigNS,
BSON(TagsType::ns(coordinatorDoc.getTempReshardingNss().ns())), // query
BSON("$set" << BSON("ns" << coordinatorDoc.getSourceNss().ns())), // update
false, // upsert
true // multi
);
// Update the 'ns' field to be the original collection namespace for all tags documents that
// currently have 'ns' as the temporary collection namespace
auto tagsRes = ShardingCatalogManager::get(opCtx)->writeToConfigDocumentInTxn(
opCtx, TagsType::ConfigNS, tagsRequest, txnNumber);
}
/**
* Executes metadata changes in a transaction without bumping the collection version.
*/
void executeMetadataChangesInTxn(
OperationContext* opCtx,
unique_function<void(OperationContext*, TxnNumber)> changeMetadataFunc) {
ShardingCatalogManager::withTransaction(opCtx,
NamespaceString::kConfigReshardingOperationsNamespace,
[&](OperationContext* opCtx, TxnNumber txnNumber) {
changeMetadataFunc(opCtx, txnNumber);
});
}
} // namespace
namespace resharding {
CollectionType createTempReshardingCollectionType(
OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
const ChunkVersion& chunkVersion,
const BSONObj& collation) {
CollectionType collType(coordinatorDoc.getTempReshardingNss(),
chunkVersion.epoch(),
opCtx->getServiceContext()->getPreciseClockSource()->now(),
coordinatorDoc.getReshardingUUID());
collType.setKeyPattern(coordinatorDoc.getReshardingKey());
collType.setDefaultCollation(collation);
collType.setUnique(false);
collType.setTimestamp(chunkVersion.getTimestamp());
TypeCollectionReshardingFields tempEntryReshardingFields(coordinatorDoc.getReshardingUUID());
tempEntryReshardingFields.setState(coordinatorDoc.getState());
auto recipientFields = constructRecipientFields(coordinatorDoc);
tempEntryReshardingFields.setRecipientFields(std::move(recipientFields));
collType.setReshardingFields(std::move(tempEntryReshardingFields));
collType.setAllowMigrations(false);
return collType;
}
void writeDecisionPersistedState(OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
OID newCollectionEpoch,
boost::optional<Timestamp> newCollectionTimestamp) {
// No need to bump originalNss version because its epoch will be changed.
executeMetadataChangesInTxn(opCtx, [&](OperationContext* opCtx, TxnNumber txnNumber) {
// Update the config.reshardingOperations entry
writeToCoordinatorStateNss(opCtx, coordinatorDoc, txnNumber);
// Remove the config.collections entry for the temporary collection
writeToConfigCollectionsForTempNss(
opCtx, coordinatorDoc, boost::none, boost::none, txnNumber);
// Update the config.collections entry for the original namespace to reflect the new
// shard key, new epoch, and new UUID
updateConfigCollectionsForOriginalNss(
opCtx, coordinatorDoc, newCollectionEpoch, newCollectionTimestamp, txnNumber);
// Remove all chunk and tag documents associated with the original collection, then
// update the chunk and tag docs currently associated with the temp nss to be associated
// with the original nss
removeChunkAndTagsDocsForOriginalNss(
opCtx, coordinatorDoc, newCollectionTimestamp, txnNumber);
updateChunkAndTagsDocsForTempNss(
opCtx, coordinatorDoc, newCollectionEpoch, newCollectionTimestamp, txnNumber);
});
}
} // namespace resharding
ChunkVersion calculateChunkVersionForInitialChunks(OperationContext* opCtx) {
boost::optional<Timestamp> timestamp;
if (feature_flags::gShardingFullDDLSupportTimestampedVersion.isEnabled(
serverGlobalParams.featureCompatibility)) {
const auto now = VectorClock::get(opCtx)->getTime();
timestamp = now.clusterTime().asTimestamp();
}
return ChunkVersion(1, 0, OID::gen(), timestamp);
}
std::vector<DonorShardEntry> constructDonorShardEntries(const std::set<ShardId>& donorShardIds) {
std::vector<DonorShardEntry> donorShards;
std::transform(donorShardIds.begin(),
donorShardIds.end(),
std::back_inserter(donorShards),
[](const ShardId& shardId) -> DonorShardEntry {
DonorShardContext donorCtx;
donorCtx.setState(DonorStateEnum::kUnused);
return DonorShardEntry{shardId, std::move(donorCtx)};
});
return donorShards;
}
std::vector<RecipientShardEntry> constructRecipientShardEntries(
const std::set<ShardId>& recipientShardIds) {
std::vector<RecipientShardEntry> recipientShards;
std::transform(recipientShardIds.begin(),
recipientShardIds.end(),
std::back_inserter(recipientShards),
[](const ShardId& shardId) -> RecipientShardEntry {
RecipientShardContext recipientCtx;
recipientCtx.setState(RecipientStateEnum::kUnused);
return RecipientShardEntry{shardId, std::move(recipientCtx)};
});
return recipientShards;
}
void ReshardingCoordinatorExternalStateImpl::insertCoordDocAndChangeOrigCollEntry(
OperationContext* opCtx, const ReshardingCoordinatorDocument& coordinatorDoc) {
auto originalCollType = Grid::get(opCtx)->catalogClient()->getCollection(
opCtx, coordinatorDoc.getSourceNss(), repl::ReadConcernLevel::kMajorityReadConcern);
const auto collation = originalCollType.getDefaultCollation();
ShardingCatalogManager::get(opCtx)->bumpCollectionVersionAndChangeMetadataInTxn(
opCtx, coordinatorDoc.getSourceNss(), [&](OperationContext* opCtx, TxnNumber txnNumber) {
// Insert the coordinator document to config.reshardingOperations.
invariant(coordinatorDoc.getActive());
try {
writeToCoordinatorStateNss(opCtx, coordinatorDoc, txnNumber);
} catch (const ExceptionFor<ErrorCodes::DuplicateKey>& ex) {
auto extraInfo = ex.extraInfo<DuplicateKeyErrorInfo>();
if (extraInfo->getKeyPattern().woCompare(BSON("active" << 1)) == 0) {
uasserted(ErrorCodes::ReshardCollectionInProgress,
str::stream()
<< "Only one resharding operation is allowed to be active at a "
"time, aborting resharding op for "
<< coordinatorDoc.getSourceNss());
}
throw;
}
// Update the config.collections entry for the original collection to include
// 'reshardingFields'
updateConfigCollectionsForOriginalNss(
opCtx, coordinatorDoc, boost::none, boost::none, txnNumber);
});
}
ReshardingCoordinatorExternalState::ParticipantShardsAndChunks
ReshardingCoordinatorExternalStateImpl::calculateParticipantShardsAndChunks(
OperationContext* opCtx, const ReshardingCoordinatorDocument& coordinatorDoc) {
const auto cm = uassertStatusOK(
Grid::get(opCtx)->catalogCache()->getShardedCollectionRoutingInfoWithRefresh(
opCtx, coordinatorDoc.getSourceNss()));
std::set<ShardId> donorShardIds;
cm.getAllShardIds(&donorShardIds);
std::set<ShardId> recipientShardIds;
std::vector<ChunkType> initialChunks;
// The database primary must always be a recipient to ensure it ends up with consistent
// collection metadata.
recipientShardIds.emplace(cm.dbPrimary());
if (const auto& chunks = coordinatorDoc.getPresetReshardedChunks()) {
auto version = calculateChunkVersionForInitialChunks(opCtx);
// Use the provided shardIds from presetReshardedChunks to construct the
// recipient list.
for (const BSONObj& obj : *chunks) {
recipientShardIds.emplace(
obj.getStringField(ReshardedChunk::kRecipientShardIdFieldName));
auto reshardedChunk =
ReshardedChunk::parse(IDLParserErrorContext("ReshardedChunk"), obj);
if (version.getTimestamp()) {
initialChunks.emplace_back(
coordinatorDoc.getReshardingUUID(),
ChunkRange{reshardedChunk.getMin(), reshardedChunk.getMax()},
version,
reshardedChunk.getRecipientShardId());
} else {
initialChunks.emplace_back(
coordinatorDoc.getTempReshardingNss(),
ChunkRange{reshardedChunk.getMin(), reshardedChunk.getMax()},
version,
reshardedChunk.getRecipientShardId());
}
version.incMinor();
}
} else {
int numInitialChunks = coordinatorDoc.getNumInitialChunks()
? *coordinatorDoc.getNumInitialChunks()
: cm.numChunks();
ShardKeyPattern shardKey(coordinatorDoc.getReshardingKey());
const auto tempNs = coordinatorDoc.getTempReshardingNss();
boost::optional<std::vector<mongo::TagsType>> parsedZones;
if (auto rawBSONZones = coordinatorDoc.getZones()) {
parsedZones.emplace();
parsedZones->reserve(rawBSONZones->size());
for (const auto& zone : *rawBSONZones) {
parsedZones->push_back(uassertStatusOK(TagsType::fromBSON(zone)));
}
}
auto initialSplitter = ReshardingSplitPolicy::make(opCtx,
coordinatorDoc.getSourceNss(),
tempNs,
shardKey,
numInitialChunks,
std::move(parsedZones));
// Note: The resharding initial split policy doesn't care about what is the real primary
// shard, so just pass in a random shard.
const SplitPolicyParams splitParams{
tempNs,
coordinatorDoc.getReshardingUUID(),
*donorShardIds.begin(),
ChunkEntryFormat::getForVersionCallerGuaranteesFCVStability(
ServerGlobalParams::FeatureCompatibility::Version::kVersion50)};
auto splitResult = initialSplitter.createFirstChunks(opCtx, shardKey, splitParams);
initialChunks = std::move(splitResult.chunks);
for (const auto& chunk : initialChunks) {
recipientShardIds.insert(chunk.getShard());
}
}
return {constructDonorShardEntries(donorShardIds),
constructRecipientShardEntries(recipientShardIds),
initialChunks};
}
void ReshardingCoordinatorExternalStateImpl::writeParticipantShardsAndTempCollInfo(
OperationContext* opCtx,
const ReshardingCoordinatorDocument& updatedCoordinatorDoc,
std::vector<ChunkType> initialChunks,
std::vector<BSONObj> zones) {
ShardingCatalogManager::get(opCtx)->bumpCollectionVersionAndChangeMetadataInTxn(
opCtx,
updatedCoordinatorDoc.getSourceNss(),
[&](OperationContext* opCtx, TxnNumber txnNumber) {
// Update on-disk state to reflect latest state transition.
writeToCoordinatorStateNss(opCtx, updatedCoordinatorDoc, txnNumber);
updateConfigCollectionsForOriginalNss(
opCtx, updatedCoordinatorDoc, boost::none, boost::none, txnNumber);
// Insert the config.collections entry for the temporary resharding collection. The
// chunks all have the same epoch, so picking the last chunk here is arbitrary.
auto chunkVersion = initialChunks.back().getVersion();
writeToConfigCollectionsForTempNss(
opCtx, updatedCoordinatorDoc, chunkVersion, CollationSpec::kSimpleSpec, txnNumber);
insertChunkAndTagDocsForTempNss(opCtx, std::move(initialChunks), zones, txnNumber);
});
}
void ReshardingCoordinatorExternalStateImpl::
writeStateTransitionAndCatalogUpdatesThenBumpShardVersions(
OperationContext* opCtx, const ReshardingCoordinatorDocument& coordinatorDoc) {
// Run updates to config.reshardingOperations and config.collections in a transaction
auto nextState = coordinatorDoc.getState();
std::vector<NamespaceString> collNames = {coordinatorDoc.getSourceNss()};
if (nextState < CoordinatorStateEnum::kDecisionPersisted ||
nextState == CoordinatorStateEnum::kError) {
collNames.emplace_back(coordinatorDoc.getTempReshardingNss());
}
ShardingCatalogManager::get(opCtx)->bumpMultipleCollectionVersionsAndChangeMetadataInTxn(
opCtx, collNames, [&](OperationContext* opCtx, TxnNumber txnNumber) {
// Update the config.reshardingOperations entry
writeToCoordinatorStateNss(opCtx, coordinatorDoc, txnNumber);
// Update the config.collections entry for the original collection
updateConfigCollectionsForOriginalNss(
opCtx, coordinatorDoc, boost::none, boost::none, txnNumber);
// Update the config.collections entry for the temporary resharding collection. If we've
// already persisted the decision that the operation will succeed, we've removed the
// entry for the temporary collection and updated the entry with original namespace to
// have the new shard key, UUID, and epoch
if (nextState < CoordinatorStateEnum::kDecisionPersisted ||
nextState == CoordinatorStateEnum::kError) {
writeToConfigCollectionsForTempNss(
opCtx, coordinatorDoc, boost::none, boost::none, txnNumber);
}
});
}
void ReshardingCoordinatorExternalStateImpl::removeCoordinatorDocAndReshardingFields(
OperationContext* opCtx,
const ReshardingCoordinatorDocument& coordinatorDoc,
boost::optional<Status> abortReason) {
// If the coordinator needs to abort and isn't in kInitializing, additional collections need to
// be cleaned up in the final transaction. Otherwise, cleanup for abort and success are the
// same.
invariant(
(coordinatorDoc.getState() == CoordinatorStateEnum::kDecisionPersisted && !abortReason) ||
(abortReason && coordinatorDoc.getState() == CoordinatorStateEnum::kInitializing));
ReshardingCoordinatorDocument updatedCoordinatorDoc = coordinatorDoc;
updatedCoordinatorDoc.setState(CoordinatorStateEnum::kDone);
emplaceAbortReasonIfExists(updatedCoordinatorDoc, abortReason);
ShardingCatalogManager::get(opCtx)->bumpCollectionVersionAndChangeMetadataInTxn(
opCtx,
updatedCoordinatorDoc.getSourceNss(),
[&](OperationContext* opCtx, TxnNumber txnNumber) {
// Remove entry for this resharding operation from config.reshardingOperations
writeToCoordinatorStateNss(opCtx, updatedCoordinatorDoc, txnNumber);
// Remove the resharding fields from the config.collections entry
updateConfigCollectionsForOriginalNss(
opCtx, updatedCoordinatorDoc, boost::none, boost::none, txnNumber);
});
}
std::shared_ptr<repl::PrimaryOnlyService::Instance> ReshardingCoordinatorService::constructInstance(
BSONObj initialState) {
return std::make_shared<ReshardingCoordinator>(
this, std::move(initialState), std::make_shared<ReshardingCoordinatorExternalStateImpl>());
}
ExecutorFuture<void> ReshardingCoordinatorService::_rebuildService(
std::shared_ptr<executor::ScopedTaskExecutor> executor, const CancellationToken& token) {
return AsyncTry([this] {
auto nss = getStateDocumentsNS();
AllowOpCtxWhenServiceRebuildingBlock allowOpCtxBlock(Client::getCurrent());
auto opCtxHolder = cc().makeOperationContext();
auto opCtx = opCtxHolder.get();
DBDirectClient client(opCtx);
BSONObj result;
client.runCommand(
nss.db().toString(),
BSON("createIndexes"
<< nss.coll().toString() << "indexes"
<< BSON_ARRAY(BSON("key" << BSON("active" << 1) << "name"
<< kReshardingCoordinatorActiveIndexName
<< "unique" << true))),
result);
uassertStatusOK(getStatusFromCommandResult(result));
})
.until([token](Status status) { return shouldStopAttemptingToCreateIndex(status, token); })
.withBackoffBetweenIterations(kExponentialBackoff)
.on(**executor, CancellationToken::uncancelable());
}
ReshardingCoordinatorService::ReshardingCoordinator::ReshardingCoordinator(
const ReshardingCoordinatorService* coordinatorService,
const BSONObj& state,
std::shared_ptr<ReshardingCoordinatorExternalState> externalState)
: PrimaryOnlyService::TypedInstance<ReshardingCoordinator>(),
_id(state["_id"].wrap().getOwned()),
_coordinatorService(coordinatorService),
_coordinatorDoc(ReshardingCoordinatorDocument::parse(
IDLParserErrorContext("ReshardingCoordinatorStateDoc"), state)),
_markKilledExecutor(std::make_shared<ThreadPool>([] {
ThreadPool::Options options;
options.poolName = "ReshardingCoordinatorCancelableOpCtxPool";
options.minThreads = 1;
options.maxThreads = 1;
return options;
}())),
_reshardingCoordinatorExternalState(externalState) {
_reshardingCoordinatorObserver = std::make_shared<ReshardingCoordinatorObserver>();
}
ReshardingCoordinatorService::ReshardingCoordinator::~ReshardingCoordinator() {
invariant(_completionPromise.getFuture().isReady());
}
void ReshardingCoordinatorService::ReshardingCoordinator::installCoordinatorDoc(
OperationContext* opCtx, const ReshardingCoordinatorDocument& doc) noexcept {
invariant(doc.getReshardingUUID() == _coordinatorDoc.getReshardingUUID());
BSONObjBuilder bob;
bob.append("newState", CoordinatorState_serializer(doc.getState()));
bob.append("oldState", CoordinatorState_serializer(_coordinatorDoc.getState()));
bob.append("namespace", doc.getSourceNss().toString());
bob.append("collectionUUID", doc.getSourceUUID().toString());
bob.append("reshardingUUID", doc.getReshardingUUID().toString());
ShardingLogging::get(opCtx)->logChange(opCtx,
"resharding.coordinator.transition",
doc.getSourceNss().toString(),
bob.obj(),
ShardingCatalogClient::kMajorityWriteConcern);
LOGV2_INFO(5343001,
"Transitioned resharding coordinator state",
"newState"_attr = CoordinatorState_serializer(doc.getState()),
"oldState"_attr = CoordinatorState_serializer(_coordinatorDoc.getState()),
"namespace"_attr = doc.getSourceNss(),
"collectionUUID"_attr = doc.getSourceUUID(),
"reshardingUUID"_attr = doc.getReshardingUUID());
_coordinatorDoc = doc;
}
ExecutorFuture<void> waitForMinimumOperationDuration(
std::shared_ptr<executor::TaskExecutor> executor, const CancellationToken& token) {
// Ensure to have at least `minDuration` elapsed after starting the operation and before
// engaging the critical section, unless the operation is already interrupted or canceled.
const auto minDuration =
Milliseconds(resharding::gReshardingMinimumOperationDurationMillis.load());
const auto elapsed =
ReshardingMetrics::get(cc().getServiceContext())->getOperationElapsedTime().get();
// As `ReshardingMetrics` may use a different clock source, the following is to estimate the
// time on the executor clock source when the operation was started. This estimation also allows
// logging both `startedOn` and `resumedOn` using a single clock source.
const auto estimatedStart = executor->now() - elapsed;
return executor->sleepUntil(estimatedStart + minDuration, token)
.then([executor, estimatedStart] {
LOGV2_INFO(5391801,
"Resuming operation after waiting for minimum resharding operation duration",
"startedOn"_attr = estimatedStart,
"resumedOn"_attr = executor->now());
});
}
void markCompleted(const Status& status) {
auto metrics = ReshardingMetrics::get(cc().getServiceContext());
// TODO SERVER-52770 to process the cancellation of resharding operations.
if (status.isOK())
metrics->onCompletion(ReshardingOperationStatusEnum::kSuccess);
else
metrics->onCompletion(ReshardingOperationStatusEnum::kFailure);
}
BSONObj createFlushReshardingStateChangeCommand(const NamespaceString& nss) {
_flushReshardingStateChange cmd(nss);
cmd.setDbName(nss.db());
return cmd.toBSON(
BSON(WriteConcernOptions::kWriteConcernField << WriteConcernOptions::Majority));
}
ExecutorFuture<ReshardingCoordinatorDocument>
ReshardingCoordinatorService::ReshardingCoordinator::_runUntilReadyToPersistDecision(
const std::shared_ptr<executor::ScopedTaskExecutor>& executor) noexcept {
return ExecutorFuture<void>(**executor)
.then([this, executor] { _insertCoordDocAndChangeOrigCollEntry(); })
.then([this, executor] { _calculateParticipantsAndChunksThenWriteToDisk(); })
.onCompletion([this, executor](Status status) {
if (_ctHolder->isSteppingOrShuttingDown()) {
// Propagate any errors from the coordinator stepping down.
return ExecutorFuture<void>(**executor, status);
}
if (_coordinatorDoc.getState() < CoordinatorStateEnum::kPreparingToDonate) {
// Propagate any errors if the coordinator failed before transitioning to
// kPreparingToDonate, meaning participants were never and should never be made
// aware of this failed resharding operation.
invariant(!status.isOK());
return ExecutorFuture<void>(**executor, status);
}
// Regardless of error or non-error, guarantee that once the coordinator completes its
// transition to kPreparingToDonate, participants are aware of the resharding operation
// and their state machines are created.
return ExecutorFuture<void>(**executor)
.then([this, executor] { _tellAllDonorsToRefresh(executor); })