void MoveChunkRequest::appendAsCommand(BSONObjBuilder* builder,
const NamespaceString& nss,
const ChunkVersion& shardVersion,
const ConnectionString& configServerConnectionString,
const ShardId& fromShardId,
const ShardId& toShardId,
const ChunkRange& range,
int64_t maxChunkSizeBytes,
const MigrationSecondaryThrottleOptions& secondaryThrottle,
bool waitForDelete,
bool takeDistLock) {
invariant(builder->asTempObj().isEmpty());
invariant(nss.isValid());
builder->append(kMoveChunk, nss.ns());
shardVersion.appendForCommands(builder);
builder->append(kConfigServerConnectionString, configServerConnectionString.toString());
builder->append(kFromShardId, fromShardId.toString());
builder->append(kToShardId, toShardId.toString());
range.append(builder);
builder->append(kMaxChunkSizeBytes, static_cast<long long>(maxChunkSizeBytes));
secondaryThrottle.append(builder);
builder->append(kWaitForDelete, waitForDelete);
builder->append(kTakeDistLock, takeDistLock);
}
StatusWith<boost::optional<ChunkRange>> splitChunkAtMultiplePoints(
OperationContext* txn,
const ShardId& shardId,
const NamespaceString& nss,
const ShardKeyPattern& shardKeyPattern,
ChunkVersion collectionVersion,
const BSONObj& minKey,
const BSONObj& maxKey,
const std::vector<BSONObj>& splitPoints) {
invariant(!splitPoints.empty());
invariant(minKey.woCompare(maxKey) < 0);
const size_t kMaxSplitPoints = 8192;
if (splitPoints.size() > kMaxSplitPoints) {
return {ErrorCodes::BadValue,
str::stream() << "Cannot split chunk in more than " << kMaxSplitPoints
<< " parts at a time."};
}
BSONObjBuilder cmd;
cmd.append("splitChunk", nss.ns());
cmd.append("configdb",
Grid::get(txn)->shardRegistry()->getConfigServerConnectionString().toString());
cmd.append("from", shardId.toString());
cmd.append("keyPattern", shardKeyPattern.toBSON());
collectionVersion.appendForCommands(&cmd);
cmd.append(kMinKey, minKey);
cmd.append(kMaxKey, maxKey);
cmd.append("splitKeys", splitPoints);
BSONObj cmdObj = cmd.obj();
Status status{ErrorCodes::InternalError, "Uninitialized value"};
BSONObj cmdResponse;
auto shard = Grid::get(txn)->shardRegistry()->getShard(txn, shardId);
if (!shard) {
status =
Status(ErrorCodes::ShardNotFound, str::stream() << "shard " << shardId << " not found");
} else {
auto cmdStatus = shard->runCommand(txn,
ReadPreferenceSetting{ReadPreference::PrimaryOnly},
"admin",
cmdObj,
Shard::RetryPolicy::kNotIdempotent);
if (!cmdStatus.isOK()) {
status = std::move(cmdStatus.getStatus());
} else {
status = std::move(cmdStatus.getValue().commandStatus);
cmdResponse = std::move(cmdStatus.getValue().response);
}
}
if (!status.isOK()) {
log() << "Split chunk " << redact(cmdObj) << " failed" << causedBy(redact(status));
return {status.code(), str::stream() << "split failed due to " << status.toString()};
}
BSONElement shouldMigrateElement;
status = bsonExtractTypedField(cmdResponse, kShouldMigrate, Object, &shouldMigrateElement);
if (status.isOK()) {
auto chunkRangeStatus = ChunkRange::fromBSON(shouldMigrateElement.embeddedObject());
if (!chunkRangeStatus.isOK()) {
return chunkRangeStatus.getStatus();
}
return boost::optional<ChunkRange>(std::move(chunkRangeStatus.getValue()));
} else if (status != ErrorCodes::NoSuchKey) {
warning()
<< "Chunk migration will be skipped because splitChunk returned invalid response: "
<< redact(cmdResponse) << ". Extracting " << kShouldMigrate << " field failed"
<< causedBy(redact(status));
}
return boost::optional<ChunkRange>();
}
StatusWith<boost::optional<ChunkRange>> splitChunkAtMultiplePoints(
OperationContext* txn,
const ShardId& shardId,
const NamespaceString& nss,
const ShardKeyPattern& shardKeyPattern,
ChunkVersion collectionVersion,
const ChunkRange& chunkRange,
const std::vector<BSONObj>& splitPoints) {
invariant(!splitPoints.empty());
const size_t kMaxSplitPoints = 8192;
if (splitPoints.size() > kMaxSplitPoints) {
return {ErrorCodes::BadValue,
str::stream() << "Cannot split chunk in more than " << kMaxSplitPoints
<< " parts at a time."};
}
// Sanity check that we are not attempting to split at the boundaries of the chunk. This check
// is already performed at chunk split commit time, but we are performing it here for parity
// with old auto-split code, which might rely on it.
if (SimpleBSONObjComparator::kInstance.evaluate(chunkRange.getMin() == splitPoints.front())) {
const std::string msg(str::stream() << "not splitting chunk " << chunkRange.toString()
<< ", split point "
<< splitPoints.front()
<< " is exactly on chunk bounds");
return {ErrorCodes::CannotSplit, msg};
}
if (SimpleBSONObjComparator::kInstance.evaluate(chunkRange.getMax() == splitPoints.back())) {
const std::string msg(str::stream() << "not splitting chunk " << chunkRange.toString()
<< ", split point "
<< splitPoints.back()
<< " is exactly on chunk bounds");
return {ErrorCodes::CannotSplit, msg};
}
BSONObjBuilder cmd;
cmd.append("splitChunk", nss.ns());
cmd.append("configdb",
Grid::get(txn)->shardRegistry()->getConfigServerConnectionString().toString());
cmd.append("from", shardId.toString());
cmd.append("keyPattern", shardKeyPattern.toBSON());
collectionVersion.appendForCommands(&cmd);
chunkRange.append(&cmd);
cmd.append("splitKeys", splitPoints);
BSONObj cmdObj = cmd.obj();
Status status{ErrorCodes::InternalError, "Uninitialized value"};
BSONObj cmdResponse;
auto shardStatus = Grid::get(txn)->shardRegistry()->getShard(txn, shardId);
if (!shardStatus.isOK()) {
status = shardStatus.getStatus();
} else {
auto cmdStatus = shardStatus.getValue()->runCommandWithFixedRetryAttempts(
txn,
ReadPreferenceSetting{ReadPreference::PrimaryOnly},
"admin",
cmdObj,
Shard::RetryPolicy::kNotIdempotent);
if (!cmdStatus.isOK()) {
status = std::move(cmdStatus.getStatus());
} else {
status = std::move(cmdStatus.getValue().commandStatus);
cmdResponse = std::move(cmdStatus.getValue().response);
}
}
if (!status.isOK()) {
log() << "Split chunk " << redact(cmdObj) << " failed" << causedBy(redact(status));
return {status.code(), str::stream() << "split failed due to " << status.toString()};
}
BSONElement shouldMigrateElement;
status = bsonExtractTypedField(cmdResponse, kShouldMigrate, Object, &shouldMigrateElement);
if (status.isOK()) {
auto chunkRangeStatus = ChunkRange::fromBSON(shouldMigrateElement.embeddedObject());
if (!chunkRangeStatus.isOK()) {
return chunkRangeStatus.getStatus();
}
return boost::optional<ChunkRange>(std::move(chunkRangeStatus.getValue()));
} else if (status != ErrorCodes::NoSuchKey) {
warning()
<< "Chunk migration will be skipped because splitChunk returned invalid response: "
<< redact(cmdResponse) << ". Extracting " << kShouldMigrate << " field failed"
<< causedBy(redact(status));
}
return boost::optional<ChunkRange>();
}