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|
// @file d_state.cpp
/**
* Copyright (C) 2008 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/s/d_state.h"
#include <map>
#include <string>
#include <vector>
#include "mongo/client/connpool.h"
#include "mongo/client/global_conn_pool.h"
#include "mongo/client/remote_command_runner_impl.h"
#include "mongo/client/remote_command_targeter_factory_impl.h"
#include "mongo/db/auth/action_set.h"
#include "mongo/db/auth/action_type.h"
#include "mongo/db/auth/authorization_manager.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/privilege.h"
#include "mongo/db/commands.h"
#include "mongo/db/db.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/lasterror.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/repl/replication_coordinator_global.h"
#include "mongo/db/wire_version.h"
#include "mongo/executor/task_executor.h"
#include "mongo/s/catalog/legacy/catalog_manager_legacy.h"
#include "mongo/s/client/shard_connection.h"
#include "mongo/s/client/shard_registry.h"
#include "mongo/s/client/sharding_connection_hook.h"
#include "mongo/s/config.h"
#include "mongo/s/grid.h"
#include "mongo/s/metadata_loader.h"
#include "mongo/s/stale_exception.h"
#include "mongo/stdx/memory.h"
#include "mongo/util/concurrency/mutex.h"
#include "mongo/util/concurrency/ticketholder.h"
#include "mongo/util/log.h"
#include "mongo/util/stringutils.h"
namespace mongo {
using boost::optional;
using std::endl;
using std::string;
using std::stringstream;
using std::vector;
namespace {
const auto clientSCI = Client::declareDecoration<optional<ShardedConnectionInfo>>();
} // namespace
bool isMongos() {
return false;
}
// -----ShardingState START ----
ShardingState::ShardingState()
: _enabled(false),
_configServerTickets( 3 /* max number of concurrent config server refresh threads */ ) {
}
bool ShardingState::enabled() {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _enabled;
}
string ShardingState::getConfigServer() {
stdx::lock_guard<stdx::mutex> lk(_mutex);
invariant(_enabled);
return grid.catalogManager()->connectionString().toString();
}
void ShardingState::initialize(const string& server) {
uassert(18509,
"Unable to obtain host name during sharding initialization.",
!getHostName().empty());
shardingState._initialize(server);
}
// TODO: Consolidate and eliminate these various ways of setting / validating shard names
bool ShardingState::setShardName( const string& name ) {
return setShardNameAndHost( name, "" );
}
std::string ShardingState::getShardName() {
stdx::lock_guard<stdx::mutex> lk(_mutex);
return _shardName;
}
bool ShardingState::setShardNameAndHost( const string& name, const string& host ) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
if ( _shardName.size() == 0 ) {
// TODO SERVER-2299 remotely verify the name is sound w.r.t IPs
_shardName = name;
string clientAddr = cc().clientAddress(true);
log() << "remote client " << clientAddr << " initialized this host "
<< ( host.empty() ? string( "" ) : string( "(" ) + host + ") " )
<< "as shard " << name;
return true;
}
if ( _shardName == name )
return true;
string clientAddr = cc().clientAddress(true);
warning() << "remote client " << clientAddr << " tried to initialize this host "
<< ( host.empty() ? string( "" ) : string( "(" ) + host + ") " )
<< "as shard " << name
<< ", but shard name was previously initialized as " << _shardName;
return false;
}
void ShardingState::gotShardName( const string& name ) {
gotShardNameAndHost( name, "" );
}
void ShardingState::gotShardNameAndHost( const string& name, const string& host ) {
if ( setShardNameAndHost( name, host ) )
return;
string clientAddr = cc().clientAddress(true);
stringstream ss;
// Same error as above, to match for reporting
ss << "remote client " << clientAddr << " tried to initialize this host "
<< ( host.empty() ? string( "" ) : string( "(" ) + host + ") " )
<< "as shard " << name
<< ", but shard name was previously initialized as " << _shardName;
msgasserted( 13298 , ss.str() );
}
void ShardingState::clearCollectionMetadata() {
stdx::lock_guard<stdx::mutex> lk(_mutex);
_collMetadata.clear();
}
// TODO we shouldn't need three ways for checking the version. Fix this.
bool ShardingState::hasVersion( const string& ns ) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
CollectionMetadataMap::const_iterator it = _collMetadata.find(ns);
return it != _collMetadata.end();
}
bool ShardingState::hasVersion( const string& ns , ChunkVersion& version ) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
CollectionMetadataMap::const_iterator it = _collMetadata.find(ns);
if ( it == _collMetadata.end() )
return false;
CollectionMetadataPtr p = it->second;
version = p->getShardVersion();
return true;
}
ChunkVersion ShardingState::getVersion(const string& ns) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
CollectionMetadataMap::const_iterator it = _collMetadata.find( ns );
if ( it != _collMetadata.end() ) {
CollectionMetadataPtr p = it->second;
return p->getShardVersion();
}
else {
return ChunkVersion( 0, 0, OID() );
}
}
void ShardingState::donateChunk(OperationContext* txn,
const string& ns,
const BSONObj& min,
const BSONObj& max,
ChunkVersion version) {
invariant(txn->lockState()->isCollectionLockedForMode(ns, MODE_X));
stdx::lock_guard<stdx::mutex> lk( _mutex );
CollectionMetadataMap::const_iterator it = _collMetadata.find( ns );
verify( it != _collMetadata.end() ) ;
CollectionMetadataPtr p = it->second;
// empty shards should have version 0
version =
( p->getNumChunks() > 1 ) ?
version : ChunkVersion( 0, 0, p->getCollVersion().epoch() );
ChunkType chunk;
chunk.setMin( min );
chunk.setMax( max );
string errMsg;
CollectionMetadataPtr cloned( p->cloneMigrate( chunk, version, &errMsg ) );
// uassert to match old behavior, TODO: report errors w/o throwing
uassert( 16855, errMsg, NULL != cloned.get() );
// TODO: a bit dangerous to have two different zero-version states - no-metadata and
// no-version
_collMetadata[ns] = cloned;
}
void ShardingState::undoDonateChunk(OperationContext* txn,
const string& ns,
CollectionMetadataPtr prevMetadata) {
invariant(txn->lockState()->isCollectionLockedForMode(ns, MODE_X));
stdx::lock_guard<stdx::mutex> lk( _mutex );
log() << "ShardingState::undoDonateChunk acquired _mutex" << endl;
CollectionMetadataMap::iterator it = _collMetadata.find( ns );
verify( it != _collMetadata.end() );
it->second = prevMetadata;
}
bool ShardingState::notePending(OperationContext* txn,
const string& ns,
const BSONObj& min,
const BSONObj& max,
const OID& epoch,
string* errMsg ) {
invariant(txn->lockState()->isCollectionLockedForMode(ns, MODE_X));
stdx::lock_guard<stdx::mutex> lk( _mutex );
CollectionMetadataMap::const_iterator it = _collMetadata.find( ns );
if ( it == _collMetadata.end() ) {
*errMsg = str::stream() << "could not note chunk " << "[" << min << "," << max << ")"
<< " as pending because the local metadata for " << ns
<< " has changed";
return false;
}
CollectionMetadataPtr metadata = it->second;
// This can currently happen because drops aren't synchronized with in-migrations
// The idea for checking this here is that in the future we shouldn't have this problem
if ( metadata->getCollVersion().epoch() != epoch ) {
*errMsg = str::stream() << "could not note chunk " << "[" << min << "," << max << ")"
<< " as pending because the epoch for " << ns
<< " has changed from "
<< epoch << " to " << metadata->getCollVersion().epoch();
return false;
}
ChunkType chunk;
chunk.setMin( min );
chunk.setMax( max );
CollectionMetadataPtr cloned( metadata->clonePlusPending( chunk, errMsg ) );
if ( !cloned ) return false;
_collMetadata[ns] = cloned;
return true;
}
bool ShardingState::forgetPending(OperationContext* txn,
const string& ns,
const BSONObj& min,
const BSONObj& max,
const OID& epoch,
string* errMsg ) {
invariant(txn->lockState()->isCollectionLockedForMode(ns, MODE_X));
stdx::lock_guard<stdx::mutex> lk( _mutex );
CollectionMetadataMap::const_iterator it = _collMetadata.find( ns );
if ( it == _collMetadata.end() ) {
*errMsg = str::stream() << "no need to forget pending chunk "
<< "[" << min << "," << max << ")"
<< " because the local metadata for " << ns << " has changed";
return false;
}
CollectionMetadataPtr metadata = it->second;
// This can currently happen because drops aren't synchronized with in-migrations
// The idea for checking this here is that in the future we shouldn't have this problem
if ( metadata->getCollVersion().epoch() != epoch ) {
*errMsg = str::stream() << "no need to forget pending chunk "
<< "[" << min << "," << max << ")"
<< " because the epoch for " << ns << " has changed from "
<< epoch << " to " << metadata->getCollVersion().epoch();
return false;
}
ChunkType chunk;
chunk.setMin( min );
chunk.setMax( max );
CollectionMetadataPtr cloned( metadata->cloneMinusPending( chunk, errMsg ) );
if ( !cloned ) return false;
_collMetadata[ns] = cloned;
return true;
}
void ShardingState::splitChunk(OperationContext* txn,
const string& ns,
const BSONObj& min,
const BSONObj& max,
const vector<BSONObj>& splitKeys,
ChunkVersion version ) {
invariant(txn->lockState()->isCollectionLockedForMode(ns, MODE_X));
stdx::lock_guard<stdx::mutex> lk( _mutex );
CollectionMetadataMap::const_iterator it = _collMetadata.find( ns );
verify( it != _collMetadata.end() ) ;
ChunkType chunk;
chunk.setMin( min );
chunk.setMax( max );
string errMsg;
CollectionMetadataPtr cloned( it->second->cloneSplit( chunk, splitKeys, version, &errMsg ) );
// uassert to match old behavior, TODO: report errors w/o throwing
uassert( 16857, errMsg, NULL != cloned.get() );
_collMetadata[ns] = cloned;
}
void ShardingState::mergeChunks(OperationContext* txn,
const string& ns,
const BSONObj& minKey,
const BSONObj& maxKey,
ChunkVersion mergedVersion ) {
invariant(txn->lockState()->isCollectionLockedForMode(ns, MODE_X));
stdx::lock_guard<stdx::mutex> lk( _mutex );
CollectionMetadataMap::const_iterator it = _collMetadata.find( ns );
verify( it != _collMetadata.end() );
string errMsg;
CollectionMetadataPtr cloned( it->second->cloneMerge( minKey,
maxKey,
mergedVersion,
&errMsg ) );
// uassert to match old behavior, TODO: report errors w/o throwing
uassert( 17004, errMsg, NULL != cloned.get() );
_collMetadata[ns] = cloned;
}
void ShardingState::resetMetadata( const string& ns ) {
stdx::lock_guard<stdx::mutex> lk( _mutex );
warning() << "resetting metadata for " << ns << ", this should only be used in testing"
<< endl;
_collMetadata.erase( ns );
}
Status ShardingState::refreshMetadataIfNeeded( OperationContext* txn,
const string& ns,
const ChunkVersion& reqShardVersion,
ChunkVersion* latestShardVersion )
{
// The _configServerTickets serializes this process such that only a small number of threads
// can try to refresh at the same time.
LOG( 2 ) << "metadata refresh requested for " << ns << " at shard version "
<< reqShardVersion << endl;
//
// Queuing of refresh requests starts here when remote reload is needed. This may take time.
// TODO: Explicitly expose the queuing discipline.
//
_configServerTickets.waitForTicket();
TicketHolderReleaser needTicketFrom( &_configServerTickets );
//
// Fast path - check if the requested version is at a higher version than the current
// metadata version or a different epoch before verifying against config server.
//
CollectionMetadataPtr storedMetadata;
{
stdx::lock_guard<stdx::mutex> lk( _mutex );
CollectionMetadataMap::iterator it = _collMetadata.find( ns );
if ( it != _collMetadata.end() ) storedMetadata = it->second;
}
ChunkVersion storedShardVersion;
if ( storedMetadata ) storedShardVersion = storedMetadata->getShardVersion();
*latestShardVersion = storedShardVersion;
if ( storedShardVersion >= reqShardVersion &&
storedShardVersion.epoch() == reqShardVersion.epoch() ) {
// Don't need to remotely reload if we're in the same epoch with a >= version
return Status::OK();
}
//
// Slow path - remotely reload
//
// Cases:
// A) Initial config load and/or secondary take-over.
// B) Migration TO this shard finished, notified by mongos.
// C) Dropping a collection, notified (currently) by mongos.
// D) Stale client wants to reload metadata with a different *epoch*, so we aren't sure.
if ( storedShardVersion.epoch() != reqShardVersion.epoch() ) {
// Need to remotely reload if our epochs aren't the same, to verify
LOG( 1 ) << "metadata change requested for " << ns << ", from shard version "
<< storedShardVersion << " to " << reqShardVersion
<< ", need to verify with config server" << endl;
}
else {
// Need to remotely reload since our epochs aren't the same but our version is greater
LOG( 1 ) << "metadata version update requested for " << ns
<< ", from shard version " << storedShardVersion << " to " << reqShardVersion
<< ", need to verify with config server" << endl;
}
return doRefreshMetadata(txn, ns, reqShardVersion, true, latestShardVersion);
}
Status ShardingState::refreshMetadataNow(OperationContext* txn,
const string& ns,
ChunkVersion* latestShardVersion) {
return doRefreshMetadata(txn, ns, ChunkVersion(0, 0, OID()), false, latestShardVersion);
}
void ShardingState::_initialize(const string& server) {
// Ensure only one caller at a time initializes
stdx::lock_guard<stdx::mutex> lk(_mutex);
if (_enabled) {
// TODO: Do we need to throw exception if the config servers have changed from what we
// already have in place? How do we test for that?
return;
}
ShardedConnectionInfo::addHook();
std::string errmsg;
ConnectionString configServerCS = ConnectionString::parse(server, errmsg);
uassert(28633,
str::stream() << "Invalid config server connection string: " << errmsg,
configServerCS.isValid());
auto catalogManager = stdx::make_unique<CatalogManagerLegacy>();
uassertStatusOK(catalogManager->init(configServerCS));
auto shardRegistry = stdx::make_unique<ShardRegistry>(
stdx::make_unique<RemoteCommandTargeterFactoryImpl>(),
stdx::make_unique<RemoteCommandRunnerImpl>(0),
std::unique_ptr<executor::TaskExecutor>{nullptr},
catalogManager.get());
grid.init(std::move(catalogManager), std::move(shardRegistry));
_enabled = true;
}
Status ShardingState::doRefreshMetadata( OperationContext* txn,
const string& ns,
const ChunkVersion& reqShardVersion,
bool useRequestedVersion,
ChunkVersion* latestShardVersion )
{
// The idea here is that we're going to reload the metadata from the config server, but
// we need to do so outside any locks. When we get our result back, if the current metadata
// has changed, we may not be able to install the new metadata.
//
// Get the initial metadata
// No DBLock is needed since the metadata is expected to change during reload.
//
CollectionMetadataPtr beforeMetadata;
{
stdx::lock_guard<stdx::mutex> lk( _mutex );
// We can't reload if sharding is not enabled - i.e. without a config server location
if (!_enabled) {
string errMsg = str::stream() << "cannot refresh metadata for " << ns
<< " before sharding has been enabled";
warning() << errMsg;
return Status(ErrorCodes::NotYetInitialized, errMsg);
}
// We also can't reload if a shard name has not yet been set.
if (_shardName.empty()) {
string errMsg = str::stream() << "cannot refresh metadata for " << ns
<< " before shard name has been set";
warning() << errMsg;
return Status(ErrorCodes::NotYetInitialized, errMsg);
}
CollectionMetadataMap::iterator it = _collMetadata.find(ns);
if (it != _collMetadata.end()) {
beforeMetadata = it->second;
}
}
ChunkVersion beforeShardVersion;
ChunkVersion beforeCollVersion;
if ( beforeMetadata ) {
beforeShardVersion = beforeMetadata->getShardVersion();
beforeCollVersion = beforeMetadata->getCollVersion();
}
*latestShardVersion = beforeShardVersion;
//
// Determine whether we need to diff or fully reload
//
bool fullReload = false;
if ( !beforeMetadata ) {
// We don't have any metadata to reload from
fullReload = true;
}
else if ( useRequestedVersion && reqShardVersion.epoch() != beforeShardVersion.epoch() ) {
// It's not useful to use the metadata as a base because we think the epoch will differ
fullReload = true;
}
//
// Load the metadata from the remote server, start construction
//
LOG( 0 ) << "remotely refreshing metadata for " << ns
<< ( useRequestedVersion ?
string( " with requested shard version " ) + reqShardVersion.toString() : "" )
<< ( fullReload ?
", current shard version is " : " based on current shard version " )
<< beforeShardVersion
<< ", current metadata version is " << beforeCollVersion << endl;
string errMsg;
MetadataLoader mdLoader;
CollectionMetadata* remoteMetadataRaw = new CollectionMetadata();
CollectionMetadataPtr remoteMetadata( remoteMetadataRaw );
Timer refreshTimer;
Status status =
mdLoader.makeCollectionMetadata(grid.catalogManager(),
ns,
getShardName(),
fullReload ? NULL : beforeMetadata.get(),
remoteMetadataRaw);
long long refreshMillis = refreshTimer.millis();
if ( status.code() == ErrorCodes::NamespaceNotFound ) {
remoteMetadata.reset();
remoteMetadataRaw = NULL;
}
else if ( !status.isOK() ) {
warning() << "could not remotely refresh metadata for " << ns
<< causedBy( status.reason() ) << endl;
return status;
}
ChunkVersion remoteShardVersion;
ChunkVersion remoteCollVersion;
if ( remoteMetadata ) {
remoteShardVersion = remoteMetadata->getShardVersion();
remoteCollVersion = remoteMetadata->getCollVersion();
}
//
// Get ready to install loaded metadata if needed
//
CollectionMetadataPtr afterMetadata;
ChunkVersion afterShardVersion;
ChunkVersion afterCollVersion;
ChunkVersion::VersionChoice choice;
// If we choose to install the new metadata, this describes the kind of install
enum InstallType {
InstallType_New, InstallType_Update, InstallType_Replace, InstallType_Drop,
InstallType_None
} installType = InstallType_None; // compiler complains otherwise
{
// Exclusive collection lock needed since we're now potentially changing the metadata,
// and don't want reads/writes to be ongoing.
ScopedTransaction transaction(txn, MODE_IX);
Lock::DBLock dbLock(txn->lockState(), nsToDatabaseSubstring(ns), MODE_IX);
Lock::CollectionLock collLock(txn->lockState(), ns, MODE_X);
//
// Get the metadata now that the load has completed
//
stdx::lock_guard<stdx::mutex> lk( _mutex );
// Don't reload if our config server has changed or sharding is no longer enabled
if (!_enabled) {
string errMsg = str::stream() << "could not refresh metadata for " << ns
<< ", sharding is no longer enabled";
warning() << errMsg;
return Status(ErrorCodes::NotYetInitialized, errMsg);
}
CollectionMetadataMap::iterator it = _collMetadata.find( ns );
if ( it != _collMetadata.end() ) afterMetadata = it->second;
if ( afterMetadata ) {
afterShardVersion = afterMetadata->getShardVersion();
afterCollVersion = afterMetadata->getCollVersion();
}
*latestShardVersion = afterShardVersion;
//
// Resolve newer pending chunks with the remote metadata, finish construction
//
status = mdLoader.promotePendingChunks( afterMetadata.get(), remoteMetadataRaw );
if ( !status.isOK() ) {
warning() << "remote metadata for " << ns
<< " is inconsistent with current pending chunks"
<< causedBy( status.reason() ) << endl;
return status;
}
//
// Compare the 'before', 'after', and 'remote' versions/epochs and choose newest
// Zero-epochs (sentinel value for "dropped" collections), are tested by
// !epoch.isSet().
//
choice = ChunkVersion::chooseNewestVersion( beforeCollVersion,
afterCollVersion,
remoteCollVersion );
if ( choice == ChunkVersion::VersionChoice_Remote ) {
dassert(!remoteCollVersion.epoch().isSet() ||
remoteShardVersion >= beforeShardVersion);
if ( !afterCollVersion.epoch().isSet() ) {
// First metadata load
installType = InstallType_New;
dassert( it == _collMetadata.end() );
_collMetadata.insert( make_pair( ns, remoteMetadata ) );
}
else if ( remoteCollVersion.epoch().isSet() &&
remoteCollVersion.epoch() == afterCollVersion.epoch() ) {
// Update to existing metadata
installType = InstallType_Update;
// Invariant: If CollMetadata was not found, version should be have been 0.
dassert( it != _collMetadata.end() );
it->second = remoteMetadata;
}
else if ( remoteCollVersion.epoch().isSet() ) {
// New epoch detected, replacing metadata
installType = InstallType_Replace;
// Invariant: If CollMetadata was not found, version should be have been 0.
dassert( it != _collMetadata.end() );
it->second = remoteMetadata;
}
else {
dassert( !remoteCollVersion.epoch().isSet() );
// Drop detected
installType = InstallType_Drop;
_collMetadata.erase( it );
}
*latestShardVersion = remoteShardVersion;
}
}
// End _mutex
// End DBWrite
//
// Do messaging based on what happened above
//
string localShardVersionMsg =
beforeShardVersion.epoch() == afterShardVersion.epoch() ?
afterShardVersion.toString() :
beforeShardVersion.toString() + " / " + afterShardVersion.toString();
if ( choice == ChunkVersion::VersionChoice_Unknown ) {
string errMsg = str::stream()
<< "need to retry loading metadata for " << ns
<< ", collection may have been dropped or recreated during load"
<< " (loaded shard version : " << remoteShardVersion.toString()
<< ", stored shard versions : " << localShardVersionMsg
<< ", took " << refreshMillis << "ms)";
warning() << errMsg;
return Status( ErrorCodes::RemoteChangeDetected, errMsg );
}
if ( choice == ChunkVersion::VersionChoice_Local ) {
LOG( 0 ) << "metadata of collection " << ns << " already up to date (shard version : "
<< afterShardVersion.toString() << ", took " << refreshMillis << "ms)"
<< endl;
return Status::OK();
}
dassert( choice == ChunkVersion::VersionChoice_Remote );
switch( installType ) {
case InstallType_New:
LOG( 0 ) << "collection " << ns << " was previously unsharded"
<< ", new metadata loaded with shard version " << remoteShardVersion
<< endl;
break;
case InstallType_Update:
LOG( 0 ) << "updating metadata for " << ns << " from shard version "
<< localShardVersionMsg << " to shard version " << remoteShardVersion
<< endl;
break;
case InstallType_Replace:
LOG( 0 ) << "replacing metadata for " << ns << " at shard version "
<< localShardVersionMsg << " with a new epoch (shard version "
<< remoteShardVersion << ")" << endl;
break;
case InstallType_Drop:
LOG( 0 ) << "dropping metadata for " << ns << " at shard version "
<< localShardVersionMsg << ", took " << refreshMillis << "ms" << endl;
break;
default:
verify( false );
break;
}
if ( installType != InstallType_Drop ) {
LOG( 0 ) << "collection version was loaded at version " << remoteCollVersion
<< ", took " << refreshMillis << "ms" << endl;
}
return Status::OK();
}
void ShardingState::appendInfo(BSONObjBuilder& builder) {
stdx::lock_guard<stdx::mutex> lk(_mutex);
builder.appendBool("enabled", _enabled);
if (!_enabled) {
return;
}
builder.append("configServer", grid.catalogManager()->connectionString().toString());
builder.append("shardName", _shardName);
BSONObjBuilder versionB(builder.subobjStart("versions"));
for (CollectionMetadataMap::const_iterator it = _collMetadata.begin();
it != _collMetadata.end();
++it) {
CollectionMetadataPtr metadata = it->second;
versionB.appendTimestamp(it->first, metadata->getShardVersion().toLong());
}
versionB.done();
}
bool ShardingState::needCollectionMetadata( Client* client, const string& ns ) const {
if ( ! _enabled )
return false;
if ( ! ShardedConnectionInfo::get( client, false ) )
return false;
return true;
}
CollectionMetadataPtr ShardingState::getCollectionMetadata( const string& ns ) {
stdx::lock_guard<stdx::mutex> lk( _mutex );
CollectionMetadataMap::const_iterator it = _collMetadata.find( ns );
if ( it == _collMetadata.end() ) {
return CollectionMetadataPtr();
}
else {
return it->second;
}
}
ShardingState shardingState;
// -----ShardingState END ----
// -----ShardedConnectionInfo START ----
ShardedConnectionInfo::ShardedConnectionInfo() {
_forceVersionOk = false;
}
ShardedConnectionInfo* ShardedConnectionInfo::get( Client* client, bool create ) {
auto& current = clientSCI(client);
if (!current && create) {
LOG(1) << "entering shard mode for connection" << endl;
current = boost::in_place();
}
return current ? ¤t.value() : nullptr;
}
void ShardedConnectionInfo::reset(Client* client) {
clientSCI(client) = boost::none;
}
const ChunkVersion ShardedConnectionInfo::getVersion( const string& ns ) const {
NSVersionMap::const_iterator it = _versions.find( ns );
if ( it != _versions.end() ) {
return it->second;
}
else {
return ChunkVersion( 0, 0, OID() );
}
}
void ShardedConnectionInfo::setVersion( const string& ns , const ChunkVersion& version ) {
_versions[ns] = version;
}
void ShardedConnectionInfo::addHook() {
static mongo::mutex lock;
static bool done = false;
stdx::lock_guard<stdx::mutex> lk(lock);
if (!done) {
log() << "first cluster operation detected, adding sharding hook to enable versioning "
"and authentication to remote servers";
globalConnPool.addHook(new ShardingConnectionHook(false));
shardConnectionPool.addHook(new ShardingConnectionHook(true));
done = true;
}
}
class MongodShardCommand : public Command {
public:
MongodShardCommand( const char * n ) : Command( n ) {
}
virtual bool slaveOk() const {
return false;
}
virtual bool adminOnly() const {
return true;
}
};
bool haveLocalShardingInfo( Client* client, const string& ns ) {
if ( ! shardingState.enabled() )
return false;
if ( ! shardingState.hasVersion( ns ) )
return false;
return ShardedConnectionInfo::get(client, false) != NULL;
}
class UnsetShardingCommand : public MongodShardCommand {
public:
UnsetShardingCommand() : MongodShardCommand("unsetSharding") {}
virtual void help( stringstream& help ) const {
help << "internal";
}
virtual bool isWriteCommandForConfigServer() const { return false; }
virtual bool slaveOk() const { return true; }
virtual void addRequiredPrivileges(const std::string& dbname,
const BSONObj& cmdObj,
std::vector<Privilege>* out) {
ActionSet actions;
actions.addAction(ActionType::internal);
out->push_back(Privilege(ResourcePattern::forClusterResource(), actions));
}
bool run(OperationContext* txn,
const string&,
BSONObj& cmdObj,
int,
string& errmsg,
BSONObjBuilder& result) {
ShardedConnectionInfo::reset(txn->getClient());
return true;
}
} unsetShardingCommand;
class SetShardVersion : public MongodShardCommand {
public:
SetShardVersion() : MongodShardCommand("setShardVersion") {}
virtual void help( stringstream& help ) const {
help << "internal";
}
virtual bool slaveOk() const { return true; }
virtual bool isWriteCommandForConfigServer() const { return false; }
virtual void addRequiredPrivileges(const std::string& dbname,
const BSONObj& cmdObj,
std::vector<Privilege>* out) {
ActionSet actions;
actions.addAction(ActionType::internal);
out->push_back(Privilege(ResourcePattern::forClusterResource(), actions));
}
bool checkConfigOrInit(OperationContext* txn,
const string& configdb,
bool authoritative,
string& errmsg,
BSONObjBuilder& result,
bool locked = false ) const {
if ( configdb.size() == 0 ) {
errmsg = "no configdb";
return false;
}
if ( shardingState.enabled() ) {
if ( configdb == shardingState.getConfigServer() )
return true;
result.append( "configdb" , BSON( "stored" << shardingState.getConfigServer() <<
"given" << configdb ) );
errmsg = str::stream() << "mongos specified a different config database string : "
<< "stored : " << shardingState.getConfigServer()
<< " vs given : " << configdb;
return false;
}
if ( ! authoritative ) {
result.appendBool( "need_authoritative" , true );
errmsg = "first setShardVersion";
return false;
}
if ( locked ) {
ShardingState::initialize(configdb);
return true;
}
ScopedTransaction transaction(txn, MODE_X);
Lock::GlobalWrite lk(txn->lockState());
return checkConfigOrInit(txn, configdb, authoritative, errmsg, result, true);
}
bool run(OperationContext* txn,
const string&,
BSONObj& cmdObj,
int,
string& errmsg,
BSONObjBuilder& result) {
// Compatibility error for < v3.0 mongoses still active in the cluster
// TODO: Remove post-3.0
if (!cmdObj["serverID"].eoo()) {
// This mongos is too old to talk to us
string errMsg = stream() << "v3.0 mongod is incompatible with v2.6 mongos, "
<< "a v2.6 mongos may be running in the v3.0 cluster at "
<< txn->getClient()->clientAddress(false);
error() << errMsg;
return appendCommandStatus(result, Status(ErrorCodes::ProtocolError, errMsg));
}
// Steps
// 1. check basic config
// 2. extract params from command
// 3. fast check
// 4. slow check (LOCKS)
// step 1
Client* client = txn->getClient();
LastError::get(client).disable();
ShardedConnectionInfo* info = ShardedConnectionInfo::get( client, true );
bool authoritative = cmdObj.getBoolField( "authoritative" );
// check config server is ok or enable sharding
if (!checkConfigOrInit(
txn, cmdObj["configdb"].valuestrsafe(), authoritative, errmsg, result)) {
return false;
}
// check shard name is correct
if ( cmdObj["shard"].type() == String ) {
// The shard host is also sent when using setShardVersion, report this host if there
// is an error.
shardingState.gotShardNameAndHost( cmdObj["shard"].String(),
cmdObj["shardHost"].str() );
}
// Handle initial shard connection
if( cmdObj["version"].eoo() && cmdObj["init"].trueValue() ){
result.append( "initialized", true );
// Send back wire version to let mongos know what protocol we can speak
result.append( "minWireVersion", minWireVersion );
result.append( "maxWireVersion", maxWireVersion );
return true;
}
string ns = cmdObj["setShardVersion"].valuestrsafe();
if ( ns.size() == 0 ) {
errmsg = "need to specify namespace";
return false;
}
// we can run on a slave up to here
if (!repl::getGlobalReplicationCoordinator()->canAcceptWritesForDatabase(
nsToDatabase(ns))) {
result.append( "errmsg" , "not master" );
result.append( "note" , "from post init in setShardVersion" );
return false;
}
// step 2
if( ! ChunkVersion::canParseBSON( cmdObj, "version" ) ){
errmsg = "need to specify version";
return false;
}
const ChunkVersion version = ChunkVersion::fromBSON( cmdObj, "version" );
// step 3
const ChunkVersion oldVersion = info->getVersion(ns);
const ChunkVersion globalVersion = shardingState.getVersion(ns);
oldVersion.addToBSON( result, "oldVersion" );
if ( version.isWriteCompatibleWith( globalVersion )) {
// mongos and mongod agree!
if ( !oldVersion.isWriteCompatibleWith( version )) {
if ( oldVersion < globalVersion &&
oldVersion.hasEqualEpoch( globalVersion )) {
info->setVersion( ns, version );
}
else if ( authoritative ) {
// this means there was a drop and our version is reset
info->setVersion( ns, version );
}
else {
result.append( "ns", ns );
result.appendBool( "need_authoritative", true );
errmsg = "verifying drop on '" + ns + "'";
return false;
}
}
return true;
}
// step 4
// Cases below all either return OR fall-through to remote metadata reload.
const bool isDropRequested = !version.isSet() && globalVersion.isSet();
if (isDropRequested) {
if ( ! authoritative ) {
result.appendBool( "need_authoritative" , true );
result.append( "ns" , ns );
globalVersion.addToBSON( result, "globalVersion" );
errmsg = "dropping needs to be authoritative";
return false;
}
// Fall through to metadata reload below
}
else {
// Not Dropping
// TODO: Refactor all of this
if ( version < oldVersion && version.hasEqualEpoch( oldVersion ) ) {
errmsg = str::stream() << "this connection already had a newer version "
<< "of collection '" << ns << "'";
result.append( "ns" , ns );
version.addToBSON( result, "newVersion" );
globalVersion.addToBSON( result, "globalVersion" );
return false;
}
// TODO: Refactor all of this
if ( version < globalVersion && version.hasEqualEpoch( globalVersion ) ) {
while ( shardingState.inCriticalMigrateSection() ) {
log() << "waiting till out of critical section" << endl;
shardingState.waitTillNotInCriticalSection( 10 );
}
errmsg = str::stream() << "shard global version for collection is higher "
<< "than trying to set to '" << ns << "'";
result.append( "ns" , ns );
version.addToBSON( result, "version" );
globalVersion.addToBSON( result, "globalVersion" );
result.appendBool( "reloadConfig" , true );
return false;
}
if ( ! globalVersion.isSet() && ! authoritative ) {
// Needed b/c when the last chunk is moved off a shard,
// the version gets reset to zero, which should require a reload.
while ( shardingState.inCriticalMigrateSection() ) {
log() << "waiting till out of critical section" << endl;
shardingState.waitTillNotInCriticalSection( 10 );
}
// need authoritative for first look
result.append( "ns" , ns );
result.appendBool( "need_authoritative" , true );
errmsg = "first time for collection '" + ns + "'";
return false;
}
// Fall through to metadata reload below
}
ChunkVersion currVersion;
Status status = shardingState.refreshMetadataIfNeeded(txn, ns, version, &currVersion);
if (!status.isOK()) {
// The reload itself was interrupted or confused here
errmsg = str::stream() << "could not refresh metadata for " << ns
<< " with requested shard version " << version.toString()
<< ", stored shard version is " << currVersion.toString()
<< causedBy( status.reason() );
warning() << errmsg << endl;
result.append( "ns" , ns );
version.addToBSON( result, "version" );
currVersion.addToBSON( result, "globalVersion" );
result.appendBool( "reloadConfig", true );
return false;
}
else if ( !version.isWriteCompatibleWith( currVersion ) ) {
// We reloaded a version that doesn't match the version mongos was trying to
// set.
errmsg = str::stream() << "requested shard version differs from"
<< " config shard version for " << ns
<< ", requested version is " << version.toString()
<< " but found version " << currVersion.toString();
OCCASIONALLY warning() << errmsg << endl;
// WARNING: the exact fields below are important for compatibility with mongos
// version reload.
result.append( "ns" , ns );
currVersion.addToBSON( result, "globalVersion" );
// If this was a reset of a collection or the last chunk moved out, inform mongos to
// do a full reload.
if (currVersion.epoch() != version.epoch() || !currVersion.isSet() ) {
result.appendBool( "reloadConfig", true );
// Zero-version also needed to trigger full mongos reload, sadly
// TODO: Make this saner, and less impactful (full reload on last chunk is bad)
ChunkVersion( 0, 0, OID() ).addToBSON( result, "version" );
// For debugging
version.addToBSON( result, "origVersion" );
}
else {
version.addToBSON( result, "version" );
}
return false;
}
info->setVersion( ns , version );
return true;
}
} setShardVersionCmd;
class GetShardVersion : public MongodShardCommand {
public:
GetShardVersion() : MongodShardCommand("getShardVersion") {}
virtual void help( stringstream& help ) const {
help << " example: { getShardVersion : 'alleyinsider.foo' } ";
}
virtual bool isWriteCommandForConfigServer() const { return false; }
virtual Status checkAuthForCommand(ClientBasic* client,
const std::string& dbname,
const BSONObj& cmdObj) {
if (!AuthorizationSession::get(client)->isAuthorizedForActionsOnResource(
ResourcePattern::forExactNamespace(NamespaceString(parseNs(dbname, cmdObj))),
ActionType::getShardVersion)) {
return Status(ErrorCodes::Unauthorized, "Unauthorized");
}
return Status::OK();
}
virtual std::string parseNs(const std::string& dbname, const BSONObj& cmdObj) const {
return parseNsFullyQualified(dbname, cmdObj);
}
bool run(OperationContext* txn,
const string&,
BSONObj& cmdObj,
int,
string& errmsg,
BSONObjBuilder& result) {
const string ns = cmdObj["getShardVersion"].valuestrsafe();
if (ns.size() == 0) {
errmsg = "need to specify full namespace";
return false;
}
if (shardingState.enabled()) {
result.append("configServer", shardingState.getConfigServer());
}
else {
result.append("configServer", "");
}
result.appendTimestamp("global", shardingState.getVersion(ns).toLong());
ShardedConnectionInfo* const info = ShardedConnectionInfo::get(txn->getClient(), false);
result.appendBool("inShardedMode", info != NULL);
if (info) {
result.appendTimestamp("mine", info->getVersion(ns).toLong());
}
else {
result.appendTimestamp("mine", 0);
}
if (cmdObj["fullMetadata"].trueValue()) {
CollectionMetadataPtr metadata = shardingState.getCollectionMetadata(ns);
if (metadata) {
result.append("metadata", metadata->toBSON());
}
else {
result.append("metadata", BSONObj());
}
}
return true;
}
} getShardVersion;
class ShardingStateCmd : public MongodShardCommand {
public:
ShardingStateCmd() : MongodShardCommand( "shardingState" ) {}
virtual bool isWriteCommandForConfigServer() const { return true; }
virtual void addRequiredPrivileges(const std::string& dbname,
const BSONObj& cmdObj,
std::vector<Privilege>* out) {
ActionSet actions;
actions.addAction(ActionType::shardingState);
out->push_back(Privilege(ResourcePattern::forClusterResource(), actions));
}
bool run(OperationContext* txn,
const string& dbname,
BSONObj& cmdObj,
int,
string& errmsg,
BSONObjBuilder& result) {
ScopedTransaction transaction(txn, MODE_IX);
Lock::DBLock dbXLock(txn->lockState(), dbname, MODE_X);
OldClientContext ctx(txn, dbname);
shardingState.appendInfo( result );
return true;
}
} shardingStateCmd;
/**
* @ return true if not in sharded mode
or if version for this client is ok
*/
static bool shardVersionOk(Client* client,
const string& ns,
string& errmsg,
ChunkVersion& received,
ChunkVersion& wanted) {
if ( ! shardingState.enabled() )
return true;
if (!repl::getGlobalReplicationCoordinator()->canAcceptWritesForDatabase(
nsToDatabase(ns))) {
// right now connections to secondaries aren't versioned at all
return true;
}
ShardedConnectionInfo* info = ShardedConnectionInfo::get( client, false );
if ( ! info ) {
// this means the client has nothing sharded
// so this allows direct connections to do whatever they want
// which i think is the correct behavior
return true;
}
if ( info->inForceVersionOkMode() ) {
return true;
}
// TODO : all collections at some point, be sharded or not, will have a version
// (and a CollectionMetadata)
received = info->getVersion( ns );
if (ChunkVersion::isIgnoredVersion(received)) {
return true;
}
wanted = shardingState.getVersion( ns );
if( received.isWriteCompatibleWith( wanted ) ) return true;
//
// Figure out exactly why not compatible, send appropriate error message
// The versions themselves are returned in the error, so not needed in messages here
//
// Check epoch first, to send more meaningful message, since other parameters probably
// won't match either
if( ! wanted.hasEqualEpoch( received ) ){
errmsg = str::stream() << "version epoch mismatch detected for " << ns << ", "
<< "the collection may have been dropped and recreated";
return false;
}
if( ! wanted.isSet() && received.isSet() ){
errmsg = str::stream() << "this shard no longer contains chunks for " << ns << ", "
<< "the collection may have been dropped";
return false;
}
if( wanted.isSet() && ! received.isSet() ){
errmsg = str::stream() << "this shard contains versioned chunks for " << ns << ", "
<< "but no version set in request";
return false;
}
if( wanted.majorVersion() != received.majorVersion() ){
//
// Could be > or < - wanted is > if this is the source of a migration,
// wanted < if this is the target of a migration
//
errmsg = str::stream() << "version mismatch detected for " << ns << ", "
<< "stored major version " << wanted.majorVersion()
<< " does not match received " << received.majorVersion();
return false;
}
// Those are all the reasons the versions can mismatch
verify( false );
return false;
}
void ensureShardVersionOKOrThrow(Client* client, const std::string& ns) {
string errmsg;
ChunkVersion received;
ChunkVersion wanted;
if (!shardVersionOk(client, ns, errmsg, received, wanted)) {
StringBuilder sb;
sb << "[" << ns << "] shard version not ok: " << errmsg;
throw SendStaleConfigException(ns, sb.str(), received, wanted);
}
}
void usingAShardConnection( const string& addr ) {
}
void saveGLEStats(const BSONObj& result, StringData hostString) {
// Declared in cluster_last_error_info.h.
//
// This can be called in mongod, which is unfortunate. To fix this,
// we can redesign how connection pooling works on mongod for sharded operations.
}
}
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