예제 #1
0
        bool run(OperationContext* txn,
                 const string& dbname,
                 BSONObj& jsobj,
                 int,
                 string& errmsg,
                 BSONObjBuilder& result,
                 bool fromRepl ) {
            // calls renamecollection which does a global lock, so we must too:
            //
            Lock::GlobalWrite globalWriteLock(txn->lockState());
            WriteUnitOfWork wunit(txn->recoveryUnit());
            Client::Context ctx(txn, dbname);

            Database* db = ctx.db();

            stopIndexBuilds(txn, db, jsobj);
            BackgroundOperation::assertNoBgOpInProgForDb(dbname.c_str());

            string shortSource = jsobj.getStringField( "convertToCapped" );
            string longSource = dbname + "." + shortSource;
            double size = jsobj.getField( "size" ).number();

            if ( shortSource.empty() || size == 0 ) {
                errmsg = "invalid command spec";
                return false;
            }

            string shortTmpName = str::stream() << "tmp.convertToCapped." << shortSource;
            string longTmpName = str::stream() << dbname << "." << shortTmpName;

            if ( db->getCollection( txn, longTmpName ) ) {
                Status status = db->dropCollection( txn, longTmpName );
                if ( !status.isOK() )
                    return appendCommandStatus( result, status );
            }

            Status status = cloneCollectionAsCapped( txn, db, shortSource, shortTmpName, size, true, false );

            if ( !status.isOK() )
                return appendCommandStatus( result, status );

            verify( db->getCollection( txn, longTmpName ) );

            status = db->dropCollection( txn, longSource );
            if ( !status.isOK() )
                return appendCommandStatus( result, status );

            status = db->renameCollection( txn, longTmpName, longSource, false );
            if ( !status.isOK() )
                return appendCommandStatus( result, status );

            if (!fromRepl)
                repl::logOp(txn, "c",(dbname + ".$cmd").c_str(), jsobj);

            wunit.commit();
            return true;
        }
예제 #2
0
    void run() {
        NamespaceString source("unittests.rollback_rename_collection_src");
        NamespaceString target("unittests.rollback_rename_collection_dest");
        const ServiceContext::UniqueOperationContext opCtxPtr = cc().makeOperationContext();
        OperationContext& opCtx = *opCtxPtr;

        dropDatabase(&opCtx, source);
        dropDatabase(&opCtx, target);

        Lock::GlobalWrite globalWriteLock(&opCtx);
        OldClientContext ctx(&opCtx, source.ns());

        {
            WriteUnitOfWork uow(&opCtx);
            ASSERT(!collectionExists(&ctx, source.ns()));
            ASSERT(!collectionExists(&ctx, target.ns()));
            auto options = capped ? BSON("capped" << true << "size" << 1000) : BSONObj();
            ASSERT_OK(userCreateNS(&opCtx,
                                   ctx.db(),
                                   source.ns(),
                                   options,
                                   CollectionOptions::parseForCommand,
                                   defaultIndexes));
            uow.commit();
        }
        ASSERT(collectionExists(&ctx, source.ns()));
        ASSERT(!collectionExists(&ctx, target.ns()));

        // END OF SETUP / START OF TEST

        {
            WriteUnitOfWork uow(&opCtx);
            ASSERT_OK(renameCollection(&opCtx, source, target));
            ASSERT(!collectionExists(&ctx, source.ns()));
            ASSERT(collectionExists(&ctx, target.ns()));
            if (!rollback) {
                uow.commit();
            }
        }
        if (rollback) {
            ASSERT(collectionExists(&ctx, source.ns()));
            ASSERT(!collectionExists(&ctx, target.ns()));
        } else {
            ASSERT(!collectionExists(&ctx, source.ns()));
            ASSERT(collectionExists(&ctx, target.ns()));
        }
    }
예제 #3
0
        virtual bool run(OperationContext* txn,
                         const string& dbname,
                         BSONObj& cmdObj,
                         int,
                         string& errmsg,
                         BSONObjBuilder& result,
                         bool fromRepl) {

            ScopedTransaction transaction(txn, MODE_X);
            Lock::GlobalWrite globalWriteLock(txn->lockState());

            ReplicationCoordinator* replCoord = getGlobalReplicationCoordinator();
            if (getGlobalReplicationCoordinator()->getSettings().usingReplSets()) {
                const MemberState memberState = replCoord->getMemberState();
                if (memberState.startup()) {
                    return appendCommandStatus(result, Status(ErrorCodes::NotYetInitialized,
                                                              "no replication yet active"));
                }
                if (memberState.primary() ||
                        !replCoord->setFollowerMode(MemberState::RS_STARTUP2)) {
                    return appendCommandStatus(result, Status(ErrorCodes::NotSecondary,
                                                              "primaries cannot resync"));
                }
                BackgroundSync::get()->setInitialSyncRequestedFlag(true);
                return true;
            }

            // below this comment pertains only to master/slave replication
            if ( cmdObj.getBoolField( "force" ) ) {
                if ( !waitForSyncToFinish(txn, errmsg ) )
                    return false;
                replAllDead = "resync forced";
            }
            // TODO(dannenberg) replAllDead is bad and should be removed when masterslave is removed
            if (!replAllDead) {
                errmsg = "not dead, no need to resync";
                return false;
            }
            if ( !waitForSyncToFinish(txn, errmsg ) )
                return false;

            ReplSource::forceResyncDead( txn, "client" );
            result.append( "info", "triggered resync for all sources" );

            return true;
        }
예제 #4
0
        virtual bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {

            if ( cmdObj.firstElement().type() != Array ) {
                errmsg = "ops has to be an array";
                return false;
            }

            BSONObj ops = cmdObj.firstElement().Obj();

            {
                // check input
                BSONObjIterator i( ops );
                while ( i.more() ) {
                    BSONElement e = i.next();
                    if (!_checkOperation(e, errmsg)) {
                        return false;
                    }
                }
            }

            // SERVER-4328 todo : is global ok or does this take a long time? i believe multiple 
            // ns used so locking individually requires more analysis
            Lock::GlobalWrite globalWriteLock(txn->lockState());

            DBDirectClient db(txn);

            // Preconditions check reads the database state, so needs to be done locked
            if ( cmdObj["preCondition"].type() == Array ) {
                BSONObjIterator i( cmdObj["preCondition"].Obj() );
                while ( i.more() ) {
                    BSONObj f = i.next().Obj();

                    DBDirectClient db( txn );
                    BSONObj realres = db.findOne( f["ns"].String() , f["q"].Obj() );

                    // Apply-ops would never have a $where matcher, so use the default callback,
                    // which will throw an error if $where is found.
                    Matcher m(f["res"].Obj());
                    if ( ! m.matches( realres ) ) {
                        result.append( "got" , realres );
                        result.append( "whatFailed" , f );
                        errmsg = "pre-condition failed";
                        return false;
                    }
                }
            }

            // apply
            int num = 0;
            int errors = 0;
            
            BSONObjIterator i( ops );
            BSONArrayBuilder ab;
            const bool alwaysUpsert = cmdObj.hasField("alwaysUpsert") ?
                    cmdObj["alwaysUpsert"].trueValue() : true;
            
            while ( i.more() ) {
                BSONElement e = i.next();
                const BSONObj& temp = e.Obj();

                // Ignore 'n' operations.
                const char *opType = temp["op"].valuestrsafe();
                if (*opType == 'n') continue;

                string ns = temp["ns"].String();

                // Run operations under a nested lock as a hack to prevent yielding.
                //
                // The list of operations is supposed to be applied atomically; yielding
                // would break atomicity by allowing an interruption or a shutdown to occur
                // after only some operations are applied.  We are already locked globally
                // at this point, so taking a DBLock on the namespace creates a nested lock,
                // and yields are disallowed for operations that hold a nested lock.
                //
                // We do not have a wrapping WriteUnitOfWork so it is possible for a journal
                // commit to happen with a subset of ops applied.
                // TODO figure out what to do about this.
                Lock::DBLock lk(txn->lockState(), nsToDatabaseSubstring(ns), MODE_X);
                invariant(txn->lockState()->isRecursive());

                Client::Context ctx(txn, ns);
                bool failed = repl::applyOperation_inlock(txn,
                                                          ctx.db(),
                                                          temp,
                                                          false,
                                                          alwaysUpsert);
                ab.append(!failed);
                if ( failed )
                    errors++;

                num++;

                logOpForDbHash(ns.c_str());
            }

            result.append( "applied" , num );
            result.append( "results" , ab.arr() );

            if ( ! fromRepl ) {
                // We want this applied atomically on slaves
                // so we re-wrap without the pre-condition for speed

                string tempNS = str::stream() << dbname << ".$cmd";

                // TODO: possibly use mutable BSON to remove preCondition field
                // once it is available
                BSONObjIterator iter(cmdObj);
                BSONObjBuilder cmdBuilder;

                while (iter.more()) {
                    BSONElement elem(iter.next());
                    if (strcmp(elem.fieldName(), "preCondition") != 0) {
                        cmdBuilder.append(elem);
                    }
                }

                // We currently always logOp the command regardless of whether the individial ops
                // succeeded and rely on any failures to also happen on secondaries. This isn't
                // perfect, but it's what the command has always done and is part of its "correct"
                // behavior.
                WriteUnitOfWork wunit(txn);
                repl::logOp(txn, "c", tempNS.c_str(), cmdBuilder.done());
                wunit.commit();
            }

            if (errors != 0) {
                return false;
            }

            return true;
        }
예제 #5
0
파일: sync_tail.cpp 프로젝트: lbazz/mongo
// static
Status SyncTail::syncApply(OperationContext* txn,
                           const BSONObj& op,
                           bool convertUpdateToUpsert,
                           ApplyOperationInLockFn applyOperationInLock,
                           ApplyCommandInLockFn applyCommandInLock,
                           IncrementOpsAppliedStatsFn incrementOpsAppliedStats) {
    if (inShutdown()) {
        return Status::OK();
    }

    // Count each log op application as a separate operation, for reporting purposes
    CurOp individualOp(txn);

    const char* ns = op.getStringField("ns");
    verify(ns);

    const char* opType = op["op"].valuestrsafe();

    bool isCommand(opType[0] == 'c');
    bool isNoOp(opType[0] == 'n');

    if ((*ns == '\0') || (*ns == '.')) {
        // this is ugly
        // this is often a no-op
        // but can't be 100% sure
        if (!isNoOp) {
            error() << "skipping bad op in oplog: " << op.toString();
        }
        return Status::OK();
    }

    if (isCommand) {
        MONGO_WRITE_CONFLICT_RETRY_LOOP_BEGIN {
            // a command may need a global write lock. so we will conservatively go
            // ahead and grab one here. suboptimal. :-(
            Lock::GlobalWrite globalWriteLock(txn->lockState());

            // special case apply for commands to avoid implicit database creation
            Status status = applyCommandInLock(txn, op);
            incrementOpsAppliedStats();
            return status;
        }
        MONGO_WRITE_CONFLICT_RETRY_LOOP_END(txn, "syncApply_command", ns);
    }

    auto applyOp = [&](Database* db) {
        // For non-initial-sync, we convert updates to upserts
        // to suppress errors when replaying oplog entries.
        txn->setReplicatedWrites(false);
        DisableDocumentValidation validationDisabler(txn);

        Status status =
            applyOperationInLock(txn, db, op, convertUpdateToUpsert, incrementOpsAppliedStats);
        if (!status.isOK() && status.code() == ErrorCodes::WriteConflict) {
            throw WriteConflictException();
        }
        return status;
    };

    if (isNoOp || (opType[0] == 'i' && nsToCollectionSubstring(ns) == "system.indexes")) {
        auto opStr = isNoOp ? "syncApply_noop" : "syncApply_indexBuild";
        MONGO_WRITE_CONFLICT_RETRY_LOOP_BEGIN {
            Lock::DBLock dbLock(txn->lockState(), nsToDatabaseSubstring(ns), MODE_X);
            OldClientContext ctx(txn, ns);
            return applyOp(ctx.db());
        }
        MONGO_WRITE_CONFLICT_RETRY_LOOP_END(txn, opStr, ns);
    }
예제 #6
0
        virtual bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {

            if ( cmdObj.firstElement().type() != Array ) {
                errmsg = "ops has to be an array";
                return false;
            }

            BSONObj ops = cmdObj.firstElement().Obj();

            {
                // check input
                BSONObjIterator i( ops );
                while ( i.more() ) {
                    BSONElement e = i.next();
                    if ( e.type() == Object )
                        continue;
                    errmsg = "op not an object: ";
                    errmsg += e.fieldName();
                    return false;
                }
            }

            // SERVER-4328 todo : is global ok or does this take a long time? i believe multiple 
            // ns used so locking individually requires more analysis
            Lock::GlobalWrite globalWriteLock(txn->lockState());

            // Preconditions check reads the database state, so needs to be done locked
            if ( cmdObj["preCondition"].type() == Array ) {
                BSONObjIterator i( cmdObj["preCondition"].Obj() );
                while ( i.more() ) {
                    BSONObj f = i.next().Obj();

                    DBDirectClient db( txn );
                    BSONObj realres = db.findOne( f["ns"].String() , f["q"].Obj() );

                    // Apply-ops would never have a $where matcher, so use the default callback,
                    // which will throw an error if $where is found.
                    Matcher m(f["res"].Obj());
                    if ( ! m.matches( realres ) ) {
                        result.append( "got" , realres );
                        result.append( "whatFailed" , f );
                        errmsg = "pre-condition failed";
                        return false;
                    }
                }
            }

            // apply
            int num = 0;
            int errors = 0;
            
            BSONObjIterator i( ops );
            BSONArrayBuilder ab;
            const bool alwaysUpsert = cmdObj.hasField("alwaysUpsert") ?
                    cmdObj["alwaysUpsert"].trueValue() : true;
            
            while ( i.more() ) {
                BSONElement e = i.next();
                const BSONObj& temp = e.Obj();

                string ns = temp["ns"].String();

                // Run operations under a nested lock as a hack to prevent them from yielding.
                //
                // The list of operations is supposed to be applied atomically; yielding would break
                // atomicity by allowing an interruption or a shutdown to occur after only some
                // operations are applied.  We are already locked globally at this point, so taking
                // a DBWrite on the namespace creates a nested lock, and yields are disallowed for
                // operations that hold a nested lock.
                Lock::DBWrite lk(txn->lockState(), ns);
                invariant(txn->lockState()->isRecursive());

                Client::Context ctx(ns);
                bool failed = repl::applyOperation_inlock(txn,
                                                             ctx.db(),
                                                             temp,
                                                             false,
                                                             alwaysUpsert);
                ab.append(!failed);
                if ( failed )
                    errors++;

                num++;

                logOpForDbHash(ns.c_str());
            }

            result.append( "applied" , num );
            result.append( "results" , ab.arr() );

            if ( ! fromRepl ) {
                // We want this applied atomically on slaves
                // so we re-wrap without the pre-condition for speed

                string tempNS = str::stream() << dbname << ".$cmd";

                // TODO: possibly use mutable BSON to remove preCondition field
                // once it is available
                BSONObjIterator iter(cmdObj);
                BSONObjBuilder cmdBuilder;

                while (iter.more()) {
                    BSONElement elem(iter.next());
                    if (strcmp(elem.fieldName(), "preCondition") != 0) {
                        cmdBuilder.append(elem);
                    }
                }

                repl::logOp(txn, "c", tempNS.c_str(), cmdBuilder.done());
            }

            return errors == 0;
        }
예제 #7
0
        virtual bool run(OperationContext* txn,
                         const string& dbname,
                         BSONObj& cmdObj,
                         int,
                         string& errmsg,
                         BSONObjBuilder& result,
                         bool fromRepl) {
            Lock::GlobalWrite globalWriteLock(txn->lockState());
            string source = cmdObj.getStringField( name.c_str() );
            string target = cmdObj.getStringField( "to" );

            // We stay in source context the whole time. This is mostly to set the CurOp namespace.
            Client::Context ctx(txn, source);

            if ( !NamespaceString::validCollectionComponent(target.c_str()) ) {
                errmsg = "invalid collection name: " + target;
                return false;
            }
            if ( source.empty() || target.empty() ) {
                errmsg = "invalid command syntax";
                return false;
            }

            if (!fromRepl) { // If it got through on the master, need to allow it here too
                Status sourceStatus = userAllowedWriteNS(source);
                if (!sourceStatus.isOK()) {
                    errmsg = "error with source namespace: " + sourceStatus.reason();
                    return false;
                }

                Status targetStatus = userAllowedWriteNS(target);
                if (!targetStatus.isOK()) {
                    errmsg = "error with target namespace: " + targetStatus.reason();
                    return false;
                }
            }

            if (NamespaceString(source).coll() == "system.indexes"
                || NamespaceString(target).coll() == "system.indexes") {
                errmsg = "renaming system.indexes is not allowed";
                return false;
            }

            Database* const sourceDB = dbHolder().get(txn, nsToDatabase(source));
            Collection* const sourceColl = sourceDB ? sourceDB->getCollection(txn, source)
                                                    : NULL;
            if (!sourceColl) {
                errmsg = "source namespace does not exist";
                return false;
            }

            {
                // Ensure that collection name does not exceed maximum length.
                // Ensure that index names do not push the length over the max.
                // Iterator includes unfinished indexes.
                IndexCatalog::IndexIterator sourceIndIt =
                    sourceColl->getIndexCatalog()->getIndexIterator( txn, true );
                int longestIndexNameLength = 0;
                while ( sourceIndIt.more() ) {
                    int thisLength = sourceIndIt.next()->indexName().length();
                    if ( thisLength > longestIndexNameLength )
                        longestIndexNameLength = thisLength;
                }

                unsigned int longestAllowed =
                    min(int(NamespaceString::MaxNsCollectionLen),
                        int(NamespaceString::MaxNsLen) - 2/*strlen(".$")*/ - longestIndexNameLength);
                if (target.size() > longestAllowed) {
                    StringBuilder sb;
                    sb << "collection name length of " << target.size()
                       << " exceeds maximum length of " << longestAllowed
                       << ", allowing for index names";
                    errmsg = sb.str();
                    return false;
                }
            }

            const std::vector<BSONObj> indexesInProg = stopIndexBuilds(txn, sourceDB, cmdObj);
            // Dismissed on success
            ScopeGuard indexBuildRestorer = MakeGuard(IndexBuilder::restoreIndexes, indexesInProg);

            Database* const targetDB = dbHolder().openDb(txn, nsToDatabase(target));

            {
                WriteUnitOfWork wunit(txn);

                // Check if the target namespace exists and if dropTarget is true.
                // If target exists and dropTarget is not true, return false.
                if (targetDB->getCollection(txn, target)) {
                    if (!cmdObj["dropTarget"].trueValue()) {
                        errmsg = "target namespace exists";
                        return false;
                    }

                    Status s = targetDB->dropCollection(txn, target);
                    if ( !s.isOK() ) {
                        errmsg = s.toString();
                        return false;
                    }
                }

                // If we are renaming in the same database, just
                // rename the namespace and we're done.
                if (sourceDB == targetDB) {
                    Status s = targetDB->renameCollection(txn,
                                                          source,
                                                          target,
                                                          cmdObj["stayTemp"].trueValue() );
                    if (!s.isOK()) {
                        return appendCommandStatus(result, s);
                    }

                    if (!fromRepl) {
                        repl::logOp(txn, "c", (dbname + ".$cmd").c_str(), cmdObj);
                    }

                    wunit.commit();
                    indexBuildRestorer.Dismiss();
                    return true;
                }

                wunit.commit();
            }

            // If we get here, we are renaming across databases, so we must copy all the data and
            // indexes, then remove the source collection.

            // Create the target collection. It will be removed if we fail to copy the collection.
            // TODO use a temp collection and unset the temp flag on success.
            Collection* targetColl = NULL;
            {
                CollectionOptions options;
                options.setNoIdIndex();

                if (sourceColl->isCapped()) {
                    const CollectionOptions sourceOpts =
                        sourceColl->getCatalogEntry()->getCollectionOptions(txn);

                    options.capped = true;
                    options.cappedSize = sourceOpts.cappedSize;
                    options.cappedMaxDocs = sourceOpts.cappedMaxDocs;
                }

                WriteUnitOfWork wunit(txn);

                // No logOp necessary because the entire renameCollection command is one logOp.
                targetColl = targetDB->createCollection(txn, target, options);
                if (!targetColl) {
                    errmsg = "Failed to create target collection.";
                    return false;
                }

                wunit.commit();
            }

            // Dismissed on success
            ScopeGuard targetCollectionDropper = MakeGuard(dropCollection, txn, targetDB, target);

            MultiIndexBlock indexer(txn, targetColl);
            indexer.allowInterruption();

            // Copy the index descriptions from the source collection, adjusting the ns field.
            {
                std::vector<BSONObj> indexesToCopy;
                IndexCatalog::IndexIterator sourceIndIt =
                    sourceColl->getIndexCatalog()->getIndexIterator( txn, true );
                while (sourceIndIt.more()) {
                    const BSONObj currIndex = sourceIndIt.next()->infoObj();

                    // Process the source index.
                    BSONObjBuilder newIndex;
                    newIndex.append("ns", target);
                    newIndex.appendElementsUnique(currIndex);
                    indexesToCopy.push_back(newIndex.obj());
                }
                indexer.init(indexesToCopy);
            }

            {
                // Copy over all the data from source collection to target collection.
                boost::scoped_ptr<RecordIterator> sourceIt(sourceColl->getIterator(txn));
                while (!sourceIt->isEOF()) {
                    txn->checkForInterrupt(false);

                    const BSONObj obj = sourceColl->docFor(txn, sourceIt->getNext());

                    WriteUnitOfWork wunit(txn);
                    // No logOp necessary because the entire renameCollection command is one logOp.
                    Status status = targetColl->insertDocument(txn, obj, &indexer, true).getStatus();
                    if (!status.isOK())
                        return appendCommandStatus(result, status);
                    wunit.commit();
                }
            }

            Status status = indexer.doneInserting();
            if (!status.isOK())
                return appendCommandStatus(result, status);

            {
                // Getting here means we successfully built the target copy. We now remove the
                // source collection and finalize the rename.
                WriteUnitOfWork wunit(txn);

                Status status = sourceDB->dropCollection(txn, source);
                if (!status.isOK())
                    return appendCommandStatus(result, status);

                indexer.commit();

                if (!fromRepl) {
                    repl::logOp(txn, "c", (dbname + ".$cmd").c_str(), cmdObj);
                }

                wunit.commit();
            }

            indexBuildRestorer.Dismiss();
            targetCollectionDropper.Dismiss();
            return true;
        }
예제 #8
0
Status renameCollection(OperationContext* txn,
                        const NamespaceString& source,
                        const NamespaceString& target,
                        bool dropTarget,
                        bool stayTemp) {
    DisableDocumentValidation validationDisabler(txn);

    ScopedTransaction transaction(txn, MODE_X);
    Lock::GlobalWrite globalWriteLock(txn->lockState());
    // We stay in source context the whole time. This is mostly to set the CurOp namespace.
    OldClientContext ctx(txn, source.ns());

    bool userInitiatedWritesAndNotPrimary = txn->writesAreReplicated() &&
        !repl::getGlobalReplicationCoordinator()->canAcceptWritesFor(source);

    if (userInitiatedWritesAndNotPrimary) {
        return Status(ErrorCodes::NotMaster,
                      str::stream() << "Not primary while renaming collection " << source.ns()
                                    << " to "
                                    << target.ns());
    }

    Database* const sourceDB = dbHolder().get(txn, source.db());
    Collection* const sourceColl = sourceDB ? sourceDB->getCollection(source.ns()) : nullptr;
    if (!sourceColl) {
        return Status(ErrorCodes::NamespaceNotFound, "source namespace does not exist");
    }

    {
        // Ensure that collection name does not exceed maximum length.
        // Ensure that index names do not push the length over the max.
        // Iterator includes unfinished indexes.
        IndexCatalog::IndexIterator sourceIndIt =
            sourceColl->getIndexCatalog()->getIndexIterator(txn, true);
        int longestIndexNameLength = 0;
        while (sourceIndIt.more()) {
            int thisLength = sourceIndIt.next()->indexName().length();
            if (thisLength > longestIndexNameLength)
                longestIndexNameLength = thisLength;
        }

        unsigned int longestAllowed =
            std::min(int(NamespaceString::MaxNsCollectionLen),
                     int(NamespaceString::MaxNsLen) - 2 /*strlen(".$")*/ - longestIndexNameLength);
        if (target.size() > longestAllowed) {
            StringBuilder sb;
            sb << "collection name length of " << target.size() << " exceeds maximum length of "
               << longestAllowed << ", allowing for index names";
            return Status(ErrorCodes::InvalidLength, sb.str());
        }
    }

    BackgroundOperation::assertNoBgOpInProgForNs(source.ns());

    Database* const targetDB = dbHolder().openDb(txn, target.db());

    {
        WriteUnitOfWork wunit(txn);

        // Check if the target namespace exists and if dropTarget is true.
        // If target exists and dropTarget is not true, return false.
        if (targetDB->getCollection(target)) {
            if (!dropTarget) {
                return Status(ErrorCodes::NamespaceExists, "target namespace exists");
            }

            Status s = targetDB->dropCollection(txn, target.ns());
            if (!s.isOK()) {
                return s;
            }
        }

        // If we are renaming in the same database, just
        // rename the namespace and we're done.
        if (sourceDB == targetDB) {
            Status s = targetDB->renameCollection(txn, source.ns(), target.ns(), stayTemp);
            if (!s.isOK()) {
                return s;
            }

            getGlobalServiceContext()->getOpObserver()->onRenameCollection(
                txn, NamespaceString(source), NamespaceString(target), dropTarget, stayTemp);

            wunit.commit();
            return Status::OK();
        }

        wunit.commit();
    }

    // If we get here, we are renaming across databases, so we must copy all the data and
    // indexes, then remove the source collection.

    // Create the target collection. It will be removed if we fail to copy the collection.
    // TODO use a temp collection and unset the temp flag on success.
    Collection* targetColl = nullptr;
    {
        CollectionOptions options = sourceColl->getCatalogEntry()->getCollectionOptions(txn);

        WriteUnitOfWork wunit(txn);

        // No logOp necessary because the entire renameCollection command is one logOp.
        bool shouldReplicateWrites = txn->writesAreReplicated();
        txn->setReplicatedWrites(false);
        targetColl = targetDB->createCollection(txn,
                                                target.ns(),
                                                options,
                                                false);  // _id index build with others later.
        txn->setReplicatedWrites(shouldReplicateWrites);
        if (!targetColl) {
            return Status(ErrorCodes::OutOfDiskSpace, "Failed to create target collection.");
        }

        wunit.commit();
    }

    // Dismissed on success
    ScopeGuard targetCollectionDropper = MakeGuard(dropCollection, txn, targetDB, target.ns());

    MultiIndexBlock indexer(txn, targetColl);
    indexer.allowInterruption();

    // Copy the index descriptions from the source collection, adjusting the ns field.
    {
        std::vector<BSONObj> indexesToCopy;
        IndexCatalog::IndexIterator sourceIndIt =
            sourceColl->getIndexCatalog()->getIndexIterator(txn, true);
        while (sourceIndIt.more()) {
            const BSONObj currIndex = sourceIndIt.next()->infoObj();

            // Process the source index.
            BSONObjBuilder newIndex;
            newIndex.append("ns", target.ns());
            newIndex.appendElementsUnique(currIndex);
            indexesToCopy.push_back(newIndex.obj());
        }
        indexer.init(indexesToCopy);
    }

    {
        // Copy over all the data from source collection to target collection.
        auto cursor = sourceColl->getCursor(txn);
        while (auto record = cursor->next()) {
            txn->checkForInterrupt();

            const auto obj = record->data.releaseToBson();

            WriteUnitOfWork wunit(txn);
            // No logOp necessary because the entire renameCollection command is one logOp.
            bool shouldReplicateWrites = txn->writesAreReplicated();
            txn->setReplicatedWrites(false);
            Status status = targetColl->insertDocument(txn, obj, &indexer, true);
            txn->setReplicatedWrites(shouldReplicateWrites);
            if (!status.isOK())
                return status;
            wunit.commit();
        }
    }

    Status status = indexer.doneInserting();
    if (!status.isOK())
        return status;

    {
        // Getting here means we successfully built the target copy. We now remove the
        // source collection and finalize the rename.
        WriteUnitOfWork wunit(txn);

        bool shouldReplicateWrites = txn->writesAreReplicated();
        txn->setReplicatedWrites(false);
        Status status = sourceDB->dropCollection(txn, source.ns());
        txn->setReplicatedWrites(shouldReplicateWrites);
        if (!status.isOK())
            return status;

        indexer.commit();

        getGlobalServiceContext()->getOpObserver()->onRenameCollection(
            txn, NamespaceString(source), NamespaceString(target), dropTarget, stayTemp);

        wunit.commit();
    }

    targetCollectionDropper.Dismiss();
    return Status::OK();
}
예제 #9
0
파일: apply_ops.cpp 프로젝트: ambroff/mongo
        virtual bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {

            if ( cmdObj.firstElement().type() != Array ) {
                errmsg = "ops has to be an array";
                return false;
            }

            BSONObj ops = cmdObj.firstElement().Obj();

            {
                // check input
                BSONObjIterator i( ops );
                while ( i.more() ) {
                    BSONElement e = i.next();
                    if (!_checkOperation(e, errmsg)) {
                        return false;
                    }
                }
            }

            // SERVER-4328 todo : is global ok or does this take a long time? i believe multiple 
            // ns used so locking individually requires more analysis
            ScopedTransaction scopedXact(txn, MODE_X);
            Lock::GlobalWrite globalWriteLock(txn->lockState());

            if (!fromRepl &&
                !repl::getGlobalReplicationCoordinator()->canAcceptWritesForDatabase(dbname)) {
                return appendCommandStatus(result, Status(ErrorCodes::NotMaster, str::stream()
                    << "Not primary while applying ops to database " << dbname));
            }

            // Preconditions check reads the database state, so needs to be done locked
            if ( cmdObj["preCondition"].type() == Array ) {
                BSONObjIterator i( cmdObj["preCondition"].Obj() );
                while ( i.more() ) {
                    BSONObj f = i.next().Obj();

                    DBDirectClient db( txn );
                    BSONObj realres = db.findOne( f["ns"].String() , f["q"].Obj() );

                    // Apply-ops would never have a $where matcher, so use the default callback,
                    // which will throw an error if $where is found.
                    Matcher m(f["res"].Obj());
                    if ( ! m.matches( realres ) ) {
                        result.append( "got" , realres );
                        result.append( "whatFailed" , f );
                        errmsg = "pre-condition failed";
                        return false;
                    }
                }
            }

            // apply
            int num = 0;
            int errors = 0;
            
            BSONObjIterator i( ops );
            BSONArrayBuilder ab;
            const bool alwaysUpsert = cmdObj.hasField("alwaysUpsert") ?
                    cmdObj["alwaysUpsert"].trueValue() : true;
            
            while ( i.more() ) {
                BSONElement e = i.next();
                const BSONObj& temp = e.Obj();

                // Ignore 'n' operations.
                const char *opType = temp["op"].valuestrsafe();
                if (*opType == 'n') continue;

                const string ns = temp["ns"].String();

                // Run operations under a nested lock as a hack to prevent yielding.
                //
                // The list of operations is supposed to be applied atomically; yielding
                // would break atomicity by allowing an interruption or a shutdown to occur
                // after only some operations are applied.  We are already locked globally
                // at this point, so taking a DBLock on the namespace creates a nested lock,
                // and yields are disallowed for operations that hold a nested lock.
                //
                // We do not have a wrapping WriteUnitOfWork so it is possible for a journal
                // commit to happen with a subset of ops applied.
                // TODO figure out what to do about this.
                Lock::GlobalWrite globalWriteLockDisallowTempRelease(txn->lockState());

                // Ensures that yielding will not happen (see the comment above).
                DEV {
                    Locker::LockSnapshot lockSnapshot;
                    invariant(!txn->lockState()->saveLockStateAndUnlock(&lockSnapshot));
                };

                OldClientContext ctx(txn, ns);

                Status status(ErrorCodes::InternalError, "");
                while (true) {
                    try {
                        // We assume that in the WriteConflict retry case, either the op rolls back
                        // any changes it makes or is otherwise safe to rerun.
                        status =
                            repl::applyOperation_inlock(txn, ctx.db(), temp, false, alwaysUpsert);
                        break;
                    }
                    catch (const WriteConflictException& wce) {
                        LOG(2) << "WriteConflictException in applyOps command, retrying.";
                        txn->recoveryUnit()->commitAndRestart();
                        continue;
                    }
                }

                ab.append(status.isOK());
                if (!status.isOK()) {
                    errors++;
                }

                num++;

                WriteUnitOfWork wuow(txn);
                logOpForDbHash(txn, ns.c_str());
                wuow.commit();
            }

            result.append( "applied" , num );
            result.append( "results" , ab.arr() );

            if ( ! fromRepl ) {
                // We want this applied atomically on slaves
                // so we re-wrap without the pre-condition for speed

                string tempNS = str::stream() << dbname << ".$cmd";

                // TODO: possibly use mutable BSON to remove preCondition field
                // once it is available
                BSONObjIterator iter(cmdObj);
                BSONObjBuilder cmdBuilder;

                while (iter.more()) {
                    BSONElement elem(iter.next());
                    if (strcmp(elem.fieldName(), "preCondition") != 0) {
                        cmdBuilder.append(elem);
                    }
                }

                const BSONObj cmdRewritten = cmdBuilder.done();

                // We currently always logOp the command regardless of whether the individial ops
                // succeeded and rely on any failures to also happen on secondaries. This isn't
                // perfect, but it's what the command has always done and is part of its "correct"
                // behavior.
                while (true) {
                    try {
                        WriteUnitOfWork wunit(txn);
                        getGlobalEnvironment()->getOpObserver()->onApplyOps(txn,
                                                                            tempNS,
                                                                            cmdRewritten);
                        wunit.commit();
                        break;
                    }
                    catch (const WriteConflictException& wce) {
                        LOG(2) <<
                            "WriteConflictException while logging applyOps command, retrying.";
                        txn->recoveryUnit()->commitAndRestart();
                        continue;
                    }
                }
            }

            if (errors != 0) {
                return false;
            }

            return true;
        }