/**
* Creates a create collection oplog entry with given optime.
*/
OplogEntry makeCreateCollectionOplogEntry(OpTime opTime,
const NamespaceString& nss = NamespaceString("test.t")) {
BSONObjBuilder bob;
bob.appendElements(opTime.toBSON());
bob.append("h", 1LL);
bob.append("op", "c");
bob.append("ns", nss.getCommandNS());
bob.append("o", BSON("create" << nss.coll()));
return OplogEntry(bob.obj());
}
/**
* Creates an insert oplog entry with given optime and namespace.
*/
OplogEntry makeInsertDocumentOplogEntry(OpTime opTime,
const NamespaceString& nss,
const BSONObj& documentToInsert) {
BSONObjBuilder bob;
bob.appendElements(opTime.toBSON());
bob.append("h", 1LL);
bob.append("op", "i");
bob.append("ns", nss.ns());
bob.append("o", documentToInsert);
return OplogEntry(bob.obj());
}
/**
* Creates an update oplog entry with given optime and namespace.
*/
OplogEntry makeUpdateDocumentOplogEntry(OpTime opTime,
const NamespaceString& nss,
const BSONObj& documentToUpdate,
const BSONObj& updatedDocument) {
BSONObjBuilder bob;
bob.appendElements(opTime.toBSON());
bob.append("h", 1LL);
bob.append("op", "u");
bob.append("ns", nss.ns());
bob.append("o2", documentToUpdate);
bob.append("o", updatedDocument);
return OplogEntry(bob.obj());
}
void ReplicationRecoveryImpl::_applyToEndOfOplog(OperationContext* opCtx,
const Timestamp& oplogApplicationStartPoint,
const Timestamp& topOfOplog) {
invariant(!oplogApplicationStartPoint.isNull());
invariant(!topOfOplog.isNull());
// Check if we have any unapplied ops in our oplog. It is important that this is done after
// deleting the ragged end of the oplog.
if (oplogApplicationStartPoint == topOfOplog) {
log() << "No oplog entries to apply for recovery. Start point is at the top of the oplog.";
return; // We've applied all the valid oplog we have.
} else if (oplogApplicationStartPoint > topOfOplog) {
severe() << "Applied op " << oplogApplicationStartPoint.toBSON()
<< " not found. Top of oplog is " << topOfOplog.toBSON() << '.';
fassertFailedNoTrace(40313);
}
log() << "Replaying stored operations from " << oplogApplicationStartPoint.toBSON()
<< " (exclusive) to " << topOfOplog.toBSON() << " (inclusive).";
OplogBufferLocalOplog oplogBuffer(oplogApplicationStartPoint);
oplogBuffer.startup(opCtx);
RecoveryOplogApplierStats stats;
auto writerPool = OplogApplier::makeWriterPool();
OplogApplier::Options options;
options.allowNamespaceNotFoundErrorsOnCrudOps = true;
options.skipWritesToOplog = true;
// During replication recovery, the stableTimestampForRecovery refers to the stable timestamp
// from which we replay the oplog.
// For startup recovery, this will be the recovery timestamp, which is the stable timestamp that
// the storage engine recovered to on startup. For rollback recovery, this will be the last
// stable timestamp, returned when we call recoverToStableTimestamp.
// We keep track of this for prepared transactions so that when we apply a commitTransaction
// oplog entry, we can check if it occurs before or after the stable timestamp and decide
// whether the operations would have already been reflected in the data.
options.stableTimestampForRecovery = oplogApplicationStartPoint;
OplogApplierImpl oplogApplier(nullptr,
&oplogBuffer,
&stats,
nullptr,
_consistencyMarkers,
_storageInterface,
options,
writerPool.get());
OplogApplier::BatchLimits batchLimits;
batchLimits.bytes = OplogApplier::calculateBatchLimitBytes(opCtx, _storageInterface);
batchLimits.ops = OplogApplier::getBatchLimitOperations();
OpTime applyThroughOpTime;
OplogApplier::Operations batch;
while (
!(batch = fassert(50763, oplogApplier.getNextApplierBatch(opCtx, batchLimits))).empty()) {
applyThroughOpTime = uassertStatusOK(oplogApplier.multiApply(opCtx, std::move(batch)));
}
stats.complete(applyThroughOpTime);
invariant(oplogBuffer.isEmpty(),
str::stream() << "Oplog buffer not empty after applying operations. Last operation "
"applied with optime: "
<< applyThroughOpTime.toBSON());
invariant(applyThroughOpTime.getTimestamp() == topOfOplog,
str::stream() << "Did not apply to top of oplog. Applied through: "
<< applyThroughOpTime.toString()
<< ". Top of oplog: "
<< topOfOplog.toString());
oplogBuffer.shutdown(opCtx);
// We may crash before setting appliedThrough. If we have a stable checkpoint, we will recover
// to that checkpoint at a replication consistent point, and applying the oplog is safe.
// If we don't have a stable checkpoint, then we must be in startup recovery, and not rollback
// recovery, because we only roll back to a stable timestamp when we have a stable checkpoint.
// Startup recovery from an unstable checkpoint only ever applies a single batch and it is safe
// to replay the batch from any point.
_consistencyMarkers->setAppliedThrough(opCtx, applyThroughOpTime);
}