void run() {
Client::initThread("ReplBatcher");
OperationContextImpl txn;
auto replCoord = ReplicationCoordinator::get(&txn);
while (!_inShutdown.load()) {
Timer batchTimer;
OpQueue ops;
// tryPopAndWaitForMore returns true when we need to end a batch early
while (!_syncTail->tryPopAndWaitForMore(&txn, &ops) &&
(ops.getSize() < replBatchLimitBytes) && !_inShutdown.load()) {
int now = batchTimer.seconds();
// apply replication batch limits
if (!ops.empty()) {
if (now > replBatchLimitSeconds)
break;
if (ops.getDeque().size() > replBatchLimitOperations)
break;
}
const int slaveDelaySecs = durationCount<Seconds>(replCoord->getSlaveDelaySecs());
if (!ops.empty() && slaveDelaySecs > 0) {
const BSONObj lastOp = ops.back().raw;
const unsigned int opTimestampSecs = lastOp["ts"].timestamp().getSecs();
// Stop the batch as the lastOp is too new to be applied. If we continue
// on, we can get ops that are way ahead of the delay and this will
// make this thread sleep longer when handleSlaveDelay is called
// and apply ops much sooner than we like.
if (opTimestampSecs > static_cast<unsigned int>(time(0) - slaveDelaySecs)) {
break;
}
}
if (MONGO_FAIL_POINT(rsSyncApplyStop)) {
break;
}
// keep fetching more ops as long as we haven't filled up a full batch yet
}
// For pausing replication in tests
while (MONGO_FAIL_POINT(rsSyncApplyStop) && !_inShutdown.load()) {
sleepmillis(0);
}
stdx::unique_lock<stdx::mutex> lk(_mutex);
while (!_ops.empty()) {
// Block until the previous batch has been taken.
if (_inShutdown.load())
return;
_cv.wait(lk);
}
_ops = std::move(ops);
_cv.notify_all();
}
}
/* applies oplog from "now" until endOpTime using the applier threads for initial sync*/
void SyncTail::_applyOplogUntil(OperationContext* txn, const OpTime& endOpTime) {
unsigned long long bytesApplied = 0;
unsigned long long entriesApplied = 0;
while (true) {
OpQueue ops;
OperationContextImpl ctx;
while (!tryPopAndWaitForMore(&ops, getGlobalReplicationCoordinator())) {
// nothing came back last time, so go again
if (ops.empty()) continue;
// Check if we reached the end
const BSONObj currentOp = ops.back();
const OpTime currentOpTime = currentOp["ts"]._opTime();
// When we reach the end return this batch
if (currentOpTime == endOpTime) {
break;
}
else if (currentOpTime > endOpTime) {
severe() << "Applied past expected end " << endOpTime << " to " << currentOpTime
<< " without seeing it. Rollback?" << rsLog;
fassertFailedNoTrace(18693);
}
// apply replication batch limits
if (ops.getSize() > replBatchLimitBytes)
break;
if (ops.getDeque().size() > replBatchLimitOperations)
break;
};
if (ops.empty()) {
severe() << "got no ops for batch...";
fassertFailedNoTrace(18692);
}
const BSONObj lastOp = ops.back().getOwned();
// Tally operation information
bytesApplied += ops.getSize();
entriesApplied += ops.getDeque().size();
multiApply(ops.getDeque());
OpTime lastOpTime = applyOpsToOplog(&ops.getDeque());
// if the last op applied was our end, return
if (lastOpTime == endOpTime) {
LOG(1) << "SyncTail applied " << entriesApplied
<< " entries (" << bytesApplied << " bytes)"
<< " and finished at opTime " << endOpTime.toStringPretty();
return;
}
} // end of while (true)
}
BSONObj SyncTail::oplogApplySegment(const BSONObj& applyGTEObj, const BSONObj& minValidObj,
MultiSyncApplyFunc func) {
OpTime applyGTE = applyGTEObj["ts"]._opTime();
OpTime minValid = minValidObj["ts"]._opTime();
// We have to keep track of the last op applied to the data, because there's no other easy
// way of getting this data synchronously. Batches may go past minValidObj, so we need to
// know to bump minValid past minValidObj.
BSONObj lastOp = applyGTEObj;
OpTime ts = applyGTE;
time_t start = time(0);
time_t now = start;
unsigned long long n = 0, lastN = 0;
while( ts < minValid ) {
OpQueue ops;
while (ops.getSize() < replBatchLimitBytes) {
if (tryPopAndWaitForMore(&ops)) {
break;
}
// apply replication batch limits
now = time(0);
if (!ops.empty()) {
if (now > replBatchLimitSeconds)
break;
if (ops.getDeque().size() > replBatchLimitOperations)
break;
}
}
setOplogVersion(ops.getDeque().front());
multiApply(ops.getDeque(), func);
n += ops.getDeque().size();
if ( n > lastN + 1000 ) {
if (now - start > 10) {
// simple progress metering
log() << "replSet initialSyncOplogApplication applied "
<< n << " operations, synced to "
<< ts.toStringPretty() << rsLog;
start = now;
lastN = n;
}
}
// we want to keep a record of the last op applied, to compare with minvalid
lastOp = ops.getDeque().back();
OpTime tempTs = lastOp["ts"]._opTime();
applyOpsToOplog(&ops.getDeque());
ts = tempTs;
}
return lastOp;
}
//BOOST_AUTO_TEST_CASE(opqueue_test)
int test_main(int, char *[])
{
OpQueue q;
Op::Ptr p(new Op(1, std::bind(&foo, eng::Library::Ptr())));
BOOST_CHECK(q.empty());
tid_t old_id = p->id();
Op* old_ptr = p.get();
q.add(p);
BOOST_CHECK(!q.empty());
BOOST_CHECK(p == nullptr);
Op::Ptr p2(q.pop());
BOOST_CHECK(p2.get() == old_ptr);
BOOST_CHECK(p2->id() == old_id);
BOOST_CHECK(q.empty());
return 0;
}
/* tail an oplog. ok to return, will be re-called. */
void SyncTail::oplogApplication() {
ReplicationCoordinator* replCoord = getGlobalReplicationCoordinator();
ApplyBatchFinalizer finalizer(replCoord);
OperationContextImpl txn;
OpTime originalEndOpTime(getMinValid(&txn).end);
while (!inShutdown()) {
OpQueue ops;
Timer batchTimer;
int lastTimeChecked = 0;
do {
int now = batchTimer.seconds();
// apply replication batch limits
if (!ops.empty()) {
if (now > replBatchLimitSeconds)
break;
if (ops.getDeque().size() > replBatchLimitOperations)
break;
}
// occasionally check some things
// (always checked in the first iteration of this do-while loop, because
// ops is empty)
if (ops.empty() || now > lastTimeChecked) {
BackgroundSync* bgsync = BackgroundSync::get();
if (bgsync->getInitialSyncRequestedFlag()) {
// got a resync command
return;
}
lastTimeChecked = now;
// can we become secondary?
// we have to check this before calling mgr, as we must be a secondary to
// become primary
tryToGoLiveAsASecondary(&txn, replCoord);
}
const int slaveDelaySecs = durationCount<Seconds>(replCoord->getSlaveDelaySecs());
if (!ops.empty() && slaveDelaySecs > 0) {
const BSONObj lastOp = ops.back();
const unsigned int opTimestampSecs = lastOp["ts"].timestamp().getSecs();
// Stop the batch as the lastOp is too new to be applied. If we continue
// on, we can get ops that are way ahead of the delay and this will
// make this thread sleep longer when handleSlaveDelay is called
// and apply ops much sooner than we like.
if (opTimestampSecs > static_cast<unsigned int>(time(0) - slaveDelaySecs)) {
break;
}
}
if (MONGO_FAIL_POINT(rsSyncApplyStop)) {
break;
}
// keep fetching more ops as long as we haven't filled up a full batch yet
} while (!tryPopAndWaitForMore(&txn, &ops, replCoord) && // tryPopAndWaitForMore returns
// true when we need to end a
// batch early
(ops.getSize() < replBatchLimitBytes) &&
!inShutdown());
// For pausing replication in tests
while (MONGO_FAIL_POINT(rsSyncApplyStop)) {
sleepmillis(0);
if (inShutdown())
return;
}
if (ops.empty()) {
continue;
}
const BSONObj lastOp = ops.back();
handleSlaveDelay(lastOp);
// Set minValid to the last OpTime that needs to be applied, in this batch or from the
// (last) failed batch, whichever is larger.
// This will cause this node to go into RECOVERING state
// if we should crash and restart before updating finishing.
const OpTime start(getLastSetTimestamp(), OpTime::kUninitializedTerm);
// Take the max of the first endOptime (if we recovered) and the end of our batch.
const auto lastOpTime = fassertStatusOK(28773, OpTime::parseFromOplogEntry(lastOp));
// Setting end to the max of originalEndOpTime and lastOpTime (the end of the batch)
// ensures that we keep pushing out the point where we can become consistent
// and allow reads. If we recover and end up doing smaller batches we must pass the
// originalEndOpTime before we are good.
//
// For example:
// batch apply, 20-40, end = 40
// batch failure,
// restart
// batch apply, 20-25, end = max(25, 40) = 40
// batch apply, 25-45, end = 45
const OpTime end(std::max(originalEndOpTime, lastOpTime));
// This write will not journal/checkpoint.
setMinValid(&txn, {start, end});
OpTime finalOpTime = multiApply(&txn, ops);
setNewTimestamp(finalOpTime.getTimestamp());
setMinValid(&txn, end, DurableRequirement::None);
finalizer.record(finalOpTime);
}
}
/* tail an oplog. ok to return, will be re-called. */
void SyncTail::oplogApplication() {
while( 1 ) {
OpQueue ops;
verify( !Lock::isLocked() );
Timer batchTimer;
int lastTimeChecked = 0;
do {
if (theReplSet->isPrimary()) {
massert(16620, "there are ops to sync, but I'm primary", ops.empty());
return;
}
int now = batchTimer.seconds();
// apply replication batch limits
if (!ops.empty()) {
if (now > replBatchLimitSeconds)
break;
if (ops.getDeque().size() > replBatchLimitOperations)
break;
}
// occasionally check some things
// (always checked in the first iteration of this do-while loop, because
// ops is empty)
if (ops.empty() || now > lastTimeChecked) {
{
boost::unique_lock<boost::mutex> lock(theReplSet->initialSyncMutex);
if (theReplSet->initialSyncRequested) {
// got a resync command
return;
}
}
lastTimeChecked = now;
// can we become secondary?
// we have to check this before calling mgr, as we must be a secondary to
// become primary
if (!theReplSet->isSecondary()) {
OpTime minvalid;
OperationContextImpl txn;
theReplSet->tryToGoLiveAsASecondary(&txn, minvalid);
}
// normally msgCheckNewState gets called periodically, but in a single node
// replset there are no heartbeat threads, so we do it here to be sure. this is
// relevant if the singleton member has done a stepDown() and needs to come back
// up.
if (theReplSet->config().members.size() == 1 &&
theReplSet->myConfig().potentiallyHot()) {
Manager* mgr = theReplSet->mgr;
// When would mgr be null? During replsettest'ing, in which case we should
// fall through and actually apply ops as if we were a real secondary.
if (mgr) {
mgr->send(stdx::bind(&Manager::msgCheckNewState, theReplSet->mgr));
sleepsecs(1);
// There should never be ops to sync in a 1-member set, anyway
return;
}
}
}
const int slaveDelaySecs = theReplSet->myConfig().slaveDelay;
if (!ops.empty() && slaveDelaySecs > 0) {
const BSONObj& lastOp = ops.getDeque().back();
const unsigned int opTimestampSecs = lastOp["ts"]._opTime().getSecs();
// Stop the batch as the lastOp is too new to be applied. If we continue
// on, we can get ops that are way ahead of the delay and this will
// make this thread sleep longer when handleSlaveDelay is called
// and apply ops much sooner than we like.
if (opTimestampSecs > static_cast<unsigned int>(time(0) - slaveDelaySecs)) {
break;
}
}
// keep fetching more ops as long as we haven't filled up a full batch yet
} while (!tryPopAndWaitForMore(&ops) && // tryPopAndWaitForMore returns true
// when we need to end a batch early
(ops.getSize() < replBatchLimitBytes));
// For pausing replication in tests
while (MONGO_FAIL_POINT(rsSyncApplyStop)) {
sleepmillis(0);
}
const BSONObj& lastOp = ops.getDeque().back();
setOplogVersion(lastOp);
handleSlaveDelay(lastOp);
// Set minValid to the last op to be applied in this next batch.
// This will cause this node to go into RECOVERING state
// if we should crash and restart before updating the oplog
theReplSet->setMinValid(lastOp);
if (BackgroundSync::get()->isAssumingPrimary()) {
LOG(1) << "about to apply batch up to optime: "
<< ops.getDeque().back()["ts"]._opTime().toStringPretty();
}
multiApply(ops.getDeque(), multiSyncApply);
if (BackgroundSync::get()->isAssumingPrimary()) {
LOG(1) << "about to update oplog to optime: "
<< ops.getDeque().back()["ts"]._opTime().toStringPretty();
}
applyOpsToOplog(&ops.getDeque());
// If we're just testing (no manager), don't keep looping if we exhausted the bgqueue
if (!theReplSet->mgr) {
BSONObj op;
if (!peek(&op)) {
return;
}
}
}
}
/* applies oplog from "now" until endOpTime using the applier threads for initial sync*/
void InitialSync::_applyOplogUntil(OperationContext* txn, const OpTime& endOpTime) {
unsigned long long bytesApplied = 0;
unsigned long long entriesApplied = 0;
while (true) {
OpQueue ops;
auto replCoord = repl::ReplicationCoordinator::get(txn);
while (!tryPopAndWaitForMore(txn, &ops)) {
// nothing came back last time, so go again
if (ops.empty())
continue;
// Check if we reached the end
const BSONObj currentOp = ops.back().raw;
const OpTime currentOpTime =
fassertStatusOK(28772, OpTime::parseFromOplogEntry(currentOp));
// When we reach the end return this batch
if (currentOpTime == endOpTime) {
break;
} else if (currentOpTime > endOpTime) {
severe() << "Applied past expected end " << endOpTime << " to " << currentOpTime
<< " without seeing it. Rollback?";
fassertFailedNoTrace(18693);
}
// apply replication batch limits
if (ops.getSize() > replBatchLimitBytes)
break;
if (ops.getDeque().size() > replBatchLimitOperations)
break;
};
if (ops.empty()) {
severe() << "got no ops for batch...";
fassertFailedNoTrace(18692);
}
const BSONObj lastOp = ops.back().raw.getOwned();
// Tally operation information
bytesApplied += ops.getSize();
entriesApplied += ops.getDeque().size();
const OpTime lastOpTime = multiApply(txn, ops);
replCoord->setMyLastAppliedOpTime(lastOpTime);
setNewTimestamp(lastOpTime.getTimestamp());
if (inShutdown()) {
return;
}
// if the last op applied was our end, return
if (lastOpTime == endOpTime) {
LOG(1) << "SyncTail applied " << entriesApplied << " entries (" << bytesApplied
<< " bytes) and finished at opTime " << endOpTime;
return;
}
} // end of while (true)
}
/* tail an oplog. ok to return, will be re-called. */
void SyncTail::oplogApplication() {
ReplicationCoordinator* replCoord = getGlobalReplicationCoordinator();
while(!inShutdown()) {
OpQueue ops;
OperationContextImpl txn;
Timer batchTimer;
int lastTimeChecked = 0;
do {
int now = batchTimer.seconds();
// apply replication batch limits
if (!ops.empty()) {
if (now > replBatchLimitSeconds)
break;
if (ops.getDeque().size() > replBatchLimitOperations)
break;
}
// occasionally check some things
// (always checked in the first iteration of this do-while loop, because
// ops is empty)
if (ops.empty() || now > lastTimeChecked) {
BackgroundSync* bgsync = BackgroundSync::get();
if (bgsync->getInitialSyncRequestedFlag()) {
// got a resync command
Lock::DBLock lk(txn.lockState(), "local", MODE_X);
WriteUnitOfWork wunit(&txn);
Client::Context ctx(&txn, "local");
ctx.db()->dropCollection(&txn, "local.oplog.rs");
// Note: the following order is important.
// The bgsync thread uses an empty optime as a sentinel to know to wait
// for initial sync (done in this thread after we return); thus, we must
// ensure the lastAppliedOptime is empty before pausing the bgsync thread
// via stop().
// We must clear the sync source blacklist after calling stop()
// because the bgsync thread, while running, may update the blacklist.
replCoord->setMyLastOptime(&txn, OpTime());
bgsync->stop();
replCoord->clearSyncSourceBlacklist();
wunit.commit();
return;
}
lastTimeChecked = now;
// can we become secondary?
// we have to check this before calling mgr, as we must be a secondary to
// become primary
tryToGoLiveAsASecondary(&txn, replCoord);
// TODO(emilkie): This can be removed once we switch over from legacy;
// this code is what moves 1-node sets to PRIMARY state.
// normally msgCheckNewState gets called periodically, but in a single node
// replset there are no heartbeat threads, so we do it here to be sure. this is
// relevant if the singleton member has done a stepDown() and needs to come back
// up.
if (theReplSet &&
theReplSet->config().members.size() == 1 &&
theReplSet->myConfig().potentiallyHot()) {
Manager* mgr = theReplSet->mgr;
// When would mgr be null? During replsettest'ing, in which case we should
// fall through and actually apply ops as if we were a real secondary.
if (mgr) {
mgr->send(stdx::bind(&Manager::msgCheckNewState, theReplSet->mgr));
sleepsecs(1);
// There should never be ops to sync in a 1-member set, anyway
return;
}
}
}
const int slaveDelaySecs = replCoord->getSlaveDelaySecs().total_seconds();
if (!ops.empty() && slaveDelaySecs > 0) {
const BSONObj& lastOp = ops.getDeque().back();
const unsigned int opTimestampSecs = lastOp["ts"]._opTime().getSecs();
// Stop the batch as the lastOp is too new to be applied. If we continue
// on, we can get ops that are way ahead of the delay and this will
// make this thread sleep longer when handleSlaveDelay is called
// and apply ops much sooner than we like.
if (opTimestampSecs > static_cast<unsigned int>(time(0) - slaveDelaySecs)) {
break;
}
}
// keep fetching more ops as long as we haven't filled up a full batch yet
} while (!tryPopAndWaitForMore(&ops, replCoord) && // tryPopAndWaitForMore returns true
// when we need to end a batch early
(ops.getSize() < replBatchLimitBytes) &&
!inShutdown());
// For pausing replication in tests
while (MONGO_FAIL_POINT(rsSyncApplyStop)) {
sleepmillis(0);
}
if (ops.empty()) {
continue;
}
const BSONObj& lastOp = ops.getDeque().back();
handleSlaveDelay(lastOp);
if (replCoord->getCurrentMemberState().primary() &&
!replCoord->isWaitingForApplierToDrain()) {
severe() << "attempting to replicate ops while primary";
fassertFailed(28527);
}
// Set minValid to the last op to be applied in this next batch.
// This will cause this node to go into RECOVERING state
// if we should crash and restart before updating the oplog
OpTime minValid = lastOp["ts"]._opTime();
setMinValid(&txn, minValid);
multiApply(ops.getDeque());
applyOpsToOplog(&ops.getDeque());
// If we're just testing (no manager), don't keep looping if we exhausted the bgqueue
// TODO(spencer): Remove repltest.cpp dbtest or make this work with the new replication
// coordinator
if (theReplSet && !theReplSet->mgr) {
BSONObj op;
if (!peek(&op)) {
return;
}
}
}
}
/* tail an oplog. ok to return, will be re-called. */
void SyncTail::oplogApplication() {
OpQueueBatcher batcher(this);
OperationContextImpl txn;
auto replCoord = ReplicationCoordinator::get(&txn);
ApplyBatchFinalizer finalizer(replCoord);
auto minValidBoundaries = getMinValid(&txn);
OpTime originalEndOpTime(minValidBoundaries.end);
OpTime lastWriteOpTime{replCoord->getMyLastOptime()};
while (!inShutdown()) {
OpQueue ops;
do {
if (BackgroundSync::get()->getInitialSyncRequestedFlag()) {
// got a resync command
return;
}
tryToGoLiveAsASecondary(&txn, replCoord, minValidBoundaries, lastWriteOpTime);
// Blocks up to a second waiting for a batch to be ready to apply. If one doesn't become
// ready in time, we'll loop again so we can do the above checks periodically.
ops = batcher.getNextBatch(Seconds(1));
} while (!inShutdown() && ops.empty());
if (inShutdown())
return;
invariant(!ops.empty());
const BSONObj lastOp = ops.back().raw;
if (lastOp.isEmpty()) {
// This means that the network thread has coalesced and we have processed all of its
// data.
invariant(ops.getDeque().size() == 1);
if (replCoord->isWaitingForApplierToDrain()) {
replCoord->signalDrainComplete(&txn);
}
continue; // This wasn't a real op. Don't try to apply it.
}
handleSlaveDelay(lastOp);
// Set minValid to the last OpTime that needs to be applied, in this batch or from the
// (last) failed batch, whichever is larger.
// This will cause this node to go into RECOVERING state
// if we should crash and restart before updating finishing.
const OpTime start(getLastSetTimestamp(), OpTime::kUninitializedTerm);
// Take the max of the first endOptime (if we recovered) and the end of our batch.
const auto lastOpTime = fassertStatusOK(28773, OpTime::parseFromOplogEntry(lastOp));
// Setting end to the max of originalEndOpTime and lastOpTime (the end of the batch)
// ensures that we keep pushing out the point where we can become consistent
// and allow reads. If we recover and end up doing smaller batches we must pass the
// originalEndOpTime before we are good.
//
// For example:
// batch apply, 20-40, end = 40
// batch failure,
// restart
// batch apply, 20-25, end = max(25, 40) = 40
// batch apply, 25-45, end = 45
const OpTime end(std::max(originalEndOpTime, lastOpTime));
// This write will not journal/checkpoint.
setMinValid(&txn, {start, end});
lastWriteOpTime = multiApply(&txn, ops);
setNewTimestamp(lastWriteOpTime.getTimestamp());
setMinValid(&txn, end, DurableRequirement::None);
minValidBoundaries.start = {};
minValidBoundaries.end = end;
finalizer.record(lastWriteOpTime);
}
}
/* tail an oplog. ok to return, will be re-called. */
void SyncTail::oplogApplication() {
while( 1 ) {
OpQueue ops;
verify( !Lock::isLocked() );
Timer batchTimer;
int lastTimeChecked = 0;
// always fetch a few ops first
// tryPopAndWaitForMore returns true when we need to end a batch early
while (!tryPopAndWaitForMore(&ops) &&
(ops.getSize() < replBatchLimitBytes)) {
if (theReplSet->isPrimary()) {
massert(16620, "there are ops to sync, but I'm primary", ops.empty());
return;
}
int now = batchTimer.seconds();
// apply replication batch limits
if (!ops.empty()) {
if (now > replBatchLimitSeconds)
break;
if (ops.getDeque().size() > replBatchLimitOperations)
break;
}
// occasionally check some things
if (ops.empty() || now > lastTimeChecked) {
lastTimeChecked = now;
// can we become secondary?
// we have to check this before calling mgr, as we must be a secondary to
// become primary
if (!theReplSet->isSecondary()) {
OpTime minvalid;
theReplSet->tryToGoLiveAsASecondary(minvalid);
}
// normally msgCheckNewState gets called periodically, but in a single node repl set
// there are no heartbeat threads, so we do it here to be sure. this is relevant if the
// singleton member has done a stepDown() and needs to come back up.
if (theReplSet->config().members.size() == 1 &&
theReplSet->myConfig().potentiallyHot()) {
Manager* mgr = theReplSet->mgr;
// When would mgr be null? During replsettest'ing.
if (mgr) mgr->send(boost::bind(&Manager::msgCheckNewState, theReplSet->mgr));
sleepsecs(1);
// There should never be ops to sync in a 1-member set, anyway
return;
}
}
const int slaveDelaySecs = theReplSet->myConfig().slaveDelay;
if (!ops.empty() && slaveDelaySecs > 0) {
const BSONObj& lastOp = ops.getDeque().back();
const unsigned int opTimestampSecs = lastOp["ts"]._opTime().getSecs();
// Stop the batch as the lastOp is too new to be applied. If we continue
// on, we can get ops that are way ahead of the delay and this will
// make this thread sleep longer when handleSlaveDelay is called
// and apply ops much sooner than we like.
if (opTimestampSecs > static_cast<unsigned int>(time(0) - slaveDelaySecs)) {
break;
}
}
}
// For pausing replication in tests
while (MONGO_FAIL_POINT(rsSyncApplyStop)) {
sleepmillis(0);
}
const BSONObj& lastOp = ops.getDeque().back();
setOplogVersion(lastOp);
handleSlaveDelay(lastOp);
// Set minValid to the last op to be applied in this next batch.
// This will cause this node to go into RECOVERING state
// if we should crash and restart before updating the oplog
theReplSet->setMinValid(lastOp);
multiApply(ops.getDeque(), multiSyncApply);
applyOpsToOplog(&ops.getDeque());
}
}