bool run(OperationContext* txn,
const string& dbname,
BSONObj& cmdObj,
int,
string& errmsg,
BSONObjBuilder& result) {
LastError *le = &LastError::get(txn->getClient());
le->disable();
le->appendSelf(result, true);
if (le->isValid())
result.append("nPrev", le->getNPrev());
else
result.append("nPrev", -1);
return true;
}
bool run(OperationContext* txn, const string& dbname,
BSONObj& cmdObj,
int,
string& errmsg,
BSONObjBuilder& result) {
//
// Correct behavior here is very finicky.
//
// 1. The first step is to append the error that occurred on the previous operation.
// This adds an "err" field to the command, which is *not* the command failing.
//
// 2. Next we parse and validate write concern options. If these options are invalid
// the command fails no matter what, even if we actually had an error earlier. The
// reason for checking here is to match legacy behavior on these kind of failures -
// we'll still get an "err" field for the write error.
//
// 3. If we had an error on the previous operation, we then return immediately.
//
// 4. Finally, we actually enforce the write concern. All errors *except* timeout are
// reported with ok : 0.0, to match legacy behavior.
//
// There is a special case when "wOpTime" and "wElectionId" are explicitly provided by
// the client (mongos) - in this case we *only* enforce the write concern if it is
// valid.
//
// We always need to either report "err" (if ok : 1) or "errmsg" (if ok : 0), even if
// err is null.
//
LastError *le = &LastError::get(txn->getClient());
le->disable();
// Always append lastOp and connectionId
Client& c = *txn->getClient();
if (repl::getGlobalReplicationCoordinator()->getReplicationMode() ==
repl::ReplicationCoordinator::modeReplSet) {
const repl::OpTime lastOp = repl::ReplClientInfo::forClient(c).getLastOp();
if (!lastOp.isNull()) {
result.append("lastOp", lastOp.getTimestamp());
// TODO(siyuan) Add "lastOpTerm"
}
}
// for sharding; also useful in general for debugging
result.appendNumber( "connectionId" , c.getConnectionId() );
Timestamp lastTimestamp;
BSONField<Timestamp> wOpTimeField("wOpTime");
FieldParser::FieldState extracted = FieldParser::extract(cmdObj, wOpTimeField,
&lastTimestamp, &errmsg);
if (!extracted) {
result.append("badGLE", cmdObj);
appendCommandStatus(result, false, errmsg);
return false;
}
repl::OpTime lastOpTime;
bool lastOpTimePresent = extracted != FieldParser::FIELD_NONE;
if (!lastOpTimePresent) {
// Use the client opTime if no wOpTime is specified
lastOpTime = repl::ReplClientInfo::forClient(c).getLastOp();
// TODO(siyuan) Fix mongos to supply wOpTimeTerm, then parse out that value here
} else {
// TODO(siyuan) Don't use the default term after fixing mongos.
lastOpTime = repl::OpTime(lastTimestamp, repl::OpTime::kDefaultTerm);
}
OID electionId;
BSONField<OID> wElectionIdField("wElectionId");
extracted = FieldParser::extract(cmdObj, wElectionIdField,
&electionId, &errmsg);
if (!extracted) {
result.append("badGLE", cmdObj);
appendCommandStatus(result, false, errmsg);
return false;
}
bool electionIdPresent = extracted != FieldParser::FIELD_NONE;
bool errorOccurred = false;
// Errors aren't reported when wOpTime is used
if ( !lastOpTimePresent ) {
if ( le->getNPrev() != 1 ) {
errorOccurred = LastError::noError.appendSelf( result, false );
}
else {
errorOccurred = le->appendSelf( result, false );
}
}
BSONObj writeConcernDoc = cmdObj;
// Use the default options if we have no gle options aside from wOpTime/wElectionId
const int nFields = cmdObj.nFields();
bool useDefaultGLEOptions = (nFields == 1) ||
(nFields == 2 && lastOpTimePresent) ||
(nFields == 3 && lastOpTimePresent && electionIdPresent);
WriteConcernOptions writeConcern;
if (useDefaultGLEOptions) {
writeConcern = repl::getGlobalReplicationCoordinator()->getGetLastErrorDefault();
}
Status status = writeConcern.parse( writeConcernDoc );
//
// Validate write concern no matter what, this matches 2.4 behavior
//
if ( status.isOK() ) {
// Ensure options are valid for this host
status = validateWriteConcern( writeConcern );
}
if ( !status.isOK() ) {
result.append( "badGLE", writeConcernDoc );
return appendCommandStatus( result, status );
}
// Don't wait for replication if there was an error reported - this matches 2.4 behavior
if ( errorOccurred ) {
dassert( !lastOpTimePresent );
return true;
}
// No error occurred, so we won't duplicate these fields with write concern errors
dassert( result.asTempObj()["err"].eoo() );
dassert( result.asTempObj()["code"].eoo() );
// If we got an electionId, make sure it matches
if (electionIdPresent) {
if (repl::getGlobalReplicationCoordinator()->getReplicationMode() !=
repl::ReplicationCoordinator::modeReplSet) {
// Ignore electionIds of 0 from mongos.
if (electionId != OID()) {
errmsg = "wElectionId passed but no replication active";
result.append("code", ErrorCodes::BadValue);
return false;
}
}
else {
if (electionId != repl::getGlobalReplicationCoordinator()->getElectionId()) {
LOG(3) << "oid passed in is " << electionId
<< ", but our id is "
<< repl::getGlobalReplicationCoordinator()->getElectionId();
errmsg = "election occurred after write";
result.append("code", ErrorCodes::WriteConcernFailed);
return false;
}
}
}
txn->setWriteConcern(writeConcern);
txn->setMessage( "waiting for write concern" );
WriteConcernResult wcResult;
status = waitForWriteConcern( txn, lastOpTime, &wcResult );
wcResult.appendTo( writeConcern, &result );
// For backward compatibility with 2.4, wtimeout returns ok : 1.0
if ( wcResult.wTimedOut ) {
dassert( !wcResult.err.empty() ); // so we always report err
dassert( !status.isOK() );
result.append( "errmsg", "timed out waiting for slaves" );
result.append( "code", status.code() );
return true;
}
return appendCommandStatus( result, status );
}