void replyToQuery(int queryResultFlags,
AbstractMessagingPort* p,
Message& requestMsg,
const void* data,
int size,
int nReturned,
int startingFrom,
long long cursorId) {
OpQueryReplyBuilder reply;
reply.bufBuilderForResults().appendBuf(data, size);
reply.send(p, queryResultFlags, requestMsg, nReturned, startingFrom, cursorId);
}
void replyToQuery(int queryResultFlags,
const transport::SessionHandle& session,
Message& requestMsg,
const void* data,
int size,
int nReturned,
int startingFrom,
long long cursorId) {
OpQueryReplyBuilder reply;
reply.bufBuilderForResults().appendBuf(data, size);
reply.send(session, queryResultFlags, requestMsg, nReturned, startingFrom, cursorId);
}
void Strategy::queryOp(OperationContext* txn, Request& request) {
verify(!NamespaceString(request.getns()).isCommand());
globalOpCounters.gotQuery();
QueryMessage q(request.d());
NamespaceString ns(q.ns);
ClientBasic* client = txn->getClient();
AuthorizationSession* authSession = AuthorizationSession::get(client);
Status status = authSession->checkAuthForFind(ns, false);
audit::logQueryAuthzCheck(client, ns, q.query, status.code());
uassertStatusOK(status);
LOG(3) << "query: " << q.ns << " " << q.query << " ntoreturn: " << q.ntoreturn
<< " options: " << q.queryOptions;
if (q.ntoreturn == 1 && strstr(q.ns, ".$cmd"))
throw UserException(8010, "something is wrong, shouldn't see a command here");
if (q.queryOptions & QueryOption_Exhaust) {
uasserted(18526,
string("the 'exhaust' query option is invalid for mongos queries: ") + q.ns +
" " + q.query.toString());
}
// Determine the default read preference mode based on the value of the slaveOk flag.
ReadPreference readPreferenceOption = (q.queryOptions & QueryOption_SlaveOk)
? ReadPreference::SecondaryPreferred
: ReadPreference::PrimaryOnly;
ReadPreferenceSetting readPreference(readPreferenceOption, TagSet());
BSONElement rpElem;
auto readPrefExtractStatus = bsonExtractTypedField(
q.query, LiteParsedQuery::kWrappedReadPrefField, mongo::Object, &rpElem);
if (readPrefExtractStatus.isOK()) {
auto parsedRps = ReadPreferenceSetting::fromBSON(rpElem.Obj());
uassertStatusOK(parsedRps.getStatus());
readPreference = parsedRps.getValue();
} else if (readPrefExtractStatus != ErrorCodes::NoSuchKey) {
uassertStatusOK(readPrefExtractStatus);
}
auto canonicalQuery = CanonicalQuery::canonicalize(q, ExtensionsCallbackNoop());
uassertStatusOK(canonicalQuery.getStatus());
// If the $explain flag was set, we must run the operation on the shards as an explain command
// rather than a find command.
if (canonicalQuery.getValue()->getParsed().isExplain()) {
const LiteParsedQuery& lpq = canonicalQuery.getValue()->getParsed();
BSONObj findCommand = lpq.asFindCommand();
// We default to allPlansExecution verbosity.
auto verbosity = ExplainCommon::EXEC_ALL_PLANS;
const bool secondaryOk = (readPreference.pref != ReadPreference::PrimaryOnly);
rpc::ServerSelectionMetadata metadata(secondaryOk, readPreference);
BSONObjBuilder explainBuilder;
uassertStatusOK(
Strategy::explainFind(txn, findCommand, lpq, verbosity, metadata, &explainBuilder));
BSONObj explainObj = explainBuilder.done();
replyToQuery(0, // query result flags
request.p(),
request.m(),
static_cast<const void*>(explainObj.objdata()),
explainObj.objsize(),
1, // numResults
0, // startingFrom
CursorId(0));
return;
}
// Do the work to generate the first batch of results. This blocks waiting to get responses from
// the shard(s).
std::vector<BSONObj> batch;
// 0 means the cursor is exhausted. Otherwise we assume that a cursor with the returned id can
// be retrieved via the ClusterCursorManager.
auto cursorId = ClusterFind::runQuery(txn, *canonicalQuery.getValue(), readPreference, &batch);
uassertStatusOK(cursorId.getStatus());
// Fill out the response buffer.
int numResults = 0;
OpQueryReplyBuilder reply;
for (auto&& obj : batch) {
obj.appendSelfToBufBuilder(reply.bufBuilderForResults());
numResults++;
}
reply.send(request.p(),
0, // query result flags
request.m(),
numResults,
0, // startingFrom
cursorId.getValue());
}
void Strategy::clientCommandOp(OperationContext* txn, Request& request) {
QueryMessage q(request.d());
LOG(3) << "command: " << q.ns << " " << q.query << " ntoreturn: " << q.ntoreturn
<< " options: " << q.queryOptions;
if (q.queryOptions & QueryOption_Exhaust) {
uasserted(18527,
string("the 'exhaust' query option is invalid for mongos commands: ") + q.ns +
" " + q.query.toString());
}
NamespaceString nss(request.getns());
// Regular queries are handled in strategy_shard.cpp
verify(nss.isCommand() || nss.isSpecialCommand());
if (handleSpecialNamespaces(txn, request, q))
return;
int loops = 5;
bool cmChangeAttempted = false;
while (true) {
try {
BSONObj cmdObj = q.query;
{
BSONElement e = cmdObj.firstElement();
if (e.type() == Object &&
(e.fieldName()[0] == '$' ? str::equals("query", e.fieldName() + 1)
: str::equals("query", e.fieldName()))) {
// Extract the embedded query object.
if (cmdObj.hasField(Query::ReadPrefField.name())) {
// The command has a read preference setting. We don't want
// to lose this information so we copy this to a new field
// called $queryOptions.$readPreference
BSONObjBuilder finalCmdObjBuilder;
finalCmdObjBuilder.appendElements(e.embeddedObject());
BSONObjBuilder queryOptionsBuilder(
finalCmdObjBuilder.subobjStart("$queryOptions"));
queryOptionsBuilder.append(cmdObj[Query::ReadPrefField.name()]);
queryOptionsBuilder.done();
cmdObj = finalCmdObjBuilder.obj();
} else {
cmdObj = e.embeddedObject();
}
}
}
OpQueryReplyBuilder reply;
{
BSONObjBuilder builder(reply.bufBuilderForResults());
Command::runAgainstRegistered(txn, q.ns, cmdObj, builder, q.queryOptions);
}
reply.sendCommandReply(request.p(), request.m());
return;
} catch (const StaleConfigException& e) {
if (loops <= 0)
throw e;
loops--;
log() << "retrying command: " << q.query;
// For legacy reasons, ns may not actually be set in the exception :-(
string staleNS = e.getns();
if (staleNS.size() == 0)
staleNS = q.ns;
ShardConnection::checkMyConnectionVersions(txn, staleNS);
if (loops < 4)
versionManager.forceRemoteCheckShardVersionCB(txn, staleNS);
} catch (const DBException& e) {
if (e.getCode() == ErrorCodes::IncompatibleCatalogManager) {
fassert(28791, !cmChangeAttempted);
cmChangeAttempted = true;
grid.forwardingCatalogManager()->waitForCatalogManagerChange(txn);
} else {
OpQueryReplyBuilder reply;
{
BSONObjBuilder builder(reply.bufBuilderForResults());
Command::appendCommandStatus(builder, e.toStatus());
}
reply.sendCommandReply(request.p(), request.m());
return;
}
}
}
}
void replyToQuery(int queryResultFlags, Message& response, const BSONObj& resultObj) {
OpQueryReplyBuilder reply;
resultObj.appendSelfToBufBuilder(reply.bufBuilderForResults());
reply.putInMessage(&response, queryResultFlags, /*nReturned*/ 1);
}
void Strategy::clientCommandOp(OperationContext* txn, Request& request) {
const QueryMessage q(request.d());
LOG(3) << "command: " << q.ns << " " << redact(q.query) << " ntoreturn: " << q.ntoreturn
<< " options: " << q.queryOptions;
if (q.queryOptions & QueryOption_Exhaust) {
uasserted(18527,
string("the 'exhaust' query option is invalid for mongos commands: ") + q.ns +
" " + q.query.toString());
}
const NamespaceString nss(request.getns());
invariant(nss.isCommand() || nss.isSpecialCommand());
if (handleSpecialNamespaces(txn, request, q))
return;
BSONObj cmdObj = q.query;
{
BSONElement e = cmdObj.firstElement();
if (e.type() == Object && (e.fieldName()[0] == '$' ? str::equals("query", e.fieldName() + 1)
: str::equals("query", e.fieldName()))) {
// Extract the embedded query object.
if (cmdObj.hasField(Query::ReadPrefField.name())) {
// The command has a read preference setting. We don't want to lose this information
// so we copy this to a new field called $queryOptions.$readPreference
BSONObjBuilder finalCmdObjBuilder;
finalCmdObjBuilder.appendElements(e.embeddedObject());
BSONObjBuilder queryOptionsBuilder(finalCmdObjBuilder.subobjStart("$queryOptions"));
queryOptionsBuilder.append(cmdObj[Query::ReadPrefField.name()]);
queryOptionsBuilder.done();
cmdObj = finalCmdObjBuilder.obj();
} else {
cmdObj = e.embeddedObject();
}
}
}
// Handle command option maxTimeMS.
uassert(ErrorCodes::InvalidOptions,
"no such command option $maxTimeMs; use maxTimeMS instead",
cmdObj[QueryRequest::queryOptionMaxTimeMS].eoo());
const int maxTimeMS =
uassertStatusOK(QueryRequest::parseMaxTimeMS(cmdObj[QueryRequest::cmdOptionMaxTimeMS]));
if (maxTimeMS > 0) {
txn->setDeadlineAfterNowBy(Milliseconds{maxTimeMS});
}
int loops = 5;
while (true) {
try {
OpQueryReplyBuilder reply;
{
BSONObjBuilder builder(reply.bufBuilderForResults());
runAgainstRegistered(txn, q.ns, cmdObj, builder, q.queryOptions);
}
reply.sendCommandReply(request.session(), request.m());
return;
} catch (const StaleConfigException& e) {
if (loops <= 0)
throw e;
loops--;
log() << "Retrying command " << redact(q.query) << causedBy(e);
// For legacy reasons, ns may not actually be set in the exception :-(
string staleNS = e.getns();
if (staleNS.size() == 0)
staleNS = q.ns;
ShardConnection::checkMyConnectionVersions(txn, staleNS);
if (loops < 4)
versionManager.forceRemoteCheckShardVersionCB(txn, staleNS);
} catch (const DBException& e) {
OpQueryReplyBuilder reply;
{
BSONObjBuilder builder(reply.bufBuilderForResults());
Command::appendCommandStatus(builder, e.toStatus());
}
reply.sendCommandReply(request.session(), request.m());
return;
}
}
}