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DM-52371: Unnecessary serialization during query parsing, analysis and registration in Qserv #958

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DM-52371: Unnecessary serialization during query parsing, analysis and registration in Qserv #958

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d632dd7
UserQueryFactory mutex change.
jgates108 Sep 4, 2025
1936a24
Relocated mutex so it no longer covers query parsing.
jgates108 Sep 5, 2025
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10 changes: 10 additions & 0 deletions src/ccontrol/UserQueryFactory.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -298,6 +298,11 @@ UserQuery::Ptr UserQueryFactory::newUserQuery(std::string const& aQuery, std::st
}
auto stmt = parser->getSelectStmt();

// Parsing doesn't need protection, but CSS in analyze query does and
// some of the uq related calls may require protection, but it
// isn't clear.
std::lock_guard<std::mutex> factoryLock(_factoryMtx);

// handle special database/table names
if (_stmtRefersToProcessListTable(stmt, defaultDb)) {
return _makeUserQueryProcessList(stmt, _userQuerySharedResources, userQueryId, resultDb, aQuery,
Expand Down Expand Up @@ -378,12 +383,14 @@ UserQuery::Ptr UserQueryFactory::newUserQuery(std::string const& aQuery, std::st
}
return uq;
} else if (UserQueryType::isSelectResult(query, userJobId)) {
std::lock_guard<std::mutex> factoryLock(_factoryMtx);
auto uq = std::make_shared<UserQueryAsyncResult>(userJobId, _userQuerySharedResources->czarId,
_userQuerySharedResources->queryMetadata);
LOGS(_log, LOG_LVL_DEBUG, "make UserQueryAsyncResult: userJobId=" << userJobId);
return uq;
} else if (UserQueryType::isShowProcessList(query, full)) {
LOGS(_log, LOG_LVL_DEBUG, "make UserQueryProcessList: full=" << (full ? 'y' : 'n'));
std::lock_guard<std::mutex> factoryLock(_factoryMtx);
try {
return std::make_shared<UserQueryProcessList>(full, _userQuerySharedResources->qMetaSelect,
_userQuerySharedResources->czarId, userQueryId,
Expand All @@ -392,10 +399,12 @@ UserQuery::Ptr UserQueryFactory::newUserQuery(std::string const& aQuery, std::st
return std::make_shared<UserQueryInvalid>(exc.what());
}
} else if (UserQueryType::isCall(query)) {
std::lock_guard<std::mutex> factoryLock(_factoryMtx);
auto parser = std::make_shared<ParseRunner>(
query, _userQuerySharedResources->makeUserQueryResources(userQueryId, resultDb));
return parser->getUserQuery();
} else if (UserQueryType::isSet(query)) {
std::lock_guard<std::mutex> factoryLock(_factoryMtx);
ParseRunner::Ptr parser;
try {
parser = std::make_shared<ParseRunner>(query);
Expand All @@ -414,6 +423,7 @@ UserQuery::Ptr UserQueryFactory::newUserQuery(std::string const& aQuery, std::st
}
return uq;
} else {
std::lock_guard<std::mutex> factoryLock(_factoryMtx);
// something that we don't recognize
auto uq = std::make_shared<UserQueryInvalid>("Invalid or unsupported query: " + query);
return uq;
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4 changes: 4 additions & 0 deletions src/ccontrol/UserQueryFactory.h
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Expand Up @@ -103,6 +103,10 @@ class UserQueryFactory : private boost::noncopyable {
boost::asio::io_service _asioIoService;
std::unique_ptr<boost::asio::io_service::work> _asioWork;
std::unique_ptr<std::thread> _asioTimerThread;

/// Protects CSS in `qs->analyzeQuery(query, stmt);` and
/// protects uq calls that alter the database.
std::mutex _factoryMtx;
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@jgates108 jgates108 Sep 5, 2025

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CSS and all of these other things should be made thread safe, but that's a much bigger job and CSS is about to be under the microscope for other reasons in the next couple of weeks.

};

} // namespace lsst::qserv::ccontrol
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8 changes: 2 additions & 6 deletions src/czar/Czar.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -224,12 +224,8 @@ SubmitResult Czar::submitQuery(string const& query, map<string, string> const& h

// make new UserQuery
// this is atomic
ccontrol::UserQuery::Ptr uq;
{
lock_guard<mutex> lock(_mutex);
uq = _uqFactory->newUserQuery(query, defaultDb, getQdispSharedResources(), userQueryId, msgTableName,
resultDb);
}
ccontrol::UserQuery::Ptr uq = _uqFactory->newUserQuery(query, defaultDb, getQdispSharedResources(),
userQueryId, msgTableName, resultDb);

// Add logging context with query ID
QSERV_LOGCONTEXT_QUERY(uq->getQueryId());
Expand Down