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#include <base/defines.h>
#include <Core/SettingsQuirks.h>
#include <Core/Settings.h>
#include <Poco/Environment.h>
#include <Poco/Platform.h>
#include <Common/VersionNumber.h>
#include <Common/logger_useful.h>
namespace
{
/// Detect does epoll_wait with nested epoll fds works correctly.
/// Polling nested epoll fds from epoll_wait is required for async_socket_for_remote and use_hedged_requests.
///
/// It may not be reliable in 5.5+ [1], that has been fixed in 5.7+ [2] or 5.6.13+.
///
/// [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=339ddb53d373
/// [2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0c54a6a44bf3
bool nestedEpollWorks(Poco::Logger * log)
{
if (Poco::Environment::os() != POCO_OS_LINUX)
return true;
DB::VersionNumber linux_version(Poco::Environment::osVersion());
/// the check is correct since there will be no more 5.5.x releases.
if (linux_version >= DB::VersionNumber{5, 5, 0} && linux_version < DB::VersionNumber{5, 6, 13})
{
if (log)
LOG_WARNING(log, "Nested epoll_wait has some issues on kernels [5.5.0, 5.6.13). You should upgrade it to avoid possible issues.");
return false;
}
return true;
}
/// See also QUERY_PROFILER_DEFAULT_SAMPLE_RATE_NS in Core/Defines.h
#if !defined(SANITIZER)
bool queryProfilerWorks() { return true; }
#else
bool queryProfilerWorks() { return false; }
#endif
}
namespace DB
{
/// Update some settings defaults to avoid some known issues.
void applySettingsQuirks(Settings & settings, Poco::Logger * log)
{
if (!nestedEpollWorks(log))
{
if (!settings.async_socket_for_remote.changed && settings.async_socket_for_remote)
{
settings.async_socket_for_remote = false;
if (log)
LOG_WARNING(log, "async_socket_for_remote has been disabled (you can explicitly enable it still)");
}
if (!settings.async_query_sending_for_remote.changed && settings.async_query_sending_for_remote)
{
settings.async_query_sending_for_remote = false;
if (log)
LOG_WARNING(log, "async_query_sending_for_remote has been disabled (you can explicitly enable it still)");
}
if (!settings.use_hedged_requests.changed && settings.use_hedged_requests)
{
settings.use_hedged_requests = false;
if (log)
LOG_WARNING(log, "use_hedged_requests has been disabled (you can explicitly enable it still)");
}
}
if (!queryProfilerWorks())
{
if (settings.query_profiler_real_time_period_ns)
{
settings.query_profiler_real_time_period_ns = 0;
if (log)
LOG_WARNING(log, "query_profiler_real_time_period_ns has been disabled (due to server had been compiled with sanitizers)");
}
if (settings.query_profiler_cpu_time_period_ns)
{
settings.query_profiler_cpu_time_period_ns = 0;
if (log)
LOG_WARNING(log, "query_profiler_cpu_time_period_ns has been disabled (due to server had been compiled with sanitizers)");
}
}
}
}
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