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bmahler pushed a commit to branch 1.6.x
in repository https://gitbox.apache.org/repos/asf/mesos.git
commit 2e0b848f3cd7a2ed03b3da0754d8a6609f8f5880
Author: Benjamin Mahler <bmah...@apache.org>
AuthorDate: Thu May 16 11:42:26 2019 +0200
Added logging of slow reverse DNS when accepting SSL connections.
Slow reverse DNS lookup is a serious issue since today it is done
synchronously from the event loop thread, see MESOS-9339 and
related tickets. Logging slow requests will substantially improve
debugging.
Review: https://reviews.apache.org/r/70653
---
3rdparty/libprocess/src/libevent_ssl_socket.cpp | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/3rdparty/libprocess/src/libevent_ssl_socket.cpp
b/3rdparty/libprocess/src/libevent_ssl_socket.cpp
index 436b389..520ec41 100644
--- a/3rdparty/libprocess/src/libevent_ssl_socket.cpp
+++ b/3rdparty/libprocess/src/libevent_ssl_socket.cpp
@@ -26,6 +26,7 @@
#include <process/ssl/flags.hpp>
#include <stout/net.hpp>
+#include <stout/stopwatch.hpp>
#include <stout/synchronized.hpp>
#include <stout/os/close.hpp>
@@ -1152,7 +1153,19 @@ void
LibeventSSLSocketImpl::accept_SSL_callback(AcceptRequest* request)
Option<string> peer_hostname = None();
if (request->ip.isSome()) {
+ Stopwatch watch;
+
+ watch.start();
Try<string> hostname = net::getHostname(request->ip.get());
+ watch.stop();
+
+ // Due to MESOS-9339, a slow reverse DNS lookup will cause
+ // serious issues as it blocks the event loop thread.
+ if (watch.elapsed() > Milliseconds(100)) {
+ LOG(WARNING) << "Reverse DNS lookup for '" << *request->ip << "'"
+ << " took " << watch.elapsed().ms() << "ms"
+ << ", slowness is problematic (see MESOS-9339)";
+ }
if (hostname.isError()) {
VLOG(2) << "Could not determine hostname of peer: "
