Send raylet error logs through the log monitor

python/ray/log_monitor.py

@@ -90,10 +90,12 @@ def close_all_files(self):
 
     def update_log_filenames(self):
         """Update the list of log files to monitor."""
-        # we only monior worker log files
+        # output of user code is written here
         log_file_paths = glob.glob("{}/worker*[.out|.err]".format(
             self.logs_dir))
-        for file_path in log_file_paths:
+        # segfaults and other serious errors are logged here
+        raylet_err_paths = glob.glob("{}/raylet*.err".format(self.logs_dir))
+        for file_path in log_file_paths + raylet_err_paths:
             if os.path.isfile(
                     file_path) and file_path not in self.log_filenames:
                 self.log_filenames.add(file_path)
@@ -195,6 +197,8 @@ def check_log_files_and_publish_updates(self):
                     file_info.worker_pid = int(
                         lines_to_publish[0].split(" ")[-1])
                     lines_to_publish = lines_to_publish[1:]
+                elif "/raylet" in file_info.filename:
+                    file_info.worker_pid = "raylet"
 
             # Record the current position in the file.
             file_info.file_position = file_info.file_handle.tell()

python/ray/worker.py

@@ -1594,15 +1594,22 @@ def print_logs(redis_client, threads_stopped):
             num_consecutive_messages_received += 1
 
             data = json.loads(ray.utils.decode(msg["data"]))
+
+            def color_for(data):
+                if data["pid"] == "raylet":
+                    return colorama.Fore.YELLOW
+                else:
+                    return colorama.Fore.CYAN
+
             if data["ip"] == localhost:
                 for line in data["lines"]:
                     print("{}{}(pid={}){} {}".format(
-                        colorama.Style.DIM, colorama.Fore.CYAN, data["pid"],
+                        colorama.Style.DIM, color_for(data), data["pid"],
                         colorama.Style.RESET_ALL, line))
             else:
                 for line in data["lines"]:
                     print("{}{}(pid={}, ip={}){} {}".format(
-                        colorama.Style.DIM, colorama.Fore.CYAN, data["pid"],
+                        colorama.Style.DIM, color_for(data), data["pid"],
                         data["ip"], colorama.Style.RESET_ALL, line))
 
             if (num_consecutive_messages_received % 100 == 0

src/ray/util/logging.cc

@@ -11,11 +11,28 @@
 #include <iostream>
 
 #ifdef RAY_USE_GLOG
+#include <sys/stat.h>
 #include "glog/logging.h"
 #endif
 
 namespace ray {
 
+#ifdef RAY_USE_GLOG
+struct StdoutLogger : public google::base::Logger {
+  virtual void Write(bool /* should flush */, time_t /* timestamp */, const char *message,
+                     int length) {
+    // note: always flush otherwise it never shows up in raylet.out
+    std::cout << std::string(message, length) << std::flush;
+  }
+
+  virtual void Flush() { std::cout.flush(); }
+
+  virtual google::uint32 LogSize() { return 0; }
+};
+
+static StdoutLogger stdout_logger_singleton;
+#endif
+
 // This is the default implementation of ray log,
 // which is independent of any libs.
 class CerrLog {
@@ -122,7 +139,12 @@ void RayLog::StartRayLog(const std::string &app_name, RayLogLevel severity_thres
 #ifdef RAY_USE_GLOG
   google::InitGoogleLogging(app_name_.c_str());
   int mapped_severity_threshold = GetMappedSeverity(severity_threshold_);
-  google::SetStderrLogging(mapped_severity_threshold);
+  google::SetStderrLogging(GetMappedSeverity(RayLogLevel::ERROR));
+  for (int i = static_cast<int>(severity_threshold_);
+       i <= static_cast<int>(RayLogLevel::FATAL); ++i) {
+    int level = GetMappedSeverity(static_cast<RayLogLevel>(i));
+    google::base::SetLogger(level, &stdout_logger_singleton);
+  }
   // Enable log file if log_dir_ is not empty.
   if (!log_dir_.empty()) {
     auto dir_ends_with_slash = log_dir_;