[tune] Report failures in a separate table (#6160)

* Report errors in a separate table.

* Single error file.

python/ray/tune/progress_reporter.py

@@ -1,11 +1,8 @@
 from __future__ import print_function
 
-import os
-
-from ray.tune.result import (DEFAULT_RESULT_KEYS, CONFIG_PREFIX, PID,
+from ray.tune.result import (DEFAULT_RESULT_KEYS, CONFIG_PREFIX,
                              EPISODE_REWARD_MEAN, MEAN_ACCURACY, MEAN_LOSS,
-                             HOSTNAME, TRAINING_ITERATION, TIME_TOTAL_S,
-                             TIMESTEPS_TOTAL)
+                             TRAINING_ITERATION, TIME_TOTAL_S, TIMESTEPS_TOTAL)
 from ray.tune.util import flatten_dict
 
 try:
@@ -129,48 +126,47 @@ def trial_progress_str(trials, metrics=None, fmt="psql", max_rows=100):
     # Pre-process trials to figure out what columns to show.
     keys = list(metrics or DEFAULT_PROGRESS_KEYS)
     keys = [k for k in keys if any(t.last_result.get(k) for t in trials)]
-    has_failed = any(t.error_file for t in trials)
-    # Build rows.
+
+    # Build trial rows.
     trial_table = []
     params = list(set().union(*[t.evaluated_params for t in trials]))
     for trial in trials[:min(num_trials, max_rows)]:
-        trial_table.append(_get_trial_info(trial, params, keys, has_failed))
+        trial_table.append(_get_trial_info(trial, params, keys))
     # Parse columns.
     parsed_columns = [REPORTED_REPRESENTATIONS.get(k, k) for k in keys]
     columns = ["Trial name", "status", "loc"]
-    columns += ["failures", "error file"] if has_failed else []
     columns += params + parsed_columns
     messages.append(
         tabulate(trial_table, headers=columns, tablefmt=fmt, showindex=False))
+
+    # Build trial error rows.
+    failed = [t for t in trials if t.error_file]
+    if len(failed) > 0:
+        messages.append("Number of errored trials: {}".format(len(failed)))
+        error_table = []
+        for trial in failed:
+            row = [str(trial), trial.num_failures, trial.error_file]
+            error_table.append(row)
+        columns = ["Trial name", "# failures", "error file"]
+        messages.append(
+            tabulate(
+                error_table, headers=columns, tablefmt=fmt, showindex=False))
+
     return delim.join(messages)
 
 
-def _get_trial_info(trial, parameters, metrics, include_error_data=False):
+def _get_trial_info(trial, parameters, metrics):
     """Returns the following information about a trial:
 
-    name | status | loc | # failures | error_file | params... | metrics...
+    name | status | loc | params... | metrics...
 
     Args:
         trial (Trial): Trial to get information for.
         parameters (List[str]): Names of trial parameters to include.
         metrics (List[str]): Names of metrics to include.
-        include_error_data (bool): Include error file and # of failures.
     """
     result = flatten_dict(trial.last_result)
-    trial_info = [str(trial), trial.status]
-    trial_info += [_location_str(result.get(HOSTNAME), result.get(PID))]
-    if include_error_data:
-        # TODO(ujvl): File path is too long to display in a single row.
-        trial_info += [trial.num_failures, trial.error_file]
+    trial_info = [str(trial), trial.status, str(trial.address)]
     trial_info += [result.get(CONFIG_PREFIX + param) for param in parameters]
     trial_info += [result.get(metric) for metric in metrics]
     return trial_info
-
-
-def _location_str(hostname, pid):
-    if not pid:
-        return ""
-    elif hostname == os.uname()[1]:
-        return "pid={}".format(pid)
-    else:
-        return "{}:{}".format(hostname, pid)

python/ray/tune/trial.py

@@ -260,12 +260,11 @@ class Trial(object):
     def write_error_log(self, error_msg):
         if error_msg and self.logdir:
             self.num_failures += 1  # may be moved to outer scope?
-            error_file = os.path.join(self.logdir,
-                                      "error_{}.txt".format(date_str()))
-            with open(error_file, "a+") as f:
-                f.write("Failure # {}".format(self.num_failures) + "\n")
+            self.error_file = os.path.join(self.logdir, "error.txt")
+            with open(self.error_file, "a+") as f:
+                f.write("Failure # {} (occurred at {})\n".format(
+                    self.num_failures, date_str()))
                 f.write(error_msg + "\n")
-            self.error_file = error_file
             self.error_msg = error_msg
 
     def should_stop(self, result):