Track native HTTP failed attempt timing

scripts/bench_episode_byte_cache.py

@@ -620,6 +620,7 @@ def _print_range_timing_summary(fetch_pool: dict[str, float]) -> None:
         ("range_body_s", "http body drain"),
         ("range_chunk_gap_s", "http chunk wait"),
         ("range_join_s", "join response chunks"),
+        ("range_failed_attempt_s", "http failed attempts"),
         ("range_retry_sleep_s", "http retry sleep"),
     ):
         value = fetch_pool.get(key)
@@ -627,8 +628,18 @@ def _print_range_timing_summary(fetch_pool: dict[str, float]) -> None:
             print(f"| {label} | {value * 1000 / range_jobs:.3f} |")
     if "range_retry_attempts" in fetch_pool:
         print(f"| http retries | {fetch_pool['range_retry_attempts'] / range_jobs:.3f} |")
+    if "range_exception_attempts" in fetch_pool:
+        print(f"| http exceptions | {fetch_pool['range_exception_attempts'] / range_jobs:.3f} |")
     if fetch_pool.get("range_failed_requests"):
         print(f"| http failed requests | {fetch_pool['range_failed_requests']:.0f} |")
+    exception_counts = {
+        key.removeprefix("range_exception_"): value
+        for key, value in fetch_pool.items()
+        if key.startswith("range_exception_")
+    }
+    if exception_counts:
+        summary = ", ".join(f"{name}={count:.0f}" for name, count in sorted(exception_counts.items()))
+        print(f"| http exception counts | {summary} |")
     status_counts = {
         key.removeprefix("range_status_"): value
         for key, value in fetch_pool.items()

src/lerobot/datasets/episode_video_streaming.py

@@ -344,14 +344,25 @@ class NativeHTTPRangeFetcher:
         last_exc: Exception | None = None
         retry_attempts = 0.0
         retry_sleep_s = 0.0
+        failed_attempt_s = 0.0
+        exception_attempts = 0.0
+        exception_counts: dict[str, float] = {}
         for attempt in range(self.max_retries + 1):
+            attempt_start = time.perf_counter()
             try:
                 payload, status_code, timings = self._read_range_response_once(url, headers)
                 timings["range_retry_attempts"] = retry_attempts
                 timings["range_retry_sleep_s"] = retry_sleep_s
+                timings["range_failed_attempt_s"] = failed_attempt_s
+                timings["range_exception_attempts"] = exception_attempts
+                timings.update(exception_counts)
                 return payload, status_code, timings
             except self._RETRYABLE_EXCEPTIONS as exc:
                 last_exc = exc
+                failed_attempt_s += time.perf_counter() - attempt_start
+                exception_attempts += 1.0
+                exception_key = f"range_exception_{type(exc).__name__}"
+                exception_counts[exception_key] = exception_counts.get(exception_key, 0.0) + 1.0
                 if attempt >= self.max_retries:
                     break
                 retry_attempts += 1.0
@@ -362,6 +373,9 @@ class NativeHTTPRangeFetcher:
             range_failed_requests=1.0,
             range_retry_attempts=retry_attempts,
             range_retry_sleep_s=retry_sleep_s,
+            range_failed_attempt_s=failed_attempt_s,
+            range_exception_attempts=exception_attempts,
+            **exception_counts,
         )
         if last_exc is None:
             raise RuntimeError("HTTP range request failed without an exception")