chore: remove unused DEFAULT_MAX_PARALLEL dead code

Author: manascb1344

DEPLOY.md

@@ -142,6 +142,5 @@ GitHub retries webhooks when responses are slow or network issues occur. This is
 | `BLOCK_NETWORK` | No | `false` | Fully isolate sandbox network |
 | `CACHE_VOLUME_NAME` | No | - | Modal Volume name for persistent `/cache` mount |
 | `MODAL_REGION` | No | - | Modal region for sandbox deployment |
-| `DEFAULT_MAX_PARALLEL` | No | `2` | Default max concurrent sandboxes |
 | `SANDBOX_EXTRA_ENV` | No | - | JSON string of extra env vars for sandboxes |
 | `GITHUB_ENTERPRISE_DOMAIN` | No | - | Custom domain for GitHub Enterprise |

README.md

@@ -166,7 +166,6 @@ sequenceDiagram
 | `CACHE_VOLUME_NAME` | No | | Modal Volume name for persistent `/cache` |
 | `MODAL_REGION` | No | | Modal region for sandbox deployment |
 | `SANDBOX_EXTRA_ENV` | No | | JSON string of extra env vars for sandboxes |
-| `DEFAULT_MAX_PARALLEL` | No | `2` | Default max concurrent sandboxes |
 | `GITHUB_ENTERPRISE_DOMAIN` | No | | Custom domain for GitHub Enterprise |
 
 ## Limitations

runner/config.py

@@ -77,20 +77,23 @@
     except json.JSONDecodeError:
         logging.getLogger("runner").warning("SANDBOX_EXTRA_ENV is not valid JSON, ignoring")
 
-# Default max concurrent sandboxes
-try:
-    DEFAULT_MAX_PARALLEL = max(1, int(os.environ.get("DEFAULT_MAX_PARALLEL", "2")))
-except ValueError:
-    logging.getLogger("runner").warning("Invalid DEFAULT_MAX_PARALLEL; using default=2")
-    DEFAULT_MAX_PARALLEL = 2
-
 # GitHub runner group ID
 try:
     RUNNER_GROUP_ID = int(os.environ.get("RUNNER_GROUP_ID", "1"))
 except ValueError:
     logging.getLogger("runner").warning("Invalid RUNNER_GROUP_ID; using default=1")
     RUNNER_GROUP_ID = 1
 
+# Sandbox spawn retry configuration (for transient failures under load)
+try:
+    SANDBOX_MAX_RETRIES = max(0, int(os.environ.get("SANDBOX_MAX_RETRIES", "3")))
+except ValueError:
+    logging.getLogger("runner").warning("Invalid SANDBOX_MAX_RETRIES; using default=3")
+    SANDBOX_MAX_RETRIES = 3
+
+# Backoff delays in seconds for sandbox spawn retries (exponential)
+SANDBOX_RETRY_BACKOFF = [1, 2, 4]
+
 
 def get_gpu_config(gpu_key: str):
     """Resolve a GPU label key to a Modal GPU config object."""