Stop leaking JetStream consumers on reopen; tighten reconnect detection (2.0.3)

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "serverish"
-version = "2.0.2"
+version = "2.0.3"
 description = "helpers for server alike projects"
 authors = ["Mikołaj Kałuszyński", "MMME team"]
 readme = "README.md"

serverish/messenger/msg_reader.py

@@ -292,10 +292,13 @@ async def read_batch(self) -> None:
                             log.debug(self.fmt(f"No messages available, finishing due to nowait"))
                             raise self.EndIterationException('nowait')
 
-                        # Non-nowait mode: wait for NEW messages to arrive
-                        # Break into shorter intervals to allow health checks and reconnection handling
-                        blocking_interval = 10.0  # Check every 10 seconds
-                        max_wait_cycles = 10  # Total wait: 10 * 10s = 100s
+                        # Non-nowait mode: wait for NEW messages to arrive.
+                        # Break into shorter intervals so the reconnect-needed
+                        # check at the top of the loop runs often enough that
+                        # low-rate subjects don't sit on a stale subscription
+                        # for tens of seconds after a NATS reconnect.
+                        blocking_interval = 2.0
+                        max_wait_cycles = 50  # Total wait: 50 * 2s = 100s (unchanged)
 
                         for cycle in range(max_wait_cycles):
                             # Check for reconnection before each wait cycle
@@ -621,12 +624,28 @@ async def _reopen(self) -> None:
         max_retries = 3
         for attempt in range(max_retries):
             try:
-                # Clean up existing subscription
+                # Clean up existing subscription. `unsubscribe()` only detaches the
+                # local handle; the JetStream consumer must be deleted explicitly
+                # or it leaks server-side across every reconnect (one orphan per
+                # reopen, accumulating until the stream's consumer cap or the
+                # process restarts).
                 if self.pull_subscription is not None:
+                    try:
+                        ci = await self.pull_subscription.consumer_info()
+                    except Exception as e:
+                        log.debug(f"Error fetching consumer_info during reopen attempt {attempt + 1}: {e}")
+                        ci = None
                     try:
                         await self.pull_subscription.unsubscribe()
                     except Exception as e:
                         log.debug(f"Error unsubscribing during reopen attempt {attempt + 1}: {e}")
+                    if ci is not None:
+                        try:
+                            await self.connection.js.delete_consumer(stream=ci.stream_name, consumer=ci.name)
+                        except nats.js.errors.NotFoundError:
+                            pass  # already gone, nothing to delete
+                        except Exception as e:
+                            log.debug(f"Error deleting old consumer during reopen attempt {attempt + 1}: {e}")
 
                 # Create new consumer configuration
                 consumer_conf = await self._create_consumer_cfg()