Make the stratifier drop a client id if it's still trying to send to a client that no longer exists in the connector

src/connector.c

@@ -177,18 +177,23 @@ static int drop_client(conn_instance_t *ci, client_instance_t *client)
 	return fd;
 }
 
+static void stratifier_drop_client(ckpool_t *ckp, int64_t id)
+{
+	char buf[256];
+
+	sprintf(buf, "dropclient=%ld", id);
+	send_proc(ckp->stratifier, buf);
+}
+
 /* Invalidate this instance. Remove them from the hashtables we look up
  * regularly but keep the instances in a linked list indefinitely in case we
  * still reference any of its members. */
 static void invalidate_client(ckpool_t *ckp, conn_instance_t *ci, client_instance_t *client)
 {
-	char buf[256];
-
 	drop_client(ci, client);
 	if (ckp->passthrough)
 		return;
-	sprintf(buf, "dropclient=%ld", client->id);
-	send_proc(ckp->stratifier, buf);
+	stratifier_drop_client(ckp, client->id);
 }
 
 static void send_client(conn_instance_t *ci, int64_t id, char *buf);
@@ -492,12 +497,16 @@ static void send_client(conn_instance_t *ci, int64_t id, char *buf)
 	ck_runlock(&ci->lock);
 
 	if (unlikely(fd == -1)) {
+		ckpool_t *ckp = ci->pi->ckp;
+
 		if (client) {
 			/* This shouldn't happen */
 			LOGWARNING("Client id %ld disconnected but fd already invalidated!", id);
-			invalidate_client(ci->pi->ckp, ci, client);
-		} else
+			invalidate_client(ckp, ci, client);
+		} else {
 			LOGINFO("Connector failed to find client id %ld to send to", id);
+			stratifier_drop_client(ckp, id);
+		}
 		free(buf);
 		return;
 	}