[debug]: add some debug log (#699)

Co-authored-by: shihaobai <baishihao@sensetime.com>

Author: shihaobai

lightllm/server/router/model_infer/model_rpc.py

@@ -93,15 +93,23 @@ def exposed_add_batch(self, batch_id, reqs):
 
     # @calculate_time(show=False, min_cost_ms=300)
     def exposed_prefill_batch(self, batch_id):
-        if self.world_size != 1:
-            batch_id = obtain(batch_id)
-        return self.backend.prefill_batch(batch_id)
+        try:
+            if self.world_size != 1:
+                batch_id = obtain(batch_id)
+            return self.backend.prefill_batch(batch_id)
+        except Exception as e:
+            err_msg = str(e)
+            logger.exception(f"Batch prefill encountered an unexpected ERROR: {err_msg}")
 
     # @calculate_time(show=True, min_cost_ms=200)
     def exposed_decode_batch(self, batch_id):
-        if self.world_size != 1:
-            batch_id = obtain(batch_id)
-        return self.backend.decode_batch(batch_id)
+        try:
+            if self.world_size != 1:
+                batch_id = obtain(batch_id)
+            return self.backend.decode_batch(batch_id)
+        except Exception as e:
+            err_msg = str(e)
+            logger.exception(f"Batch decode encountered an unexpected ERROR: {err_msg}")
 
     # @calculate_time(show=True, min_cost_ms=0.1)
     def exposed_filter_batch(self, batch_id, req_id_list, finished_req_id_list):