code: def task_4(data_size, host):
      """
      task_4:
          before upgrade: create collection, insert data, flush, and create index
          after upgrade: get collection, load with multi replicas, search, insert data, load with multi replicas and search
      """
      prefix = "task_4_"
      connections.connect(host=host, port=19530, timeout=60)
      col_list = get_collections(prefix, check=True)
      assert len(col_list) > 0
      load_and_search(prefix, replicas=NUM_REPLICAS)
      create_collections_and_insert_data(
          prefix, flush=False, count=data_size
      )
      load_and_search(prefix, replicas=NUM_REPLICAS)
  
file_path: milvus/tests/python_client/deploy/scripts/action_after_upgrade.py
imports: from pymilvus import connections
  import sys
  from common.milvus_sys import MilvusSys
  from utils import *
label_desc: Use image node_id 4 for calling a global function with example usage: task_4(data_size, host) without return types