[skip ci] update milvus_benchmark (#4288)

Co-authored-by: Nzw <zw@milvus.io>

tests/milvus_benchmark/README.md

@@ -2,9 +2,19 @@
 
 ### Description：
 
-- Test cases can be organized with `yaml `
+This project is used to test performance/reliability/stability for milvus server
+- Test cases can be organized with `yaml`
 - Test can run with local mode or helm mode
 
+### Usage:
+`pip install requirements.txt`
+
+if using local mode, the following libs is optional
+
+`pymongo==3.10.0` 
+
+`kubernetes==10.0.1`
+
 ### Demos：
 
 1. Using jenkins + helm mode：
@@ -26,13 +36,14 @@ The following are the searching performance test suite：
 1. search_performance: the test type，also we have`build_performance`,`insert_performance`,`accuracy`,`stability`,`search_stability`
 2. tables: list of test cases
 3. The following fields are in the `table` field：
-   - server: milvus的server_config
-   - table_name: currently support one table
+   - server: run host
+   - milvus: config in milvus
+   - collection_name: currently support one collection
    - run_count: search count
-   - search_params: params of search_vectors
+   - search_params: params of query
 
 ## Test result：
 
 The result of searching performance![](assets/milvus-nightly-performance-new-jenkins.png)
 
-Test result will be uploaded, and will be used to judge if the test run pass or failed
+Test result will be uploaded if tests run in helm mode, and will be used to judge if the test run pass or failed

tests/milvus_benchmark/main.py

@@ -12,7 +12,6 @@ from logging import handlers
 from yaml import full_load, dump
 from local_runner import LocalRunner
 from docker_runner import DockerRunner
-from k8s_runner import K8sRunner
 import parser
 
 DEFAULT_IMAGE = "milvusdb/milvus:latest"
@@ -54,6 +53,7 @@ def get_image_tag(image_version, image_type):
 
 
 def queue_worker(queue):
+    from k8s_runner import K8sRunner
     while not queue.empty():
         q = queue.get()
         suite = q["suite"]