diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1cefe1fb6e..2023622910 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -57,6 +57,7 @@ Please mark all change in change log and use the issue from GitHub
 -   \#1577 Row count incorrect if delete vectors then create index
 -   \#1580 Old segment folder not removed after merge/compact if create_index is called before adding data
 -   \#1590 Server down caused by failure to write file during concurrent mixed operations
+-   \#1601 External link bug in HTTP doc
 
 ## Feature
 -   \#216 Add CLI to get server info
diff --git a/core/src/server/web_impl/README.md b/core/src/server/web_impl/README.md
index 6100894df9..3abe5a462c 100644
--- a/core/src/server/web_impl/README.md
+++ b/core/src/server/web_impl/README.md
@@ -391,7 +391,7 @@ $ curl -X GET "http://127.0.0.1:19121/collections?offset=0&page_size=1" -H "acce
       "metric_type": "L2",
       "count": 0,
       "index": "FLAT",
-      "nlist": 16384
+      "index_params": {"nlist":  4096}
     }
   ],
   "count": 58
@@ -517,7 +517,7 @@ $ curl -X GET "http://127.0.0.1:19121/collections/test_collection" -H "accept: a
   "metric_type": "L2",
   "count": 0,
   "index": "FLAT",
-  "index_params": {}
+  "index_params": {"nprobe":  16384}
 }
 ```
 
@@ -539,7 +539,7 @@ $ curl -X GET "http://127.0.0.1:19121/collections/test_collection?info=stat" -H
       "segments_stat": [
         {
           "count": 1000,
-          "index": "IVFFLAT",
+          "index": "FLAT",
           "segment_name": "1583727170217439000",
           "size": 5284922
         }
@@ -681,7 +681,7 @@ Updates the index type and nlist of a collection.
 | Parameter    | Description                                                                                                                                                                                              | Required? |
 | ------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------- |
 | `index_type` | The type of indexing method to query the collection. Please refer to [Index Types](https://www.milvus.io/docs/reference/index.md) for detailed introduction of supported indexes. The default is "FLAT". | No        |
-| `params`     | The extra params of indexing method to query the collection. Please refer to - [Index params](#index_param) for detailed introduction of supported indexes.                                              | No        |
+| `params`     | The extra params of indexing method to query the collection. Please refer to [Index and search parameters](#Index-and-search-parameters) for detailed introduction of supported indexes.                                              | No        |
 
 ##### Query Parameters
 
@@ -1122,7 +1122,7 @@ $ curl -X GET "http://127.0.0.1:19121/collections/test_collection/segments/15837
 | `tags`     | Tags of partitions that you need to search. You do not have to specify this value if the collection is not partitioned or you wish to search the whole collection.                           | No        |
 | `file_ids` | IDs of the vector files. You do not have to specify this value if you do not use Milvus in distributed scenarios. Also, if you assign a value to `file_ids`, the value of `tags` is ignored. | No        |
 | `vectors`  | Vectors to query.                                                                                                                                                                            | Yes       |
-| `params`   | Extra params for search. Please refer to [Search param](#index_param) to get more detail information.                                                                                        | Yes       |
+| `params`   | Extra params for search. Please refer to [Index and search parameters](#Index-and-search-parameters) to get more detail information.                                                                                        | Yes       |
 
 > Note: Type of items of vectors depends on the metric used by the collection. If the collection uses `L2` or `IP`, you must use `float`. If the collection uses `HAMMING`, `JACCARD`, or `TANIMOTO`, you must use `uint8`.
 
@@ -1510,7 +1510,7 @@ $ curl -X PUT "http://127.0.0.1:19121/system/task" -H "accept: application/json"
 { "code": 0, "message": "success" }
 ```
 
-## Index parameters
+## Index and search parameters
 
 For each index type, the RESTful API has specific index parameters and search parameters.
 
diff --git a/core/src/server/web_impl/controller/WebController.hpp b/core/src/server/web_impl/controller/WebController.hpp
index 55a51168a3..f326578405 100644
--- a/core/src/server/web_impl/controller/WebController.hpp
+++ b/core/src/server/web_impl/controller/WebController.hpp
@@ -617,10 +617,7 @@ class WebController : public oatpp::web::server::api::ApiController {
     }
 
     ADD_CORS(VectorsOp)
-    /*************
-     * Search
-     * Delete by ID
-     * */
+
     ENDPOINT("PUT", "/collections/{collection_name}/vectors", VectorsOp,
              PATH(String, collection_name), BODY_STRING(String, body)) {
         TimeRecorder tr(std::string(WEB_LOG_PREFIX) + "PUT \'/collections/" + collection_name->std_str() + "/vectors\'");
@@ -648,6 +645,12 @@ class WebController : public oatpp::web::server::api::ApiController {
         return response;
     }
 
+    ADD_CORS(SystemOptions)
+
+    ENDPOINT("OPTIONS", "/system/{info}", SystemOptions) {
+        return createResponse(Status::CODE_204, "No Content");
+    }
+
     ADD_CORS(SystemInfo)
 
     ENDPOINT("GET", "/system/{info}", SystemInfo, PATH(String, info), QUERIES(const QueryParams&, query_params)) {