From e9bb629e3e33f0b869b9ba7b255d5015938da839 Mon Sep 17 00:00:00 2001
From: Enwei <jinenwei@pingcap.com>
Date: Thu, 5 May 2022 16:50:55 +0800
Subject: [PATCH] Refine the format of JSON and add methods to change PD
 configuration (#8374)

---
 two-data-centers-in-one-city-deployment.md | 166 ++++++++++++---------
 1 file changed, 94 insertions(+), 72 deletions(-)

diff --git a/two-data-centers-in-one-city-deployment.md b/two-data-centers-in-one-city-deployment.md
index 5ced6853c113b..24fada8515331 100644
--- a/two-data-centers-in-one-city-deployment.md
+++ b/two-data-centers-in-one-city-deployment.md
@@ -88,68 +88,75 @@ cat rule.json
 [
   {
     "group_id": "pd",
-    "id": "zone-east",
-    "start_key": "",
-    "end_key": "",
-    "role": "voter",
-    "count": 2,
-    "label_constraints": [
+    "group_index": 0,
+    "group_override": false,
+    "rules": [
       {
-        "key": "zone",
-        "op": "in",
-        "values": [
-          "east"
+        "group_id": "pd",
+        "id": "zone-east",
+        "start_key": "",
+        "end_key": "",
+        "role": "voter",
+        "count": 2,
+        "label_constraints": [
+          {
+            "key": "zone",
+            "op": "in",
+            "values": [
+              "east"
+            ]
+          }
+        ],
+        "location_labels": [
+          "zone",
+          "rack",
+          "host"
         ]
-      }
-    ],
-    "location_labels": [
-      "zone",
-      "rack",
-      "host",
-    ]
-  },
-  {
-    "group_id": "pd",
-    "id": "zone-west",
-    "start_key": "",
-    "end_key": "",
-    "role": "voter",
-    "count": 1,
-    "label_constraints": [
+      },
       {
-        "key": "zone",
-        "op": "in",
-        "values": [
-          "west"
+        "group_id": "pd",
+        "id": "zone-west",
+        "start_key": "",
+        "end_key": "",
+        "role": "voter",
+        "count": 1,
+        "label_constraints": [
+          {
+            "key": "zone",
+            "op": "in",
+            "values": [
+              "west"
+            ]
+          }
+        ],
+        "location_labels": [
+          "zone",
+          "rack",
+          "host"
         ]
-      }
-    ],
-    "location_labels": [
-      "zone",
-      "rack",
-      "host"
-    ]
-  },
-  {
-    "group_id": "pd",
-    "id": "zone-west",
-    "start_key": "",
-    "end_key": "",
-    "role": "learner",
-    "count": 1,
-    "label_constraints": [
+      },
       {
-        "key": "zone",
-        "op": "in",
-        "values": [
-          "west"
+        "group_id": "pd",
+        "id": "zone-west",
+        "start_key": "",
+        "end_key": "",
+        "role": "learner",
+        "count": 1,
+        "label_constraints": [
+          {
+            "key": "zone",
+            "op": "in",
+            "values": [
+              "west"
+            ]
+          }
+        ],
+        "location_labels": [
+          "zone",
+          "rack",
+          "host"
         ]
       }
-    ],
-    "location_labels": [
-      "zone",
-      "rack",
-      "host"
     ]
   }
 ]
@@ -165,24 +172,39 @@ pd-ctl config placement-rules rule-bundle save --in="rule.json"
 
 ### Enable the DR Auto-Sync mode
 
-The replication mode is controlled by PD. When deploying a cluster, you can configure the replication mode in the PD configuration file. For example:
-
-{{< copyable "" >}}
-
-```toml
-[replication-mode]
-replication-mode = "dr-auto-sync"
-[replication-mode.dr-auto-sync]
-label-key = "zone"
-primary = "east"
-dr = "west"
-primary-replicas = 2
-dr-replicas = 1
-wait-store-timeout = "1m"
-wait-sync-timeout = "1m"
-```
+The replication mode is controlled by PD. You can configure the replication mode in the PD configuration file using one of the following methods:
+
+- Method 1: Configure the PD configuration file, and then deploy a cluster.
+
+    {{< copyable "" >}}
+
+    ```toml
+    [replication-mode]
+    replication-mode = "dr-auto-sync"
+    [replication-mode.dr-auto-sync]
+    label-key = "zone"
+    primary = "east"
+    dr = "west"
+    primary-replicas = 2
+    dr-replicas = 1
+    wait-store-timeout = "1m"
+    wait-sync-timeout = "1m"
+    ```
+
+- Method 2: If you have deployed a cluster, use pd-ctl commands to modify the configurations of PD.
+
+    {{< copyable "" >}}
+
+    ```shell
+    config set replication-mode dr-auto-sync
+    config set replication-mode dr-auto-sync label-key zone
+    config set replication-mode dr-auto-sync primary east
+    config set replication-mode dr-auto-sync dr west
+    config set replication-mode dr-auto-sync primary-replicas 2
+    config set replication-mode dr-auto-sync dr-replicas 1
+    ```
 
-In the configuration above:
+Descriptions of configuration items:
 
 + `replication-mode` is the replication mode to be enabled. In the above example, it is set to `dr-auto-sync`. By default, the majority protocol is used.
 + `label-key` is used to distinguish different data centers and needs to match Placement Rules. In this example, the primary data center is "east" and the DR data center is "west".