en: add recommended configs for cluster deployment (pingcap#692)

Signed-off-by: Ran <[email protected]>

en/configure-a-tidb-cluster.md

@@ -24,15 +24,13 @@ If you are using a NUMA-based CPU, you need to enable `Static`'s CPU management
 
 ## Configure TiDB deployment
 
-To configure a TiDB deployment, you need to configure the `TiDBCluster` CR. Refer to the [TidbCluster example](https://github.com/pingcap/tidb-operator/blob/master/examples/tiflash/tidb-cluster.yaml) for an example. For the complete configurations of `TiDBCluster` CR, refer to [API documentation](https://github.com/pingcap/tidb-operator/blob/master/docs/api-references/docs.md).
+To configure a TiDB deployment, you need to configure the `TiDBCluster` CR. Refer to the [TidbCluster example](https://github.com/pingcap/tidb-operator/blob/master/examples/advanced/tidb-cluster.yaml) for an example. For the complete configurations of `TiDBCluster` CR, refer to [API documentation](https://github.com/pingcap/tidb-operator/blob/master/docs/api-references/docs.md).
 
 > **Note:**
 >
 > It is recommended to organize configurations for a TiDB cluster under a directory of `cluster_name` and save it as `${cluster_name}/tidb-cluster.yaml`.
 The modified configuration is not automatically applied to the TiDB cluster by default. The new configuration file is loaded only when the Pod restarts.
 
-It is recommended that you set `spec.configUpdateStrategy` to `RollingUpdate` to enable automatic update of configurations. This way, every time the configuration is updated, all components are rolling updated automatically, and the modified configuration is applied to the cluster.
-
 ### Cluster name
 
 The cluster name can be configured by changing `metadata.name` in the `TiDBCuster` CR.
@@ -48,6 +46,25 @@ Here are the formats of the parameters:
 
 - `spec.<pd/tidb/tikv/pump/tiflash/ticdc>.version`: the format is `imageTag`, such as `v4.0.4`
 
+### Recommended configuration
+
+#### configUpdateStrategy
+
+It is recommended that you configure `spec.configUpdateStrategy: RollingUpdate` to enable automatic update of configurations. This way, every time the configuration is updated, all components are rolling updated automatically, and the modified configuration is applied to the cluster.
+
+#### enableDynamicConfiguration
+
+It is recommended that you configure `spec.enableDynamicConfiguration: true` to enable the dynamic configuration feature.
+
+Versions required:
+
+- TiDB 4.0.1 or later versions
+- TiDB Operator 1.1.1 or later versions
+
+#### pvReclaimPolicy
+
+It is recommended that you configure `spec.pvReclaimPolicy: Retain` to ensure that the PV is retained even if the PVC is deleted. This is to ensure your data safety.
+
 ### Storage class
 
 You can set the storage class by modifying `storageClassName` of each component in `${cluster_name}/tidb-cluster.yaml` and `${cluster_name}/tidb-monitor.yaml`. For the [storage classes](configure-storage-class.md) supported by the Kubernetes cluster, check with your system administrator.