HDDS-7557. Translate "Merge Container RocksDB in DN" doc to Mandarin Chinese

hadoop-hdds/docs/content/feature/dn-merge-rocksdb.zh.md

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+---
+title: "在DataNode上合并Container的RocksDB"
+weight: 2
+menu:
+   main:
+      parent: 特性
+summary: Ozone DataNode Container模式简介V3
+---
+<!---
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
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+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+
+在 Ozone 中，用户数据被分割成blocks并存储在 HDDS Container中。Container是 Ozone/HDDS 的基本复制单元。每个Container都有自己的元数据和数据, 数据以文件形式保存在磁盘上，元数据保存在RocksDB中。
+
+目前，数据节点上的每个Container都有一个RocksDB。随着用户数据的不断增长，一个DataNode上将会有成百上千个RocksDB实例。在一个JVM中管理如此多的RocksDB实例是一个巨大的挑战。
+
+与当前使用方法不同，"Merge Container RocksDB in DN"功能将为每个Volume只使用一个RocksDB，并在此RocksDB中保存所有Container的元数据。
+
+## 配置
+
+这主要是DataNode的功能，不需要太多配置。
+
+如果更倾向于为每个Container使用一个RocksDB的模式，那么这下面的配置可以禁用上面所介绍的功能。请注意，一旦启用该功能，强烈建议以后不要再禁用。
+
+```XML
+<property>
+   <name>hdds.datanode.container.schema.v3.enabled</name>
+   <value>false</value>
+   <description>Disable or enable this feature.</description>
+</property>
+```
+
+无需任何特殊配置，单个RocksDB将会被创建在"hdds.datanode.dir"中所配置的数据卷下。
+
+对于一些有高性能要求的高级集群管理员，他/她可以利用快速存储来保存RocksDB。在这种情况下，请配置下面这两个属性。
+
+```XML
+<property>
+   <name>hdds.datanode.container.db.dir</name>
+   <value/>
+   <description>This setting is optional. Specify where the per-disk rocksdb instances will be stored.</description>
+</property>
+<property>
+   <name>hdds.datanode.failed.db.volumes.tolerated</name>
+   <value>-1</value>
+   <description>The number of db volumes that are allowed to fail before a datanode stops offering service.
+   Default -1 means unlimited, but we should have at least one good volume left.</description>
+</property>
+```
+
+### 向后兼容性 
+
+Existing containers each has one RocksDB for them will be still accessible after this feature is enabled. All container data will co-exist in an existing Ozone cluster.
+
+## 参考文献
+
+ * [设计文档]({{< ref path="design/dn-merge-rocksdb.md" lang="en">}})