单节点扩容为三节点文章地址：

https://www.modb.pro/db/190765

本文介绍了1个observer扩容为3个observer集群之后，sys租户副本调整相关问题。

主要涉及知识点为：

Locality 的设置通常用于集群的副本数升级、降级或集群的搬迁：

• 集群副本数升级

以租户为粒度，对集群中的每一个租户，增加租户下 Partition 的副本数。例如，将 Locality 由 F@z1 变更为 F@z1,F@z2,F@z，租户从 1 副本变为 3 副本。

1 系统扩容完成之后，查询节点信息

原来集群只有zone1单个节点，扩容zone2,zone3节点。

MySQL [oceanbase]> select * from __all_server;
+----------------------------+----------------------------+---------------+----------+----+-------+------------+-----------------+--------+-----------------------+------------------------------------------------------------------------+-----------+--------------------+--------------+----------------+-------------------+
| gmt_create                 | gmt_modified               | svr_ip        | svr_port | id | zone  | inner_port | with_rootserver | status | block_migrate_in_time | build_version                                                          | stop_time | start_service_time | first_sessid | with_partition | last_offline_time |
+----------------------------+----------------------------+---------------+----------+----+-------+------------+-----------------+--------+-----------------------+------------------------------------------------------------------------+-----------+--------------------+--------------+----------------+-------------------+
| 2021-12-07 15:52:36.583969 | 2021-12-07 15:52:48.009135 | 192.168.5.200 |     2882 |  1 | zone1 |       2881 |               1 | active |                     0 | 3.1.1_4-8c615943cbd25a6f7b8bdfd8677a13a21709a05e(Oct 21 2021 10:33:14) |         0 |   1638863566011754 |            0 |              1 |                 0 |
| 2021-12-07 15:56:07.681043 | 2021-12-07 15:56:30.391582 | 192.168.5.200 |     3882 |  2 | zone2 |       3881 |               0 | active |                     0 | 3.1.1_4-8c615943cbd25a6f7b8bdfd8677a13a21709a05e(Oct 21 2021 10:33:14) |         0 |   1638863788395674 |            0 |              0 |                 0 |
| 2021-12-07 15:56:11.908905 | 2021-12-07 15:56:31.793939 | 192.168.5.200 |     4882 |  3 | zone3 |       4881 |               0 | active |                     0 | 3.1.1_4-8c615943cbd25a6f7b8bdfd8677a13a21709a05e(Oct 21 2021 10:33:14) |         0 |   1638863789811151 |            0 |              0 |                 0 |
+----------------------------+----------------------------+---------------+----------+----+-------+------------+-----------------+--------+-----------------------+------------------------------------------------------------------------+-----------+--------------------+--------------+----------------+-------------------+
3 rows in set (0.000 sec)