踩坑记录之普通租户无法连接 OceanBase 数据库

复现步骤

1.创建资源单元。

CREATE RESOURCE UNIT S2 max_cpu=8, min_cpu=8, max_memory='16G',min_memory='16G',max_iops=10000,min_iops=10000,max_session_num=10000,max_disk_size='1024G';
Query OK, 0 rows affected (0.028 sec)

2.创建资源池。

CREATE RESOURCE POOL amber_1 unit=S2,unit_num=1;
Query OK, 0 rows affected (0.011 sec)

3.创建普通租户。

create tenant amber_babe resource_pool_list=("amber_1");
Query OK, 0 rows affected (1.087 sec)

4.连接 OceanBase 数据库。

obclient -h 172.30.198.252 -P 2883 -uroot@amber_babe  -A -c
ERROR 1227 (42501): Access denied

原因排查

首先查看租户 amber_babe 是否创建成功。

SELECT * FROM oceanbase.gv$tenant;
+-----------+-------------+-----------+--------------+----------------+---------------+-----------+------------------------------------+
| tenant_id | tenant_name | zone_list | primary_zone | collation_type | info          | read_only | locality                           |
+-----------+-------------+-----------+--------------+----------------+---------------+-----------+------------------------------------+
|         1 | sys         | z1;z2;z3  | z1;z2,z3     |              0 | system tenant |         0 | FULL{1}@z1, FULL{1}@z2, FULL{1}@z3 |
|      1001 | amber_babe  | z1;z2;z3  | RANDOM       |              0 |               |         0 | FULL{1}@z1, FULL{1}@z2, FULL{1}@z3 |
+-----------+-------------+-----------+--------------+----------------+---------------+-----------+------------------------------------+

从返回信息来看，租户已经创建成功。但是为什么连不上呢？

从报错信息来看，提示访问被拒绝。起初猜测是由于 clog 停写， 如果 clog_dir 目录达到了 clog_disk_usage_limit_percentage 参数设置的上限，那么写请求会停止。接下来验证我们的假设对不对。

执行以下命令查看集群配置：

SHOW PARAMETERS WHERE name IN ('clog_disk_usage_limit_percentage');
+------+----------+----------------+----------+----------------------------------+-----------+-------+----------------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+---------+-------------------+
| zone | svr_type | svr_ip | svr_port | name | data_type | value | info | section | scope | source | edit_level |
+------+----------+----------------+----------+----------------------------------+-----------+-------+----------------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+---------+-------------------+
| z2 | observer | 172.30.198.247 | 33334 | clog_disk_usage_limit_percentage | NULL | 95 | maximum of clog disk usage percentage before stop submitting or receiving logs, should be greater than clog_disk_utilization_threshold. Range: [80, 100] | TRANS | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE |
| z1 | observer | 172.30.198.246 | 33332 | clog_disk_usage_limit_percentage | NULL | 95 | maximum of clog disk usage percentage before stop submitting or receiving logs, should be greater than clog_disk_utilization_threshold. Range: [80, 100] | TRANS | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE |
| z3 | observer | 172.30.198.248 | 33336 | clog_disk_usage_limit_percentage | NULL | 95 | maximum of clog disk usage percentage before stop submitting or receiving logs, should be greater than clog_disk_utilization_threshold. Range: [80, 100] | TRANS | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE |
+------+----------+----------------+----------+----------------------------------+-----------+-------+----------------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+---------+-------------------+

查询结果显示 clog_disk_usage_limit_percentage 参数默认值为 95%。经过查看配置，发现并没有停写。因此上述假设不正确。

真正的原因是由于 IP 不在白名单之内，默认只能回环登录。如果要开放全部IP访问，需要加上 ob_tcp_invited_nodes: '%'。

解决方案

通过 ALTER TENANT 语句修改 ob_tcp_invited_nodes: '%' 变量以便允许任何客户端 IP 连接该租户。

ALTER TENANT amber_babe SET VARIABLES ob_tcp_invited_nodes='%';

或者在创建租户时直接修改 ob_tcp_invited_nodes 为 '%'。

CREATE TENANT IF NOT EXISTS amber_babe resource_pool_list=('amber_1') SET ob_tcp_invited_nodes='%';

再次尝试连接，此时连接成功：

obclient -h 172.30.198.252 -P 2883 -uroot@amber_babe  -A -c
Welcome to the OceanBase.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.6.25 OceanBase 3.1.0 (r-00672c3c730c3df6eef3b359eae548d8c2db5ea2) (Built Jun 22 2021 12:46:28)

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MySQL [(none)]>

参考

• GitHub issue
• clog_disk_usage_limit_percentage 文档
• ob_tcp_invited_nodes 文档
• 创建租户文档
• 视频教程