关于oceanbase:OceanBase-建表分区数超限报错

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OceanBase 单机租户容许创立的最大分区数是多少？作者通过分区超限谬误排查，计算出单机容许创立的最大分区数量。

作者：何文超，爱可生南区交付服务部 DBA 团队成员，次要负责 MySQL 故障解决，MySQL 高可用架构革新，OceanBase 相干技术支持。喜好足球，羽毛球。

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背景

ERROR 1499 (HY000): Too many partitions (including subpartitions) were defined

创立表报错，尽管是外部谬误，然而错误信息是指：创立了太多了分区。

[root@observer04 ~]# mysql -h10.186.64.125 -P2883 -uroot@wenchao_mysql#hwc_cluster:1682755171 -p"xxxx"  
MySQL [lss]> CREATE TABLE `wms_order` (`A1` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A1',
  `A2` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A2',
  `A3` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A3',
  `A4` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A4',
  `A5` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A5',
  `A6` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A6',
  `A7` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A7',
  `A8` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A8',
  `A9` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A9',
  `A10` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL COMMENT 'A10'
) DEFAULT CHARSET = utf8mb4 ROW_FORMAT = DYNAMIC COMPRESSION = 'zstd_1.0' REPLICA_NUM = 3 BLOCK_SIZE = 16384 USE_BLOOM_FILTER = FALSE TABLET_SIZE = 134217728 PCTFREE = 0 COMMENT = '物流订单表'
MySQL [lss]> ERROR 1499 (HY000): Too many partitions (including subpartitions) were defined

接下来咱们剖析一下问题的起因。

排查

2.1 查看参数

  1. 查看每个 OBServer 上能够创立最大的分区数量，以后是 500000。
[root@observer04 ~]# mysql -h10.186.64.125 -P2883 -uroot@sys#hwc_cluster:1682755171 -p"xxxx" -A oceanBase

MySQL [oceanBase]> select * from __all_virtual_sys_parameter_stat where name like '%_max_partition_%';
+-------+----------+---------------+----------+-------------------------------+-----------+--------+--------------+---------------------------------------------+-------------+----------+---------------+---------+---------+-------------------+
| zone  | svr_type | svr_ip        | svr_port | name                          | data_type | value  | value_strict | info                                        | need_reboot | section  | visible_level | scope   | source  | edit_level        |
+-------+----------+---------------+----------+-------------------------------+-----------+--------+--------------+---------------------------------------------+-------------+----------+---------------+---------+---------+-------------------+
| zone1 | observer | 10.186.64.122 |     2882 | _max_partition_cnt_per_server | NULL      | 500000 | NULL         | specify max partition count on one observer |        NULL | OBSERVER | NULL          | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE |
+-------+----------+---------------+----------+-------------------------------+-----------+--------+--------------+---------------------------------------------+-------------+----------+---------------+---------+---------+-------------------+
  1. 查看以后分区数量的和，目前并没有超过这个限度（500000）。
MySQL [oceanBase]> select count(*) from v$partition;
+----------+
| count(*) |
+----------+
|   421485 |
+----------+

2.2 查看回收站

  1. 查看回收站是否开启？
[root@observer04 ~]# mysql -h10.186.64.125 -P2883 -uroot@wenchao_mysql#hwc_cluster:1682755171 -p"xxxx"

MySQL [lss]> show variables like '%recy%';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| recyclebin    | ON    |
+---------------+-------+
1 row in set (0.01 sec)
  1. 查看回收站中是否存在未删除的分区表？
MySQL [lss]> show recyclebin;
+-----------------------------------------+---------------+-------+----------------------------+
| OBJECT_NAME                             | ORIGINAL_NAME | TYPE  | CREATETIME                 |
+-----------------------------------------+---------------+-------+----------------------------+
| __recycle_$_1682755171_1689139725669688 | mytable_1     | TABLE | 2023-07-12 13:28:45.687379 |
| __recycle_$_1682755171_1689139737584112 | mytable_1     | TABLE | 2023-07-12 13:28:57.584660 |
| __recycle_$_1682755171_1689139750594392 | t1            | TABLE | 2023-07-12 13:29:10.594118 |
+-----------------------------------------+---------------+-------+----------------------------+
3 rows in set (0.01 sec)

如果存在，须要和业务侧沟通是否能够清理。回收站的表清理后，发现分区表数量缩小，然而创立表仍旧报错。

  1. 查看回收站中中对象保留天数。

    MySQL [lss]> SHOW PARAMETERS LIKE 'recyclebin_object_expire_time'\G;
*************************** 1. row ***************************
   zone: zone1
  svr_type: observer
 svr_ip: 10.186.64.122
  svr_port: 2882
   name: recyclebin_object_expire_time
 data_type: NULL
  value: 0s
   info: recyclebin object expire time, default 0 that means auto purge recyclebin off. Range: [0s, +∞)
section: ROOT_SERVICE
  scope: CLUSTER
 source: DEFAULT

  2. row in set (0.02 sec)

配置项 recyclebin_object_expire_time 的取值阐明如下：

  • 当其值为 0s 时，示意敞开主动 Purge 回收站性能。
  • 当其值不为 0s 时，示意回收一段时间前进入回收站的 Schema 对象。

2.3 查看租户内存

  1. 找到分区数最多的 10 个租户。

    [root@observer04 ~]# mysql -h10.186.64.125 -P2883 -uroot@sys#hwc_cluster:1682755171 -p"xxxx"

// 1. 找到分区数最多的 10 个租户
SELECT t2.tenant_name,t2.tenant_id, t1.replica_count
FROM
 (SELECT tenant_id, COUNT(*) AS replica_count
  FROM __all_virtual_partition_info
  GROUP BY tenant_id
  ORDER BY replica_count DESC
  LIMIT 10) t1
JOIN
 (SELECT tenant_id, tenant_name
  FROM __all_tenant) t2
ON t1.tenant_id=t2.tenant_id
ORDER BY replica_count DESC;
+-------------------+-----------+---------------+
| tenant_name       | tenant_id | replica_count |
+-------------------+-----------+---------------+
| wenchao_mysql     |      1100 |        107853 |
| wenchao_01        |      1088 |         99846 |
| wenchao_02        |      1104 |         15873 |
| wenchao_03        |         1 |          3867 |
| wenchao_04        |      1044 |          3270 |
| wenchao_05        |      1066 |          2811 |
| wenchao_06        |      1079 |          2658 |
| wenchao_07        |      1103 |          2103 |
| wenchao_08        |      1057 |          2040 |
| wenchao_09        |      1016 |          1950 |

  2. rows in set (0.13 sec)

  3. 查找租户有多少表。
select count(*),svr_Ip from __all_virtual_meta_table where tenant_id=1100 and role=1 group by svr_ip;
+----------+-------------+
| count(*) | svr_Ip      |
+----------+-------------+
|   11921  |10.186.64.103|
|   11868  |10.186.64.104|
|   12013  |10.186.64.105|
+----------+-------------+
3 rows in set (0.35 sec)
  1. 计算租户须要扩容内存大小。
  • 租户以后分区总数 num=107853/ 正本数
  • 租户可用内存下限 =(1-memstore_limit_percentage)* 租户 unit 的内存大小 =(1-0.8)*24GB=4.8GB
  • 单个正本分区所需总内存 partition_mem=128k*(107853/3)+max(1000,(107853/3)/10)*400k=5.75GB

留神：单个正本分区所需总内存 > 租户可用内存下限, 租户所需内存超限, 须要对租户内存进行扩容。

  1. 依据租户内存计算最大分区数量。
  2. 单机租户容许创立的最大分区数量 =(max_memory-memstore_limit)/partition_mem_n
  3. 单机租户容许创立的最大分区数量 =(24-24*0.8)/(5.75/(107853/3))=4.8/(5.75/(107853/3))=30011
  4. partition_mem_n：指的是单个分区所需总内存

长期解决计划： 扩容租户内存。

本源治理： 不可能有限扩内存；给出业务方正当的分区数量限度，倡议业务侧正当应用分区表，制订正当的定期清理策略。

总结

根据上述计算得出：单机租户容许创立的最大分区数量为 30011，倡议业务侧留神管制分区数量，免得超限，对业务造成影响。

正文完
oceanbase
发表至： oceanbase
2023-09-06
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