作者:张乾

外星人2号,现专任六位喵星人的资深铲屎官。

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手滑误删了数据文件,并且没有可替换的节点时,先别急着提桶跑路,能够思考利用参数 server_permanent_offline_time 来重建受影响的节点。

原理:

server_permanent_offline_time 是 OceanBase 数据库中用于管制节点永恒下线时长的参数。当集群中的某个节点宕机后,零碎会依据该参数的设置值来进行相应操作。

如果节点宕机工夫小于该参数设置的值,零碎会临时不做解决,以防止频繁的数据迁徙;如果宕机工夫超过该参数设置的值,该节点被标记为永恒下线,RootService 会将该 OBServer 上蕴含的数据正本从 Paxos 成员组中删除,并在同 zone 内其余可用 OBServer 上补充数据,以保证数据正本 Paxos 成员组残缺。该参数默认值是 3600 秒,个别设置较大,以防止不必要的正本复制。此外,当永恒下线的节点从新被拉起后,其上的全副数据都须要从其余正本从新拉取。

在本场景下,即是通过调低该参数,让故障节点疾速永恒下线再从新上线,达到数据重建的目标。

请留神,此过程会占用集群肯定的资源,可能会影响性能,因而倡议在业务低峰期进行。

官网倡议

对于 server_permanent_offline_time 的实用场景和倡议值,官网提供如下:

  1. OceanBase 数据库版本升级场景:倡议将该配置项的值设置为72h。
  2. OBServer 硬件更换场景:倡议将该配置项的值设置为4h。
  3. OBServer 清空上线场景:倡议将该配置项的值设置为10m,使集群疾速上线。

筹备过程

准备一套环境

应用OBD工具疾速部署一套3节点OB以及一个OBProxy,再创立好一个租户sysbench_tenant,primary_zone为RANDOM。

注:本文基于OB 3.1.2版本,其余版本需注意另作验证。

筹备些数据

应用 sysbench 创立一个表 sbtest1 并插入1W数据。

sysbench ./oltp_insert.lua --mysql-host=10.186.60.3 --mysql-port=2883 --mysql-db=sysbenchdb --mysql-user="sysbench@sysbench_tenant"  --mysql-password=sysbench --tables=1 --table_size=10000 --threads=1 --time=600 --report-interval=10 --db-driver=mysql --db-ps-mode=disable --skip-trx=on --mysql-ignore-errors=6002,6004,4012,2013,4016,1062,5157,4038 prepare

这里改写了 sysbench 的建表语句,分了3个区,查问 sbtest1 表分区正本散布如下

MySQL [oceanbase]> select tenant.tenant_name, zone, svr_ip,svr_port, case when role=1 then 'leader' when role=2 then 'follower' else NULL end as role, count(1) as partition_cnt from __all_virtual_meta_table meta  inner join __all_tenant tenant  on meta.tenant_id=tenant.tenant_id inner join __all_virtual_table tab  on meta.tenant_id=tab.tenant_id and meta.table_id=tab.table_id where tenant.tenant_id=1001 and tab.table_name='sbtest1' group by  tenant.tenant_name,zone, svr_ip,svr_port, 5 order by  tenant.tenant_name, zone, svr_ip, role desc;+-----------------+-------+--------------+----------+----------+---------------+| tenant_name     | zone  | svr_ip       | svr_port | role     | partition_cnt |+-----------------+-------+--------------+----------+----------+---------------+| sysbench_tenant | zone1 | 10.186.64.74 |     2882 | leader   |             1 || sysbench_tenant | zone1 | 10.186.64.74 |     2882 | follower |             2 || sysbench_tenant | zone2 | 10.186.64.75 |     2882 | leader   |             1 || sysbench_tenant | zone2 | 10.186.64.75 |     2882 | follower |             2 || sysbench_tenant | zone3 | 10.186.64.79 |     2882 | leader   |             1 || sysbench_tenant | zone3 | 10.186.64.79 |     2882 | follower |             2 |+-----------------+-------+--------------+----------+----------+---------------+

开始试验

应用 sysbench 继续写入数据,维持肯定的流量,便于在节点重建后比照各节点数据是否统一。

sysbench ./oltp_insert.lua --mysql-host=10.186.60.3 --mysql-port=2883 --mysql-db=sysbenchdb --mysql-user="sysbench@sysbench_tenant"  --mysql-password=sysbench --tables=1 --table_size=10000 --threads=1 --time=300 --report-interval=10 --db-driver=mysql --db-ps-mode=disable --skip-trx=on --mysql-ignore-errors=6002,6004,4012,2013,4016,1062,5157,4038 run

删除某节点的数据文件

抉择zone3下的10.186.64.79节点,将数据文件删除。

[root@localhost data]# rm -rf 1/sstable/block_file[root@localhost data]# cd 1/sstable/[root@localhost sstable]# lltotal 0

永恒下线故障节点

1.调小参数 server_permanent_offline_time ,缩短节点永恒下线工夫

server_permanent_offline_time 默认值为3600s

MySQL [oceanbase]> alter system set server_permanent_offline_time='60s';Query OK, 0 rows affected (0.030 sec) MySQL [oceanbase]> SHOW PARAMETERS LIKE "%server_permanent_offline_time%";+-------+----------+--------------+----------+-------------------------------+-----------+-------+-----------------------------------------------------------------------------------------------------------------------------------+--------------+---------+---------+-------------------+| zone  | svr_type | svr_ip       | svr_port | name                          | data_type | value | info                                                                                                                              | section      | scope   | source  | edit_level        |+-------+----------+--------------+----------+-------------------------------+-----------+-------+-----------------------------------------------------------------------------------------------------------------------------------+--------------+---------+---------+-------------------+| zone3 | observer | 10.186.64.79 |     2882 | server_permanent_offline_time | NULL      | 60s   | the time interval between any two heartbeats beyond which a server is considered to be \'permanently\' offline. Range: [20s,+∞)   | ROOT_SERVICE | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE || zone1 | observer | 10.186.64.74 |     2882 | server_permanent_offline_time | NULL      | 60s   | the time interval between any two heartbeats beyond which a server is considered to be \'permanently\' offline. Range: [20s,+∞)   | ROOT_SERVICE | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE || zone2 | observer | 10.186.64.75 |     2882 | server_permanent_offline_time | NULL      | 60s   | the time interval between any two heartbeats beyond which a server is considered to be \'permanently\' offline. Range: [20s,+∞)   | ROOT_SERVICE | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE |+-------+----------+--------------+----------+-------------------------------+-----------+-------+-----------------------------------------------------------------------------------------------------------------------------------+--------------+---------+---------+-------------------+

2.进行故障节点对外提供服务

在kill ob过程前,倡议应用隔离(ISOLATE SERVER)或者进行(STOP SERVER)节点的命令,停掉发往该节点的申请,转移正本leader角色。在节点重建复原后,再开启流量。

# 停掉79节点服务MySQL [oceanbase]> ALTER SYSTEM STOP SERVER '10.186.64.79:2882' ZONE='zone3';  # 或者隔离ALTER SYSTEM ISOLATE SERVER '10.186.64.79:2882' ZONE='zone3';

3.kill observer过程

执行kill -9 $observer_pid,期待 server_permanent_offline_time 的工夫,该ob进入"永恒下线”状态。判断ob是否曾经永恒下线,能够查问表 __all_rootservice_event_history,存在名为 "permanent_offline "的event记录,确认工夫和ip都统一后,即可认为ob曾经永恒下线。

MySQL [oceanbase]> select * from __all_rootservice_event_history where event='permanent_offline' ; +----------------------------+--------+-------------------+--------+---------------------+-------+--------+-------+--------+-------+--------+-------+--------+-------+--------+------------+--------------+-------------+| gmt_create                 | module | event             | name1  | value1              | name2 | value2 | name3 | value3 | name4 | value4 | name5 | value5 | name6 | value6 | extra_info | rs_svr_ip    | rs_svr_port |+----------------------------+--------+-------------------+--------+---------------------+-------+--------+-------+--------+-------+--------+-------+--------+-------+--------+------------+--------------+-------------+| 2023-03-29 17:34:09.596035 | server | permanent_offline | server | "10.186.64.79:2882" |       |        |       |        |       |        |       |        |       |        |            | 10.186.64.74 |        2882 |+----------------------------+--------+-------------------+--------+---------------------+-------+--------+-------+--------+-------+--------+-------+--------+-------+--------+------------+--------------+-------------+

查问分区正本散布如下,已不存在79节点的分区正本信息,进一步确认了79节点已永恒下线。

zone2下的75节点有一个从正本降级为leader角色,此时集群依然能够持续对外服务。

MySQL [oceanbase]> select tenant.tenant_name, zone, svr_ip,svr_port, case when role=1 then 'leader' when role=2 then 'follower' else NULL end as role, count(1) as partition_cnt from __all_virtual_meta_table meta  inner join __all_tenant tenant  on meta.tenant_id=tenant.tenant_id inner join __all_virtual_table tab  on meta.tenant_id=tab.tenant_id and meta.table_id=tab.table_id where tenant.tenant_id=1001 and tab.table_name='sbtest1' group by  tenant.tenant_name,zone, svr_ip,svr_port, 5 order by  tenant.tenant_name, zone, svr_ip, role desc;+-----------------+-------+--------------+----------+----------+---------------+| tenant_name     | zone  | svr_ip       | svr_port | role     | partition_cnt |+-----------------+-------+--------------+----------+----------+---------------+| sysbench_tenant | zone1 | 10.186.64.74 |     2882 | leader   |             1 || sysbench_tenant | zone1 | 10.186.64.74 |     2882 | follower |             2 || sysbench_tenant | zone2 | 10.186.64.75 |     2882 | leader   |             2 || sysbench_tenant | zone2 | 10.186.64.75 |     2882 | follower |             1 |+-----------------+-------+--------------+----------+----------+---------------+4 rows in set (0.005 sec)

拉起故障节点,触发数据主动重建

1.启动79节点的ob过程,过程启动后会主动触发重建。

注:避免ob启动失败或存在其余问题,倡议启动前将数据文件和事务日志均清空。

[root@localhost data]# rm -rf log1/clog/*[root@localhost data]# rm -rf log1/ilog/*[root@localhost data]# rm -rf log1/slog/*[root@localhost data]# rm -rf 1/sstable/block_file[root@localhost data]# cd 1/sstable/[root@localhost sstable]# lltotal 0[root@localhost sstable]# su adminbash-4.2$ cd /home/admin/ && ./bin/observer./bin/observer

过程启动后,确认ob心跳复原状态为active,而后查看分区正在一直补足中

MySQL [oceanbase]> select svr_ip,zone,with_rootserver,status,stop_time,start_service_time,build_version from __all_server;+--------------+-------+-----------------+--------+-----------+--------------------+----------------------------------------------------------------------------------------+| svr_ip       | zone  | with_rootserver | status | stop_time        | start_service_time | build_version                                                                          |+--------------+-------+-----------------+--------+-----------+--------------------+----------------------------------------------------------------------------------------+| 10.186.64.74 | zone1 |               1 | active |                0 |   1679984798650860 | 3.1.2_10000392021123010-d4ace121deae5b81d8f0b40afbc4c02705b7fc1d(Dec 30 2021 02:47:29) || 10.186.64.75 | zone2 |               0 | active |                0 |   1679984801289281 | 3.1.2_10000392021123010-d4ace121deae5b81d8f0b40afbc4c02705b7fc1d(Dec 30 2021 02:47:29) || 10.186.64.79 | zone3 |               0 | active | 1680082329964975 |   1680082511964975 | 3.1.2_10000392021123010-d4ace121deae5b81d8f0b40afbc4c02705b7fc1d(Dec 30 2021 02:47:29) |+--------------+-------+-----------------+--------+-----------+--------------------+----------------------------------------------------------------------------------------+3 rows in set (0.002 sec) MySQL [oceanbase]> select count(*),zone from gv$partition group by zone;+----------+-------+| count(*) | zone  |+----------+-------+|     1322 | zone1 ||     1322 | zone2 ||      152 | zone3 |+----------+-------+3 rows in set (0.228 sec)  MySQL [oceanbase]> select count(*),zone from gv$partition group by zone;+----------+-------+| count(*) | zone  |+----------+-------+|     1322 | zone1 ||     1322 | zone2 ||      664 | zone3 |+----------+-------+3 rows in set (0.113 sec)MySQL [oceanbase]> select count(*),zone from gv$partition group by zone;                                                +----------+-------+| count(*) | zone  |+----------+-------+|     1322 | zone1 ||     1322 | zone2 ||     1179 | zone3 |+----------+-------+3 rows in set (0.112 sec)  MySQL [oceanbase]> select count(*),zone from gv$partition group by zone;+----------+-------+| count(*) | zone  |+----------+-------+|     1322 | zone1 ||     1322 | zone2 ||     1322 | zone3 |+----------+-------+3 rows in set (0.116 sec)

当3个zone内的分区个数统一后,同时查看zone3已存在正本信息,认为重建结束。

因为79节点处于隔离状态,所以还没有leader正本。

MySQL [oceanbase]> select tenant.tenant_name, zone, svr_ip,svr_port, case when role=1 then 'leader' when role=2 then 'follower' else NULL end as role, count(1) as partition_cnt from __all_virtual_meta_table meta  inner join __all_tenant tenant  on meta.tenant_id=tenant.tenant_id inner join __all_virtual_table tab  on meta.tenant_id=tab.tenant_id and meta.table_id=tab.table_id where tenant.tenant_id=1001 and tab.table_name='sbtest1' group by  tenant.tenant_name,zone, svr_ip,svr_port, 5 order by  tenant.tenant_name, zone, svr_ip, role desc;+-----------------+-------+--------------+----------+----------+---------------+| tenant_name     | zone  | svr_ip       | svr_port | role     | partition_cnt |+-----------------+-------+--------------+----------+----------+---------------+| sysbench_tenant | zone1 | 10.186.64.74 |     2882 | leader   |             1 || sysbench_tenant | zone1 | 10.186.64.74 |     2882 | follower |             2 || sysbench_tenant | zone2 | 10.186.64.75 |     2882 | leader   |             2 || sysbench_tenant | zone2 | 10.186.64.75 |     2882 | follower |             1 || sysbench_tenant | zone3 | 10.186.64.79 |     2882 | follower |             3 |+-----------------+-------+--------------+----------+----------+---------------+6 rows in set (0.005 sec)

2.开启故障节点服务

执行命令解除79节点的隔离状态。

ALTER SYSTEM START SERVER '10.186.64.79:2882' ZONE='zone3';

查问分区正本散布如下,leader角色已迁回79节点。

MySQL [oceanbase]> select tenant.tenant_name, zone, svr_ip,svr_port, case when role=1 then 'leader' when role=2 then 'follower' else NULL end as role, count(1) as partition_cnt from __all_virtual_meta_table meta  inner join __all_tenant tenant  on meta.tenant_id=tenant.tenant_id inner join __all_virtual_table tab  on meta.tenant_id=tab.tenant_id and meta.table_id=tab.table_id where tenant.tenant_id=1001 and tab.table_name='sbtest1' group by  tenant.tenant_name,zone, svr_ip,svr_port, 5 order by  tenant.tenant_name, zone, svr_ip, role desc;+-----------------+-------+--------------+----------+----------+---------------+| tenant_name     | zone  | svr_ip       | svr_port | role     | partition_cnt |+-----------------+-------+--------------+----------+----------+---------------+| sysbench_tenant | zone1 | 10.186.64.74 |     2882 | leader   |             1 || sysbench_tenant | zone1 | 10.186.64.74 |     2882 | follower |             2 || sysbench_tenant | zone2 | 10.186.64.75 |     2882 | leader   |             1 || sysbench_tenant | zone2 | 10.186.64.75 |     2882 | follower |             2 || sysbench_tenant | zone3 | 10.186.64.79 |     2882 | leader   |             1 || sysbench_tenant | zone3 | 10.186.64.79 |     2882 | follower |             2 |+-----------------+-------+--------------+----------+----------+---------------+

3.把server_permanent_offline_time参数的预知从新设置为默认的3600s

MySQL [oceanbase]> alter system set server_permanent_offline_time='3600s';Query OK, 0 rows affected (0.028 sec) MySQL [oceanbase]> SHOW PARAMETERS LIKE "%server_permanent_offline_time%";+-------+----------+--------------+----------+-------------------------------+-----------+-------+-----------------------------------------------------------------------------------------------------------------------------------+--------------+---------+---------+-------------------+| zone  | svr_type | svr_ip       | svr_port | name                          | data_type | value | info                                                                                                                              | section      | scope   | source  | edit_level        |+-------+----------+--------------+----------+-------------------------------+-----------+-------+-----------------------------------------------------------------------------------------------------------------------------------+--------------+---------+---------+-------------------+| zone2 | observer | 10.186.64.75 |     2882 | server_permanent_offline_time | NULL      | 3600s | the time interval between any two heartbeats beyond which a server is considered to be \'permanently\' offline. Range: [20s,+∞)   | ROOT_SERVICE | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE || zone1 | observer | 10.186.64.74 |     2882 | server_permanent_offline_time | NULL      | 3600s | the time interval between any two heartbeats beyond which a server is considered to be \'permanently\' offline. Range: [20s,+∞)   | ROOT_SERVICE | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE || zone3 | observer | 10.186.64.79 |     2882 | server_permanent_offline_time | NULL      | 3600s | the time interval between any two heartbeats beyond which a server is considered to be \'permanently\' offline. Range: [20s,+∞)   | ROOT_SERVICE | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE |+-------+----------+--------------+----------+-------------------------------+-----------+-------+-----------------------------------------------------------------------------------------------------------------------------------+--------------+---------+---------+-------------------+3 rows in set (0.007 sec)

校验各ob节点数据量

sysbench已运行完结,直连各observer,校验数据量是统一的。

[root@localhost ~]#  obclient -h10.186.64.74 -P2881 -usysbench@sysbench_tenant -Dsysbenchdb -A -psysbenchWelcome to the OceanBase.  Commands end with ; or \g.Your MySQL connection id is 3221545401Server version: 5.7.25 OceanBase 3.1.2 (r10000392021123010-d4ace121deae5b81d8f0b40afbc4c02705b7fc1d) (Built Dec 30 2021 02:47:29) 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 [sysbenchdb]> select count(*) from sbtest1;+----------+| count(*) |+----------+|    53195 |+----------+1 row in set (0.036 sec) MySQL [sysbenchdb]> exitBye[root@localhost ~]#  obclient -h10.186.64.75 -P2881 -usysbench@sysbench_tenant -Dsysbenchdb -A -psysbenchWelcome to the OceanBase.  Commands end with ; or \g.Your MySQL connection id is 3221823448Server version: 5.7.25 OceanBase 3.1.2 (r10000392021123010-d4ace121deae5b81d8f0b40afbc4c02705b7fc1d) (Built Dec 30 2021 02:47:29) 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 [sysbenchdb]> select count(*) from sbtest1;+----------+| count(*) |+----------+|    53195 |+----------+1 row in set (0.040 sec) MySQL [sysbenchdb]> exitBye[root@localhost ~]#  obclient -h10.186.64.79 -P2881 -usysbench@sysbench_tenant -Dsysbenchdb -A -psysbenchWelcome to the OceanBase.  Commands end with ; or \g.Your MySQL connection id is 3222011907Server version: 5.7.25 OceanBase 3.1.2 (r10000392021123010-d4ace121deae5b81d8f0b40afbc4c02705b7fc1d) (Built Dec 30 2021 02:47:29) 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 [sysbenchdb]> select count(*) from sbtest1;+----------+| count(*) |+----------+|    53195 |+----------+1 row in set (0.037 sec) MySQL [sysbenchdb]>

总结

数据文件损坏或者失落时,可通过调整参数 server_permanent_offline_time 来重建受影响的节点。

1.设小 server_permanent_offline_time 阈值

2.进行故障节点对外服务

3.终止该节点过程。

4.超过阈值后,节点将被标记为永恒下线,零碎会主动清空正本以及向同zone内其余节点迁徙数据。

5.启动 OB 过程,主动触发重建节点数据。

6.开启故障节点服务。

7.把server_permanent_offline_time参数改回原来的值