MGR主从不一致问题排查与修复
运行环境
linux:CentOS release 6.8 (Final)
kernel:2.6.32-642.6.2.el6.x86_64
mysql Server version: 5.7.21-20-log Percona Server (GPL),MGR单主模式
1.故障现象
解析binlog
mysqlbinlog -v --base64-output=DECODE-ROWS mysql-bin.000042 --include-gtids='1bb1b861-f776-11e6-3319-010204058070:113111655'
1bb1b861-f776-11e6-3319-010204058070:113111655 该GTID的binlog内容 ycc01 与ycc03服务器内容一致
ycc01.prod.bj2 mysql_3319 SET @@SESSION.GTID_NEXT= '1bb1b861-f776-11e6-3319-010204058070:113111655'/*!*/; # at 418534101 #190412 12:41:44 server id 58070 end_log_pos 418534182 Query thread_id=4163376 exec_time=0 error_code=0 SET TIMESTAMP=1555044104/*!*/; BEGIN /*!*/; # at 418534182 #190412 12:41:44 server id 58070 end_log_pos 418534262 Table_map: `ycc_cfcenter`.`config_center_client_list` mapped to number 108 # at 418534262 #190412 12:41:44 server id 58070 end_log_pos 418534338 Delete_rows: table id 108 flags: STMT_END_F ### DELETE FROM `ycc_cfcenter`.`config_center_client_list` ### WHERE ### @1=380183102 ### @2=206 ### @3='10.1.97.131' ### @4='5566' ### @5=1555044043209 # at 418534338 #190412 12:41:44 server id 58070 end_log_pos 418534365 Xid = 604665111 COMMIT/*!*/; ycc03.prod.bj2 mysql_3319 SET @@SESSION.GTID_NEXT= '1bb1b861-f776-11e6-3319-010204058070:113111655'/*!*/; # at 747896436 #190412 12:41:44 server id 58070 end_log_pos 747896500 Query thread_id=4163376 exec_time=0 error_code=0 SET TIMESTAMP=1555044104/*!*/; BEGIN /*!*/; # at 747896500 #190412 12:41:44 server id 58070 end_log_pos 747896580 Table_map: `ycc_cfcenter`.`config_center_client_list` mapped to number 108 # at 747896580 #190412 12:41:44 server id 58070 end_log_pos 747896656 Delete_rows: table id 108 flags: STMT_END_F ### DELETE FROM `ycc_cfcenter`.`config_center_client_list` ### WHERE ### @1=380183102 ### @2=206 ### @3='10.1.97.131' ### @4='5566' ### @5=1555044043209 # at 747896656 #190412 12:41:44 server id 58070 end_log_pos 747896683 Xid = 263747865 COMMIT/*!*/;
mysqlbinlog -v --base64-output=DECODE-ROWS mysql-bin.000042 --include-gtids='1bb1b861-f776-11e6-3319-010204058070:113111656'
1bb1b861-f776-11e6-3319-010204058070:113111656 该GTID的binlog内容 ycc01 与ycc03服务器内容不一致
ycc01.db.prod.bj2 mysql_3319 SET @@SESSION.GTID_NEXT= '1bb1b861-f776-11e6-3319-010204058070:113111656'/*!*/; # at 418534426 #190412 12:41:44 server id 58070 end_log_pos 418534507 Query thread_id=4163392 exec_time=0 error_code=0 SET TIMESTAMP=1555044104/*!*/; BEGIN /*!*/; # at 418534507 #190412 12:41:44 server id 58070 end_log_pos 418534587 Table_map: `ycc_cfcenter`.`config_center_client_list` mapped to number 108 # at 418534587 #190412 12:41:44 server id 58070 end_log_pos 418534663 Delete_rows: table id 108 flags: STMT_END_F ### DELETE FROM `ycc_cfcenter`.`config_center_client_list` ### WHERE ### @1=380183123 ### @2=136 ### @3='10.1.94.137' ### @4='5566' ### @5=1555044044493 # at 418534663 #190412 12:41:44 server id 58070 end_log_pos 418534690 Xid = 604665114 COMMIT/*!*/; ycc03.db.prod.bj2 mysql_3319
SET @@SESSION.GTID_NEXT= '1bb1b861-f776-11e6-3319-010204058070:113111656'/*!*/; # at 747896744 #190412 12:41:44 server id 58070 end_log_pos 747896808 Query thread_id=4163376 exec_time=1 error_code=0 SET TIMESTAMP=1555044104/*!*/; BEGIN /*!*/; # at 747896808 #190412 12:41:44 server id 58070 end_log_pos 747896888 Table_map: `ycc_cfcenter`.`config_center_client_list` mapped to number 108 # at 747896888 #190412 12:41:44 server id 58070 end_log_pos 747896964 Write_rows: table id 108 flags: STMT_END_F ### INSERT INTO `ycc_cfcenter`.`config_center_client_list` ### SET ### @1=380183774 ### @2=206 ### @3='10.1.97.131' ### @4='5566' ### @5=1555044104617 # at 747896964 #190412 12:41:44 server id 58070 end_log_pos 747896991 Xid = 263747869 COMMIT/*!*/;
2.原因排查
官方已经反馈社区版MySQL 5.7.26和MySQL 8.0.16 中会修复,如果是企业版客户可以申请最新的hotfix版本。
在未升级 MySQL 版本前,若再发生此类故障,在修复时需要人工检查,检查切换时binlog中 GTID 信息与新主节点对应 GTID 的信息是否一致。
如果不一致需要人工修复至一致状态,一致才可以将被踢出的原主节点加回集群。
参考文档
3.修复过程
3.1 确定故障点
查看故障节点error.log
2019 - 04 -12T12: 41 : 45.834694 + 08 : 00 3561943 [ERROR] Slave SQL for channel 'group_replication_applier' : Could not execute Write_rows event on table ycc_cfcenter.config_center_client_list; Duplicate entry ' 1 36 - 10.1 . 94.137 - 5566 ' for key ' uniq_idx_project_id ', Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY; the event' s master log FIRST, end_log_pos 327 , Error_code: 1062 2019 - 04 -12T12: 41 : 45.834713 + 08 : 00 3561943 [Warning] Slave: Duplicate entry '136-10.1.94.137-5566' for key 'uniq_idx_project_id' Error_code: 1062 |
查看故障节点当前GTID
SHOW MASTER STATUS FILE POSITION Binlog_Do_DB Binlog_Ignore_DB Executed_Gtid_Set ---------------- --------- ------------ ---------------- -------------------------------------------------- mysql-bin. 000042 747898223 1bb1b861-f776-11e6- 3319 - 010204058070 : 1 - 113111661 |
解析故障节点包含【1bb1b861-f776-11e6-3319-010204058070:1-113111661】 GTID 的binlog
##mysqlbinlog -vvv relay-bin-group_replication_applier.000053 --include-gtids="1bb1b861-f776-11e6-3319-010204058070:113111661"
SET @ @SESSION .GTID_NEXT= '1bb1b861-f776-11e6-3319-010204058070:113111661' /*!*/ ; # at 703004277 # 190412 12 : 41 : 45 server id 58070 end_log_pos 81 Query thread_id= 4163376 exec_time= 0 error_code= 0 SET TIMESTAMP= 1555044105 /*!*/ ; BEGIN /*!*/ ; # at 703004358 # 190412 12 : 41 : 45 server id 58070 end_log_pos 161 Table_map: `ycc_cfcenter`.`config_center_client_list` mapped to number 108 # at 703004438 # 190412 12 : 41 : 45 server id 58070 end_log_pos 327 Write_rows: table id 108 flags: STMT_END_F BINLOG ' ' /*!*/ ; ### INSERT INTO `ycc_cfcenter`.`config_center_client_list` ### SET ### @1 = 380183781 /* LONGINT meta=0 nullable=0 is_null=0 */ ### @2 = 206 /* LONGINT meta=0 nullable=1 is_null=0 */ ### @3 = '10.1.97.133' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */ ### @4 = '5566' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */ ### @5 = 1555044105821 /* LONGINT meta=0 nullable=1 is_null=0 */ ### INSERT INTO `ycc_cfcenter`.`config_center_client_list` ### SET ### @1 = 380183788 /* LONGINT meta=0 nullable=0 is_null=0 */ ### @2 = 136 /* LONGINT meta=0 nullable=1 is_null=0 */ ### @3 = '10.1.94.137' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */ ### @4 = '5566' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */ ### @5 = 1555044105821 /* LONGINT meta=0 nullable=1 is_null=0 */ ### INSERT INTO `ycc_cfcenter`.`config_center_client_list` ### SET ### @1 = 380183795 /* LONGINT meta=0 nullable=0 is_null=0 */ ### @2 = 206 /* LONGINT meta=0 nullable=1 is_null=0 */ ### @3 = '10.1.97.131' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */ ### @4 = '5566' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */ ### @5 = 1555044105821 /* LONGINT meta=0 nullable=1 is_null=0 */ # at 703004604 # 190412 12 : 41 : 45 server id 58070 end_log_pos 354 Xid = 604665142 COMMIT /*!*/ ; |
解析主节点binlog 确定相同内容binlog event 对应的GTID值
##mysqlbinlog -vvv mysql-bin.000042 --include-gtids="1bb1b861-f776-11e6-3319-010204058070:113111660-113111665'
SET @ @SESSION .GTID_NEXT= '1bb1b861-f776-11e6-3319-010204058070:113111662' /*!*/ ; # at 418536376 # 190412 12 : 41 : 45 server id 58070 end_log_pos 418536457 Query thread_id= 4163376 exec_time= 0 error_code= 0 SET TIMESTAMP= 1555044105 /*!*/ ; BEGIN /*!*/ ; # at 418536457 # 190412 12 : 41 : 45 server id 58070 end_log_pos 418536537 Table_map: `ycc_cfcenter`.`config_center_client_list` mapped to number 108 # at 418536537 # 190412 12 : 41 : 45 server id 58070 end_log_pos 418536703 Write_rows: table id 108 flags: STMT_END_F BINLOG ' ' /*!*/ ; ### INSERT INTO `ycc_cfcenter`.`config_center_client_list` ### SET ### @1 = 380183781 /* LONGINT meta=0 nullable=0 is_null=0 */ ### @2 = 206 /* LONGINT meta=0 nullable=1 is_null=0 */ ### @3 = '10.1.97.133' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */ ### @4 = '5566' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */ ### @5 = 1555044105821 /* LONGINT meta=0 nullable=1 is_null=0 */ ### INSERT INTO `ycc_cfcenter`.`config_center_client_list` ### SET ### @1 = 380183788 /* LONGINT meta=0 nullable=0 is_null=0 */ ### @2 = 136 /* LONGINT meta=0 nullable=1 is_null=0 */ ### @3 = '10.1.94.137' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */ ### @4 = '5566' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */ ### @5 = 1555044105821 /* LONGINT meta=0 nullable=1 is_null=0 */ ### INSERT INTO `ycc_cfcenter`.`config_center_client_list` ### SET ### @1 = 380183795 /* LONGINT meta=0 nullable=0 is_null=0 */ ### @2 = 206 /* LONGINT meta=0 nullable=1 is_null=0 */ ### @3 = '10.1.97.131' /* VARSTRING(300) meta=300 nullable=1 is_null=0 */ ### @4 = '5566' /* VARSTRING(90) meta=90 nullable=1 is_null=0 */ ### @5 = 1555044105821 /* LONGINT meta=0 nullable=1 is_null=0 */ # at 418536703 # 190412 12 : 41 : 45 server id 58070 end_log_pos 418536730 Xid = 604665142 COMMIT /*!*/ ; |
3.2 确定故障点结果汇总
1.故障节点提示 Duplicate entry '136-10.1.94.137-5566' for key 'uniq_idx_project_id' 有唯一约束冲突
2.故障节点当前GTID 【1bb1b861-f776-11e6-3319-010204058070:1-113111660】
3.故障节点与主节点GTID相差一个值,相同binlog event 主节点GTID【1bb1b861-f776-11e6-3319-010204058070:113111662】 故障节点【1bb1b861-f776-11e6-3319-010204058070:113111661】
3.3 故障节点修复过程
3.3.1 停止故障节点MGR服务
STOP group_replication;
SET GLOBAL super_read_only=0
3.3.2 删除冲突键数据
DELETE FROM config_center_client_list WHERE project_id=136 AND client_ip='10.1.94.137' AND PORT=5566
3.3.3 清除故障节点GTID信息
RESET MASTER
3.3.4 重置故障节点GTID信息,故障节点因唯一约束冲突未重做的binlog event,在主节点对应的GTID为【1bb1b861-f776-11e6-3319-010204058070:113111662】。
SET @@GLOBAL.GTID_PURGED='1bb1b861-f776-11e6-3319-010204058070:1-113111661';
START group_replication;
SHOW MASTER STATUS
3.3.5 在故障节点执行, 需要跳过的GTID只有一个,也可以用以下方法,这样就不需要reset masert。
STOP group_replication;
SET GLOBAL super_read_only=0
set sql_log_bin=0
DELETE FROM config_center_client_list WHERE project_id=136 AND client_ip='10.1.94.137' AND PORT=5566
set sql_log_bin=1
set session gtid_next="1bb1b861-f776-11e6-3319-010204058070:113111661";
begin;commit;
set session gtid_next="AUTOMATIC";
START group_replication;