资兴网站设计,wordpress 小工具代码,淄博seo网络推广,产品推广策略怎么写1.三种保护模式– Maximum protection在Maximum protection下#xff0c; 可以保证从库和主库数据完全一样#xff0c;做到zero data loss.事务同时在主从两边提交完成#xff0c;才算事务完成。如果从库宕机或者网络出现问题#xff0c;主从库不能通讯#xff0c;主库也立…1.三种保护模式– Maximum protection在Maximum protection下 可以保证从库和主库数据完全一样做到zero data loss.事务同时在主从两边提交完成才算事务完成。如果从库宕机或者网络出现问题主从库不能通讯主库也立即宕机。在这种方式下具有最高的保护等级。但是这种模式对主库性能影响很大要求高速的网络连接。– Maximum availability在Maximum availability模式下如果和从库的连接正常运行方式等同Maximum protection模式事务也是主从库同时提交。如果从库和主库失去联系则主库自动切换到Maximum performance模式下运行保证主库具有最大的可用性。– Maximum performance在Maximum performance主库把归档的 archived log通过arch进程传递给从库在这种方式下主库运行性能最高但是不能保证数据不丢失且丢失的数据受redo log的大小影响。在redo log过大的情况下可能一天都没有归档一个日志可以通过手工切换日志的方式来减小数据的丢失。2.模式切换(Maximum performance切换至Maximum availability)a.查看保护的模式DGbroker查看DGMGRL show configuration verbose;Configuration - dgcProtection Mode: MaxPerformanceDatabases:atest1 - Primary databaseatest2 - Physical standby databaseProperties:FastStartFailoverThreshold 30OperationTimeout 30FastStartFailoverLagLimit 30CommunicationTimeout 180ObserverReconnect 0FastStartFailoverAutoReinstate TRUEFastStartFailoverPmyShutdown TRUEBystandersFollowRoleChange ALLObserverOverride FALSEExternalDestination1 ExternalDestination2 PrimaryLostWriteAction CONTINUEFast-Start Failover: DISABLEDConfiguration Status:SUCCESSsqlplus查看SQL select database_role,protection_mode,protection_level from v$database;DATABASE_ROLE PROTECTION_MODE PROTECTION_LEVEL---------------- -------------------- --------------------PRIMARY MAXIMUM PERFORMANCE MAXIMUM PERFORMANCEb.查看备库的日志传输模式(参数LogXptMode(sync:同步传输/async:异步传输))DGMGRL show database verbose atest2;Database - atest2Role: PHYSICAL STANDBYIntended State: APPLY-ONTransport Lag: 0 seconds (computed 1 second ago)Apply Lag: 0 seconds (computed 1 second ago)Apply Rate: 97.00 KByte/sReal Time Query: ONInstance(s):atestProperties:DGConnectIdentifier atest2ObserverConnectIdentifier LogXptMode syncDelayMins 0Binding optionalMaxFailure 0MaxConnections 1ReopenSecs 300NetTimeout 30RedoCompression DISABLELogShipping ONPreferredApplyInstance ApplyInstanceTimeout 0ApplyParallel AUTOStandbyFileManagement AUTOArchiveLagTarget 0LogArchiveMaxProcesses 4LogArchiveMinSucceedDest 1DbFileNameConvert LogFileNameConvert FastStartFailoverTarget InconsistentProperties (monitor)InconsistentLogXptProps (monitor)SendQEntries (monitor)LogXptStatus (monitor)RecvQEntries (monitor)ApplyLagThreshold 0TransportLagThreshold 0TransportDisconnectedThreshold 30SidName atestStaticConnectIdentifier (DESCRIPTION(ADDRESS(PROTOCOLtcp)(HOSTvijay02.database.com)(PORT1521))(CONNECT_DATA(SERVICE_NAMEatest2_DGMGRL)(INSTANCE_NAMEatest)(SERVERDEDICATED)))StandbyArchiveLocation /u01/app/oracle/oradata/ATEST/archivelogAlternateLocation LogArchiveTrace 0LogArchiveFormat %t_%s_%r.dbfTopWaitEvents (monitor)Database Status:SUCCESSc.如果LogXptMode的值为async就要将其修改为syncDGMGRL edit database atest1 set property logxptmodesync;Property logxptmode updatedd.修改完之后再次确认LogXptMode的值如步骤be.切换模式(如果切换失败则再次去确认备库LogXptMode的值)DGMGRL edit configuration set protection mode as maxavailability;Succeeded.f. 确认数据库的的保护模式如步骤ag.需要注意的是步骤c中修改的sync是备库的值切记3.个人小结a.三种模式在可以在DGbroker中自由切换(使用步骤2的方式)(在测试库中)正常情况下数据库能迅速反应过来(查看保护模式的时候)。b.使用Maximum performance的时候参数(备库)LogXptMode设置为async就好/c.使用Maximum protection或者Maximum availability的时候参数(备库)LogXptMode要设置为sync。d.(经测试)使用Maximum protection时当备库出现异常(如网络问题数据库宕机)主库会挂起(告警日志会报如下错误)当备库恢复正常之后主库也会恢复。LGWR: Error 1034 attaching to RFS for reconnecte.使用Maximum protection时在当备库出现异常的情况下当主库挂起时(主库)可以强制切换到 Maximum performance但当重新切回Maximum protection(在备库恢复时)主库需重启。DGMGRL edit configuration set protection mode as maxprotection;Operation requires shutdown of instance atest on database atest1Shutting down instance atest...Unable to connect to databaseORA-12545: Connect failed because target host or object does not existFailed.Warning: You are no longer connected to ORACLE.Please complete the following steps to finish the operation:shut down instance atest of database atest1start up instance atest of database atest1以上内容是小编给大家分享的Oracle数据库 DGbroker三种保护模式的切换的相关内容希望大家喜欢同时也感谢大家一直以来对脚本之家网站的支持与厚爱。
