Remote duplicate database facility featuring safe master audit trail
(safeMAT) checkpointing
    1.
    发明授权
    Remote duplicate database facility featuring safe master audit trail (safeMAT) checkpointing 失效
    远程重复数据库设施,具有安全的主审核跟踪(safeMAT)检查点

    公开(公告)号:US5794252A

    公开(公告)日:1998-08-11

    申请号:US767452

    申请日:1996-12-16

    摘要: A local computer system has local database, application programs that modify the local database, an a transaction manager that stores audit records in a local audit trail reflecting those application program modifications to the local database. A remotely located computer system has a backup database. A remote data duplication facility (RDF) is partially located in the local computer system and partially in the remote computer for maintaining virtual synchronization of the backup database with the local database. The RDF includes an extractor process executed by said local computer system, and a receiver process and a plurality of updater processes executed by the remote computer system. The extractor process extracts audit records from a local audit trail and transmits those records to the receiver process. The receiver process distributes the audit records into one or more image trail files that are associated with a particular updater process. Each updater process reads the audit records in its assigned image trail file and initiates redo operations of database modifications denoted in at least a subset of the audit records against the backup database. Each image trail file has a corresponding image trail buffer that is used to accumulate a number of audit records before they are stored in the corresponding image trail file. Before an updater process applies an audit record against the backup database, it requests from the receiver process the status of the transaction associated with the audit record. Status audit records are stored in a transaction status table as well as in a master image trail file. The RDF system herein described provides a method and system for assuring that each audit record is preserved in the system in the event a failure occurs to any of the processes in the RDF.

    摘要翻译: 本地计算机系统具有本地数据库,修改本地数据库的应用程序,一个将审计记录存储在本地审计跟踪中的反映对本地数据库的应用程序修改的事务管理器。 位于远程的计算机系统具有备份数据库。 远程数据复制设备(RDF)部分位于本地计算机系统中,部分位于远程计算机中,用于维护备份数据库与本地数据库的虚拟同步。 RDF包括由所述本地计算机系统执行的提取器处理,以及由远程计算机系统执行的接收器处理和多个更新程序。 提取程序从本地审计跟踪中提取审计记录,并将这些记录传送到接收者进程。 接收器过程将审核记录分配到与特定更新程序相关联的一个或多个图像跟踪文件中。 每个更新程序读取其分配的图像跟踪文件中的审核记录,并启动对备份数据库的至少一个审计记录子集中的数据库修改的重做操作。 每个图像跟踪文件具有相应的图像跟踪缓冲区,用于在将多个审核记录存储在相应的图像跟踪文件中之前累积许多审核记录。 在更新程序进程对备份数据库应用审计记录之前,它向接收方请求与审计记录相关联的事务的状态。 状态审核记录存储在事务状态表以及主映像跟踪文件中。 本文描述的RDF系统提供了一种方法和系统,用于确保在RDF中的任何进程发生故障的情况下,系统中保留每个审核记录。

    Remote duplicate databased facility with triple contingency protection
    2.
    发明授权
    Remote duplicate databased facility with triple contingency protection 失效
    远程复制数据库设施,具有三重应急保护

    公开(公告)号:US5799323A

    公开(公告)日:1998-08-25

    申请号:US790544

    申请日:1997-01-30

    摘要: A primary computer system has a database, application programs that modify the local database, and a transaction manager that stores audit records in a local audit trail reflecting those application program modifications to the local database. A plurality of parallel backup systems are used to provide "triple contingency protection" of the data on the primary computer system. However, if the primary system suffers a sudden catastrophic failure, the parallel backup systems will generally be left in inconsistent states. To restart the application programs on one of the backup system, the parallel backup are first synchronized with each other, and then transaction processing is restarted with one of the backup systems as the new primary system, and the other backup systems as the backups to the new primary system. In addition, in order to enable any single backup system's database to be brought into a self consistent state, backup volume Updaters are stopped after database updates for all transactions committed on the primary system before a specified time have been completely applied to the backup system's database. After any reports requiring a self consistent database have been generated, operation of the Updaters is resumed.

    摘要翻译: 主计算机系统具有数据库,修改本地数据库的应用程序,以及将本地数据库的应用程序修改反映到本地审计跟踪中的审计记录的事务管理器。 多个并行备份系统用于在主计算机系统上提供数据的“三重应急保护”。 然而,如果主系统遇到突发的灾难性故障,则并行备份系统通常将处于不一致的状态。 要在其中一个备份系统上重新启动应用程序,首先将并行备份进行同步,然后以其中一个备份系统作为新的主系统重新启动事务处理,其他备份系统作为备份 新的主要系统。 此外,为了使任何单个备份系统的数据库能够处于自我一致状态,在指定时间完全应用到备份系统的数据库之前,在主系统上提交的所有事务的数据库更新后,将停止备份卷更新程序 。 在生成了需要自动一致的数据库的任何报告之后,恢复更新程序的操作。

    Method for providing recovery from a failure in a system utilizing
distributed audit
    3.
    发明授权
    Method for providing recovery from a failure in a system utilizing distributed audit 失效
    使用分布式审计从系统故障中提供恢复的方法

    公开(公告)号:US5832203A

    公开(公告)日:1998-11-03

    申请号:US377381

    申请日:1995-01-23

    IPC分类号: G06F11/14 G06F11/00

    CPC分类号: G06F11/1471

    摘要: An improved recovery method utilizes sequence numbers to order log records and reduce the excess compensating actions due to a failure during recovery. Next undo records are written to the log after a preset number of compensating actions which include the sequence number of the record currently being scanned. After a failure, all records between the next undo record and the record having the sequence number included in the next undo record are ignored during when the log is scanned backwards.

    摘要翻译: 改进的恢复方法利用序列号来排序日志记录,并减少由于恢复期间的故障引起的多余的补偿动作。 在预设数量的补偿动作(包括当前正在扫描的记录的序列号)之后,下一个撤消记录将写入日志。 失败后,在向后扫描日志时,将忽略下一个撤销记录与下一个撤销记录中包含序列号的记录之间的所有记录。

    System and method for stopping updates at a specified timestamp in a
remote duplicate database facility
    4.
    发明授权
    System and method for stopping updates at a specified timestamp in a remote duplicate database facility 失效
    用于在远程重复数据库设施中以指定的时间戳停止更新的系统和方法

    公开(公告)号:US5799322A

    公开(公告)日:1998-08-25

    申请号:US790542

    申请日:1997-01-30

    摘要: A primary computer system has a database, application programs that modify the local database, and a transaction manager that stores audit records in a local audit trail reflecting those application program modifications to the local database. A plurality of parallel backup systems are used to provide "triple contingency protection" of the data on the primary computer system. However, if the primary system suffers a sudden catastrophic failure, the parallel backup systems will generally be left in inconsistent states. To restart the application programs on one of the backup system, the parallel backup are first synchronized with each other, and then transaction processing is restarted with one of the backup systems as the new primary system, and the other backup systems as the backups to the new primary system. In addition, in order to enable any single backup system's database to be brought into a self consistent state, backup volume Updaters are stopped after database updates for all transactions committed on the primary system before a specified time have been completely applied to the backup system's database. After any reports requiring a self consistent database have been generated, operation of the Updaters is resumed.

    摘要翻译: 主计算机系统具有数据库,修改本地数据库的应用程序,以及将本地数据库的应用程序修改反映到本地审计跟踪中的审计记录的事务管理器。 多个并行备份系统用于在主计算机系统上提供数据的“三重应急保护”。 然而,如果主系统遇到突发的灾难性故障,则并行备份系统通常将处于不一致的状态。 要在其中一个备份系统上重新启动应用程序,首先将并行备份进行同步,然后以其中一个备份系统作为新的主系统重新启动事务处理,其他备份系统作为备份 新的主要系统。 此外,为了使任何单个备份系统的数据库能够处于自我一致状态,在指定时间完全应用到备份系统的数据库之前,在主系统上提交的所有事务的数据库更新后,将停止备份卷更新程序 。 在生成了需要自动一致的数据库的任何报告之后,恢复更新程序的操作。

    System and method for replication of distributed databases that span multiple primary nodes
    5.
    发明授权
    System and method for replication of distributed databases that span multiple primary nodes 有权
    复制跨越多个主节点的分布式数据库的系统和方法

    公开(公告)号:US06785696B2

    公开(公告)日:2004-08-31

    申请号:US09872323

    申请日:2001-06-01

    IPC分类号: G06F1730

    摘要: A method and system for backing up primary nodes onto backup nodes where the primary nodes can each originate a distributed transaction and can participate in a distributed transaction. The backup nodes, after a primary node failure, undo all transactions whose state is unknown on the backup node and all committed transactions which, if kept, would lead to an inconsistent set of backup nodes. First, committed transactions are undone if commits for them were not received on all back up nodes to the primary nodes that participated in the transaction. Second, all committed transactions that potentially depend on the committed transactions that were undone are also undone. Only those transactions that are provably independent of the committed transactions that were undone are kept. The result is a set of back up nodes which can support operations until the failing primary node is restored.

    摘要翻译: 将主节点备份到备份节点上的方法和系统,其中主节点可以各自发起分布式事务并且可以参与分布式事务。 备份节点在主节点发生故障后,撤销备份节点上状态未知的所有事务,如果保留,那么备份节点将导致不一致的备份节点集。 首先,如果提交的事务在所有备份节点上没有收到参与事务的主节点,那么提交的事务将被撤销。 其次,所有提交的交易,可能依赖于已撤销的提交交易也已撤销。 只有那些可以独立于被撤销的承诺交易的交易才被保留。 结果是一组备份节点,可以支持操作,直到故障主节点恢复。

    Ultra-high speed database replication with multiple audit logs
    6.
    发明授权
    Ultra-high speed database replication with multiple audit logs 失效
    具有多个审核日志的超高速数据库复制

    公开(公告)号:US06782399B2

    公开(公告)日:2004-08-24

    申请号:US09883066

    申请日:2001-06-15

    IPC分类号: G06F1730

    摘要: A method and system for high-speed database replication. Audit update records and audit backout records are generated by the primary system, and are transmitted to the backup system in multiple streams in parallel. The backup system stores the received audit records as audit image trails, and applies the audit updates and audit backouts to the backup database without regard to whether the transactions committed or aborted and without regard to whether the backup system received a complete set of the audit records pertaining to the transactions. Upon the occurrence of a predetermined event, the backup system applies all the audit updates and backouts it received, and subsequently “undoes” questionable audit updates and audit backouts.

    摘要翻译: 一种用于高速数据库复制的方法和系统。 审计更新记录和审计备份记录由主系统生成,并且以多个流并行传输到备份系统。 备份系统将接收到的审核记录存储为审计图像路径,并将审核更新和审核回退应用于备份数据库,而不考虑事务是否提交或中止,而不考虑备份系统是否收到完整的审核记录集 涉及交易。 在发生预定事件时,备份系统应用其接收的所有审核更新和退出,随后“撤销”可疑的审计更新和审核退出。

    System and method for purging database update image files after completion of associated transactions
    7.
    发明授权
    System and method for purging database update image files after completion of associated transactions 有权
    在关联交易完成后清除数据库更新图像文件的系统和方法

    公开(公告)号:US06553392B1

    公开(公告)日:2003-04-22

    申请号:US09418425

    申请日:1999-10-14

    IPC分类号: G06F1200

    摘要: A primary computer system has a database, application programs that modify the local database, and a transaction manager that stores audit records in a local image trail reflecting those application program modifications to the local database. In a remote backup system, a Receiver process receives audit records from the primary system. The audit records include audit update and audit backout records indicating database updates and database backouts generated by transactions executing on the primary system. The Receiver stores the audit update and audit backout records in one or more image trails. For each image trail there is an Updater process that applies to a backup database volume the database updates and backouts indicated by the audit update and audit backout records in the image trail. The remote backup system periodically executes a file purge procedure, which identifies the oldest transaction table from among the transaction tables in the last image trail file accessed for each of the image trails. Then, for each image trail, the file purge procedure accesses the image trial files in a predefined chronological order and for each accessed image trail file it compares a first set of newest transaction identifiers in the file's transaction table with a second set of oldest transaction identifiers in the identified oldest transaction table. The procedure purges the accessed image trail file only when all of the transaction identifiers in the first set are older than corresponding transaction identifiers in the second set.

    摘要翻译: 主计算机系统具有数据库,修改本地数据库的应用程序,以及将本地数据库中的应用程序修改反映到本地映像路径中的审计记录的事务管理器。 在远程备份系统中,Receiver进程从主系统接收审核记录。 审计记录包括审计更新和审计退出记录,指示在主系统上执行的事务生成的数据库更新和数据库备份。 接收器将审核更新和审核回退记录存储在一个或多个图像路径中。 对于每个图像路径,有一个Updater进程适用于备份数据库卷,数据库更新和回溯由审计更新指示,并在图像跟踪中审核备份记录。 远程备份系统定期执行文件清除过程,该过程从为每个映像路径访问的最后一个图像跟踪文件中的事务表中标识最早的事务表。 然后,对于每个图像轨迹,文件清除程序以预定的时间顺序访问图像试验文件,并且对于每个访问的图像跟踪文件,它将文件的事务表中的第一组最新事务标识符与第二组最旧的事务标识符进行比较 在识别的最旧的事务表中。 只有当第一组中的所有事务标识符都比第二组中的对应事务标识符更旧时,该过程将清除所访问的映像跟踪文件。

    Remote duplicate database facility with improved throughput and fault
tolerance
    8.
    发明授权
    Remote duplicate database facility with improved throughput and fault tolerance 失效
    远程重复数据库设施,具有提高的吞吐量和容错能力

    公开(公告)号:US5835915A

    公开(公告)日:1998-11-10

    申请号:US761725

    申请日:1996-12-06

    IPC分类号: G06F11/14 G06F11/20 G06F17/30

    摘要: A local computer system has a local database, application programs that modify the local database, and a transaction manager that stores audit records in a local audit trail reflecting those application program modifications to the local database. Each audit record has an associated audit trail position. A remotely located computer system has a backup database. A remote data duplication facility (RDF) is partially located in the local computer system and partially in the remote computer for maintaining virtual synchronization of the backup database with the local database. The RDF includes an extractor process executed by said local computer system, and a receiver process and a plurality of updater processes executed by the remote computer system. The extractor process extracts audit records from the local audit trail and transmits those records to the receiver process. When the receiver process detects that it is receiving audit records not in accordance with a predefined sequence, it transmits an error message to the extractor process. Otherwise it distributes the received audit records to a plurality of image trail files in the remote computer system for processing by updater processes, which initiate redo operations of database modifications denoted in at least a subset of the audit records against the backup database. The extractor process responds to each error message by obtaining a restart audit trail position value from the receiver process and then extracting audit records from the local audit trail starting at that restart audit trail position value.

    摘要翻译: 本地计算机系统具有本地数据库,修改本地数据库的应用程序以及将本地数据库中的应用程序修改反映到本地审计跟踪中的审计记录的事务管理器。 每个审计记录都有一个关联的审计跟踪位置。 位于远程的计算机系统具有备份数据库。 远程数据复制设备(RDF)部分位于本地计算机系统中,部分位于远程计算机中,用于维护备份数据库与本地数据库的虚拟同步。 RDF包括由所述本地计算机系统执行的提取器处理,以及由远程计算机系统执行的接收器处理和多个更新程序。 提取程序从本地审计跟踪中提取审计记录,并将这些记录传送到接收者进程。 当接收者进程检测到它正在接收不符合预定义序列的审核记录时,它向提取器进程发送错误消息。 否则,它将接收到的审计记录分发到远程计算机系统中的多个图像跟踪文件,以便由更新程序进行处理,该更新程序开始针对备份数据库在至少一个审计记录子集中表示的数据库修改的重做操作。 提取器进程通过从接收器进程获取重新启动审计跟踪位置值来响应每个错误消息,然后从该重新启动审核跟踪位置值开始从本地审计跟踪提取审计记录。

    High speed system and method for replicating a large database at a remote location
    10.
    发明授权
    High speed system and method for replicating a large database at a remote location 失效
    用于在远程位置复制大数据库的高速系统和方法

    公开(公告)号:US06584477B1

    公开(公告)日:2003-06-24

    申请号:US09418427

    申请日:1999-10-14

    IPC分类号: G06F1730

    摘要: A primary computer system has a database, application programs that modify the local database, and a transaction manager that stores audit records in a local image trail reflecting those application program modifications to the local database. In a remote backup system, a Receiver process receives audit records from the primary system. The audit records include audit update and audit backout records indicating database updates and database backouts generated by transactions executing on the primary system. The Receiver stores the audit update and audit backout records in one or more image trails. For each image trail there is an Updater process that applies to a backup database volume the database updates and backouts indicated by the audit update and audit backout records in the image trail. The audit update and audit backout records are applied to the backup database volume in same order that they are stored in the image trail, without regard to whether corresponding transactions in the primary system committed or aborted. Upon the occurrence of a predefined event, such as failure of the primary system, the backup system determines a set of primary system transactions for which a commit/abort outcome is unknown. For each image trail, the corresponding Updater completes applying database updates and backouts to the backup database volume. Then, the Updater backs out database updates for the transactions for which the commit/abort outcome has been determined to be unknown.

    摘要翻译: 主计算机系统具有数据库,修改本地数据库的应用程序,以及将本地数据库中的应用程序修改反映到本地映像路径中的审计记录的事务管理器。 在远程备份系统中,Receiver进程从主系统接收审核记录。 审计记录包括审计更新和审计退出记录,指示在主系统上执行的事务生成的数据库更新和数据库备份。 接收器将审核更新和审核回退记录存储在一个或多个图像路径中。 对于每个图像路径,有一个Updater进程适用于备份数据库卷,数据库更新和回溯由审计更新指示,并在图像跟踪中审核备份记录。 审核更新和审核备份记录将以与存储在映像路径中的顺序相同的顺序应用于备份数据库卷,而不考虑主系统中对应的事务是否提交或中止。 在发生诸如主系统故障的预定义事件之后,备份系统确定提交/中止结果未知的一组主系统事务。 对于每个图像路径,相应的Updater完成将数据库更新和回退应用到备份数据库卷。 然后,Updater备份提交/中止结果已被确定为未知的事务的数据库更新。