公开(公告)号：US09361348B1

公开(公告)日：2016-06-07

申请号：US14444220

申请日：2014-07-28

Applicant: Google Inc.

Inventor： Kenneth M. Ashcraft ,  Vishal Kasera ,  Jean-Michel Leon ,  Amit Agarwal

IPC: G06F17/30 ,  H04L29/08

CPC classification number: G06F17/30575 ,  G06F12/0806 ,  G06F17/30303 ,  H04L49/9005 ,  H04L67/02 ,  H04L67/42

Abstract: A database server receives a request from a client application for performing a data transaction on persistent data storage. The request is sent to a set of replication servers. An acknowledgement for the request is received from each replication server, including a start sequence number and an end sequence number for data that is stored in local cache of the replication server, and a latest committed sequence number for data that was written to the persistent data storage by the replication server. A maximum value of latest committed sequence numbers received from the set of replication servers is determined. For each replication server, it is examined whether there is a gap between the start sequence number for data stored in local cache and the maximum value of the latest committed sequence numbers. Based on the examining, it is determined whether there is an occurrence of loss of data.

Abstract translation: 数据库服务器从客户端应用程序接收用于执行持久数据存储的数据事务的请求。 请求被发送到一组复制服务器。 从每个复制服务器接收到对请求的确认，包括存储在复制服务器的本地缓存中的数据的起始序列号和结束序列号，以及写入持久数据的数据的最新提交序列号 由复制服务器存储。 确定从复制服务器集合接收到的最新提交的序列号的最大值。 对于每个复制服务器，检查存储在本地高速缓存中的数据的起始序列号与最近提交的序列号的最大值之间是否存在间隙。 根据检查，确定是否存在数据丢失的发生。