公开(公告)号：US08924347B1

公开(公告)日：2014-12-30

申请号：US13646019

申请日：2012-10-05

Applicant: Google Inc.

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

IPC: G06F17/30

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

Abstract: A replication server receives a first write request from a database server for writing first data to persistent data storage. The replication server determines that the first write request is designated as asynchronous. In response to determining that the first write request is asynchronous, the first data is saved to local cache at the replication server and an acknowledgement is sent to the database server. The local cache stores second data to be written to persistent data storage when the first data is saved to the local cache. The first data and the second data are written from the local cache to the persistent data storage in a batch operation.

Abstract translation: 复制服务器从数据库服务器接收第一个写入请求，用于将第一个数据写入持久数据存储。 复制服务器确定第一个写请求被指定为异步。 响应于确定第一写请求是异步的，第一数据被保存到复制服务器上的本地缓存，并且将确认发送到数据库服务器。 当第一数据被保存到本地高速缓存时，本地高速缓存存储要写入永久数据存储的第二数据。 将第一数据和第二数据从本地高速缓存写入到批处理操作中的持久数据存储。

公开(公告)号：US08838539B1

公开(公告)日：2014-09-16

申请号：US13646015

申请日：2012-10-05

Applicant: Google Inc.

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

IPC: G06F17/30

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。