我们可以在故障转移期间使用只读副本在AWS Multi-AZ RDS mysql实例中实现读取操作的可用性。但是在这种情况下写入操作会发生什么？< / p>
答案 0 :(得分：3)
During a Multi-AZ fail-over in MySQL, AWS will change your RDS instance's DNS entry from one server to another. This switch-over takes about a minute or two.
During this time, your application will be unable to connect to the main instance (since the DNS is pointing to the bad server). Your application will receive connection failures. So you cannot read or write.
Once your app receives the new DNS values, it will then connect to the second server where read and write commands will work as expected.
After the fail-over, the original (now theoretically bad) server is replaced and/or fixed and becomes the backup for the new main server.
More information about the fail-over process: http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concepts.MultiAZ.html