实现可靠Redis集群双主实例架构（redis集群双主实例）
Nowadays, Redis is widely used to store and manage data in applications due to its high performance, excellent scalability and reliability. However, when the amount of Redis data increases, single instance structure can not guarantee the high avlability and scalability, so it is strongly recommended to use Redis cluster mode.
The Redis cluster is designed to increase the avlability of the data and can redistribute the data across multiple nodes. Most Redis clusters have a single master-slave architecture, where one primary instance handles the reads and writes, and the other instances acts as slaves, to ensure data redundancy.
However, even with this single master-slave architecture, when the master instance fls, it takes time to detect the flure and switch the master instance to restore avlability. In addition, while the switching process is running, the cluster will be unavlable. In order to address this issue and guarantee the high avlability of Redis cluster, a double master architecture can be used.
Double master architecture is essentially two copies of the Redis master instance with two different designated master nodes, doing the same job. All read and write operations will be replicated across both instances. This can provide higher business avlability and help to achieve real high scalability in Redis. Moreover, when one of them is down or unavlable, an automatic flover will switch the master instance immediately to the other one, reducing the avlability disruption to almost 0.
And to implement double master architecture, there are several avlable options. First of all, Redis replication can be used. It can be used to asynchronously replicate Redis data from master instance to the other master instance. In addition, n-way replication, master-master roles auto-switching, and Redis Sentinel can also be used to build a double master cluster. All of these tools are open products and avlable online.
Additionally, to help Redis administrators better understand and setup the double master architecture, there are some useful documents online which can provide a detled step-by-step guide on how to setup Redis double master instance. It covers all the basic information from installation to configuration and replication setup, as well as some troubleshooting tips.
In conclusion, the double master architecture for Redis cluster provides better high avlability and scalability for applications. With the proper setup, Redis administrators can benefit from this flover mechanism and build a reliable and secure Redis cluster for their applications.
