如何正确暂停Redis服务器（如何暂停redis服务器）

Nowadays, Redis has beenecome an important part of many applications, which makes it necessary to know how to correctly pause the server. In this article, I will expln some common situations and solutions for correctly pausing the Redis server.

Firstly, the most common situation is to pause the Redis server temporarily and quickly. In this case, the most convenient way is to use the Redis command SAVE. By calling this command, a snapshot of all data stored in memory can be copied to disk. After executing the command, the Redis engine will stop its service without closing the server.

Alternatively, issuing the command BGSAVE will also trigger the Redis engine to stop its service. The only difference between them is the timing of executing the command. SAVE get executed directly whereas BGSAVE is queued in the background.

Secondly, if Redis service needs to be paused for a long time, the server needs to be shut down gracefully. The key is to execute the Redis command SHUTDOWN. This command will save the data stored in the memory to the disk and make Redis stop its service gracefully.

Morever, if a client processing data asks for a graceful pause, the client can set the KEYTTL parameter with a sufficient long period. It will give Redis server time to process its data without interruptions.

Finally, the Redis service may be automatically paused because of the internal server configuration. The most common situation is to limit the maximum memory used by Redis in the configuration. In this case, a pause may happen if the Maxmemory parameter is met and the internal policy is configured to “noeviction”. In this case, the Redis engine typically stops its service and user needs to fix the underlying problem to resume the service.

To recap, there are several ways to pause Redis server. In most cases, the easiest way is to use the SAVE or BGSAVE command. For a long period pause, executing the command SHUTDOWN can save all existing data and stop the service gracefully. In addition, the KEYTTL parameter should be considered in scenarios when a client requests a long pause from the server. Finally, when the maximum memory used by Redis is exceeded, the internal configuration may cause an unexpected pause of the service.

In conclusion, pausing the Redis server correctly is necessary for many applications to work properly. By understanding the core commands and settings, users can avoid data loss and resume the service quickly and properly.