If it is not it will sleep for some time and retry from the start.
Ruby redis setnx.
Redis in ruby chapter 4 adding the missing options to the set command.
C4 sends setnx lock foo in order to acquire the lock.
A ruby client that tries to match redis api one to one while still providing an idiomatic interface.
See rubydoc info for the api docs of the latest published gem.
Now you re ready to start using redis.
Supports both blocking and non blocking semantics.
Setnx set if not exists.
You can interact with redis directly using redis cli but if you want to work with redis from ruby you should use a gem.
Redis setnx 命令 redis 字符串 string redis setnx set if not exists 命令在指定的 key 不存在时 为 key 设置指定的值 语法 redis setnx 命令基本语法如下 redis 127 0 0 1 6379 setnx key name value 可用版本 1 0 0 返回值 设置成功 返回 1 设置失败.
The redis setex command is used to set some string value with specified timeout in seconds in redis key.
There is demand for additional variants such as setexnx becuase it is a pretty common pattern in caching and sessions handling to set an object only if not already inside the cache and setting it with an expire.
Psetex set with milliseconds expire.
Distributed mutex in ruby using redis.
Ok if the value is set to key or null if the value does not set.
Set is one of the most used redis commands and has many variants.
There are a few gems available.
In the following example only one thread process server can enter the locked block at one time.
You may have to run redis server on another terminal to start the server before you can connect to it.
The idea was taken from the official setnx doc.
Setex set with expire.
C4 sends get lock foo to check if the lock expired.
The crashed client c3 still holds it so redis will reply with 0 to c4.
Gem install redis you can connect to redis by instantiating the redis class.
This command is equivalent to executing the following commands.
O 1 set key to hold the string value and set key to timeout after a given number of seconds.
