Redis: Atomic get and conditional set

Question

I'd like to perform an atomic GET in Redis, and if the value returned is equal to some expected value, I'd like to do a SET, but I want to chain all of this together as one atomic operation. (I'm trying to set a flag that indicates whether any process is writing data to disk, as only one process may be permitted to do so.)

Is it possible to accomplish this with Redis?

I have seen documentation on MULTI operations but I haven't seen conditional operations i MULTI operations. Any suggestions others can offer with this would be greatly appreciated!

Answer 1

You can do both the GET and set operations on the redis server itself using Lua scripts. They're atomic and allow you to add logic too.