I just merged SSL support into Redis unstable. This feature has an interesting story that I want to tell you. It was kinda of a "process" to reach the right solution, or at least a solution that looks a lot better than the alternatives.
Many wanted SSL in the past, however the first very serious effort at providing a concrete pull request that implemented SSL in all the channels, including Replication, Redis Sentinel, Redis Cluster, was from AWS. The work of two smart folks there.
Thanks to this work, we understood that to implement SSL just as a "minimal code change" effort was not going to work. SSL is very different from normal sockets, and has different assumptions, certain things are asynchronous where sockets are synchronous, N bytes may become M.
After this experience and a revision of the PR, my friend Yossi at Redis Labs said he wanted to test a different approach. To create a new "connection" abstraction to abstract away normal sockets and SSL connections. But once he started working, he continued.
So after the prototype he went implementing also a mechanism to fix the worst problem with replication, the fact that SSL sockets could not easily change owner (different process). We (including the original PR authors at AWS) discussed it and found a solution we liked.
Yossi, with a big help from Oran, another Redis "veteran" from Redis Labs, implemented this remaining part. The result is an SSL patch that was actually a pleasure to read: I could never have imagined this happening.
SSL in Redis remains "opt in", you have to compile Redis with SSL support if you want it, so normal users will not have extra dependences. All in all I'm very happy about the process. Here is the link at the PR: github.com/antirez/redis/…
I want to say a big thank you to my colleagues at Redis Labs that wrote the patch, and to the folks at AWS that wrote the initial implementation, that was also very useful to understand how to imagine the v2 design and implement it.
