Indeed I feel happy to announce that we have released Midas, an on-the-fly schema migration tool for MongoDB. This is a moment of rejoice for my team and myself here at EqualExperts, where I am currently heading the RnD efforts. This is the second open-source product after Tayra – an incremental backup and restore tool for MongoDB was released last year.
So what does Midas do? Just in a nutshell, applications have to hand-roll their own schema migration infrastructure or use some third-party tool. It is difficult to migrate TBs of data without downtime (unacceptable from SLA stand-point!). This is where Midas fills the gap. It intercepts responses at MongoDB Protocol level and upgrades or downgrades document schema in-transit. As Midas works at protocol level, it is agnostic of Language specific MongoDB drivers (Ruby, Python, C# and Java drivers) and their versions within those languages. Further, Midas is Agnostic of the MongoDB configurations like Standalone, Replica Sets, Sharded environments.
For further information, you can view the slides below:
It is open-source, so feel free to send us a pull-request on https://github.com/EqualExperts/Midas. I welcome feedback and please let us know your experiences as well. Cheers!