A Surprisingly Small Changekrayaproductionengineering
In the very early days of megabus, with the database server under heavy load, and the primary bottleneck, I’d cobbled together a quick mirroring system to buy us some time. I didn’t think it would actually work, but all it did was mirror every write to a second database server.
I knew that it was temporary - a sticking plaster which wasn’t that sticky. For the most part, the worst issue was some of the IDs would be reversed in the follower. At least, that was the worst, until we started getting overbookings.