Anyone who has been on a night time support rotation can relate to the 3 AM phone call that gets you groggily out of bed, has you fixing some simple, but important problem, and then leaves you staring at the ceiling by 4 AM wondering if you should just go into work, because you know you aren't getting back to sleep. All of the engineers in our office have been there, done that, and didn't like it very much. That's one of the reasons we focus so much on resilient operations for SymmetricDS including our "Hands Off" Recovery of data synchronization. "Hands Off" recovery is pretty much exactly what it sounds like. SymmetricDS has been built from the ground up to recover and keep databases in sync without manual intervention any time it possibly can.

"Hands Off" Recovery features in SymmetricDS have been refined over the years as we have built and helped maintain large data synchronization scenarios for our customers. When synchronizing two or three databases, manual intervention doesn't matter as much, but when synchronizing ten to fifty thousand databases it really becomes a "must have."

With large node network data sync scenarios, there are always a handful of databases that are offline or unreachable for one reason or another. A backhoe cuts through a network line, a hurricane causes long term power failures, a database becomes corrupt or needs regularly scheduled maintenance. Regardless of the reason, these outages need to be handled with the minimum amount of intervention, zero if possible. So when a database in your node network goes offline, SymmetricDS detects it, lets you know that it is having problems reaching that database, and then patiently keeps trying until the underlying cause rectifies itself. That might mean a network technician restoring network connectivity, a lineman bringing power back online or a database administrator fixing things up on the database end. Regardless, once the underlying problem is solved, SymmetricDS simply picks up where it left off and gets data back in sync. No manual intervention needed. So, you can sit back and watch it happen, or better yet, sleep through it!

Greg Wilmer
Author: Greg Wilmer

Greg has over 25 years experience in Information Technology spanning roles from developer to architect to VP and CIO.  He has designed and implemented products and systems for small shops, to Fortune 500 companies across many vertical markets including Retail, Health Care, Oil and Gas, Aerospace and many more.  His software experience spans signal processor work for AWACS planes to large scale integration projects for global enterprises.  He holds a Bachelors Degree in Computer Science from the Ohio State University and a Masters Degree in Engineering from MIT focusing on product design and development.