Today is the start of the Web 2.0 Expo conference. It is going to be a busy day. I am looking forward to catching Jay Parkinson talking about new business models in Health 2.0.
To warm up I am attending a session by Dave Engberg on Sync-ing between web and client applications. Dave is CTO of Evernote - a hybrid note taking application.
In building a hybrid app Evernote went with full replication and synchronization.
They chose to have one master copy with the option of multiple slaves.
They also chose to use n intelligent update scheme that records an object's state and replicate using update sequence numbers. There is also no locking of records. ie. You don't block the web app from working while a sync takes place.
Their hybrid approach means that they can deal with the disconnected client, eg. while on a plane.
But how do they deal with phone devices when they don't have capacity for a full copy of the client's data. Evernote's Single Master design leverages the IMAP interaction model.The service is the ultimate arbiter.The Replication model uses Update Sequence Numbers. This leverages the Active Directory model.
Time to drop out of this session and head to Web 2.Open.