An interesting question came up recently. How do we want to handle sharding failures?

For example, let us say that I have a 3 nodes clusters of RavenDB, serving posts for a blog (just to give some random example). The way the sharding has been setup, we are doing sharding using Round Robin based on posts (so each post goes to a different machine, and anything related to post goes to the same node as the post). Here is how it can be set:

Now, we want to display the main page, and we would like to show the most recent posts. We can do this using the following code:

The question is, what would happen if the second server if offline?

I’ll give several alternative in the next few posts.