README
¶
Alternator - Client-side load balancing - Go
Introduction
As explained in the toplevel README, DynamoDB applications
are usually aware of a single endpoint, a single URL to which they
connect - e.g., http://dynamodb.us-east-1.amazonaws.com. But Alternator
is distributed over a cluster of nodes and we would like the application to
send requests to all these nodes - not just to one. This is important for two
reasons: high availability (the failure of a single Alternator node should
not prevent the client from proceeding) and load balancing over all
Alternator nodes.
One of the ways to do this is to provide a modified library, which will allow a mostly-unmodified application which is only aware of one "enpoint URL" to send its requests to many different Alternator nodes.
Our intention is not to fork the existing AWS client library for Go. Rather, our intention is to provide a small library which tacks on to the existing "aws-sdk-go" library which the application is already using, and makes it do the right thing for Alternator.
The alternatorlb library
The Go integration exists in two flavors. The v1 directory contains
a snippet for integrating Alternator with the aws-sdk-go-v1, while the
v2 directory contains a Go module, that can be used with
the aws-sdk-go-v2. See the README.md of these respective directories for more
details on how to use them.
Directories