Besu-private. Fixed number of nodes deployed on the network (3>4)

lib/besu-private/README.md

@@ -25,6 +25,6 @@ Open here: **[Besu Private Chain on aws-samples](https://github.com/aws-samples/
 
 The [AWS CDK stack](https://github.com/worldwide-asset-exchange/wax-aws-cdk) deploys the system that:
 
-1. Exposes the JSON-based Remote Procedure Call (RPC) API of 3-node Besu private network through NLB over AWS Private Link. (3 nodes is the minimum required for the functioning of IBFT consensus)
+1. Exposes the JSON-based Remote Procedure Call (RPC) API of 4-node Besu private network through NLB over AWS Private Link. (3 nodes is the minimum required for the functioning of IBFT consensus and 1 more is needed to tolerate a single faulty node)
 2. Nodes run as Docker containers on [Amazon Elastic Container Service](https://aws.amazon.com/ecs/) (ECS) backed by [Amazon Elastic Compute Cloud](https://aws.amazon.com/ec2/) (EC2)and [Amazon Elastic Block Storage](https://aws.amazon.com/ebs/) (EBS) services with [Autoscaling Group](https://docs.aws.amazon.com/autoscaling/ec2/userguide/auto-scaling-groups.html) (ASG) for automatic recovery.
 3. Nodes store secret keys in [AWS Secrets Manager](https://docs.aws.amazon.com/secretsmanager/latest/userguide/intro.html) to protect them from deletion during recovery. [AWS Lambda](https://aws.amazon.com/lambda/) functions keep track of the mapping between running container nodes and their secrets in a [Amazon DynamoDB](https://aws.amazon.com/dynamodb/) table. They update the mapping if nodes are terminated and replaced by new containers.