From 415b965ba18b367f6497fe8f6f78a012fab776cd Mon Sep 17 00:00:00 2001 From: Corey Quinn Date: Wed, 2 Oct 2019 11:00:01 -0700 Subject: [PATCH] Data Transfer Gotcha Updates --- README.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/README.md b/README.md index f81bf75..6d3b0c2 100644 --- a/README.md +++ b/README.md @@ -2378,6 +2378,8 @@ Billing and Cost Management - Some of the most common gotchas: - ๐Ÿ”ธ*AZ-to-AZ traffic:* Note EC2 traffic between AZs is effectively the same as between regions. For example, deploying a Cassandra cluster across AZs is helpful for [high availability](#high-availability), but can hurt on network costs. - ๐Ÿ”ธ*Using public IPs when not necessary:* If you use an Elastic IP or public IP address of an EC2 instance, you will incur network costs, even if it is accessed locally within the AZ. + - ๐Ÿ”ธ*Managed NAT Gateway data processing:* Managed NAT Gateways are used to let traffic egress from private subnets--at a cost of 4.5ยข as a data processing fee layered on top of data transfer pricing. Past a certain point, running your own NAT instances becomes far more cost effective. + - ๐Ÿ”ธ*Some services do cross-AZ traffic for free:* Many AWS services you'd not consider on their own merits offer a hidden value of free cross-AZ data transfer. EFS, RDS, MSK, and others are examples of this. - This figure gives an overview: ![AWS Data Transfer Costs](figures/aws-data-transfer-costs.png)