Networking on LeanerCloudhttps://leanercloud.com/tags/networking.htmlRecent content in Networking on LeanerCloudHugoenThu, 20 Aug 2026 02:08:40 +0200The cross-AZ data transfer costs hiding in your database traffichttps://leanercloud.com/blog/2024-09-20-cross-az-data-transfer-costs.htmlFri, 20 Sep 2024 22:24:02 +0000https://leanercloud.com/blog/2024-09-20-cross-az-data-transfer-costs.html<h2 id="the-line-item-nobody-can-explain">The line item nobody can explain</h2> <p>Cross-AZ data transfer is one of the least understood costs on an AWS bill. It does not map to a resource you can point at, it just shows up as data transfer charges, and it grows silently as traffic increases. A common source is an application instance talking to its database across an Availability Zone boundary, paying per gigabyte in both directions for traffic that could have been free.</p>