title: Connecting to Aurora Serverless via intra-region VPC Peering
body: <p>I have two AWS accounts, which I will call <code>prod</code> and <code>dev</code>. </p>
  
  <p><code>prod</code> has an Aurora Serverless cluster (not instance!), perfectly connectable within its own VPC in the <code>prod</code> account. To save time and money, I would like to use this cluster in <code>dev</code> (obviously with read-only permissions, etc) instead of spinning up a new cluster, mostly due to volume of data and the need for parity during development.</p>
  
  <p>I have set up <code>dev</code> exactly the same as <code>prod</code>, minus the Aurora cluster and with a different CIDR block for the VPC. I have set up a VPC peering connection between the VPCs in <code>dev</code> and <code>prod</code> with DNS resolution on both VPCs and enabled in the peering connection. I have added this peering connection to the route tables for each VPC, with the affected subnets explicitly associated. I have added both CIDR and SGs (including the VPC default SG, as I read recommended on SO in a tangentially related answer) to all affected SGs (Aurora cluster SG, SG for Lambda that is calling out to Aurora, default SG for VPC in both accounts). I also added the CIDR blocks to the ACL explicitly.</p>
  
  <p>I can't get any kind of connection whatsoever. Documentation on whether this is even possible leads me in a recursive loop of not-quite-useful information, though it does seem the intra-region peering should be possible. I am no network expert, so it's entirely possible I have just horribly misconfigured something along the way, but I can't find any guides or useful documentation for this particular situation.</p>
  
  <p>Is this even possible? Is there a checklist somewhere of changes to be made to allow connections like this (outside of the severely lacking AWS docs on VPC peering)? Route tables, subnets, security groups, ACLs, VPC peering connections...it's a lot of pieces and I feel like at this point I have just missed something, despite having torn down/reconfigured this setup via several guides.</p>