GAE Datastore Administration - webpage is not available

Question

I was looking to check out the experimental backup/restore feature of the app-engine datastore, so I followed the instructions and enabled "Datastore Administration" as explained in the link.

After doing so, instead of seeing the Datastore administration controls in the dashboard I am getting a "This webpage is not available" on chrome and "Server not found" on Firefox.

I understand this is experimental but still any help from the app-engine team would be appreciated in terms of what's going on with this feature :)

UPDATE: I tried this on another app (with an empty datastore) and the Datastore Administration page comes up normally.

Answer 1

A few things to check:

• Are you using the new high availability datastore? The docs don't specify but it's likely this experimental feature is not compatible with the deprecated master/slave datastore.

• If your app is using Java, you have to deploy a non-default Python app to use the backup/restore feature (search for "a note for java developers" on the page).

• How large is your datastore? It may take awhile to enable the feature on very large datastores.

• How long is your app's name? The error you are seeing is DNS related. The Datastore Admin feature seems to make a request to:

  ah-builtin-python-bundle-dot-latest-dot-[YOUR APP NAME].appspot.com

  at one point. Due to the length of that subdomain name, if your app name is longer than roughly 23 characters, you'll get a DNS error because DNS is limited to 63 characters per domain section:

  http://en.wikipedia.org/wiki/Domain_Name_System#Domain_name_syntax

  In my limited testing, I was able to get to a longer domain name by adding the ah-builtin-python-bundle... domain name directly to my system's etc/host file:

  http://en.wikipedia.org/wiki/Hosts_(file)