Why is there a sudden increase in TTransportException?

We're recently receiving a lot of com.evernote.thrift.transport.TTransportException with HTTP codes 400, 429, 418.

429 corresponds to Too Many Requests but it was handled with EDAMSystemException RATE_LIMIT_REACHED before.

We managed to make contact with Evernote developer support where they came to the realisation that a change their end was causing our issues.

We'd observed:

• rate limits being far stricter than normal
• rate limit errors being empty 429 responses, therefore not being picked up by the correct error handling on the SDK (we using Ruby)

Our issue is fixed now. My hope is that the change that fixed things for us has been rolled out to everyone, but if not I recommend emailing devsupport@evernote.com.