Apigee occasionally returns 503 without checking my server

[systemsdevelopm]

I've noticed we're getting occasional 503 messages returned from our Apigee API but as far as I can tell it isn't coming from out backend servers. Here's an excerpt from a debug trace that caught it in action and screenshots of exactly the same request failing and passing.

It doesn't happen consistently and it doesn't look like it is contacting my server at all

debugtrace.txt

[adevegowda]

@Craig Stanton,

From the information visible in the screenshots, I see that 503 is caused after 3045ms. Most likely 503 would be caused due to connection time out error. That is Edge's Message Processor would try to connect to your backend server, but if it's unable to establish the connection within 3 seconds (3000ms), then it fails with connection time out error and send 503 as the response.

You can read more about the difference causes for 503 Service Unavailable error and how to resolve in this playbook.

If you still need further help, please contact Apigee Support

[systemsdevelopm]

The makes a certain amount of sense, as far as ai can tell all the ones that are failing are taking 3000+ ms, but I can't work out why. My server does not appear to be getting the requests and is not failing any of my automated availability monitoring. Is there any way to run things like ping or trace route from Apigee to see what happens to the requests in-between?

[systemsdevelopm]

So it turns out this was caused by a new IP address in use by Apigee. We had whitelisted the IPs from Apigee to get into our network and a new one popped up 4.5 days ago, we were denying it access.

[adevegowda]

@Craig Stanton

That explains why you were seeing the issue intermittently. Thanks for the update.