Comment 11 for bug 1567655

To follow on, I was thinking that there might be a reasonable intermediary solution. I think changing a 500 -> 504 is kind of pointless for the user. They still don't get any useful data.

That being said... we used to have a similar sub select issue on some part of the detailed server list. And what we did was skip over the rows that were deleted. It's a little more complicated because this is another rest service, however I think that building a standard of returning something like a 206 and just marking out the security_groups as 'UNKNOWN' would be ok here. Because 95% of the information will be accessible, but we can indicate this is not perfect information, but it might be good enough for your use case.