[Remops] Attn bigapple admin: Rate-limiting woes

[pyradic]

Dear bigapple admin:

Starting a few days ago, you appear to have introduced strict rate- 
limiting on your system.  This includes two things:

  - no more than two connections allowed from any host at any time  
(transient failure)

  - no more than 30 messages allowed from any host in a given period  
(permanent failure)

The combination is unfortunate.  Here's what happens:

Parallel delivery of freshly submitted messages results in a number  
of transient failures, because the "two connections at a time" limit  
kicks in.  Those are recorded and collected in the queue.  They are  
retried every so often, and may fail again due to the same limit.   
Eventually, they are moved into a separate queue of aged messages so  
as not to hinder delivery of fresher messages.  No problem so far.

Every so often, the system will still try to run the queue of aged  
messages.  There's a good chance more than 30 messages to bigapple  
have accumulated by then.  They are delivered all in a row, not in  
parallel (we're down to a single queue runner by then), but within a  
very short time.  This time, your second rate-limit kicks in, and  
this time, your system indicates it's a permanent failure.  The  
message is bounced to mixmaster, then discarded.

As I see it, you have four options:

  - leave things as they are and live with intermittent failures

  - persuade others to use linear instead of parallel delivery

  - turn off either of the two rate-limits

  - change the error message for the second rate limit to a transient  
failure code

I think the last option would be easiest and best. :-)

Regards,
mas

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