Channel stops accepting puts

[rhasson]

Hi,

I'm running into an obscure issue that I can't figure out. So I set up a inbound channel that takes HTTP requests coming from a client. Then I take those requests off the channel, process them and put them back onto an outbound channel. The server then takes the modified requests off the outbound channel and replies back to the client. When I send 2 or more concurrent requests to the server, the outbound channel becomes corrupt after 2 puts.

This is what the outbound channel looks like BEFORE any requests are sent:
utbound
{ buf:
{ buf: { length: 0, array: [Object], head: 0, tail: 0 },
n: 100 },
xform:
{ '@@transducer/step': [Function],
'@@transducer/result': [Function] },
takes:
{ length: 1,
array: [ [Object], , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ],
head: 1,
tail: 0 },
puts:
{ length: 0,
array: [ , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ],
head: 0,
tail: 0 },
dirty_takes: 1,
dirty_puts: 0,
closed: false }

And this is what it looks like AFTER 2 concurrent requests:
outbound
{ buf:
{ buf: { length: 0, array: [Object], head: 2, tail: 2 },
n: 100 },
xform:
{ '@@transducer/step': [Function],
'@@transducer/result': [Function] },
takes:
{ length: 0,
array: [ null, null, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ],
head: 2,
tail: 2 },
puts:
{ length: 0,
array: [ , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ],
head: 0,
tail: 0 },
dirty_takes: 2,
dirty_puts: 0,
closed: false }

The only difference I can tell is that when this issue happens the "takes" array is missing the object at the end of it. If I issue requests manually the array grows as I expect and that object remains at the end of the array.

My code is in this gist: https://gist.github.com/rhasson/0460a2b261cf5422ec8f

The way to reproduce this problem is to run Apache Bench with concurrency of 2 or more, for example:

ab -n 4 -c 2 -p incomingcall.json -T 'application/json' -m POST http://localhost:9000/actions

Thanks,
Roy