johnynek
commented
8 years ago There actually are tests:
We are just not running those tests in the Memory/ConcurrentMemory platforms.
They may not work correctly because I guess there is a hidden assumption that there is no pipelining for the logic of that to be correct (for each key, you have to push it all the way through before you can process the next value for that key). As such, we need to detect those nodes and combine them into one operation to handle it correctly (something storm still does not do, as of this writing).
Memory did not support it, so clearly we are not exercising it.
See note in: #638