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From Jeff Zhang <zjf...@gmail.com>
Subject Confusing Yarn RPC Configuration
Date Tue, 18 Aug 2015 03:40:50 GMT
I use yarn.resourcemanager.connect.max-wait.ms to control how much time to
wait for setting up RM connection. But the weird thing I found that this
configuration is not the real max wait time. Actually Yarn will convert it
to retry count with configuration
Let's say yarn.resourcemanager.connect.max-wait.ms=10000 and
yarn.resourcemanager.connect.retry-interval.ms=2000, then yarn will create
RetryUpToMaximumCountWithFixedSleep with max count = 5 (10000/2000)
Because for each RM connection, there's retry policy inside of hadoop RPC.
Let's say ipc.client.connect.retry.interval=1000
and ipc.client.connect.max.retries=10, so for each RM connection it will
try 10 times and totally cost 10 seconds (1000*10).  So overall for the RM
connection it would cost 50 seconds (10 * 5), and this number is not
consistent with yarn.resourcemanager.connect.max-wait.ms which confuse
users. I am not sure the purpose of 2 rounds of retry policy (Yarn side and
RPC internal side), should it be only 1 round of retry policy and yarn
related configuration is just for override the RPC configuration ?

BTW, I believe it is the same issue for node manage connection.

Best Regards

Jeff Zhang

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