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From 기준 <0ctopus13pr...@gmail.com>
Subject RPC and Service difference?
Date Fri, 28 Apr 2017 16:07:36 GMT
Hi!

I'm using kudu 1.3, impala 2.7.

I'm investigating about extreamly slow scan read in impala's profiling.

So i digged source impala, kudu's source code.

And i concluded this as a connection throughput problem.

As i found out, impala use below steps to send scan request to kudu.

1. RunScannerThread -> Create new scan threads
2. ProcessScanToken -> Open
3. KuduScanner:GetNext
4. Send Scan RPC -> Send scan rpc continuously

So i checked kudu's rpc configurations.

--rpc_num_acceptors_per_address=1
--rpc_num_service_threads=20
--rpc_service_queue_length=50


Here are my questions.

1. Does acceptor accept all rpc requests and toss those to proper service?
So, Scan rpc -> Acceptor -> RpcService?

2. If i want to increase input throughput then should i increase
'--rpc_num_service_threads' right?

3. Why '--rpc_num_acceptors_per_address' has so small value compared
to --rpc_num_service_threads? Because I'm going to increase that value
too, do you think this is a bad idea? if so can you plz describe
reason?

Thanks for replying me!

Have a nice day~ :)

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