slow 2 node cluster

Erik Søe Sørensen ess at
Sun Nov 20 07:21:36 EST 2011

This depends quite a bit on the sizes of your objects.
Supposing an average size of 2KB, and n=3: on each write, on average 1.5 of the replicas would be on the other node, implying inter-node network traffic of 1.5*2KB=3KB (and this is just in one direction).
If your inter-node network connection is indeed 10Mbit ~  1MB/s, then 300 writes/s * 3KB = 0.9MB/s would just about saturate the connection.

You may want to check the network utilization.
From: riak-users-bounces at [riak-users-bounces at] On Behalf Of Catalin Constantin [dazoot at]
Sent: 20 November 2011 11:10
To: riak-users at
Subject: slow 2 node cluster


I am trying to evaluate / run some tests on a 4 mil dataset.
I have 2 nodes setup (different machines - 8GB ram each, I7 cpus).
10 MB connection between them.

I am trying to insert data into riak using w=1 and dw=1 (also tried with dw = 0, w = 0).
For each risk object i have 4 indexes (2 binary 2 int).
Riak backend is leveldb.

I can't get more than 300 inserts per second.
I have also tried running 2 threads each hitting the different node. Nothing changed too much.

Is this normal behavior ?

Catalin Constantin

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