Tuesday, September 09, 2008

Linear Scalability of MySQL Cluster using DBT2

To achieve linear scalability of MySQL Cluster using the DBT2
benchmark has been a goal of mine for a long time now. Last
week I finally found the last issue that limited the scalability.
As usual when you discovered the issue it was trivial (in this
case it was fixed by inserting 3 0's in the NDB handler code).

We can now achieve ~41k TPM on a 2-node cluster, ~81k on a
4-node cluster and ~159k TPM on a 8-node cluster giving roughly
97% improved performance by doubling number of nodes. So there
is nothing limiting us now from achieving all the way up to
1M TPM except lack of hardware :)

I've learned a lot about what affects scalability and what
affects performance of MySQL Cluster by performing those
experiments and I'll continue writing up those experiences on
my blog here. I have also uploaded a new DBT2 version where I
added a lot of new features to the DBT2, improved performance
of the benchmark itself and also ensured that running with many
parallel DBT2 drivers do still provide correct results when
adding the results together. It can be downloaded from