Hi,

I have a question about the way of socket communication between mysqld and ndbd.

I have performed the benchmark on MySQL Cluster by two types of configuration of MySQL Cluster. 1) One configuration is that SQL node and Data node are located on different servers and 2) the other configuration is that SQL node and Data are located on the same server.

Actually, we have two configuration below: Four Data Nodes and two replicas and four SQL nodes. (1) For four servers, we sited mysqld and ndbd in each server together. (2) For eight servers, we sited mysqld and ndbd in each server respectively.

We got the performance data which shows that the same server configuration(1) is better than the different server configuration(2).

Question: When mysqld and ndbd are on one same server, why does this configuration lead to better performance than the mysqld and ndbd different node configuration? Is communication overhead or response time reduced in comparison with different server configuration? Is this recognition valid?

Regards, Y. Nakayama