[Pdns-users] Dealing with high concurrency and MySQL backend

[Mohamed Lrhazi]

Hello,

I run a resperf test against a fresh setup of
pdns-2.9.22-10.el6.x86_64, on CentOS 6, on an ESX VM with 2vCPUs and 2
GB RAM.
mysql is: mysql-server-5.1.52-1.el6_0.1.x86_64, all rpms from EPEL,
with no tweaks of configs....

The respserf is using a query file made up of all my records, about
50,000, duplicated several times to make it a bit over a million
lines.

pdns crashes with error:

5003 questions waiting for database attention. Limit is 5000, respawning

Is it possible to tweak MySQL (InnoDB) to handle such load?
What would be my options, in order to perform well under such high
amount of concurrent queries? Is MySQL an option at all?

Could pdns caching help? Could one warm it up somehow so as to load
the intire data set into the cache? Would that be serious for real
world traffic?

Thanks a lot.
Mohamed.