Here's your problem:

> Mar 18 22:47:14.579 5 named[]: running on Linux x86_64 2.6.32.67 #1 SMP Sat Aug 29 13:24:08 EDT 2015
> Mar 18 22:47:14.579 5 named[]: built with '--enable-full-report' '--with-openssl=/usr/local/openssl-1.0.2' '--with-libxml2=no' 'LDFLAGS=-L/usr/local/lib64'

Prior to 9.10, "--enable-threads" was not turned on by default on Linux.

Build 9.9 with that option and it should get better.