From: Matt Nordhoff Date: Thu, 30 Jan 2020 14:31:33 +0000 (+0000) Subject: Add distributor-threads setting to rec performance docs X-Git-Tag: auth-4.3.0-beta2~53^2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fpull%2F8764%2Fhead;p=thirdparty%2Fpdns.git Add distributor-threads setting to rec performance docs --- diff --git a/pdns/recursordist/docs/performance.rst b/pdns/recursordist/docs/performance.rst index f46eb40327..43391c9eaa 100644 --- a/pdns/recursordist/docs/performance.rst +++ b/pdns/recursordist/docs/performance.rst @@ -20,8 +20,10 @@ Set :ref:`setting-threads` to your number of CPU cores (but values above 8 rarel Threading and distribution of queries ------------------------------------- -When running with several threads, you can either ask PowerDNS to start a special thread to dispatch the incoming queries to the workers by setting :ref:`setting-pdns-distributes-queries` to true, or let the worker threads handle the incoming queries themselves. -The dispatch thread enabled by :ref:`setting-pdns-distributes-queries` tries to send the same queries to the same thread to maximize the cache-hit ratio, but it might become a bottleneck if the incoming queries rate is too high to be handled by a single thread. +When running with several threads, you can either ask PowerDNS to start one or more special threads to dispatch the incoming queries to the workers by setting :ref:`setting-pdns-distributes-queries` to true, or let the worker threads handle the incoming queries themselves. + +The dispatch thread enabled by :ref:`setting-pdns-distributes-queries` tries to send the same queries to the same thread to maximize the cache-hit ratio. +If the incoming query rate is so high that the dispatch thread becomes a bottleneck, you can increase :ref:`setting-distributor-threads` to use more than one. If :ref:`setting-pdns-distributes-queries` is set to false and either ``SO_REUSEPORT`` support is not available or the :ref:`setting-reuseport` directive is set to false, all worker threads share the same listening sockets. @@ -32,6 +34,9 @@ If ``SO_REUSEPORT`` support is available and :ref:`setting-reuseport` is set to .. versionadded:: 4.1.0 The :ref:`setting-cpu-map` parameter can be used to pin worker threads to specific CPUs, in order to keep caches as warm as possible and optimize memory access on NUMA systems. +.. versionadded:: 4.2.0 + The :ref:`setting-distributor-threads` parameter can be used to run more than one distributor thread. + Performance tips ----------------