Update overload-queue-length and overload-drops documentation

It wasn't clear to be what overload-queue-length did until I looked at
the code

diff --git a/docs/performance.rst b/docs/performance.rst
index d2730788339741d3a622cdf0a363289eb98059d0..5df12241342f241b2f5215e6752ea05cd038c7cb 100644 (file)
--- a/docs/performance.rst
+++ b/docs/performance.rst
@@ -236,7 +236,7 @@ Number of currently open TCP connections
 
 overload-drops
 ^^^^^^^^^^^^^^
-Number of questions dropped because backends overloaded
+Number of questions dropped because backends overloaded (backends are overloaded if they have more queries outstanding then the value of :ref:`setting-overload-queue-length`)
 
 .. _stat-packetcache-hit:
 

diff --git a/docs/settings.rst b/docs/settings.rst
index 17d61bebdf2a8d43d0a3820943691c9ea3945ca5..9d68d0c82af6cf01a33a434e008ee67977926394 100644 (file)
--- a/docs/settings.rst
+++ b/docs/settings.rst
@@ -1369,7 +1369,8 @@ Secondary name servers.
 -  Default: 0 (disabled)
 
 If this many packets are waiting for database attention, answer any new
-questions strictly from the packet cache.
+questions strictly from the packet cache. Packets not in the cache will
+be dropped, and :ref:`_stat-overload-drops` will be incremented.
 
 .. _setting-prevent-self-notification: