From: Aram Sargsyan Date: Tue, 15 Apr 2025 14:57:52 +0000 (+0000) Subject: Document the new unreachable cache behavior X-Git-Tag: v9.21.9~3^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0f2fba46ad4f5bcce6ad72098f51bf464eac913c;p=thirdparty%2Fbind9.git Document the new unreachable cache behavior Update the documentaion to include information about how the cache's exponential backoff works, and how to clear the cache. --- diff --git a/doc/arm/config-auth.inc.rst b/doc/arm/config-auth.inc.rst index b054fb0904f..77d1c7ae99e 100644 --- a/doc/arm/config-auth.inc.rst +++ b/doc/arm/config-auth.inc.rst @@ -87,6 +87,13 @@ The numbers in parentheses in the following text refer to the numbered items in from the primary (as described in section 2 a. above). If the zone file has changed, propagation is practically immediate. +.. Note:: When a primary server is unreachable, :iscman:`named` initially caches + that information for 10 seconds. After that initial period, :iscman:`named` + may try that server again; if the server remains unresponsive, + :iscman:`named` caches its unreachable status for up to 640 seconds using an + exponential backoff. During that time :iscman:`named` does not try to contact + the affected server. The cache can be cleared using :option:`rndc flush`. + The authoritative samples all use NOTIFY but identify the statements used, so that they can be removed if not required.