From 92132ae94b8ddb1993cf9aaa2741f577276e3dd1 Mon Sep 17 00:00:00 2001 From: Remi Gacogne Date: Thu, 2 Mar 2017 15:36:44 +0100 Subject: [PATCH] auth: Document that the cache respect the answer's TTL --- docs/markdown/authoritative/performance.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/markdown/authoritative/performance.md b/docs/markdown/authoritative/performance.md index a1e23729f0..3284024b34 100644 --- a/docs/markdown/authoritative/performance.md +++ b/docs/markdown/authoritative/performance.md @@ -12,7 +12,7 @@ Different backends will have different characteristics - some will want to have This is done with the [`distributor-threads`](settings.md#distributor-threads) setting which says how many distributors will be opened for each receiver thread. Of special importance is the choice between 1 or more backends. In case of only 1 thread, PowerDNS reverts to unthreaded operation which may be a lot faster, depending on your operating system and architecture. -Another very important setting is [`cache-ttl`](settings.md#cache-ttl). PowerDNS caches entire packets it sends out so as to save the time to query backends to assemble all data. The default setting of 20 seconds may be low for high traffic sites, a value of 60 seconds rarely leads to problems. +Another very important setting is [`cache-ttl`](settings.md#cache-ttl). PowerDNS caches entire packets it sends out so as to save the time to query backends to assemble all data. The default setting of 20 seconds may be low for high traffic sites, a value of 60 seconds rarely leads to problems. Please be aware that if any TTL in the answer is shorter than this setting, the packet cache will respect the answer's shortest TTL. Some PowerDNS operators set cache-ttl to many hours or even days, and use [`pdns_control`](running.md#pdns_control)` purge` to selectively or globally notify PowerDNS of changes made in the backend. Also look at the [Query Cache](#query-cache) described in this chapter. It may materially improve your performance. -- 2.47.2