From: Luca Toscano <elukey@apache.org>
Date: Sat, 18 Jun 2016 10:13:42 +0000 (+0000)
Subject: Follow up about DNS Resolution cache in mod-proxy after
X-Git-Tag: 2.5.0-alpha~1496
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=567b147f98a2e174ce609bfc3382ac7cb7eb2b84;p=thirdparty%2Fapache%2Fhttpd.git

Follow up about DNS Resolution cache in mod-proxy after
a users@ email thread ("mod_proxy and DNS resolving").
Review from devs would be really appreciated, I'd like to
backport this info asap to 2.4.x.




git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1748948 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/docs/manual/mod/mod_proxy.xml b/docs/manual/mod/mod_proxy.xml
index 5e3a90ef305..c557eccb608 100644
--- a/docs/manual/mod/mod_proxy.xml
+++ b/docs/manual/mod/mod_proxy.xml
@@ -304,13 +304,14 @@ ProxyPass "/examples" "http://backend.example.com/examples" timeout=10
       <directive module="mod_proxy">BalancerMember</directive>.</p>
 
       <note><title>DNS resolution for origin domains</title>
-      <p>The DNS domain resolution happens when the socket to
-        the origin server is created for the first time.
-        When connection pooling is used, the DNS resolution is performed
-        again only when the <code>ttl</code> of the connection expires
-        (please check <directive module="mod_proxy">ProxyPass</directive>
-        parameters).
-        This means that httpd does not perform any DNS resolution caching.
+      <p>DNS resolution happens when the socket to
+        the origin domain is created for the first time.
+        When connection pooling is used, each backend domain is resolved 
+        only once per child process, and reused for all further connections 
+        until the child is recycled. This information should to be considered 
+        while planning DNS maintenance tasks involving backend domains. 
+        Please also check <directive module="mod_proxy">ProxyPass</directive>
+        parameters for more details about connection reuse.
         </p>
       </note>