From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Weimer Subject: Re: [PATCH] dns: Apply a default TTL to records obtained from getaddrinfo() Date: Tue, 19 May 2020 16:17:55 +0200 Message-ID: <87blmkgga4.fsf@oldenburg2.str.redhat.com> References: <158981176590.872823.11683683537698750702.stgit@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <158981176590.872823.11683683537698750702.stgit@warthog.procyon.org.uk> (David Howells's message of "Mon, 18 May 2020 15:22:45 +0100") Sender: linux-kernel-owner@vger.kernel.org To: David Howells Cc: linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-afs@lists.infradead.org, ceph-devel@vger.kernel.org, keyrings@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: ceph-devel.vger.kernel.org * David Howells: > Fix this to apply a default TTL of 10mins in the event that we haven't got > one. This can be configured in /etc/keyutils/key.dns_resolver.conf by > adding the line: > > default_ttl: > > to the file. If the name resolution is not needed continuously, but only for the connection attempt, I suggest to use a much shorter TTL, like five seconds or so. I'm worried that if the implied TTL is too long, some system administrators will have to figure out how to invalidate the DNS cache. Thanks, Florian From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Weimer Date: Tue, 19 May 2020 14:17:55 +0000 Subject: Re: [PATCH] dns: Apply a default TTL to records obtained from getaddrinfo() Message-Id: <87blmkgga4.fsf@oldenburg2.str.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit List-Id: References: <158981176590.872823.11683683537698750702.stgit@warthog.procyon.org.uk> In-Reply-To: <158981176590.872823.11683683537698750702.stgit@warthog.procyon.org.uk> (David Howells's message of "Mon, 18 May 2020 15:22:45 +0100") To: David Howells Cc: linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-afs@lists.infradead.org, ceph-devel@vger.kernel.org, keyrings@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org * David Howells: > Fix this to apply a default TTL of 10mins in the event that we haven't got > one. This can be configured in /etc/keyutils/key.dns_resolver.conf by > adding the line: > > default_ttl: > > to the file. If the name resolution is not needed continuously, but only for the connection attempt, I suggest to use a much shorter TTL, like five seconds or so. I'm worried that if the implied TTL is too long, some system administrators will have to figure out how to invalidate the DNS cache. Thanks, Florian