Wietse Venema via Postfix-users wrote in <4ypcfw1rmdzj...@spike.porcupine.org>: |Joachim Lindenberg: ... |Joachim Lindenberg: |> To some extend the approach probably replaces blocking calls on |> TCP layer with blocking calls on DNS. If we see DNS also moving | |Postfix blocks on DNS. The SMTP reads and writes are also blocking. |The TLS reads and writes are non-blocking if implemented in tlsproxy, |and blocking if implemented in the SMTP client itself.
Only to note that RRs can be and usually are cached. (I use dnsmasq for almost a quarter of a century, but today most Linux (also systemd) and BSD including Apple have some local DNS cache, and even mostly active by default i would say.) So -- i have heard that from several people, this "at first it increases DNS load" -- whereas yes, you have to look up that, with the now i would really assume normal local caching (despite the fact that this is on "operating system level", application-level caching, especially with a long running server, was a reality over two decades ago, that much is plain) you do have a one-to-many from DNS and email traffic, "usually". Eg # dig _imaps._tcp.gmail.com SRV ... _imaps._tcp.gmail.com. 21600 IN SRV 5 0 993 imap.gmail.com. Six hours. # dig _smtps._tcp.sdaoden.eu SRV ... _smtps._tcp.sdaoden.eu. 14400 IN SRV 0 1 26 sdaoden.eu. Four hours. (I do not control that, i have only a web form.) --steffen | |Der Kragenbaer, The moon bear, |der holt sich munter he cheerfully and one by one |einen nach dem anderen runter wa.ks himself off |(By Robert Gernhardt) | |In Fall and Winter, feel "The Dropbear Bard"s pint(er). | |The banded bear |without a care, |Banged on himself for e'er and e'er | |Farewell, dear collar bear _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
