Package: djbdns-installer Version: 1.05-11 Severity: wishlist Tags: patch Attached is a patch for improving the performance of djbdns under high load. This patch makes djbdns-1.05 cache its mmap() of the data.cdb file up to a maximum of one second, which substantially reduces the number of times that the database file needs to be mapped and unmapped (patch credit goes to Lennert Buytenhek).
Kind Regards, Michael Shuler
>From [EMAIL PROTECTED] Sat Jul 23 15:19:58 2005 X-VM-v5-Data: ([nil nil nil nil nil nil nil nil nil] ["1512" "Tuesday" "20" "April" "2004" "13:06:49" "+0200" "Lennert Buytenhek" "[EMAIL PROTECTED]" nil "61" "patch to make djbdns 1.05 cache its mmap() of the data.cdb file" "^From:" nil nil "4" nil nil nil nil nil nil nil nil nil] nil) Return-Path: <[EMAIL PROTECTED]> Delivered-To: [EMAIL PROTECTED] Received: (qmail 9047 invoked by alias); 23 Jul 2005 15:19:58 -0000 Delivered-To: [EMAIL PROTECTED] Received: (qmail 9044 invoked by uid 500); 23 Jul 2005 15:19:58 -0000 Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dog; d=wantstofly.org; b=IWNClqptgImEp3WfkGIht8VKuoHgvQcYS2QB6tjfjVSIFs+iulN4Fg1yMtJiDL3D ; Message-ID: <[EMAIL PROTECTED]> X-Original-To: buytenh Delivered-To: [EMAIL PROTECTED] User-Agent: Mutt/1.4.1i X-Keywords: X-UID: 800 From: Lennert Buytenhek <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Subject: patch to make djbdns 1.05 cache its mmap() of the data.cdb file Date: Tue, 20 Apr 2004 13:06:49 +0200 Hi, This patch makes djbdns 1.05 cache its mmap() of the data.cdb file up to a maximum of one second. Under high query load, this substantially reduces the number of times that the database file needs to be mapped and unmapped, and gives a two-digit percentage performance improvement under 100% system load (as discussed on the djbdns mailing list.) Could you stick a copy of the patch on www.tinydns.org please? I don't have anywhere to host it myself at this point, and I would like to see it on that page -- is that acceptable to you? thanks, Lennert diff -urN djbdns-1.05.orig/tdlookup.c djbdns-1.05/tdlookup.c --- djbdns-1.05.orig/tdlookup.c 2001-02-11 22:11:45.000000000 +0100 +++ djbdns-1.05/tdlookup.c 2004-04-18 13:56:13.000000000 +0200 @@ -280,15 +280,24 @@ int respond(char *q,char qtype[2],char ip[4]) { - int fd; + static struct tai cdb_valid = { 0 }; + static int fd = -1; + struct tai one_second; int r; char key[6]; tai_now(&now); - fd = open_read("data.cdb"); - if (fd == -1) return 0; - cdb_init(&c,fd); - + if (tai_less(&cdb_valid, &now)) { + if (fd != -1) { + cdb_free(&c); + close(fd); + } + fd = open_read("data.cdb"); + if (fd == -1) return 0; + cdb_init(&c,fd); + tai_uint(&one_second, 1); + tai_add(&cdb_valid, &now, &one_second); + } byte_zero(clientloc,2); key[0] = 0; key[1] = '%'; @@ -304,7 +313,5 @@ r = doit(q,qtype); - cdb_free(&c); - close(fd); return r; } ----- End forwarded message -----
