とある IRC チャネルで DNS ソフトウェアの話になって、当然 BIND や djbdns があがってくるわけなんですが、うち PowerDNS つかってて、ベンチマークとった資料とかあるよ、と言ったら、あんま事例ないと思うのでブログで公開するとうれしい人が多いかも、と Ficia を アツく語る人 から言われたので公開します。2年ちょいぐらい前につくった資料で、細かいこと忘れちゃってますし、社内向けに書いたものを公開するので、マズいところは省いたりしてます。
まずは VM 環境で、BIND + DLZ と PowerDNS（どちらもバックエンドに MySQL を使用）のパフォーマンス比較した資料を公開します。
dlz "Mysql zone" {
database "mysql
{host=localhost dbname=dns_data ssl=false}
{select zone from dns_records where zone = '%zone%'}
{select ttl, type, mx_priority, case when lower(type)='txt' then concat('\"', data, '\"')
else data end from dns_records where zone '%record%'
and not (type 'NS')}
{select ttl, type, mx_priority, data, resp_person, serial, refresh, retry, expire, minimum
from dns_records where zone 'SOA' or type='NS')}
{select ttl, type, host, mx_priority, data, resp_person, serial, refresh, retry, expire,
minimum from dns_records where zone 'SOA' or type = 'NS')}
{select zone from xfr_table where zone '%client%'}
{update data_count set count '%zone%'}";
};
mysql> select * from dns_records;
+-------------+------+------+--------------+-------+-------------+---------+-------+---------+---------+----------+-------------------+------------+
| zone | host | type | data | ttl | mx_priority | refresh | retry | expire | minimum | serial | resp_person | primary_ns |
+-------------+------+------+--------------+-------+-------------+---------+-------+---------+---------+----------+-------------------+------------+
| example.org | @ | SOA | localhost. | 86400 | 10 | 3600 | 200 | 3600000 | 3600 | 20070919 | test.example.org. | NULL |
| example.org | www | A | 192.168.32.1 | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL |
| example.org | abc | A | 192.168.32.2 | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL |
| example.org | test | A | 192.168.32.3 | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL | NULL |
+-------------+------+------+--------------+-------+-------------+---------+-------+---------+---------+----------+-------------------+------------+
mysql> show index from dns_records;
+-------------+------------+------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment |
+-------------+------------+------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| dns_records | 1 | host_index | 1 | host | A | NULL | 20 | NULL | YES | BTREE | |
| dns_records | 1 | zone_index | 1 | zone | A | NULL | 30 | NULL | YES | BTREE | |
| dns_records | 1 | type_index | 1 | type | A | NULL | 8 | NULL | YES | BTREE | |
+-------------+------------+------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
test.example.org A
# queryperf -d ~/dlz_test.dat -s 127.0.0.1 -l 10
DNS Query Performance Testing Tool
Version: $Id: queryperf.c,v 1.8.192.3 2005/10/29 00:21:12 jinmei Exp $
[Status] Processing input data
[Status] Sending queries (beginning with 127.0.0.1)
[Status] Testing complete
Statistics:
Parse input file: multiple times
Run time limit: 10 seconds
Ran through file: 974 times
Queries sent: 975 queries
Queries completed: 975 queries
Queries lost: 0 queries
Queries delayed(?): 0 queries
RTT max: 2.775003 sec
RTT min: 0.043778 sec
RTT average: 0.253777 sec
RTT std deviation: 0.335064 sec
RTT out of range: 0 queries
Percentage completed: 100.00%
Percentage lost: 0.00%
Started at: Thu Sep 20 19:38:22 2007
Finished at: Thu Sep 20 19:38:35 2007
Ran for: 12.619786 seconds
Queries per second: 77.259630 qps
mysql> select * from records;
+----+-----------+--------------------+------+-------------------------+-------+------+-------------+
| id | domain_id | name | type | content | ttl | prio | change_date |
+----+-----------+--------------------+------+-------------------------+-------+------+-------------+
| 1 | 1 | test.com | SOA | localhost ahu@ds9a.nl 1 | 86400 | NULL | NULL |
| 2 | 1 | test.com | NS | dns-us1.powerdns.net | 86400 | NULL | NULL |
| 3 | 1 | test.com | NS | dns-eu1.powerdns.net | 86400 | NULL | NULL |
| 4 | 1 | www.test.com | A | 199.198.197.196 | 120 | NULL | NULL |
| 5 | 1 | mail.test.com | A | 195.194.193.192 | 120 | NULL | NULL |
| 6 | 1 | localhost.test.com | A | 127.0.0.1 | 120 | NULL | NULL |
| 7 | 1 | test.com | MX | mail.test.com | 120 | 25 | NULL |
+----+-----------+--------------------+------+-------------------------+-------+------+-------------+
mysql> show index from records;
+---------+------------+----------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment |
+---------+------------+----------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
| records | 0 | PRIMARY | 1 | id | A | 7 | NULL | NULL | | BTREE | |
| records | 1 | rec_name_index | 1 | name | A | 7 | NULL | NULL | YES | BTREE | |
| records | 1 | nametype_index | 1 | name | A | 7 | NULL | NULL | YES | BTREE | |
| records | 1 | nametype_index | 2 | type | A | 7 | NULL | NULL | YES | BTREE | |
| records | 1 | domain_id | 1 | domain_id | A | 2 | NULL | NULL | YES | BTREE | |
+---------+------------+----------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+
www.test.com A
# queryperf -d ~/pdns_test.dat -s 127.0.0.1 -l 10
DNS Query Performance Testing Tool
Version: $Id: queryperf.c,v 1.8.192.3 2005/10/29 00:21:12 jinmei Exp $
[Status] Processing input data
[Status] Sending queries (beginning with 127.0.0.1)
[Status] Testing complete
Statistics:
Parse input file: multiple times
Run time limit: 10 seconds
Ran through file: 42159 times
Queries sent: 42160 queries
Queries completed: 42160 queries
Queries lost: 0 queries
Queries delayed(?): 0 queries
RTT max: 0.013259 sec
RTT min: 0.000331 sec
RTT average: 0.002268 sec
RTT std deviation: 0.001248 sec
RTT out of range: 0 queries
Percentage completed: 100.00%
Percentage lost: 0.00%
Started at: Thu Sep 20 19:36:47 2007
Finished at: Thu Sep 20 19:36:57 2007
Ran for: 10.000367 seconds
Queries per second: 4215.845278 qps
BIND + DLZ: 77.259630 qps、PowerDNS: 4215.845278 qps で PowerDNS の圧勝。これは BIND + DLZ がリクエスト毎に MySQL 問い合わせしてるのに対し、PowerDNS はメモリにキャッシュしていちいち MySQL に問い合わせないから、だろう。