More Related Content
Similar to 081108huge_data.ppt
Similar to 081108huge_data.ppt (20)
081108huge_data.ppt
- 20. VFS データ構造関係図 superblock inode dentry file address_space page page page inode inode 1 * 1 * 1 1 1 1 1 1 (2) offset (1) inode 番号
- 24. メモリを増やすことで I/O 負荷軽減 14:10:01 CPU %user %nice %system %iowait %idle 14:20:01 all 8.58 0.00 5.84 16.58 69.00 14:30:01 all 7.41 0.00 5.14 17.81 69.63 14:40:01 all 7.74 0.00 4.97 18.56 68.73 14:50:01 all 7.02 0.00 5.01 16.24 71.72 14:10:01 CPU %user %nice %system %iowait %idle 14:10:01 all 18.16 0.00 11.56 0.80 69.49 14:20:01 all 12.48 0.00 9.47 0.88 77.17 14:30:01 all 14.20 0.00 10.17 0.91 74.72 14:40:01 all 13.25 0.00 9.74 0.75 76.25 メモリ 4GB メモリ 8GB
- 25. 透過的に作用する 18:20:01 kbmemfree kbmemused %memused kbbuffers kbcached kbswpfree kbswpused %swpused kbswpcad 18:30:01 3566992 157272 4.22 11224 50136 2048276 0 0.00 0 18:40:01 3546264 178000 4.78 12752 66548 2048276 0 0.00 0 18:50:01 112628 3611636 96.98 4312 3499144 2048232 44 0.00 44 OS 起動直後に数 GB のファイルを read した結果
- 38. インデックスの効果の例 mysql> select url from entry where eid = 9615899; +------------------------------------------------------------------------------+ | url | +------------------------------------------------------------------------------+ | http://builder.japan.zdnet.com/member/u87200/blog/2008/08/10/entry_27012867/ | +------------------------------------------------------------------------------+ 1 row in set ( 0.00 sec ) mysql> select url from entry use index(hoge) where eid = 9615899; ... 200 秒待っても結果が返って来ない
- 50. JOIN を排除 where ... in ... を利用 mysql> select eid from bookmark where uid = 169848 limit 5; +-----+ | eid | +-----+ | 0 | | 4 | | 5 | | 6 | | 7 | +-----+ 5 rows in set (0.01 sec) mysql> select url from entry where eid in (0, 4, 5, 6, 7) ; +-------------------------------------------------------------------+ | url | +-------------------------------------------------------------------+ | http://blog.bulknews.net/mt/archives/001537.html | | http://www.wrightthisway.com/Articles/000154.html | | http://internet.watch.impress.co.jp/cda/news/2005/02/10/6438.html | | http://headlines.yahoo.co.jp/hl?a=20050210-00000136-kyodo-bus_all | +-------------------------------------------------------------------+ 4 rows in set (0.12 sec)