アクセスパターンマイニングによるOSレベルでの動的なI/O最適化

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(1)社団法人情報処理学会研究報告 IPSJ SIG Technical Report. 2008－DBS－146 (13) 2008／9／22. ࠕࠢ࠮ࠬࡄ࠲࡯ࡦࡑࠗ࠾ࡦࠣߦࠃࠆ OS ࡟ࡌ࡞ߢߩേ⊛ߥ I/O ᦨㆡൻ ਄↰ 㜞ᓼ̐. ᐔᚻ ാቝ̐̐. ጊฬ ᣧੱ̑. ̐ᣧⒷ↰ᄢቇᄢቇ㒮ၮᐙℂᎿቇ⎇ⓥ⑼ ‫ޥ‬169-8555 ᧲੩ㇺᣂኋ඙ᄢਭ଻ 3-4-1 ̐̐ᣧⒷ↰ᄢቇࡔ࠺ࠖࠕࡀ࠶࠻ࡢ࡯ࠢ࠮ࡦ࠲࡯ ‫ޥ‬169-8050 ᧲੩ㇺᣂኋ඙ᚭႦ↸ 1-104 ̑ᣧⒷ↰ᄢቇℂᎿቇⴚ㒮 ‫ޥ‬169-8555 ᧲੩ㇺᣂኋ඙ᄢਭ଻ 3-4-1 ࿖┙ᖱႎቇ⎇ⓥᚲ ‫ޥ‬101-8430 ᧲੩ㇺජઍ↰඙৻࠷ᯅ 2-1-2 E-mail: ̐̑{ueda, hirate, yamana}@yama.info.waseda.ac.jp ޽ࠄ߹ߒ CPU ߩ Many ࠦࠕൻߦࠃࠆਗ೉ᕈ⢻ߩะ਄ߦࠃࠅ㧘ࠬ࠻࡟࡯ࠫߦࠃࠆࡄࡈࠜ࡯ࡑࡦࠬࡏ࠻࡞ࡀ࠶ࠢ߇ એ೨ߦ߽Ⴧߒߡ໧㗴ߣߥߞߡ߈ߡ޿ࠆ㧚Many ࠦࠕⅣႺߢߪ᭽‫߇ࡦ࡚ࠪ࡯ࠤ࡝ࡊࠕߥޘ‬ਗ೉ߦേ૞ߔࠆߚ߼㧘OS ࡟ ࡌ࡞ߢߩࠕࡊ࡝ࠤ࡯࡚ࠪࡦᮮᢿߥ I/O ᦨㆡൻ߇ᔅ㗇ߣ⠨߃ࠄࠇࠆ㧚߹ߚ㧘ࠕࡊ࡝ࠤ࡯࡚ࠪࡦ᭴ᚑ߇ⶄ㔀ߦߥࠆߣ㧘 ੱᚻߦࠃࠆ࠴ࡘ࡯࠾ࡦ߽ࠣ࿎㔍ߦߥࠆߚ߼㧘⥄േ⊛ߥ I/O ᦨㆡൻߩᔅⷐᕈ߇㜞߹ࠆߣ੍ᗐߐࠇࠆ㧚ᧄ⺰ᢥߢߪ㧘OS ౝߦ߅޿ߡࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩࡈࠔࠗ࡞ࠕࠢ࠮ࠬࡠࠣ߆ࠄࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ᛽಴ߒ㧘࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘ⟎឵ࠕ ࡞ࠧ࡝࠭ࡓߩല₸ᡷༀߦ೑↪ߔࠆᚻᴺࠍឭ᩺ߔࠆ㧚ឭ᩺ᚻᴺࠍ Linux 2.6.26 ߳ታⵝߒ㧘࠺࡯࠲ࡌ࡯ࠬࡌࡦ࠴ࡑ࡯ࠢ ߢ޽ࠆ DBT-2 (TPC-C) ߦࠃࠅ⹏ଔࠍⴕߞߚߣߎࠈ㧘ᦨᄢߢ 5.24%ߩ࠻࡜ࡦ࡚ࠩࠢࠪࡦᕈ⢻ߩᡷༀࠍ⏕⹺ߢ߈ߚ㧚 ࠠ࡯ࡢ࡯࠼ ࠬ࠻࡟࡯ࠫ㧘ࠕࠢ࠮ࠬࡄ࠲࡯ࡦ㧘ࠝࡍ࡟࡯࠹ࠖࡦࠣࠪࠬ࠹ࡓ㧘࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘ. Dynamic I/O Optimization with Access Pattern Mining at OS Level Takanori UEDA̐. Yu HIRATE̐̐ and. Hayato YAMANȂ. ̐Graduate School of Science and Engineering, Waseda University 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555 Japan ̐̐Media Network Center, Waseda University 1-104, Totsuka-cho, Shinjuku-ku, Tokyo 169-8050 Japan ̑Science and Engineering, Waseda University 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555 Japan National Institute of Informatics 2-1-2, Hitotsubashi, Chiyoda-ku, Tokyo 101-8430 Japan E-mail: ̐̑{ueda, hirate, yamana}@yama.info.waseda.ac.jp Abstract Many-core CPU improves parallel performance but also raises problem of storage performance bottleneck. I/O optimization should be taken at operating system level because various applications are executed in parallel on many-core CPU environment and I/O optimization requires cross-cutting knowledge about applications. We propose a new method which uses disk access patterns for improving efficiency of disk cache replacement algorithm. Our method is now implemented at Linux 2.6.26 and extracts access patterns from file access logs of applications. The experimental results show our method improved DBT-2 (TPC-C) transaction performance up-to 5.24%. Keyword Storage, Access Patterns, Operating System, Disk Cache. 1. ߪ ߓ ߼ ߦ. ᚒ‫⎇ߩޘ‬ⓥ⋡ᮡߪ㧘ࠬ࠻࡟࡯ࠫߩࡏ࠻࡞ࡀ࠶ࠢࠍ࠰. ࠬ࠻࡟࡯ࠫߩࡏ࠻࡞ࡀ࠶ࠢߪ߹ߔ߹ߔᷓೞߦߥࠆ. ࡈ ࠻ ࠙ ࠚ ࠕ ⊛ ߦ シ ᷫ ߔ ࠆ ᚻ ᴺ ߩ 㐿 ⊒ ߢ ޽ ࠆ 㧚․ ߦ 㧘OS. ߣ ⹺ ⼂ ߐ ࠇ ߪ ߓ ߼ ߡ ޿ ࠆ 㧚Intel ߪ 㧘 ‫ ޟ‬1996 ᐕ ߆ ࠄ 2006. ߩᯏ᭴ࠍᡷ⦟ߔࠆߎߣࠍ⋡ᜰߒߡ޿ࠆ㧚ࠬ࠻࡟࡯ࠫࠍ. ᐕ ߩ 10 ᐕ 㑆 ߢ CPU ߩ ᕈ ⢻ ߪ 30 ୚ ߦ ߥ ߞ ߚ ߇ 㧘 HDD. ߣࠅ߹ߊၮᧄ⊛ߥࠕ࡯ࠠ࠹ࠢ࠴ࡖߪㆊ෰ᢙචᐕ㑆ᄌൻ. ߩ ᕈ ⢻ ߪ 1.3 ୚ ⒟ ᐲ ߦ ߒ ߆ ะ ਄ ߒ ߡ ޿ ߥ ޿ ‫[ ޠ‬4]ߣ ߒ ߡ. ߒ ߡ ߎ ߥ ߆ ߞ ߚ [10]㧚 ᖱ ႎ ῜ ⊒ 㧘 ⿥ ਗ ೉ ൻ ߩ ᤨ ઍ ࠍ ೨. ޿ ࠆ 㧚 Many ࠦ ࠕ CPU ߪ ࠰ ࡈ ࠻ ࠙ ࠚ ࠕ ࠍ ਗ ೉ ߦ േ ૞ ߐ. ߦ⷗⋥ߒ߇ᔅⷐߣ⠨߃ࠄࠇࠆ㧚ߣߪ޿߃㧘ᄙߊߩ࠰ࡈ. ߖࠆߎߣߢಣℂᕈ⢻ࠍ㜞߼ࠆ߇㧘ਗ೉ߦേ૞ߔࠆ࠰ࡈ. ࠻࠙ࠚࠕ࡮ࡂ࡯࠼࠙ࠚࠕ߇㧘વ⛔⊛ߥࠬ࠻࡟࡯ࠫࠕ࡯. ࠻࠙ࠚࠕ߇ࠬ࠻࡟࡯ࠫߦኻߔࠆ࡝ࠢࠛࠬ࠻ࠍ⊒↢ߐߖ. ࠠ࠹ࠢ࠴ࡖߩߚ߼ߦ⸳⸘ߐࠇߡ߅ࠅ㧘ࠬ࠻࡟࡯ࠫࠕ࡯. ࠆߣ㧘ࠕࠢ࠮ࠬ㓸ਛߦࠃࠅࠬ࠻࡟࡯ࠫߩࡏ࠻࡞ࡀ࠶ࠢ. ࠠ࠹ࠢ࠴ࡖߩᄢⷙᮨߥᡷᄌߪ࿎㔍ߢ޽ࠆ㧚ߒ߆ߒ㧘ᡷ. ߇ ᷓ ೞ ߦ ߥ ࠆ 㧚 Many ࠦ ࠕ CPU ߦ ࠃ ࠆ ಣ ℂ ᕈ ⢻ ߩ ะ ਄. ⦟ ߇ OS ౝ ߢ ߣ ߤ ߹ ࠇ ߫ 㧘 ᣢ ሽ ࠕ ࡊ ࡝ ࠤ ࡯ ࠪ ࡚ ࡦ ߣ ᣢ. ࠍ⏕ታߥ߽ߩߦߔࠆߚ߼ߦߪ㧘ࠬ࠻࡟࡯ࠫߩࡏ࠻࡞ࡀ. ሽࡂ࡯࠼࠙ࠚࠕߪᄌᦝߥߒߢേ૞ߢ߈ࠆ㧚ߔߥࠊߜ㧘. ࠶ࠢኻ╷߇ᔅⷐਇนᰳߢ޽ࠆߎߣߪ⇼޿ࠃ߁߇ߥ޿㧚. ㅘㆊ⊛ߦࠬ࠻࡟࡯ࠫࠕࠢ࠮ࠬߩ㜞ㅦൻࠍታ⃻ߔࠆߎߣ. － 73 －.

(2) ߇ߢ߈ࠆ㧚 ⃻ ઍ ߩ OS ߪ 㧘 ‛ ℂ ࡔ ࡕ ࡝ ߣ ࠬ ࠻ ࡟ ࡯ ࠫ 㑆 ߩ ࡄ ࡈ ࠜ. 2.1. OS 䊧䊔䊦䈪䈱േ ⊛ 䈭ᦨ ㆡ ൻ 䈱ᔅ ⷐ ᕈ 䈫೑ ὐ ੹ ᓟ ᥉ ෸ ߔ ࠆ ߎ ߣ ߇ ⏕ ታ ߥ Many ࠦ ࠕ CPU Ⅳ Ⴚ ߢ ߪ 㧘. ࡯ࡑࡦࠬᏅࠍ⵬߁ߚ߼ߦ㧘࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘࠍ‛ℂ. 1 ߟ ߩ OS ਄ ߢ ᭽ ‫ ߇ ࡦ ࡚ ࠪ ࡯ ࠤ ࡝ ࡊ ࠕ ߥ ޘ‬േ ૞ ߔ ࠆ ߎ. ࡔࡕ࡝਄ߦ⏕଻ߔࠆ㧚੹ᓟ㧘‛ℂࡔࡕ࡝ߩኈ㊂߇Ⴧ߃. ߣߦߥࠆ㧚ߤߩࠃ߁ߥࠕࡊ࡝ࠤ࡯࡚ࠪࡦ᭴ᚑߦߥࠆ߆. ࠆߦ઻޿࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘߦ૶↪ߢ߈ࠆ㗔ၞ߽Ⴧ߃. ߪታㆇ↪ᤨ߹ߢਇ᣿ߢ޽ࠅ㧘ࠕࡊ࡝ࠤ࡯࡚ࠪࡦ᭴ᚑ߽. ࠆߣ⠨߃ࠄࠇࠆ߇㧘ᛒ߁࠺࡯࠲㊂߽หߓࠃ߁ߦჇ߃ࠆ. േ ⊛ ߦ ᄌ ൻ ߒ ߡ ޿ ߊ ߣ ੍ ᗐ ߐ ࠇ ࠆ 㧚 ․ ቯ ߩ I/O ࠬ ࠤ ࠫ. ߣᕁࠊࠇࠆ㧚⚿ᨐߣߒߡ޿ߟߩᤨઍ߽࠺ࠖࠬࠢࠠࡖ࠶. ࡘ࡯࡜߿ࠠࡖ࠶ࠪࡘ⟎឵ࠕ࡞ࠧ࡝࠭ࡓࠍ૶޿⛯ߌࠆߩ. ࠪ ࡘ ኈ ㊂ ߪ ਇ ⿷ ߔ ࠆ 㧚 ߘ ߒ ߡ 㧘 I/O ߇ ᄙ ⊒ ߒ ߡ ࠬ ࠻ ࡟. ߢ ߪ ߥ ߊ 㧘OS ⥄ り ߇ േ ⊛ ߥ ᦨ ㆡ ൻ ࠍ ⴕ ߁ ߎ ߣ ߇ ᳞ ߼ ࠄ. ࡯ ࠫ ߇ ࡏ ࠻ ࡞ ࡀ ࠶ ࠢ ߦ ߥ ࠇ ߫ ߥ ࠆ ߶ ߤ 㧘CPU ߇ ࠕ ࠗ ࠼. ࠇ ࠆ 㧚 ․ ߦ 㧘 I/O ᓙ ߜ ߢ ૛ ߞ ߚ CPU ࡄ ࡢ ࡯ ࠍ ᵴ ↪ ߔ ࠆ. ࡞⁁ᘒߦߥࠆᤨ㑆߇㐳ߊߥࠆ㧚. ߩ ߪ 㧘 CPU ߩ ೑ ↪ ࠍ ࠬ ࠤ ࠫ ࡘ ࡯ ࡝ ࡦ ࠣ ߔ ࠆ OS ࡟ ࡌ ࡞. ᚒ ‫ ⋡ ⚳ ᦨ ߩ ޘ‬ᮡ ߪ 㧘ࠕ ࠗ ࠼ ࡞ ⁁ ᘒ ߩ CPU ⾗ Ḯ ࠍ ᦨ ᄢ 㒢ᵴ↪ߒ㧘࠰ࡈ࠻࠙ࠚࠕ⊛ߦࠬ࠻࡟࡯ࠫߩࡏ࠻࡞ࡀ࠶ ࠢ ࠍ シ ᷫ ߔ ࠆ ߎ ߣ ߦ ޽ ࠆ 㧚 CPU ߆ ࠄ ߺ ࠆ ߣ I/O ߦ ߪ 㕖. ߇ ㆡ ߒ ߡ ޿ ࠆ ߣ ᚒ ‫ ߪ ޘ‬⠨ ߃ ߡ ޿ ࠆ 1㧚. 2.2. 䉝䉪䉶䉴䊨䉫䈱᦭ ↪ ᕈ ࠕࡊ࡝ࠤ࡯࡚ࠪࡦߪ㧘೑↪ߒߡ޿ࠆ࠺࡯࠲᭴ㅧ߿ࠕ. Ᏹ ߦ 㐳 ޿ ᤨ 㑆 ߇ ᔅ ⷐ ߥ ߚ ߼ 㧘I/O ᓙ ߜ ߩ 㑆 ߦ I/O ᚢ ⇛ ߩ. ࡞ࠧ࡝࠭ࡓߦࠃߞߡ㧘ࡈࠔࠗ࡞߳ߩࠕࠢ࠮ࠬߦ৻ቯߩ. ߚ ߼ ߩ ಣ ℂ ࠍ ⴕ ߁ ₈ ੍ ߇ ޽ ࠆ 㧚 ․ ߦ Many ࠦ ࠕ Ⅳ Ⴚ ߢ. ࡄ࠲࡯ࡦࠍᜬߟߎߣ߇ᄙ޿㧚଀߃߫࠙ࠚࡉࠨ࡯ࡃߩ႐. ߪ 㧘ࠕ ࠗ ࠼ ࡞ ⁁ ᘒ ߩ CPU ࠦ ࠕ ࠍ I/O ᚢ ⇛ ߦ ᵴ ↪ ߔ ࠆ ߎ. ว 㧘޽ ࠆ HTML ࠍ ⺒ ߺ ㄟ ࠎ ߛ ޽ ߣ 㧘ߘ ߩ HTML ߆ ࠄ ࡝. ߣ߇น⢻ߣ⠨߃ࠄࠇࠆ㧚ᚒ‫ߦߢ߹ࠇߎߪޘ‬㧘ࠕࡊ࡝ࠤ. ࡦࠢߐࠇߡ޿ࠆ↹௝߽⺒ߺㄟ߻น⢻ᕈ߇㜞޿㧚࠺࡯࠲. ࡯࡚ࠪࡦߩࡈࠔࠗ࡞ࠕࠢ࠮ࠬࡠࠣ߆ࠄ᛽಴ߒߚࠕࠢ࠮. ࡌ࡯ࠬߩ႐วߪ㧘ࠗࡦ࠺࠶ࠢࠬ࠷࡝࡯ߩⷫࡁ࡯࠼ߦࠕ. ࠬࡄ࠲࡯ࡦࠍ೑↪ߔࠆߎߣߢ࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘߩࡅ. ࠢ࠮ࠬߒߚ⋥ᓟ㧘ߘߩሶࡁ࡯࠼ߩ޿ߕࠇ߆ߦࠕࠢ࠮ࠬ. ࠶࠻₸ࠍᡷༀߢ߈ࠆߎߣࠍࠪࡒࡘ࡟࡯࡚ࠪࡦߢ␜ߒߡ. ߔࠆน⢻ᕈ߇㜞޿㧚. ޿ ࠆ [12] 㧚 ᧄ ⺰ ᢥ ߢ ߪ 㧘 ߎ ࠇ ߹ ߢ ߦ ឭ ᩺ ߒ ߚ ᚻ ᴺ ࠍ. ߎ߁޿ߞߚࠕࠢ࠮ࠬࡄ࠲࡯ࡦߪ࠺࡯࠲ߦଐሽߔࠆ. Linux Kernel 2.6.26 ߦ ታ ⵝ ߒ ߚ ࡊ ࡠ ࠻ ࠲ ࠗ ࡊ ߦ ߟ ޿ ߡ. ߽ߩߢ޽ࠅ㧘ㆊ෰ߦሽ࿷ߒߚࡄ࠲࡯ࡦߪㄭ޿዁᧪߽᦭. ㅀߴࠆ㧚. ലߣ⠨߃ࠄࠇࠆ㧚߹ߚ㧘㗫಴ߒߚࠕࠢ࠮ࠬࡄ࠲࡯ࡦߪ. ᧄ ⺰ ᢥ ߩ ᭴ ᚑ ߪ ᰴ ߩ ߣ ߅ ࠅ ߢ ޽ ࠆ 㧚 2.ߢ ߪ ឭ ᩺ ࠪ ࠬ. ዁᧪߽㗫಴ߔࠆน⢻ᕈ߇㜞޿㧚ᓥߞߡ㧘ࠕࡊ࡝ࠤ࡯ࠪ. ࠹ ࡓ ߩ ᭎ ⷐ ࠍ ㅀ ߴ ࠆ 㧚 3.ߢ ߪ ឭ ᩺ ࠪ ࠬ ࠹ ࡓ ߩ ⃻ ࿷ ߩ ታ. ࡚ࡦߩࡈࠔࠗ࡞ࠕࠢ࠮ࠬࡠࠣࠍ⸥㍳ߒߡ߅ߊߎߣߢ㧘. ⵝ ߦ ߟ ޿ ߡ ㅀ ߴ ࠆ 㧚 4.ߢ ߪ DBT-2 (TPC-C)ࠍ ↪ ޿ ߚ ⹏. ࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩࡈࠔࠗ࡞ࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ᛽಴. ଔ ታ 㛎 ߩ ⚿ ᨐ ߦ ߟ ޿ ߡ ㅀ ߴ ࠆ 㧚 5.ߢ 㑐 ㅪ ⎇ ⓥ ߦ ߟ ޿ ߡ. ߔࠆߎߣ߇ߢ߈ࠆ㧚. ㅀ ߴ 㧘 6.ߢ ⚿ ⺰ ࠍ ㅀ ߴ ࠆ 㧚. ᛽಴ߒߚࠕࠢ࠮ࠬࡄ࠲࡯ࡦߪ㧘࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘ ⟎ ឵ ࠕ ࡞ ࠧ ࡝ ࠭ ࡓ ߦ ೑ ↪ ߔ ࠆ ߎ ߣ ߇ ߢ ߈ ࠆ 㧚LRU ࠍ ฽. 2. ឭ ᩺ ࠪ ࠬ ࠹ ࡓ ߩ ᭎ ⷐ. ߻ᄙߊߩࠠࡖ࠶ࠪࡘ⟎឵ࠕ࡞ࠧ࡝࠭ࡓߪ㧘ᤨ㑆⊛ዪᚲ. ឭ ᩺ ࠪ ࠬ ࠹ ࡓ ߩ ᭎ ⷐ ࿑ ࠍ ࿑ 2 ߦ ␜ ߔ 㧚ᧄ ࠪ ࠬ ࠹ ࡓ ߪ 㧘. ᕈ ߦ ၮ ߠ ޿ ߡ ࠠ ࡖ ࠶ ࠪ ࡘ ߩ ⟎ ឵ ࠍ ⴕ ߞ ߡ ޿ ࠆ 㧚ߒ ߆ ߒ 㧘. ࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩࠕࠢ࠮ࠬࡠࠣ߆ࠄ᛽಴ߒߚࠕࠢ࠮. ࠬ࠻࡟࡯ࠫࠪࠬ࠹ࡓߢߪⓨ㑆⊛ዪᚲᕈ߽⠨ᘦߒߚ⟎឵. ࠬ ࡄ ࠲ ࡯ ࡦ ߦ ࠃ ߞ ߡ 㧘OS ߇ ‛ ℂ ࡔ ࡕ ࡝ ਄ ߦ ᜬ ߟ ࠺ ࠖ ࠬ. ࠕ ࡞ ࠧ ࡝ ࠭ ࡓ ߇ ᔅ ⷐ ߢ ޽ ࠆ [9]㧚ߥ ߗ ߥ ࠄ ߫ 㧘ࡂ ࡯ ࠼ ࠺. ࠢࠠࡖ࠶ࠪࡘߩ⟎឵ࠕ࡞ࠧ࡝࠭ࡓࠍᡷༀߔࠆ㧚. ࠖࠬࠢࠍਥߣߔࠆࠬ࠻࡟࡯ࠫߪ࡜ࡦ࠳ࡓࠕࠢ࠮ࠬ߇ૐ ㅦߛ߆ࠄߢ޽ࠆ㧚ᧄ⺰ᢥߢߪ․ߦ㧘࡜ࡦ࠳ࡓࠕࠢ࠮ࠬ ߩࡄ࠲࡯ࡦࠍ↪޿ߡ࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘ⟎឵ࠕ࡞ࠧ࡝. Applications. ࠭ࡓߩല₸ࠍᡷༀߔࠆ㧚ࠕࠢ࠮ࠬࡠࠣߩ᛽಴ᣇᴺߦ㑐 Operating System. I/O Scheduler. HDD. Cache Replace. ࿑ 2㧚 ឭ ᩺ ࠪ ࠬ ࠹ ࡓ ߩ ᭎ ⷐ ࿑. SSD. ࿑ 1㧚 ౖ ဳ ⊛ ߥ ࠬ ࠻ ࡟ ࡯ ࠫ ࠕ ࡯ ࠠ ࠹ ࠢ ࠴ ࡖ. Filtering Pattern Extraction Access Patterns. Storage Systems HDD. Disk Cache. Storage Systems. File System. Applications. Operating System. Disk Cache Read-ahead System. 1 ઒ᗐൻߐࠇߚⅣႺߢߪ㧘઒ᗐࡑࠪࡦ࡟ࡌ࡞ߢⴕ߁ᔅⷐ߇ ޽ࠆ㧚. － 74 －.

(3) ߔ ࠆ ࠃ ࠅ ⹦ ߒ ޿ ⼏⺰ ߪ [12]ߢ ⴕ ߞ ߡ ޿ ࠆ 㧚. ࠬ࡟࠶࠼ߪ࡝ࡦࠣࡃ࠶ࡈࠔ߆ࠄࡠࠣࠍ⺒ߺㄟࠎߢࡄ࠲ ࡯ࡦ᛽಴ࠍⴕ߁㧚ߒߚ߇ߞߡ㧘ࡄ࠲࡯ࡦ᛽಴ࠬ࡟࠶࠼. 3. ឭ ᩺ ࠪ ࠬ ࠹ ࡓ ߩ ታ ⵝ. ߣࡠࠣ⸥㍳ߦࠃࠆᦠ߈ㄟߺߩ㑆ߢ߽ឃઁ೙ᓮࠍⴕ߁ᔅ. ᧄ ⺰ ᢥ ߢ ߪ Linux 2.6.26 ߦ ឭ ᩺ ࠪ ࠬ ࠹ ࡓ ߩ ታ ⵝ ࠍ ⴕ. ⷐ߇޽ࠆ㧚⃻࿷ߪ㧘࡝ࡦࠣࡃ࠶ࡈࠔ߳ߩᦠ߈ㄟߺߩឃ. ߞߚ㧚ࠕࠢ࠮ࠬࡠࠣߪ‛ℂࡔࡕ࡝਄ߦ⸥㍳ߔࠆ㧚ߘߩ. ઁߦߪࠬࡇࡦࡠ࠶ࠢࠍ㧘ࡄ࠲࡯ࡦ᛽಴ࠬ࡟࠶࠼ߣ࡝ࡦ. ߚ߼㧘ࠕࠢ࠮ࠬࡠࠣߩࠨࠗ࠭߇ᄢ߈ߊߥࠆߣࠪࠬ࠹ࡓ. ࠣࡃ࠶ࡈࠔ߳ߩᦠ߈ㄟߺߩឃઁߦߪ㗅ᰴࡠ࠶ࠢࠍ೑↪. ࡔࡕ࡝ࠍ࿶ㄼߔࠆ໧㗴߇޽ࠆ㧚߹ߚ㧘ࠕࠢ࠮ࠬࡠࠣߩ. ߒߡ޿ࠆ㧚. ⸥㍳ߦᔅⷐߥឃઁ೙ᓮ߇ᄙ޿ߣ㧘ࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩ. ࠬࡇࡦࡠ࠶ࠢߪࡆࠫ࡯࠙ࠚࠗ࠻ߦࠃࠆឃઁ೙ᓮᣇ. ਗ೉ᕈࠍ៊ߥ߁ߎߣߦߥࠆ㧚ߐࠄߦ㧘ࠕࠢ࠮ࠬࡄ࠲࡯. ᑼߢ޽ࠆ㧚ឃઁ඙㑆ࠍታⴕਛߩࡊࡠ࠮ࠬ߇޽ࠆ㑆㧘ឃ. ࡦߩ᛽಴ࠍࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩࠦࡦ࠹ࠠࠬ࠻਄ߢታⴕ. ઁ ඙ 㑆 ߦ ㅴ ౉ ߒ ࠃ ߁ ߣ ߔ ࠆ CPU ߪ ή 㒢 ࡞ ࡯ ࡊ ߦ ࠃ ࠅ. ߔࠆߣ㧘ࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩࡄࡈࠜ࡯ࡑࡦࠬߦᖡᓇ㗀. ᓙᯏߔࠆ㧚ឃઁ඙㑆ߩታⴕᤨ㑆߇⍴޿႐ว㧘ࡊࡠ࠮ࠬ. ࠍਈ߃ࠆ㧚. ࠍಾࠅᦧ߃ߡᓙᯏߔࠆࠃࠅ߽ࠝ࡯ࡃ࡯ࡋ࠶࠼߇ዊߐ޿㧚. ⃻࿷ߩታⵝߢߪ㧘ࠕࠢ࠮ࠬࡠࠣߩ⸥㍳᭴ㅧߦߪ࡝ࡦ. 㗅ᰴࡠ࠶ࠢߪ㧘ⶄᢙߩᦠ߈ㄟߺߩหᤨ⊒↢ࠍ⸵ߐߥ. ࠣࡃ࠶ࡈࠔࠍ↪޿ߡ޿ࠆ㧚ࠕࠢ࠮ࠬࡠࠣ⸥㍳ߦᔅⷐߥ. ޿߇㧘1 ߟߩᦠ߈ㄟߺߣⶄᢙߩ⺒ߺขࠅߩหᤨ⊒↢ߪ. ࡔࡕ࡝㊂ߣಣℂߩࠝ࡯ࡃ࡯ࡋ࠶࠼ࠍᛥ߃ࠆߚ߼ߦ㧘ࠪ. ⸵ߔ߽ߩߢ޽ࠆ㧚⺒ߺขࠅ஥ߪ㧘⺒ߺขࠅਛߦᦠ߈ㄟ. ࡯ࠤࡦࠪࡖ࡞ࠕࠢ࠮ࠬߪࡈࠖ࡞࠲ߒ㧘⸥㍳ߒߥ޿㧚ࡈ. ߺ߇⊒↢ߒߚߎߣࠍ⹺⼂ߒߚ႐ว㧘ౣᐲ࠺࡯࠲ࠍ⺒ߺ. ࠖ࡞࠲ߦߪ࠮ࠢ࠲㑆ߩ〒㔌ࠍ↪޿ߚ㧚ࠕࠢ࠮ࠬࡄ࠲࡯. ขࠅ㧘ᦨᣂߩ୯ࠍขᓧߔࠆ㧚㗅ᰴࡠ࠶ࠢࠍ↪޿ࠆߎߣ. ࡦߩ᛽಴ߪࠞ࡯ࡀ࡞ౝߩኾ↪ࠬ࡟࠶࠼߇ࡃ࠶ࠢࠣ࡜࠙. ߢ㧘ࡄ࠲࡯ࡦ᛽಴ࠬ࡟࠶࠼ߩ⺒ߺขࠅേ૞ߪ㧘࡝ࡦࠣ. ࡦ࠼ߢⴕ߁㧚એਅߎߩࠬ࡟࠶࠼ࠍࡄ࠲࡯ࡦ᛽಴ࠬ࡟࠶. ࡃ࠶ࡈࠔ߳ߩᦠ߈ㄟߺേ૞ࠍ㒖ኂߒߥ޿㧚ߒ߆ߒ㧘⺒. ࠼ߣ๭߱㧚. ߺขࠅਛߦ࡝ࡦࠣࡃ࠶ࡈࠔ߇ᦠ߈ᄌࠊߞߚ႐วߪ㧘ౣ. 3.1. 䉝䉪䉶䉴䊨䉫䈱⸥ ㍳ ᭴ ㅧ. ᐲ⺒ߺㄟߺࠍⴕ߁ᔅⷐ߇޽ࠆߚ߼㧘ࡄ࠲࡯ࡦ᛽಴ࠬ࡟. ࠕࡊ࡝ࠤ࡯࡚ࠪࡦ߇ࠕࠢ࠮ࠬߒߚࡈࠔࠗ࡞ߩ⼂೎. ࠶࠼ߩࠝ࡯ࡃ࡯ࡋ࠶࠼ߪᄢ߈ߊߥࠆน⢻ᕈ߇޽ࠆ㧚ߚ. ሶߣࡈࠔࠗ࡞ࠝࡈ࠮࠶࠻ߪ㧘ࡠ࡯ࠞ࡞‛ℂࡔࡕ࡝਄ߩ. ߛߒ㧘ࡄ࠲࡯ࡦ᛽಴ࠬ࡟࠶࠼ߪࡃ࠶ࠢࠣ࡜࠙ࡦ࠼ߢേ. ࿕ቯ㐳࡝ࡦࠣࡃ࠶ࡈࠔߦ⸥㍳ߔࠆ㧚ߎߎߢ࡝ࡦࠣࡃ࠶. ૞ߔࠆߚ߼㧘ࡄ࠲࡯ࡦ᛽಴ࠬ࡟࠶࠼ߢౣ⺒ߺㄟߺ߇⊒. ࡈ ࠔ ߣ ߪ 㧘࿑ 3 ߦ ␜ ߔ ࠃ ߁ ߦ ㈩ ೉ ࠍ Ⅳ ⁁ ߦ ߺ ߥ ߒ ߚ ߽. ↢ߒߡ߽㧘৻⥸ࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩᕈ⢻ߦ⋥ߜߦᖡᓇ. ߩߢ㧘㈩೉ߩᆎὐ߆ࠄ⸥㍳ࠍ㐿ᆎߒ㧘㈩೉ࠍ৻Ꮌߒߚ. 㗀ࠍਈ߃ࠆ߽ߩߢߪߥ޿㧚. ࠄ㧘ౣ߮㈩೉ߩᆎὐ߆ࠄⷐ⚛ࠍᦠ߈ᄌ߃ߟߟ⸥㍳ࠍ⛯. Many ࠦ ࠕ Ⅳ Ⴚ ߢ ߪ 㧘 ᦠ ߈ ㄟ ߺ ߩ ឃ ઁ ೙ ᓮ ߇ ࡏ ࠻ ࡞. ߌࠆ߽ߩߢ޽ࠆ㧚࡝ࡦࠣࡃ࠶ࡈࠔࠍ೑↪ߔࠆߎߣߢ㧘. ࡀ࠶ࠢߦߥࠆߎߣ߇⠨߃ࠄࠇࠆ㧚ߥߗߥࠄ㧘ਗ೉േ૞. ࠕࠢ࠮ࠬࡠࠣ⸥㍳ߦᔅⷐߥࡔࡕ࡝㊂ࠍ࿕ቯߦߔࠆߎߣ. ߔࠆࠕࡊ࡝ࠤ࡯࡚ࠪࡦ߇Ⴧ߃ࠆߎߣߢ㧘หᤨߦ࡝ࡦࠣ. ߇ ߢ ߈ ࠆ 㧚ߘ ߩ ৻ ᣇ ߢ 㧘ࡠ ࠣ ߇ ਄ ᦠ ߈ ߐ ࠇ ߡ ޿ ߊ ߚ ߼ 㧘. ߦᦠ߈ㄟ߽߁ߣߔࠆน⢻ᕈ߇㜞ߊߥࠆ߆ࠄߢ޽ࠆ㧚ߎ. ࡠࠣ߆ࠄࡄ࠲࡯ࡦࠍ᛽಴ߔࠆ೨ߦࡠࠣ߇ᄬࠊࠇࠆน⢻. ߩ ႐ ว ߪ 㧘CPU ߏ ߣ ߦ ࡝ ࡦ ࠣ ࠍ ߽ ߟ ߎ ߣ ߢ 㧘ࡏ ࠻ ࡞ ࡀ. ᕈ߇޽ࠆ㧚. ࠶ࠢࠍᷫࠄߔߎߣ߇น⢻ߢ޽ࠆ㧚ߘ߁ߔࠇ߫㧘⇣ߥࠆ. ࡝ࡦࠣࡃ࠶ࡈࠔ߳ߩࠕࠢ࠮ࠬߦߪឃઁ೙ᓮ߇ᔅⷐ. CPU ߇ ห ߓ ࡝ ࡦ ࠣ ߦ ᦠ ߈ ㄟ ߻ ߎ ߣ ߪ ߥ ߊ 㧘ឃ ઁ ೙ ᓮ ߪ. ߢ ޽ ࠆ 㧚⃻ ࿷ ߩ ታ ⵝ ߪ 㧘OS ਄ ߩ ో ࠕ ࡊ ࡝ ࠤ ࡯ ࠪ ࡚ ࡦ ߩ. ᔅⷐߥ޿߆ࠄߢ޽ࠆ㧚. ࠕࠢ࠮ࠬࡠࠣࠍ౒ㅢߩ࡝ࡦࠣࡃ࠶ࡈࠔߦ⸥㍳ߔࠆ㧚ߒ. 3.2. 䉝䉪䉶䉴䊨䉫䈱䊐䉞䊦䉺䈫⸥ ㍳. ߚ߇ߞߡ㧘ࡊࡠ࠮ࠬ㑆ߢ࡝ࡦࠣࡃ࠶ࡈࠔ߳ߩᦠ߈ㄟߺ. ࠕࡊ࡝ࠤ࡯࡚ࠪࡦߪࡈࠔࠗ࡞ฬߣࠝࡈ࠮࠶࠻ߦࠃ. ߇ឃઁ⊛ߦⴕࠊࠇࠆᔅⷐ߇޽ࠆ㧚߹ߚ㧘ࡄ࠲࡯ࡦ᛽಴. ࠅ ࡈ ࠔ ࠗ ࡞ ߦ ࠕ ࠢ ࠮ ࠬ ߔ ࠆ 㧚 ࡈ ࠔ ࠗ ࡞ ฬ ߪ Linux ࠞ ࡯ ࡀ ࡞ ౝ ߢ i-node ߦ ᄌ ឵ ߐ ࠇ 㧘ࡈ ࠔ ࠗ ࡞ ߇ ৻ ᗧ ߦ ⼂ ೎ ߐ. Application1. Application2. ࠇࠆ㧚࡝ࡦࠣࡃ࠶ࡈࠔߦߪ⺒ߺㄟ߹ࠇߚࡈࠔࠗ࡞ߩ i-node ߣ ࠝ ࡈ ࠮ ࠶ ࠻ ࠍ ⸥ ㍳ ߔ ࠆ 㧚 ࡈ ࠔ ࠗ ࡞ ᦠ ߈ ㄟ ߺ ᤨ. d g g. j. a a. ǹȔȳȭȃǯ. d. Ȫȳǰ Ȑȃȕǡ a. u. u. a. a e. ࠬ࠻ࠍ࡝ࡦࠣࡃ࠶ࡈࠔߦ⸥㍳ߔࠆߎߣ߇น⢻ߢ޽ࠆ㧚 ᪯ഏȭȃǯ. e e. ߦ ߪ ࡠ ࠣ ࠍ ⸥ ㍳ ߒ ߥ ޿ 㧚 ᧄ ࠪ ࠬ ࠹ ࡓ ߪ OS ౝ ߦ ታ ⵝ ߒ ߡ޿ࠆߚ߼㧘ోߡߩࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩోߡߩ࡝ࠢࠛ ߒ߆ߒ㧘ࠕࠢ࠮ࠬࡠࠣࠍోߡ⸥㍳ߒࠃ߁ߣߔࠆߣ࡝ࡦ ࠣࡃ࠶ࡈࠔ߇㗫❥ߦᦠ߈ᄌࠊࠅ㧘ࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ. ȑǿȸȳਁЈ ǹȬȃȉ. ࿑ 3㧚 ࡝ ࡦ ࠣ ࡃ ࠶ ࡈ ࠔ ߣ ឃ ઁ ೙ ᓮ. ᛽಴ߔࠆ೨ߦࡠࠣࠍᄬ߁น⢻ᕈ߇޽ࠆ㧚߹ߚ㧘ឃઁ೙ ᓮߦࠃࠆࠝ࡯ࡃ࡯ࡋ࠶࠼߽⊒↢ߔࠆน⢻ᕈ߇޽ࠆ㧚 ߘߎߢ㧘ࠪ࡯ࠤࡦࠪࡖ࡞ࠕࠢ࠮ࠬࠍࡈࠖ࡞࠲ߔࠆߎ. － 75 －.

(4) ߣߢ㧘ࡠࠣߩ⸥㍳㊂ࠍ೥ᷫߔࠆ㧚ߥߗߥࠄ㧘ࠪ࡯ࠤࡦ. ᘒ 㧘 ଀ ߃ ߫ I/O ᓙ ߜ ߩ 㓙 ߦ േ ૞ ߔ ࠆ 㧚. ࠪࡖ࡞ࠕࠢ࠮ࠬࡄ࠲࡯ࡦߪࠝࡦ࠺ࡑࡦ࠼ߩ੍᷹߇ኈᤃ. ᧄ⺰ᢥߩࠪࠬ࠹ࡓߢߪࠕࠢ࠮ࠬࡄ࠲࡯ࡦߣߒߡ㧘ࡄ. ߛ߆ࠄߢ޽ࠆ㧚ⓨ㑆⊛ዪᚲᕈߦࠃࠅ㧘ࠪ࡯ࠤࡦࠪࡖ࡞. ࠲࡯ࡦߩᏀㄝߣฝㄝߩࡉࡠ࠶ࠢ߇㧝ߟߢ޽ࠆ A o C. ࠕࠢ࠮ࠬߐࠇߚ࠺࡯࠲ߩ⋥ᓟߪ㧘ㄭ޿߁ߜߦࠪ࡯ࠤࡦ. ߣ޿ߞߚࡄ࠲࡯ࡦߩߺࠍ೑↪ߔࠆ㧚ߎߎߢ㧘ࠕ࡞ࡈࠔ. ࠪࡖ࡞ࠕࠢ࠮ࠬߐࠇࠆߣᦼᓙߢ߈ࠆ㧚ߘߩߚ߼ࠝࡦ࠺. ࡌ ࠶ ࠻ ߪ 4KB ߩ ࠺ ࠖ ࠬ ࠢ ࡉ ࡠ ࠶ ࠢ ߢ ޽ ࠅ 㧘࠮ ࠢ ࠲ ⇟ ภ. ࡑ ࡦ ࠼ ߢ వ ⺒ ߺ ߇ น ⢻ ߢ ޽ ࠆ 2 㧚߹ ߚ 㧘ࡂ ࡯ ࠼ ࠺ ࠖ ࠬ ࠢ. 㗅ߦࠕ࡞ࡈࠔࡌ࠶࠻߇ᝄߞߡ޽ࠆ߽ߩߣߔࠆ㧚ᧄ⺰ᢥ. ࠼࡜ࠗࡉߪࠪ࡯ࠤࡦࠪࡖ࡞ࠕࠢ࠮ࠬ߇㜞ㅦߢ޽ࠆ㧚ㅒ. ߩ⋡⊛ߪ࡜ࡦ࠳ࡓࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ᛽಴ߔࠆߎߣߢ. ߦ࡜ࡦ࠳ࡓࠕࠢ࠮ࠬߪ㕖Ᏹߦૐㅦߢ޽ࠆ㧚ᓥߞߡ㧘࡜. ޽ࠆߩߢ㧘 A o B ߣ޿ߞߚࠪ࡯ࠤࡦࠪࡖ࡞ࠕࠢ࠮ࠬߩ. ࡦ࠳ࡓࠕࠢ࠮ࠬߐࠇࠆ࠺࡯࠲ࠍࠠࡖ࠶ࠪࡘࡅ࠶࠻ߐߖ. ࡄ ࠲ ࡯ ࡦ ߿ 㧘B o B ߣ ޿ ߞ ߚ ᤨ 㑆 ⊛ ዪ ᚲ ᕈ ࠍ ⴫ ߔ ࡄ ࠲. ࠆߎߣ߇ᕈ⢻਄㊀ⷐߣߥࠆ㧚. ࡯ࡦߪ↢ᚑߒߥ޿㧚ࠕࠢ࠮ࠬࡄ࠲࡯ࡦߩ᛽಴ߦߪࠬ࡜. ᧄࠪࠬ࠹ࡓߩࡈࠖ࡞࠲ߦߪ࠺ࠖࠬࠢ਄ߩ࠮ࠢ࠲〒. ࠗ࠺ࠖࡦࠣ࠙ࠖࡦ࠼࠙ࠍ↪޿ߡ޿ࠆ㧚ࠕࠢ࠮ࠬࡄ࠲࡯. 㔌ࠍ↪޿ߡ޿ࠆ㧚ࠪ࡯ࠤࡦࠪࡖ࡞ࠕࠢ࠮ࠬߣߪㅪ⛯ߒ. ࡦ ߩ ᛽ ಴ ߦ 㑐 ߒ ߡ ߩ ࠃ ࠅ ⹦ ߒ ޿ ⼏⺰ ߪ [12]ߢ ⴕ ߞ ߡ ޿. ߚ࠮ࠢ࠲߳ߩࠕࠢ࠮ࠬߢ޽ࠅ㧘࡜ࡦ࠳ࡓࠕࠢ࠮ࠬߣߪ ㅪ⛯ߒߡ޿ߥ޿࠮ࠢ࠲߳ߩࠕࠢ࠮ࠬߩߎߣߢ޽ࠆ㧚ㅢ. ࠆ㧚 એਅ㧘. Ᏹ㧘࠮ࠢ࠲⇟ภ߇㔌ࠇߡ޿ࠆ߶ߤ࠺ࠖࠬࠢ਄ߢߩ〒㔌. 㓸วࠍ. x ࠍᏀㄝߦ߽ߟࠕࠢ࠮ࠬࡄ࠲࡯ࡦߩฝㄝ y ߩ Correlate ( x ). ߪ 㔌 ࠇ 㧘ࠪ ࡯ ࠢ ᤨ 㑆 ߇ ᄢ ߈ ߊ ߥ ࠆ [6]㧚ߎ ߩ ․ ᓽ ࠍ ೑ ↪. { y | x o y}. ߒ ߡ 㧘࡝ ࠬ ࠻ 1 ߦ ␜ ߒ ߚ ࠃ ߁ ߦ 㧘ᦨ ᓟ ߩ ࡈ ࠔ ࠗ ࡞ ࠕ ࠢ. ߢ޽ࠄࠊߔ㧚. ࠮ࠬߩవ㗡࠮ࠢ࠲⇟ภߣ⃻࿷ߩࡈࠔࠗ࡞ࠕࠢ࠮ࠬߩవ. 3.4. 䉝䉪䉶䉴䊌䉺䊷䊮䈮䉋䉎⋧ 㑐䊥䉥䊷䉻䊥䊮䉫. 㗡࠮ࠢ࠲⇟ภߩᏅࠍ 8 ߢഀߞߚ߽ߩ߇㑣୯ d ᧂḩߩࠕ. ᛽಴ߒߚࠕࠢ࠮ࠬࡄ࠲࡯ࡦߪ࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘ. ࠢ ࠮ ࠬ ߪ ࡈ ࠖ ࡞ ࠲ ߔ ࠆ 3 㧚 d ࠍ ᄢ ߈ ߊ ߔ ࠆ ߶ ߤ 㧘⸥ ㍳ ߐ. ߩࡅ࠶࠻₸ᡷༀߩߚ߼ߦ೑↪ߔࠆ㧚ᧄࠪࠬ࠹ࡓߪ㧘᛽. ࠇ ࠆ ࡠ ࠣ ߪ ዋ ߥ ߊ ߥ ߞ ߡ ޿ ߊ ߎ ߣ ߦ ߥ ࠆ 㧚ߔ ߥ ࠊ ߜ 㧘d. ಴ߒߚࠕࠢ࠮ࠬࡄ࠲࡯ࡦߦၮߠ޿ߡ㧘ㄭ޿዁᧪ࠕࠢ࠮. ࠍࡈࠖ࡞࠲ߩᒝߐߣߒߡ⠨߃ࠆߎߣ߇ߢ߈ࠆ㧚. ࠬ ߐ ࠇ ࠆ ߣ ੍ ᗐ ߐ ࠇ ࠆ ࠺ ࡯ ࠲ ࠍ LRU ࡝ ࠬ ࠻ ߩ ᧃ የ ߦ. ߎߎߢ㧘 d. 0 ߩ႐วߪࡈࠖ࡞࠲ήߒߦ⋧ᒰߔࠆ㧚. d. ⒖ േ ߐ ߖ 㧘ࠃ ࠅ 㐳 ߊ ࠠ ࡖ ࠶ ࠪ ࡘ ߦ ⇐ ߼ ࠆ ߎ ߣ ࠍ ⹜ ߺ ࠆ 㧚. 1 ߩ ႐ ว ߪ 㧘ห ߓ ࠝ ࡈ ࠮ ࠶ ࠻ ߳ ߩ ㅪ ⛯ ߒ ߚ ࠕ ࠢ ࠮ ࠬ ߇ࡈࠖ࡞࠲ߐࠇࠆ㧚 d 2 ߢߪ㧘ࠪ࡯ࠤࡦࠪࡖ࡞ࠕࠢ ࠮ ࠬ ߇ ࡈ ࠖ ࡞ ࠲ ߐ ࠇ ࠆ 㧚ߘ ߒ ߡ d t 3 ߢ ߪ 㧘 d ࠍ ᄢ ߈ ߊ. ߥ ࠆ ࠕ ࠗ ࠹ ࡓ 㓸 ว S ࠍ LRU ࡝ ࠬ ࠻ ߩ ᧃ የ ߦ ⒖ േ ߐ ߖ. ߔࠇ߫ߔࠆ߶ߤ㧘ࡈࠖ࡞࠲ߐࠇࠆࠕࠢ࠮ࠬߩࠪ࡯ࠢᤨ. ࠆ㧚ߎߩേ૞ߪ࡝ࠬ࠻ߩ❬߉឵߃ߢ޽ࠆߚ߼㧘ቯᢙࠝ. 㑆߇㐳ߊߥߞߡ޿ߊߎߣߦߥࠆ㧚ߎ߁ߒߡ⸥㍳ߐࠇߚ. ࡯ ࠳ ߢ ⴕ ߃ 㧘ࠬ ࠻ ࡟ ࡯ ࠫ ߳ ߩ ࡝ ࠢ ࠛ ࠬ ࠻ ߪ ⊒ ↢ ߒ ߥ ޿ 㧚. ࠕࠢ࠮ࠬࡠࠣ߆ࠄ㧘ࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ᛽಴ߔࠆ㧚. ߔߥࠊߜ㧘޽ࠆࡉࡠ࠶ࠢ A ߇ࠕࠢ࠮ࠬߐࠇߚ႐วߦ㧘 S {i | i Corrlate ( A) i LRU࡝ࠬ࠻}. ⃻ ࿷ 㧘 Linux ߩ ࠺ ࠖ ࠬ ࠢ ࠠ ࡖ ࠶ ࠪ ࡘ ࠕ ࡞ ࠧ ࡝ ࠭ ࡓ ߪ. 3.3. 䉝䉪䉶䉴䊌䉺䊷䊮䈱᛽ ಴. LRU ߩ ᡷ ⦟ ဳ ߢ ޽ ࠆ 2Q[7]߇ ၮ ߦ ߥ ߞ ߡ ޿ ࠆ [1]㧚ߎ ߩ. ࠕࠢ࠮ࠬࡄ࠲࡯ࡦߩ᛽಴ߪࠞ࡯ࡀ࡞ࠬ࡟࠶࠼ߣ๭ ߫ࠇࠆࠞ࡯ࡀ࡞ౝߩኾ↪ࠬ࡟࠶࠼߇ⴕ߁㧚ࡄ࠲࡯ࡦ᛽. ႐ว߽ห᭽ߦ㧘ࠕࠗ࠹ࡓ㓸ว S ߦᦨ߽㜞޿ఝవᐲࠍਈ ߃㧘ࠠࡖ࠶ࠪࡘߦ⇐߹ࠄߖࠆߎߣࠍ⹜ߺࠆ㧚. ಴ ࠬ ࡟ ࠶ ࠼ ߪ ఝ వ ᐲ ᦨ ૐ ߢ േ ૞ ߒ 㧘CPU ߇ ࠕ ࠗ ࠼ ࡞ ⁁. 4. ⹏ ଔ ታ 㛎. AccessLogger ( i-node, ࠝ ࡈ ࠮ ࠶ ࠻ , ࠮ ࠢ ࠲ ⇟ ภ ) { if (੹ ࿁ ߣ ೨ ࿁ ߩ ࠕ ࠢ ࠮ ࠬ ߩ వ 㗡 ࠮ ࠢ ࠲ ⇟ ภ ߩ Ꮕ /8. td. ). {. ᧄ ⺰ ᢥ ߢ ߪ 㧘ឭ ᩺ ࠪ ࠬ ࠹ ࡓ ࠍ Linux 2.6.26 ߦ ታ ⵝ ߒ 㧘 TPC-C[14] ߩ ◲ ᤃ ታ ⵝ ߢ ޽ ࠆ DBT-2[13] ߩ ᕈ ⢻ ะ ਄ ₸ ߢ ⹏ ଔ ࠍ ⴕ ߞ ߚ 㧚TPC-C ߣ ߪ TPC ߇ ╷ ቯ ߒ ߚ ࡌ ࡦ ࠴. ࠕ ࠢ ࠮ ࠬ ࡠ ࠣ ߦ i-node ߣ ࠝ ࡈ ࠮ ࠶ ࠻ ࠍ ⸥ ㍳ ߔ ࠆ 㧚. ࡑ࡯ࠢⷙᩰߢ޽ࠅ㧘෈ᄁࠅળ␠ߩࡢ࡯ࠢࡠ࡯࠼ࠍࠪࡒ. }. ࡘ࡟࡯࡚ࠪࡦߔࠆ߽ߩߢ޽ࠆ㧚ࡌࡦ࠴ࡑ࡯ࠢߩ⽶⩄ߪ. else {. ࠙ࠚࠕࡂ࠙ࠬᢙߣ࠺࡯࠲ࡌ࡯ࠬ߳ߩធ⛯ᢙߦࠃࠅ᳿߹. ࠕࠢ࠮ࠬࡠࠣߦ⸥㍳ߒߥ޿㧚. ࠆ㧚ࡌࡦ࠴ࡑ࡯ࠢ⚿ᨐߪ㧘1 ಽ㑆ߦಣℂߢ߈ࠆ࠻࡜ࡦ. }. ࠩ ࠢ ࠪ ࡚ ࡦ ᢙ (tpmC)ߢ ޽ ࠄ ࠊ ߒ 㧘 ᄙ ޿ ߶ ߤ ࠪ ࠬ ࠹ ࡓ ߩ. }. ᕈ ⢻ ߪ 㜞 ޿ 㧚ߥ ߅ 㧘DBT-2 ߪ TPC-C ߩ ◲ ᤃ ታ ⵝ ߩ ߚ. ࡝ ࠬ ࠻ 1㧚 ࠕ ࠢ ࠮ ࠬ ࡠ ࠣ ߩ ࡈ ࠖ ࡞ ࠲ ᣇ ᴺ. ߼ ౏ ᑼ ߥ TPC-C ߩ ⚿ ᨐ ߣ ߔ ࠆ ߎ ߣ ߪ ⸵ ߐ ࠇ ߥ ޿ 㧚. 2 Linux ߪ ࠪ ࡯ ࠤ ࡦ ࠪ ࡖ ࡞ ࠕ ࠢ ࠮ ࠬ ᤨ ߦ 㧘࠺ ࡈ ࠜ ࡞ ࠻ ⸳ ቯ ߢ ᦨ ᄢ 128KB ߩ వ ⺒ ߺ ࠍ ⴕ ߁ 㧚. 4.1. ታ 㛎 Ⅳ Ⴚ. ࠬ ߐ ࠇ ࠆ ߇ 㧘 ࠮ ࠢ ࠲ ⇟ ภ ߪ 512B ߩ ߚ ߼ 8 ߢ ഀ ࠆ 㧚. ࡔࡕ࡝ࠍ៞タߒߡ޿ࠆ߇㧘ឭ᩺ᚻᴺߩലᨐࠍ⏕⹺ߔࠆ. 3 ㅢ Ᏹ 㧘 Linux ࠞ ࡯ ࡀ ࡞ ౝ ߢ ࡈ ࠔ ࠗ ࡞ ߪ 4KB න ૏ ߢ ࠕ ࠢ ࠮. ⴫ 1 ߦ ታ 㛎 Ⅳ Ⴚ ࠍ ␜ ߔ 㧚 ૶ ↪ ߒ ߚ ⸘ ▚ ᯏ ߪ 8GB ߩ. － 76 －.

(5) ߚ ߼ 㧘 ࠪ ࠬ ࠹ ࡓ ࡔ ࡕ ࡝ ㊂ ࠍ ࠰ ࡈ ࠻ ࠙ ࠚ ࠕ ⊛ ߦ 768MB. ᧄ⎇ⓥߩࠃ߁ߦ࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘ⟎឵ࠕ࡞ࠧ࡝࠭ࡓ. ߆ ࠄ 2GB ߩ 㑆 ߢ ᄌ ൻ ߐ ߖ ߡ ታ 㛎 ࠍ ⴕ ߞ ߚ 㧚⹏ ଔ ߦ ߅ ޿. ߦ૶↪ߔࠆ႐ว㧘▤ℂන૏߇࠺ࠖࠬࠢࡉࡠ࠶ࠢߢ޽ࠆ. ߡ ߪ DBT-2 ࡢ ࡯ ࠢ ࡠ ࡯ ࠼ ࠍ 㧘࠙ ࠚ ࠕ ࡂ ࠙ ࠬ ᢙ 50㧘ធ ⛯. ߚ߼㧘⤘ᄢߥࡉࡠ࠶ࠢᢙࠍᛒ߁ᔅⷐ߇޽ࠆ㧚. ᢙ 8 ߦ ⸳ ቯ ߒ 㧘2 ᤨ 㑆 േ ૞ ߐ ߖ ߡ ޿ ࠆ㧔 ⴫ 2㧕㧚ߎ ߩ ႐. Li ࠄ ߪ ࠺ ࡯ ࠲ ࡑ ࠗ ࠾ ࡦ ࠣ ᚻ ᴺ ࠍ ↪ ޿ ࠆ ߎ ߣ ߢ ࠬ ࠤ. ว ߩ ࠺ ࡯ ࠲ ࡌ ࡯ ࠬ ߩ ✚ ࠨ ࠗ ࠭ ߪ ߅ ࠃ ߘ 6.0GB ߣ ߥ ߞ ߚ 㧚. ࡯ ࡜ ࡆ ࡝ ࠹ ࠖ ߩ ໧ 㗴 ࠍ ⸃ ᳿ ߒ ߡ ޿ ࠆ [11]㧚 ߒ ߆ ߒ 㧘 ࠬ. ࡄ ࠲ ࡯ ࡦ ߩ ᛽ ಴ ߪ ࠙ ࠖ ࡦ ࠼ ࠙ ࠨ ࠗ ࠭ 50㧘ᦨ ዊ ࠨ ࡐ ࡯ ࠻. ࠻࡟࡯ࠫ࡟ࡌ࡞ߢߩࠕࠢ࠮ࠬࡠࠣࠍ↪޿ߡ޿ࠆߚ߼㧘. ୯ 30 ߢ ⴕ ߞ ߡ ޿ ࠆ 㧚 ࡈ ࠖ ࡞ ࠲ ߩ ᒝ ߐ ߪ d. 2 ߢ޽ࠆ㧚. OS ߇ ▤ ℂ ߒ ߡ ޿ ࠆ ‛ ℂ ࡔ ࡕ ࡝ ਄ ߩ ࠺ ࠖ ࠬ ࠢ ࠠ ࡖ ࠶ ࠪ. ߔ ߥ ࠊ ߜ 㧘ࠪ ࡯ ࠤ ࡦ ࠪ ࡖ ࡞ ࠕ ࠢ ࠮ ࠬ ߇ ࡈ ࠖ ࡞ ࠲ ߐ ࠇ ࠆ 㧚. ࡘ ߦ ࡅ ࠶ ࠻ ߔ ࠆ ࠕ ࠢ ࠮ ࠬ ߪ ೑ ↪ ߒ ߡ ޿ ߥ ޿ 㧚 ߹ ߚ Li. ࡝ ࡦ ࠣ ࡃ ࠶ ࡈ ࠔ ߪ ⚂ 200 ਁ ࿁ ( 2 u 2 20 ࿁ )ߩ ࠕ ࠢ ࠮ ࠬ ࠍ. ࠄߪ㧘ࠪ࡯ࠤࡦࠪࡖ࡞ࠕࠢ࠮ࠬߩࡄ࠲࡯ࡦ߽᛽಴ߒߡ. ⸥㍳ߢ߈ࠆࠨࠗ࠭ߣߒߚ㧚. ޿ࠆ㧚ࠪ࡯ࠤࡦࠪࡖ࡞ࠕࠢ࠮ࠬߪࠝࡦ࠺ࡑࡦ࠼ߢߩࠕ. 4.2. ታ 㛎 ⚿ ᨐ. ࠢ࠮੍᷹ࠬ߇ኈᤃߢ޽ࠅ㧘᛽಴ߔࠆࡄ࠲࡯ࡦߣߒߡߪ. ታ㛎⚿ᨐࠍ⴫ 3 ߣ࿑ 4 ߦ␜ߔ㧚ߎߩ⚿ᨐߪ㧘ឭ᩺. ㆡಾߢߪߥ޿ߣ⠨߃ࠄࠇࠆ㧚. ᚻ ᴺ ࠍ ታ ⵝ ߒ ߚ Linux 2.6.26 ࠞ ࡯ ࡀ ࡞ ߇ ౏ ᑼ ߩ Linux. Won ࠄ ߪ 㧘ᯏ ᪾ ቇ ⠌ ߩ ᚻ ᴺ ࠍ ↪ ޿ ߡ 㧘േ ૞ ߒ ߡ ޿ ࠆ. 2.6.26 ࠞ ࡯ ࡀ ࡞ ߆ ࠄ ߤ ࠇ ߛ ߌ ᕈ ⢻ ࠍ ะ ਄ ߢ ߈ ߚ ߆ ␜ ߒ. ࠕࡊ࡝ࠤ࡯࡚ࠪࡦ߇ࡑ࡞࠴ࡔ࠺ࠖࠕࠕࡊ࡝ࠤ࡯࡚ࠪࡦ. ߚ ߽ ߩ ߢ ޽ ࠆ 㧚ߢ ࡔ ࡕ ࡝ ㊂ ߇ 768MB ߩ ᤨ ߦ 5.24%㧘1GB. ߆ุ߆ࠍ್ቯߒ㧘ࡑ࡞࠴ࡔ࠺ࠖࠕࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩ. ߩ ᤨ ߦ 4.88%ߩ ᕈ ⢻ ᡷ ༀ ࠍ ⏕ ⹺ ߢ ߈ ߚ 㧚 ㅒ ߦ ࡔ ࡕ ࡝ ㊂. ႐วߪవ⺒ߺ㊂ࠍჇടߐߖࠆߎߣߢࡄࡈࠜ࡯ࡑࡦࠬࠍ. 1.5GB ߩ ᤨ ߦ ߪ 1.10%ߩ ᕈ ⢻ ૐ ਅ ߇ ⊒ ↢ ߒ 㧘 2GB ߩ ᤨ. ᡷ ༀ ߒ ߡ ޿ ࠆ [10]㧚 ࡑ ࡞ ࠴ ࡔ ࠺ ࠖ ࠕ ࠕ ࡊ ࡝ ࠤ ࡯ ࠪ ࡚ ࡦ. ߦ ߪ ᕈ ⢻ ᄌ ൻ ߇ ᱴ ߤ ή ߆ ߞ ߚ 㧚 1.5GB એ ਄ ߢ ߪ ‛ ℂ ࡔ. ߪࠪ࡯ࠤࡦࠪࡖ࡞ࠕࠢ࠮ࠬ߇ᡰ㈩⊛ߥߚ߼㧘వ⺒ߺ㊂. ࡕ࡝߇Ⴧ߃ࠆߎߣߦࠃࠅ࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘ㊂߇లಽ. ࠍჇടߐߖࠆߎߣߢ㧘ࠪࠬ࠹ࡓᕈ⢻ࠍᡷༀߔࠆߎߣ߇. ߦߥࠅ㧘ᧄࠪࠬ࠹ࡓߦࠃࠆᕈ⢻ᡷༀ߇ߥߊߥߞߚߚ߼. ߢ߈ࠆ㧚 Ding ࠄ ߪ ⓨ 㑆 ⊛ ዪ ᚲ ᕈ ࠍ ⠨ ᘦ ߒ ߚ ࠺ ࠖ ࠬ ࠢ ࠠ ࡖ ࠶. ߣ ⠨ ߃ ࠄ ࠇ ࠆ 㧚 1.5GB ߩ ᤨ ߩ ᕈ ⢻ ૐ ਅ ߪ ታ ⵝ ߦ ࠃ ࠆ ࠝ. ࠪ ࡘ ࠕ ࡞ ࠧ ࡝ ࠭ ࡓ ࠍ ឭ ᩺ ߒ ߡ ޿ ࠆ [9]㧚Ding ࠄ ߩ ࠕ ࡞ ࠧ. ࡯ࡃ࡯ࡋ࠶࠼ߣ⠨߃ࠄࠇࠆ㧚. ࡝࠭ࡓߪ㧘࡜ࡦ࠳ࡓࠕࠢ࠮ࠬߐࠇࠆ࠺࡯࠲ߪࠃࠅ㐳ߊ ࠠࡖ࠶ࠪࡘߦ⟎ߊߴ߈ߢ޽ࠆߣ޿߁ⷰኤߦၮߠ޿ߡ޿. 5. 㑐 ㅪ ⎇ ⓥ ߎࠇ߹ߢߦ߽ࡈࠔࠗ࡞ࠕࠢ࠮ࠬߩࡄ࠲࡯ࡦࠍ᛽಴. ࠆ 㧚ᓥ ᧪ ߩ LRU ࡝ ࠬ ࠻ ߪ ᤨ 㑆 ⊛ ዪ ᚲ ᕈ ߩ ߺ ࠍ ⠨ ᘦ ߔ ࠆ. ߒ㧘ࠬ࠻࡟࡯ࠫߩ㜞ᕈ⢻ൻߦ೑↪ߔࠆ⎇ⓥ߇ⴕࠊࠇߡ. ߽ ߩ ߢ ޽ ࠆ ߇ 㧘Ding ࠄ ߪ ⓨ 㑆 ⊛ ዪ ᚲ ᕈ ߩ ᐲ ว ޿ ߦ ᔕ ߓ. ޿ ࠆ [2][3][5][8][11]㧚 HTML ߇ ࠕ ࠢ ࠮ ࠬ ߐ ࠇ ࠆ ߣ 㧘 ߘ. ߡ LRU ࡝ ࠬ ࠻ ߩ ⷐ ⚛ ࠍ േ ⊛ ߦ ਗ ߮ ᄌ ߃ ࠆ ߎ ߣ ߢ ᕈ ⢻. ߩࡍ࡯ࠫ߆ࠄ࡝ࡦࠢߐࠇߡ޿ࠆ↹௝߇ࠕࠢ࠮ࠬߐࠇࠆ. ࠍᡷༀߒߡ޿ࠆ㧚 ᧄ ⺰ ᢥ ߩ ࠪ ࠬ ࠹ ࡓ ߩ ⋡ ⊛ ߪ 㧘OS ࡟ ࡌ ࡞ ߢ ข ᓧ ߢ ߈ ࠆ. ߣ޿ߞߚࡈࠔࠗ࡞㑆ߩ⋧㑐ߪ㧘ᧁ᭴ㅧ߿ࠣ࡜ࡈߦࠃߞ ߡ ᛽ ಴ น ⢻ ߢ ޽ ࠆ [3][8]㧚ߒ ߆ ߒ 㧘ᧁ ᭴ ㅧ ߿ ࠣ ࡜ ࡈ ߦ ࠃ. ⴫ 3㧚 ឭ ᩺ ᚻ ᴺ ߦ ࠃ ࠆ ࠻ ࡜ ࡦ ࠩ ࠢ ࠪ ࡚ ࡦ ᕈ ⢻ ߩ ᄌ ൻ. ࠆࠕࠢ࠮ࠬࡄ࠲࡯ࡦߩ᛽಴ߪ㧘ࡈࠔࠗ࡞ᢙߦኻߔࠆࠬ. ࡔࡕ࡝ኈ㊂. ࠤ ࡯ ࡜ ࡆ ࡝ ࠹ ࠖ ߩ 㕙 ߢ ໧ 㗴 ⷞ ߐ ࠇ ߡ ޿ ࠆ [5][11]㧚․ ߦ 㧘. 768MB 1024MB 1536MB 2048MB. ⴫ 1㧚 ታ 㛎 Ⅳ Ⴚ. Memory Disk File System OS. Dell PowerEdge 2850 Intel 64bit Xeon 3.2GHz ×2 (HT enabled) DDR2 400 8GB (PAE36 enabled) (768MB㨪 2GB ߩ ኈ ㊂ ߢ ૶ ↪ ) Ultra SCSI 320 15000rpm RAID5 (PERC 4e/Di Standard FW 521S DRAM:256MB) ext3 Linux 2.6.26 (x86 smp). ⴫ 2㧚 ታ ⴕ ߒ ߚ ࡢ ࡯ ࠢ ࡠ ࡯ ࠼ ࠺ ࡯ ࠲ ࡌ ࡯ ࠬ ࠰ ࡈ ࠻ PostgreSQL 8.2.0 DBT-2 0.40 ࡌࡦ࠴ࡑ࡯ࠢ࠰ࡈ࠻ 50 ࠙ࠚࠕࡂ࠙ࠬᢙ 8 ធ⛯ᢙ ታⴕᤨ㑆 7,200 ⑽. 6.00% 5.00% 4.00% ᕈ⢻ะ਄₸. CPU. Ფಽ࠻࡜ࡦ࡚ࠩࠢࠪࡦᢙ ឭ᩺ᚻᴺߥߒ ឭ᩺ᚻᴺ޽ࠅ 471.99 496.70 516.53 541.75 574.10 567.79 579.35 579.55. 3.00% 2.00% 1.00% 0.00% -1.00% -2.00%. 768. 1024. 1536. 2048. 䊜䊝䊥䉰䉟䉵[MB]. ࿑ 4㧚 ឭ ᩺ ᚻ ᴺ ߦ ࠃ ࠆ DBT-2 ߩ ᕈ ⢻ ᡷ ༀ ₸ (࠙ ࠖ ࡦ ࠼ ࠙ ࠨ ࠗ ࠭ :50㧘 ᦨ ዊ ࠨ ࡐ ࡯ ࠻ ୯ :30). － 77 －.

(6) ࡠࠣ߆ࠄࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ᛽಴ߒ㧘࠺ࠖࠬࠢࠠࡖ࠶. ࡄ࠲࡯ࡦࠍ↪޿ߡ㧘࠼࡜ࠗࡉߩࠬࡇࡦ࠳࠙ࡦࠍⴕ߁ߣ. ࠪࡘ⟎឵ࠕ࡞ࠧ࡝࠭ࡓߩᕈ⢻ᡷༀߦ೑↪ߔࠆߎߣߢ޽. ޿ߞߚߎߣ߽⠨߃ࠄࠇࠆ㧚. ࠆ㧚ࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍࠕࠢ࠮ࠬࡠࠣ߆ࠄ᛽಴ߔࠆὐ ߇ Ding ࠄ ߣ ߪ ⇣ ߥ ࠆ 㧚 Li ࠄ ߣ ߪ ⇣ ߥ ࠅ 㧘 ࠪ ࡯ ࠤ ࡦ ࠪ. ⻢ㄉ. ࡖ࡞ࠕࠢ࠮ࠬࠍࡈࠖ࡞࠲ߒߡࡠࠣߩࠨࠗ࠭ࠍዊߐߊߔ. ߎߩ⎇ⓥߪ㧘ᣧⒷ↰ᄢቇࠣࡠ࡯ࡃ࡞㧯㧻㧱ࡊࡠࠣ࡜. ࠆ ߎ ߣ ߢ 㧘ಣ ℂ ⽶ ᜂ ࠍ ዊ ߐ ߊ ߔ ࠆ 㧚߹ ߚ 㧘OS ࡟ ࡌ ࡞ ߢ. ࡓ‫ ࠻ ࡦ ࠛ ࡆ ࡦ ࠕ ޟ‬㧿㨛㧯 ᢎ ⢒ ⎇ ⓥ ߩ ࿖ 㓙 ᜚ ὐ ‫ޠ‬ 㧔ᢥㇱ⑼. ޽ࠇ߫࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘߦࡅ࠶࠻ߔࠆࠕࠢ࠮ࠬߢ޽. ቇ⋭⎇ⓥ᜚ὐᒻᚑ⾌⵬ഥ㊄㧕ߦࠃࠅᡰេߐࠇߚ㧚. ߞߡ߽೑↪ߔࠆߎߣ߇ߢ߈㧘ᖱႎߩ៊ᄬ߇ߥ޿㧚ߘߩ ߚ߼㧘ࠃࠅᱜ⏕ߥࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ᛽಴ߢ߈ࠆߎߣ ߇ᦼᓙߢ߈ࠆ㧚᛽಴ߒߚࡄ࠲࡯ࡦࠍ೑↪ߒߚ⋧㑐࡝ࠝ ࡯࠳࡝ࡦࠣߪ࡝ࠬ࠻ߩਗ߮ᦧ߃ߢ޽ࠅ㧘ቯᢙࠝ࡯࠳ߢ ⴕ߃ࠆ㧚ߥ߅㧘ㆊ෰ߩ⎇ⓥߩᄙߊ߇ࠪࡒࡘ࡟࡯࡚ࠪࡦ. ᢥ [1] [2]. ߢ޽ࠆߩߦኻߒ㧘ᧄ⺰ᢥߪታᯏߢ⹏ଔࠍⴕߞߡ޿ࠆ㧚. 6. ߅ ࠊ ࠅ ߦ ᧄ⺰ᢥߢߪ㧘ࠕࡊ࡝ࠤ࡯࡚ࠪࡦߩࡈࠔࠗ࡞ࠕࠢ࠮ࠬ. [3]. ࡠࠣ߆ࠄ᛽಴ߒߚࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ↪޿ࠆߎߣߢ㧘 ࠺ࠖࠬࠢࠠࡖ࠶ࠪࡘ⟎឵ࠕ࡞ࠧ࡝࠭ࡓߩല₸ࠍᡷༀߢ ߈ ࠆ ߎ ߣ ࠍ ታ ᯏ ߢ ␜ ߒ ߚ 㧚 ឭ ᩺ ᚻ ᴺ ࠍ Linux 2.6.26 ߦ. [4]. ታ ⵝ ߒ 㧘TPC-C ߩ ◲ ᤃ ታ ⵝ ߢ ޽ ࠆ DBT-2 ࠍ ↪ ޿ ߡ ࡌ ࡦ ࠴ ࡑ ࡯ ࠢ ࠍ ⴕ ߞ ߚ 㧚 ߘ ߩ ⚿ ᨐ 㧘 ᦨ ᄢ ߢ 5.24%ߩ ࠻ ࡜ ࡦ࡚ࠩࠢࠪࡦᕈ⢻ะ਄ࠍ⏕⹺ߢ߈ߚ㧚ߘߩ৻ᣇߢ. [5]. 1.10%ߩ ᕈ ⢻ ૐ ਅ ߇ ޽ ߞ ߚ 㧚 ੹ ᓟ ታ ⵝ ࠍ ᡷ ⦟ ߒ ߡ ᕈ ⢻ ࠍะ਄ߔࠆߣ౒ߦ㧘ࠃࠅ᭽‫ߡ޿ߟߦࠢ࡯ࡑ࠴ࡦࡌߥޘ‬ ⹏ଔࠍⴕ߁੍ቯߢ޽ࠆ㧚 ⃻࿷ߩታⵝߢߪ㧘ࠕࠢ࠮ࠬࡄ࠲࡯ࡦߩ᛽಴ߦ߅޿ߡ. [6]. ࠕࡊ࡝ࠤ࡯࡚ࠪࡦࠍ඙೎ߒߡ޿ߥ޿㧚ࠕࡊ࡝ࠤ࡯࡚ࠪ ࡦߏߣߦࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ᛽಴ߔࠆߎߣߢ㧘ࠃࠅᱜ ⏕ߥࠕࠢ࠮ࠬࡄ࠲࡯ࡦࠍ᛽಴ߢ߈ࠆน⢻ᕈ߇޽ࠆ㧚ߐ ࠄߦ㧘ࠕࡊ࡝ࠤ࡯࡚ࠪࡦ㑆ߩଐሽߩ᛽಴߽ⴕ߃ࠆน⢻. [7]. ᕈ ߇ ޽ ࠆ 㧚 ଀ ߃ ߫ Web ࠨ ࡯ ࡃ ߣ ࠺ ࡯ ࠲ ࡌ ࡯ ࠬ ߩ ႐ ว 㧘 Web ࠨ ࡯ ࡃ ߦ ࠕ ࠢ ࠮ ࠬ ߇ ޽ ߞ ߚ ޽ ߣ ߦ ࠺ ࡯ ࠲ ࡌ ࡯ ࠬ ߦ. [8]. ࠕࠢ࠮ࠬ߇޽ࠆ㧚ߎߩࠃ߁ߥଐሽ㑐ଥ߽೑↪ߔࠆߎߣ ߢ 㧘 ࠃ ࠅ 㜞 ᐲ ߥ I/O ᦨ ㆡ ൻ ࠍ ⴕ ߃ ࠆ น ⢻ ᕈ ߇ ޽ ࠆ 㧚 ࠕ ࠢ ࠮ ࠬ ࡄ ࠲ ࡯ ࡦ ࠍ ೑ ↪ ߒ ߡ 㧘 SSD (Solid State. [9]. Drive)ࠍ ᵴ ↪ ߔ ࠆ ߎ ߣ ߽ ⠨ ߃ ࠄ ࠇ ࠆ 㧚 SSD ߪ ඨ ዉ ૕ ࡔ ࡕ࡝ߢ᭴ᚑߐࠇߡ޿ࠆߚ߼㧘࡜ࡦ࠳ࡓࠕࠢ࠮ࠬ߇㜞ㅦ ߢ ޽ ࠆ 㧚ᓥ ߞ ߡ 㧘᛽ ಴ ߒ ߚ ࠕ ࠢ ࠮ ࠬ ࡄ ࠲ ࡯ ࡦ ߦ ၮ ߠ ߈ 㧘. [10]. ࡜ ࡦ ࠳ ࡓ ࠕ ࠢ ࠮ ࠬ ߐ ࠇ ࠆ ࠺ ࡯ ࠲ ࠍ SSD ߦ ㈩ ⟎ ߔ ࠆ ߎ ߣߢ㧘㜞ㅦൻࠍ࿑ࠆߎߣ߽น⢻ߢ޽ࠆ㧚 ઒ ᗐ ൻ ߩ ᥉ ෸ ߽ ⠨ ᘦ ߦ ౉ ࠇ ࠆ ᔅ ⷐ ߇ ޽ ࠆ 㧚 Many ࠦ ࠕ ൻ ߦ ઻ ޿ 㧘1 บ ߩ ࡑ ࠪ ࡦ ਄ ߢ ⶄ ᢙ ߩ OS ߇ േ ૞ ߔ ࠆ ࠃ ߁ߦߥࠆߣ⠨߃ࠄࠇࠆ㧚ߎߩ႐ว㧘ࠬ࠻࡟࡯ࠫࠍ▤ℂ. [11] [12]. ߔ ࠆ ߩ ߪ OS ߢ ߪ ߥ ߊ ઒ ᗐ ࡑ ࠪ ࡦ ߣ ߥ ࠆ 㧚 ᓥ ߞ ߡ 㧘 ઒ ᗐ ࡑ ࠪ ࡦ ࡟ ࡌ ࡞ ߢ ߩ I/O ᦨ ㆡ ൻ ߩ Ꮏ ᄦ ߽ ᔅ ⷐ ߢ ޽ ࠆ 㧚 ⋭㔚ജߦኻߔࠆᬌ⸛߽ᔅⷐߢ޽ࠆ㧚ᧄࠪࠬ࠹ࡓߪ૛ ߞ ߚ CPU ࡝ ࠰ ࡯ ࠬ ࠍ ᵴ ↪ ߔ ࠆ ඨ 㕙㧘 CPU ߩ 㔚 ജ ࠍ ᶖ ⾌ߔࠆ㧚⋭㔚ജߦ⽸₂ߔࠆߚ߼ߦ㧘᛽಴ߒߚࠕࠢ࠮ࠬ. [13] [14]. － 78 －. ₂. D.P. Bovet and M. Cesati, Understanding the Linux Kernel, Third Edition, O'Reilly, Nov. 2005. G.A.S. Whittle, J.F. Pâris, A. Amer, D.D.E. Long and R. Burns, “Using Multiple Predictors to Improve the Accuracy of File Access Predictions,” In Proc. of the 20th IEEE/11th NASA Goddard Conf. on Mass Storage Systems and Technologies (MSS), pp.230-240, San Diego, US-CA, Apr. 2003. J.Griffioen and R.Appleton, “Reducing File System Latency using a Predictive Approach,” In Proc. of the USENIX Summer 1994 Tech. Conf., Boston, US-MA, Jun. 1994. J. Matthews, S. Trika, D. Hensgen, R. Coulson and K. Grimsrud, “Intel Turbo Memory: Nonvolatile Disk Caches in the Storage Hierarchy of Mainstream Computer Systems,” ACM Trans. on Storage, vol.4, no.2, article 4, May. 2008. L.Yu, G.Chen and J.Dong, “Mining Infrequently-Accessed File Correlations in Distributed File System,” In Proc. of the Joint Conf. of the 9th Asia-Pacific Web Conf. and the 8th Int'l Conf. on Web-Age Information Management (APWeb/WAIM), pp.630-641, Huang Shan, China, Jun. 2007. S.W. Schlosser, J. Schindler, S. Papadomanolakis, M. Shao, A. Ailamaki, C. Faloutsos and G. R. Ganger, “On multidimensional data and modern disks,” In Proc. of the 4th USENIX Conf. on File and Storage Technologies (FAST’05). T. Johnson and D. Shasha, “2Q: A Low Overhead High Performance Buffer Management Replacement Algorithm,” In Proc. of the 20th Int'l Conf. on Very Large Data Bases (VLDB), pp.439-450, Santiago, Chile, Sep. 1994. V.Vellanki and A.L.Chervenak, “A Cost-Benefit Scheme for High Performance Predictive Prefetching,” In Proc. of the 1999 ACM/IEEE Conf. on Supercomputing (SC), Portland, US-OR, Nov. 1999. X. Ding, S. Jiang and F. Chen, “A Buffer Cache Management Scheme Exploiting Both Temporal and Spatial Localities,” ACM Trans. on Storage, vol.3, no.2, article 5, Jun. 2007. Y. Won, H. Chang, J. RYU, Y. Kim and J. Shim, “Intelligent Storage: Cross-Layer Optimization for Soft Real-Time Workload,” ACM Trans. on Storage, vol.2, no.3, pp.255-282, Aug. 2006. Z.LI, Z.Chen and Y.Zhou, “Mining Block Correlations to Improve Storage Performance,” ACM Trans. on Storage, vol.1, no.2, pp.213-245, May 2005. ਄ ↰ 㜞 ᓼ 㧘ᐔ ᚻ ാ ቝ 㧘ጊ ฬ ᣧ ੱ 㧘 ̌ࠪࠬ࠹ࡓࠦ࡯࡞࡟ࡌ ࡞ߩࠕࠢ࠮ࠬࡠࠣࠍ↪޿ߚ࠺ࠖࠬࠢࠕࠢ࠮ࠬࡄ࠲࡯ࡦ ࡑ ࠗ ࠾ ࡦ ࠣ 㧘̍ᣣ ᧄ ࠺ ࡯ ࠲ ࡌ ࡯ ࠬ ቇ ળ ⺰ ᢥ ⹹ 㧘vol.7, no.1, pp.145-150, Jun. 2008. OSDL - OSDL Database Test 2, http://old.linux-foundation .org/lab_activities/kernel_testint/osdl_database_test_suite /osdl_dbt-2/. Transaction Processing Performance Council, http://www .tpc.org/..

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