XS Oracle 2009 Satori
- 1. Sat o r i: En ligh t e n e d Page Sh ar in g G r ze go r z M ilo s, D e r e k G . M u r r ay , St e v e n H an d , M ic h ae l Fe t t e r m an
- 2. O u t lin e • W h y sh ar e p age s? • W h y u se e n ligh t e n m e n t s? • U n iq u e se llin g p r o p o sit io n s – D u p lic at io n d e t e c t io n – Sav in gs d ist r ib u t io n – Fau lt h an d lin g • Im p le m e n t at io n • Pe r fo r m an c e r e su lt s
- 3. Page sh ar in g • Id e n t ic al O Ss sh ar e lo t s o f id e n t ic al d at a – Pr o gr am b in ar ie s – Sh ar e d lib r ar ie s – C o n figu r at io n file s • M o r e m e m o r y is alw ay s u se fu l – R e d u c e p agin g – In c r e ase p age c ac h e size – L e ss I/O , b e t t e r p e r fo r m an c e !
- 4. En ligh t e n m e n t … o r “p ar av ir t u alisat io n ” … o r “c h an gin g t h e O S” • U se in fo r m at io n fr o m t h e O S t o gu id e sh ar in g – R e d u c e s t h e o v e r h e ad • A v o id p at h o lo gic al b e h av io u r – D o u b le p agin g – H o st d e m an d p agin g • Pr o o f-o f-c o n c e p t o n L in u x
- 5. U SP 1 : d u p lic at e d e t e c t io n • Sat o r i m o n it o r s b lo c k r e ad s – H ash d at a w h e n r e ad , sh ar e p age s if id e n t ic al – B lo c k r e ad s fr o m c o m m o n su b st r at e d isk s • O t h e r sy st e m s sc an m e m o r y p e r io d ic ally – R at e lim it e d t o p r e v e n t o v e r h e ad – C an m iss sh o r t -liv e d sh ar in g o p p o r t u n it ie s
- 6. U SP 2: sav in gs d ist r ib u t io n • W an t t o e n c o u r age sh ar in g – T h e m o r e y o u sh ar e t h e m o r e m e m o r y y o u ge t – Eac h V M ge t s a sharing entitlement b ase d o n h o w m an y p age s it sh ar e s • D e flat e t h e b allo o n t o in c r e ase allo w an c e
- 7. U SP 3: fau lt h an d lin g • W h at h ap p e n s w h e n sh ar in g is b r o k e n ? – N e e d so m e m o r e m e m o r y – … b u t it ’s in u se – T y p ic ally u se h o st p agin g • M o d ify t h e O S t o n o m in at e “v o lat ile ” p age s – C le an b u ffe r c ac h e p age s – H y p e r v iso r c an r e assign t h e m w it h o u t w ar n in g – “R e p ay m e n t FIFO ” b ase d o n IB M ’s C M M
- 8. Im p le m e n t at io n • H y p e r v iso r (5351 L O C ) – B ase d o n X e n 3.1 w it h PV sh ad o w PT s – A d d e d sh ar in g-r e lat e d h y p e r c alls • D om0 (3894 L O C ) – M o d ifie d b lk t ap t o p e r fo r m h ash lo o k u p • D omU (2306 L O C ) – Po r t e d IB M ’s C M M t o X e n /x 86
- 9. O v e r h e ad s • W o r st -c ase : lar ge -c h u n k se q u e n t ial r e ad s – O v e r h e ad o f h ash in g: 0.2% – O v e r h e ad o f h ash in g + IPC : 34.8% • “R e alist ic ” b e n c h m ar k (k e r n e l c o m p ile ) – W it h o u t Sat o r i: 780 se c o n d s – Sat o r i e n ab le d : 779 se c o n d s
- 10. Effe c t iv e n e ss Kernel Compilation (256MB) 16000 14000 12000 10000 Potential 8000 Satori Pages 6000 4000 2000 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (mins)
- 11. Effe c t iv e n e ss Kernel Compilation (512MB) 30000 25000 20000 Potential 15000 Satori Pages 10000 5000 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (mins)
- 12. Effe c t iv e n e ss httperf 120000 100000 80000 Potential 60000 Satori Pages 40000 20000 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (mins)
- 13. Effe c t iv e n e ss RUBiS 30000 25000 20000 Potential 15000 Satori Pages 10000 5000 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (mins)
- 14. C o n c lu sio n s • M o r e m e m o r y m e an s m o r e p e r fo r m an c e • Page c ac h e s ar e u se fu l so u r c e s o f sh ar in g • En ligh t e n in g t h e O S av o id s h o st p agin g • Sat o r i is e ffic ie n t an d e ffe c t iv e !
- 15. Q u e st io n s?
- 16. Sat o r i: En ligh t e n e d Page Sh ar in g G r ze go r z M ilo s, D e r e k G . M u r r ay , St e v e n H an d , M ic h ae l Fe t t e r m an 1
- 17. O u t lin e • W h y sh ar e p age s? • W h y u se e n ligh t e n m e n t s? • U n iq u e se llin g p r o p o sit io n s – D u p lic at io n d e t e c t io n – Sav in gs d ist r ib u t io n – Fau lt h an d lin g • Im p le m e n t at io n • Pe r fo r m an c e r e su lt s 2
- 18. Page sh ar in g • Id e n t ic al O Ss sh ar e lo t s o f id e n t ic al d at a – Pr o gr am b in ar ie s – Sh ar e d lib r ar ie s – C o n figu r at io n file s • M o r e m e m o r y is alw ay s u se fu l – R e d u c e p agin g – In c r e ase p age c ac h e size – L e ss I/O , b e t t e r p e r fo r m an c e ! 3
- 19. En ligh t e n m e n t … o r “p ar av ir t u alisat io n ” … o r “c h an gin g t h e O S” • U se in fo r m at io n fr o m t h e O S t o gu id e sh ar in g – R e d u c e s t h e o v e r h e ad • A v o id p at h o lo gic al b e h av io u r – D o u b le p agin g – H o st d e m an d p agin g • Pr o o f-o f-c o n c e p t o n L in u x 4
- 20. U SP 1 : d u p lic at e d e t e c t io n • Sat o r i m o n it o r s b lo c k r e ad s – H ash d at a w h e n r e ad , sh ar e p age s if id e n t ic al – B lo c k r e ad s fr o m c o m m o n su b st r at e d isk s • O t h e r sy st e m s sc an m e m o r y p e r io d ic ally – R at e lim it e d t o p r e v e n t o v e r h e ad – C an m iss sh o r t -liv e d sh ar in g o p p o r t u n it ie s 5
- 21. U SP 2: sav in gs d ist r ib u t io n • W an t t o e n c o u r age sh ar in g – T h e m o r e y o u sh ar e t h e m o r e m e m o r y y o u ge t – Eac h V M ge t s a sharing entitlement b ase d o n h o w m an y p age s it sh ar e s • D e flat e t h e b allo o n t o in c r e ase allo w an c e 6
- 22. U SP 3: fau lt h an d lin g • W h at h ap p e n s w h e n sh ar in g is b r o k e n ? – N e e d so m e m o r e m e m o r y – … b u t it ’s in u se – T y p ic ally u se h o st p agin g • M o d ify t h e O S t o n o m in at e “v o lat ile ” p age s – C le an b u ffe r c ac h e p age s – H y p e r v iso r c an r e assign t h e m w it h o u t w ar n in g – “R e p ay m e n t FIFO ” b ase d o n IB M ’s C M M 7
- 23. Im p le m e n t at io n • H y p e r v iso r (5351 L O C ) – B ase d o n X e n 3.1 w it h PV sh ad o w PT s – A d d e d sh ar in g-r e lat e d h y p e r c alls • D om0 (3894 L O C ) – M o d ifie d b lk t ap t o p e r fo r m h ash lo o k u p • D omU (2306 L O C ) – Po r t e d IB M ’s C M M t o X e n /x 86 8
- 24. O v e r h e ad s • W o r st -c ase : lar ge -c h u n k se q u e n t ial r e ad s – O v e r h e ad o f h ash in g: 0.2% – O v e r h e ad o f h ash in g + IPC : 34.8% • “R e alist ic ” b e n c h m ar k (k e r n e l c o m p ile ) – W it h o u t Sat o r i: 780 se c o n d s – Sat o r i e n ab le d : 779 se c o n d s 9
- 25. Effe c t iv e n e ss Kernel Compilation (256MB) 16000 14000 12000 10000 Potential 8000 Satori Pages 6000 4000 2000 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 10 Time (mins)
- 26. Effe c t iv e n e ss Kernel Compilation (512MB) 30000 25000 20000 Potential 15000 Satori Pages 10000 5000 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 11 Time (mins)
- 27. Effe c t iv e n e ss httperf 120000 100000 80000 Potential 60000 Satori Pages 40000 20000 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 12 Time (mins)
- 28. Effe c t iv e n e ss RUBiS 30000 25000 20000 Potential 15000 Satori Pages 10000 5000 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 13 Time (mins)
- 29. C o n c lu sio n s • M o r e m e m o r y m e an s m o r e p e r fo r m an c e • Page c ac h e s ar e u se fu l so u r c e s o f sh ar in g • En ligh t e n in g t h e O S av o id s h o st p agin g • Sat o r i is e ffic ie n t an d e ffe c t iv e ! 14
- 30. Q u e st io n s? • C lic k t o ad d an o u t lin e 15