Improving Agility and Elasticity in Bare-metal Clouds. Yushi Omote, Takahiro Shinagawa, Kazuhiko Kato University of Tsukuba, The University of Tokyo

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1 Improving Agility and Elasticity in Bare-metal Clouds Yushi Omote, Takahiro Shinagawa, Kazuhiko Kato University of Tsukuba, The University of Tokyo 1

2 Bare-metal Clouds An IaaS for high performance and device functionality User transparent No Virtual Machine Physical Provider Machine 2

3 -deployment Problem Long wait time sacrifices agility and elasticity (1) Image Copy (2) Reboot from Local Disk (Tens of minutes) (A few minutes) Installer User User Image Image Image Server 3

4 Existing Approach 1 Streaming Deployment [Clerc et al. IPCCC 10] Image Server User Special Driver Network Boot + Background Copy Agility and Elasticity Performance -specific drivers are required. transparency 4

5 Existing Approach 2 Conventional s [VMware 01, Xen 03, KVM 07] User Streaming deployment with s Image Server Agility and Elasticity transparency Continuous virtualization overhead Performance 5

6 Deployment with a Special-purpose 1) Streaming deployment 2) Seamless de-virtualization Agility and Elasticity transparency Performance User User 6

7 Challenge Expose & Control Physical Devices Virtual Devices? Direct I/O? Control I/Os Expose physical interface 7

8 Device-interface-level I/O mediation A device mediator performs: Device Driver Device Mediator (1) I/O interpretation to understand I/O context (2) I/O redirection to perform network booting (3) I/O multiplexing to perform background install Physical device interface 8

9 I/O Interpretation Determine when/how to mediate I/O requests Device Driver Device Mediator Understand state transitions based on monitoring I/O Device State Transitions 9

10 I/O Redirection Data LBA=4 NUM=8 (1) Interpret Image Server (2) Redirect LBA=4 NUM=8 Small Request Interrupt (3) Restart Disk 10

11 I/O Multiplexing Status Check Request (1) Request Request Idle State Image Server (2) Emulate (3) Queue Disk 11

12 CPU/Memory Virtualization for De-virtualizable CPU Memory Guest Physical Address = Physical Address No indirection runs passively with VMX No guest scheduling 12 Identity Mapping exposes physical memory Mark regions as reserved (via BI INT15/e802)

13 De-virtualization (1) Turns off IO VM exits (2) Turns off nested paging (3) Turns off CPU virtualization Device Driver H/W Find safe I/O timing Unsynchronized TLB flush 13 Ease VM exits condition (VMXOFF Issue)

14 Performance Evaluation Deployed 32-GB Image (Ubuntu bit) -startup Time Cassandra Throughput A HPC Cluster Storage Throughput InfiniBand Latency Intel Xeon X5680 (3.33 GHz) / 96GB RAM HDD 500GB/7200 RPM SATA Mellanox InfiniBand (4X QDR) Intel EM GbE Network Card 14 Interconnected by A Mellanox Grid Director InfiniBand Switch & A FUJITSU SR- S348TC1 GbE Switch

15 -startup Time Image Copy Reboot+Firminit. Boot Boot Image Copy Proposed Streaming (NFSRoot) VM Streaming (KVM/NFS) Quick start up (8.6 times faster) Elapsed Time (sec) 15

16 Cassandra Throughput (Throughout Deployment) Proposed KVM (No Background Install) % of Baremetal 120% 110% 100% 90% 80% 70% Seamless de-virtualization Elapsed Time (sec) Eventual bare-metal performance 16

17 Storage Throughput Read Write Throughput (MB/sec) Bare-metal performance Bare-metal Deploy Devirt KVM/Local 17

18 InfiniBand RDMA latency 1.70 Bare-metal performance 1.61 Latency (usec) Baremetal Deploy Devirt KVM/Pass 18

19 Conclusion Improved agility and elasticity in bare-metal clouds De-virtualizable with streaming deployment Device-interface-level I/O mediation Achieved quick startup of an 8.6 times faster than image copy Preserved high performance & -transparency 19

20 Future work Generating device mediators from specification Reduce development cost of device mediators More advanced features of IaaS clouds Live migration and checkpointing 20

21 Thank you 21