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Related work on HAMA. Related work on HAMA. Haiyang , Sun 2012.01.04. Preview. 1. 2. 3. 4. Mater-Slave Server Model. Prediction and Prevention. RAM Cloud. Modifying the hypervisor PTE. Mater-Slave Server Model. Related work on HAMA. Primary VM The VM we want to protect
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Related work on HAMA Related work on HAMA • Haiyang, Sun • 2012.01.04
Preview 1 2 3 4 Mater-Slave Server Model Prediction and Prevention RAM Cloud Modifying the hypervisor PTE
Mater-Slave Server Model Related work on HAMA • Primary VM • The VM we want to protect • Backup VM • Replicate periodically • Different strategies
Different strategies of synchronization Related work on HAMA • Deterministic path of execution • Replay input deterministically • State check-pointing • Copy the whole state
Deterministic Strategy Related work on HAMA • referred to as the state-machine approach • Replay input deterministically • The idea is to model the primary VM as deterministic state machines that are kept in sync by starting them from the same initial state and ensuring that they receive the same input requests in the same order. • [The design of a practical system for fault-tolerant virtual machines]
Deterministic Example Related work on HAMA [The design of a practical system for fault-tolerant virtual machines]
Deterministic Strategy Related work on HAMA • 10% overhead • Require less bandwidth • Drawbacks • highly architecture-specific • difficult to be used in multi-processor environment
None-deterministic Strategy Related work on HAMA • VM-based whole-system replication • The state of the primary VM is frequently recorded and transmitted to the backup server during execution. And the checkpoint information in the backup server will be used to resume system after failure. • Bandwidth and performance problem • [Remus: High Availability via Asynchronous Virtual Machine Replication]
None-deterministic example: Remus Related work on HAMA
None-deterministic example: Remus Related work on HAMA • Require more bandwidth • 50% loss in performance • Support multi-processor
More Related work on HAMA • Existing methods for primary-backup replication may disrupt the timing behavior of an underlying service to the extent of making it unusable even in the absence of faults no matter it uses active or passive replication strategies. • [Brief Announcement: The Inherent Difficulty of Timely Primary-Backup Replication] • time-sensitive services may suffer from larger jitter and unbounded delays under high load in the primary-backup replication model • Live migration • [Live Migration of Virtual Machine Based on Full System]
Related work on HAMA Prediction and Prevention
Related work on HAMA Prediction and Prevention • Pure Software error detection • Protect memory by checking various types of memory error(buffer overflow, uninitialized read, dangling) • [First-Aid: Surviving and Preventing Memory Management Bugsduring Production Runs] • Error prediction(hardware support) • Need hardware support (processor feature of Intel MCA) • Take error events and system utilization as input • Assess error risk and correspondingly manipulates memory mappings • reduce their potential damage and loss at system level • [A Rising Tide Lifts All Boats: How Memory Error Prediction and Prevention Can Help with Virtualized System Longevity]
Related work on HAMA Cloud Memory Backup • Distributed hundreds or thousands of disks are used in parallel to recover the lost data • [Fast Crash Recovery in RAMCloud]
Related work on HAMA Modifying Hypervisor • [Using hypervisor to provide data secrecy for user applications on a per-page basis] • Modifies the both the hypervisor and the kernel • It realizes the feature of protecting user application privacy by encrypting and decrypting each memory page requested depending on the application’s access permission to the page. • 3% overhead in CPU Memory-intensive workloads
Related work on HAMA THANK YOU