Optimizing Live Migration of Virtual Machines across Wide Area Networks using Integrated Replication and Scheduling

Sumit Kumar Bose, UnisysScott Brock, UnisysRonald Leaton Skeoch, UnisysNisaruddin Shaikh, UnisysShrisha Rao, IIIT-Bangalore

Agenda

Motivation and Problem Addressed

Proposed Solution

Experimental Results

Conclusion

Motivation and Problem Addressed

Migration Latency

VM Size

Threshold

Proposed Solution – CloudSpider

Proposed Solution

Hiber-waking vs

MigrationMigration Latency

VM Size

Threshold

Contd…

• Integrated replication and scheduling of VMs.– Selectively choose appropriate clouds for VM replication– Using past cost history

• However, blindly replicating VM images leads to increased storage requirements.

• Reduce overall storage requirements due to VM image replication by exploiting commonality across different VM images using de-duplication.– Past studies show that different VM images have significant

common content due to common substrates (OS, web-servers etc).

Contd…

• VM1 and VM2 images share significant similarity.

VM1

VM1

VM1

VM2

VM2VM2

Storage cost shoots up!!!!

Contd…

• Exploit de-duplication to reduce storage cost

VM1

VM1

VM1 VM2

VM2

VM2

Trade-off between storage cost and operational cost

Contd…

• The research questions that arise in such contexts are to determine the – List of eligible sites for different VM images (Replication

phase) – Placement of the replicas at different cloud sites (replication

phase)– Primary copy from among the replicas of a VM image

(Scheduling phase)

• Our primary focus is to develop efficient replication strategies for questions (i) and (ii) using our integrated VM replication and scheduling architecture

Experiments

• We implemented the replication strategy using Java.• We extended open-source CloudSim toolkit and

incorporated the replication module in it.• We experimented extensively and simulated different

scenarios using CloudSim toolkit• To evaluate the performance of the CloudSpider algorithm

we implemented the following naïve strategies: – RandomMax – RandomMin – MaxReplica– MinReplica.

Contd…

– RandomMax and RandomMin strategies, randomly selects sites from the eligible list of a VM image for placing the replicas.

– MaxReplica and MinReplica strategies select the first few sites from the eligible list of VM for creating the replicas.

• Performance criteria: The average (over 100 simulation iterations) of total storage consumed by all the replicas belonging to all the VM images.

Contd…

• Tables 3 to 9: Shows the variation in the average storage requirement by the different strategies when the following parameters is varied:– number of data-centers – number of VM images – file size – latency threshold– savings threshold

• Results: Cloudspider shows significant reduction in cost of storage requirement.

Conclusion

• To overcome migration latencies associated with moving large sized files over the low-bandwidth networks , we propose to combine VM replication with VM scheduling.

• We compensate the additional storage requirement due to the increase in the number of replicas by exploring commonalities across different VM images using de-duplication techniques.

• The proposed architecture for integrated replication and scheduling – CloudSpider – is promising.

Page 14

Q & A

QU E S T I O N S