CloudStack Architecture Future

Sheng Liang, CTO Cloud Platforms, Citrix Systems

July 21, 2012

API Layer EC2 CloudStack

Access control

Orchestration

Engine

Plug-in

Framework

Message Bus

XenServer Resource

KVM Resource

SRX Resource

NetScaler Resource

Other Resources

Resource Management

VR CP

VM

SS

VM

vSphere Resource

Plug-ins

(for storage,

networking,

hypervisor,

etc.)

System VM

Framework

Event Framework

Users

Object Storage

AWS-style Availability

Zone

AWS-style Availability

Zone

AWS-style Availability

Zone

Future: CloudStack storage

CloudStack Mgmt Server

• Can be configured zone-wide • Supports true EBS implementations

Primary Storage

• No longer needed zone-wide NFS server • Region-wide object store for templates, ISOs

and snapshots • Templates and ISOs cached in Primary Storage

Secondary Storage

•Apache Foundation project

•Hadoop Core includes: ᵒ HDFS - Distributed file system derived from Google File System

ᵒ Map/Reduce – Distributed compute engine

•Written in Java

•Runs on Linux, Mac OS/X, Windows, and Solaris

•Optimized for commodity hardware

Now: management server clusters, zones, and regions

Object Storage

Availability Zone

Availability Zone

Availability Zone

Primary Mgmt Server Cluster

Region 1

Standby Mgmt Server Cluster

Data Center

Data Center

Data Center

DR

Object Storage

Availability Zone

Availability Zone

Availability Zone

Primary Mgmt Server Cluster

Region 2

Standby Mgmt Server Cluster

Data Center

Data Center

Data Center

DR

Future: management server cluster per zone

Object Storage

Availability Zone

Availability Zone

Availability Zone

Mgmt Server Cluster

Region 1

Mgmt Server Cluster

Data Center

Data Center

Data Center

Object Storage

Availability Zone

Availability Zone

Availability Zone

Mgmt Server Cluster

Region 2

Mgmt Server Cluster

Data Center

Data Center

Data Center

Mgmt Server Cluster

Mgmt Server Cluster

• Implement rigorous state machines for all operations

• Customizable workflow engine

• Enhance plug-in framework ᵒ Storage plug-in

• Stateless, recreatable, and restartable

• CloudStack manages auto-scaling of System VMs

• System VMs may be dedicated (e.g., virtual router) or shared (SSVM

and CPVM)

• Potentially expose System VM framework to 3rd-party VMs? ᵒ NetScaler VPX

ᵒ User VM

… … …

CloudStack Compute Nodes

S3 API VM

S3 API VM

S3 API VM

Object Store (e.g., NetApp, Hadoop, Cloudian)

S3 API

NFS, CIFS, HDFS, 3rd-Party Object

Store API, …

• Clean up access control code

• API servers run as a separate service ᵒ Running in System VM

• Built on message bus

• Treats management server DB as the desired state

• Some downsides: ᵒ Prevents use of native virt mgmt tools

ᵒ Bugs could cause disastrous results (like stopping/destroying guest VMs)

• An alternative model: CloudStack functions as a virt admin user,

enabling super admin to use native virt mgmt tools

Future model

ESXi Cluster vCenter

CloudStack Mgmt Server

Admin

Userh

XenServer Cluster

Hyper-V Cluster

vCenter Client

XenCenter

Systems Center

• Register existing virt clusters

• CloudStack must assume any of the underlying networks, storage,

hosts, and VMs can change state any time

• Expose additional virt mgmt capabilities as cloud API

Object Storage

AWS-style Availability

Zone

AWS-style Availability

Zone

AWS-style Availability

Zone

Manage existing server virt clusters

Existing Server Virt

Clusters

Existing Server Virt

Clusters

CloudStack Region

Work better. Live better.