Post on 25-Feb-2016
description
Virtual Workspaces in the GridKate Keaheykeahey@mcs.anl.gov
Argonne National Laboratory
Ian Foster, Tim Freeman, Xuehai Zhang, Daniel Galron
09/01/05 Kate Keahey, Europar 2005
The Grid Metaphor
How do we store energy?
How do we charge for energy?
How do we reliably deliver energy?
What happens if a power station fails?
How do we ensure quality of service?
What elements make for a safe and efficient power Grid?
How do we make sure that supply meets demand?
Grid Computing is much harder: heterogeneous and multi-dimensional
09/01/05 Kate Keahey, Europar 2005
The Missing Link in Grid Computing We need to define mechanisms for and dynamic
deployment and management of remote environments
Ideal environment is deployed
magichappens
Requirements: Flexibly define an environment
The more we can customize it, the more useful it is Deploy and manage such environments
Can such environments be deployed securely? How fast/dynamic can this deployment be? How can I control resources allocated to such an environment?
Dream up an ideal environment
09/01/05 Kate Keahey, Europar 2005
Virtual Workspaces Virtual Workspaces: environments that can be made
available dynamically the Grid with well-understood properties
Examples: A TeraGrid node with well-defined software environment
and adjustable access and sharing policies A physical cluster booted to a desired configuration (e.g.
Cluster on Demand) An “ATLAS node” dynamically configured using Pacman A virtual machine configured to represent a specific
environment whose resource consumption can be controlled
09/01/05 Kate Keahey, Europar 2005
Virtual Machines as Workspaces Virtual Machines
Highly customizable software configuration Enforcement properties
Grid 2004 paper: “Dynamic environments in the Grid” F. Cappello & lab: Comparison of different hypervisors
Pausing, serialization, migration Performance:
L X V USPEC INT2000 (score)
L X V ULinux build time (s)
L X V UOSDB-OLTP (tup/s)
L X V USPEC WEB99 (score)
0.00.10.20.30.40.50.60.70.80.91.01.1
SOSP 2003 paper: “Xen and the Art of Virtualization”
09/01/05 Kate Keahey, Europar 2005
Workspace Template Aspects Environment Aspect (workspace meta-data)
Generic information Name, time to live, etc.
Software partition information Software description: OS, “OSG configuration”, “application partition”, etc. Software meta-data is bundled with the actual software and attested by its
issuer Services: ssh, GRAM, pre-configured job Deployment independent
Resource allocation request (deployment time) Memory, disk, networking, etc.
See GGF JSDL standard On deployment the actual resource allocation information
becomes available
09/01/05 Kate Keahey, Europar 2005
Atomic Workspaces and Virtual Clusters
Atomic workspace One or more homogeneous workspaces
The only differences are in names Cluster/aggregate workspace
A set of interdependent heterogeneous workspaces
Example: a headnode and a set of worker nodes Interdependencies of metadata are
expressed through tags and pointers
09/01/05 Kate Keahey, Europar 2005
Deploying Workspaces in the Grid
Define workspace environment
Manage workspace
Negotiate workspace deployment characteristic
WorkspaceWizard
(VW Factory)
Workspace Management
Service(VW Repository)
Workspace Service
(VW Manager)
request a workspace
workspace meta-data
manage workspace environment
workspace metadata
Workspace
terminate workspace deployment
negotiate workspace deploymentmanage/monitor/renegotiate workspace deployment
manage activities within the workspace
09/01/05 Kate Keahey, Europar 2005
Current Implementation Current prototype using Globus Toolkit 4
Leveraging standard Grid Service features such as lifetime management
Workspace Wizard Returns workspace meta-data Very rudimentary implementation
Workspace Serivce Create: takes workspace meta-data and a deployment
descriptor Manage:
renegotiate resource allocation (moving towards a WS-Agreement model) Also traditional Grid Service management: TTL, etc.
Destroy Different options: pause, shutdown or destroy
09/01/05 Kate Keahey, Europar 2005
How dynamic is the deployment? Automatic
Protocol-based Moving towards better articulation of migration Renegotiation of resource allocation
How fast is this deployment? Deployment of workspace for EMBOSS suite:
Manual: ~45 minutes Based on pre-configured Vmware VMs: ~6 minutes Based on pre-configured Xen VM: < 1 second
How much overhead does workspace deployment add over what we have today?
09/01/05 Kate Keahey, Europar 2005
Workspace Service: Individual Workspaces
Using a paused VM allowed us to “save” on initiation time
8
8
8
0.7
0.7 1.7
0.8
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0 2 4 6 8 10 12
a)
b)
c)
job startup scenario
time (in seconds)
VM setup
VM boot
job setupGRAM job
a) GRAM job executionb) GRAM job execution in a paused Xen VMc) job execution in a booted Xen VM (pre-configured job)
09/01/05 Kate Keahey, Europar 2005
Workspace Service: Virtual Clusters
09/01/05 Kate Keahey, Europar 2005
Deploying Workspaces Across Technologies
Basic node configuration (+/-boot from image) Cluster on Demand, PXE, bcfg On the order of many minutes (~30 minutes)
Refining configuration, creating access Dynamic account with workspace service: < 1s
(mostly GT4 request processing time) Refining Installation: ~2 hours to configure an ATLAS
node using Pacman Virtual machines
Deploying images Xen: ~100 ms VMware Workstation: ~ several seconds
09/01/05 Kate Keahey, Europar 2005
Nested Workspaces
Physical machineprocure hardware
program program program
…VM
Hypervisor/OSdeploy hypervisor/OS workspace
VM VMdeploy VM workspace (with hypervisor/OS)
09/01/05 Kate Keahey, Europar 2005
Computational Grids
Hypervisor 1 Hypervisor 2 TeraGrid Configuration
Grid Power Station
Grid Protocols
Clients
09/01/05 Kate Keahey, Europar 2005
Conclusions We need mechanisms for dynamically deploying and
managing environments in the Grid Workspaces are a fundamental building block of a Grid
environment Workspaces are implemented using wide variety of
technologies VMs are a highly promising one: a “computon” for the Grid
Workspace aspects Deployment-independent environment definition Deployment-time policy and enforcement negotiation
Many challenges remain Security and deployment issues Protocols, protocols, protocols Leveraging the opportunities