From Sandbox to Playground: Virtual Environments and Quality of Service in the Grids Kate Keahey Argonne National Laboratory

IEEE Fox Valley SubsectionKate Keahey What are Grids? l Power Grid analogy: remote computing power can be accessible from your laptop in much the same way as electricity is delivered to your home

IEEE Fox Valley SubsectionKate Keahey How do Grids work today? l From Grid Services… u Discover remote resources u Start jobs on remote resources u Authenticate and authorize users and other entities u Transfer data u Globus Toolkit: a de facto standard in Grid technologies l … to commodity Grid usage u Combining and automating the use of basic Grid services u Utility computing paradigm u Provide reliable, adaptive, QoS-based execution of specific tasks

IEEE Fox Valley SubsectionKate Keahey Grid Capabilities Today Access Grid: enable people, presentation software and programs to interact Data Grid: combine distributed data and access storage within one similation Computational Grid: use access to powerful resources to run a genome analysis service Experiment Grid: combine multiple technologies in support of an experiment

IEEE Fox Valley SubsectionKate Keahey First, a little bit of theory… Resource sharing & coordinated problem solving in dynamic, multi-institutional virtual organizations Single sign-on creates a decentralized Grid domain within which Grid entities can act on behalf of the user

IEEE Fox Valley SubsectionKate Keahey …now practice Grid clients create environments More resources per user, more users per resource, more environments per resource…. How do we scale? Application developers obtain the right configuration Grid administrators resolve conflicts!

IEEE Fox Valley SubsectionKate Keahey What do we need? l Quality of Service u Sandbox a Grid computation u Reliable enforcement of policy-driven resource usage u Applications in experimental sciences, fair resource sharing, etc. l Quality of Life u Dynamic capabilities l Dynamically creating and managing remote execution environments l Dynamically configuring such environments l Easily moving in a Grid as resources come and go u Automated, hands-off Grid infrastructure

IEEE Fox Valley SubsectionKate Keahey How do we satisfy those needs? l Dynamic behavior: missing services u Creating and managing remote execution environments dynamically u Customizing such environments l Ontologies and protocols u Standardized descriptions can be processed dynamically by various Grid entities u Policy-adapting protocols will equip the system with ability to respond to needs automatically l Tools to obtain descriptions of these things easily and automatically

IEEE Fox Valley SubsectionKate Keahey Virtual Workspaces Virtual resource configuration Protection and enforcement environment Software and file configuration state Execution state Virtual Workspace Grid Middleware Interface Grid client Interface Grid clients Grid middleware interface l VWs are represented by an ontology description u Potentially integrating community policy l They can be implemented using different technologies l They can be customized to the user needs and deployed in the Grid

IEEE Fox Valley SubsectionKate Keahey Properties of Virtual Workspaces l Dynamic creation u Inherent property of Grid computation u Avoiding a maintenance nightmare (automate administration) and potential security hazard l Dynamic configuration u To reflect changing policies in the Grid (implement agreements) l Strong protection environment u Otherwise users wont trust sites and sites wont trust users l Fine-grain enforcement l Configurable architecture, software, environment u Application software/libraries/licenses u Configurable environment u Running 32-bit programs on 64-bit architectures u Running a required version of the OS (Fedora vs. RH9) u Potentially even execution state

IEEE Fox Valley SubsectionKate Keahey VWs in the Grids Client request VW EPR inspect and manage deploy & suspend use existing VW Create VW VW Factory VW Repository VW Manager create new VW Resource VW start program

IEEE Fox Valley SubsectionKate Keahey VW Services l Factory u Creates VW in terms of the implementation l e.g., VM image, pacman chache+ u May create based on an already created VW u Writes/configures access policy u May allow negotiation l VW Repository u Access to state describing a VW u Allows inspection, management, implementation-specific termination, potentially renegotiation, etc. u Soft-state lifetime management ensures termination l VW Manager u Lightweight infrastructure deploying VMs

IEEE Fox Valley SubsectionKate Keahey How can I obtain VWs? l Through automatic negotiation and establishing agreements with the community l What is an agreement? u Relationship between parties l dynamically-established and dynamically-managed u Terms l Functional, e.g., a service I can perform l Non-functional, e.g., performance, availability, etc. l Noteworthy Agreement Properties u Simple, decentralized way of expressing aggregate or proprietary policies in the system u Allow providers to gauge demand u Ephemeral, periodic, fine-grained, modifiable policy l WS-Agreement, GRAAP-WG, Global Grid Forum u Currently under public comment: see

IEEE Fox Valley SubsectionKate Keahey Implementing and Configuring Virtual Workspaces l Potential Implementation Groups u Unix accounts and Unix account tools l setrlimit, DSRT, chroot, chown, and others u Sandboxes l VServer, protection and fine-grain enforcement u Virtual Machines l VMware, Xen, and others l Deployment & configuration tools u Pacman & pacman cache l See also: u Grid 2004: From Sandbox to Playground: Dynamic Virtual Environments in the Grid

IEEE Fox Valley SubsectionKate Keahey Comparing VW Implementations l Unix accounts u Pros: efficient, ubiquitous u Cons: very limited functionality u Needs to be used in conjunction with other technologies l Pacman, additional system enforcement tools u Prototype available (GT 3.2) l u Currently on the way to become a GT4 service l Sandboxes u Pros: efficient, fine-grain enforcement, typically very lightweight u Cons: limited state enforcement u Need to be used in conjunction with other technologies

IEEE Fox Valley SubsectionKate Keahey Comparing VW Technologies (cntd) l Virtual Machines u Pros: l Flexibility (run linux on linux, 32 on 64-bit, etc.) l Enhanced security, audit forensics, etc. l Great user state management l Freezing/migration l Customized environment l A promising distribution/deployment tool u Cons: l Potential for being less efficient (emulation) l Potential for resource overhead l Poor implementation of sharing, relatively little enforcement (but can be combined with other technologies for enforcement) l Maturity issues u The potential is excellent, but needs more work

IEEE Fox Valley SubsectionKate Keahey The Need for Speed Comparison using the Fusion EFIT application

IEEE Fox Valley SubsectionKate Keahey Other efficiency concerns l Startup time l Resource usage overhead u Memory use: VMware: 24MB + 1 MB per 32 MB memory allocated u Disk use: VMware large Table 1: DVE create/destroy times LinuxVServerVMware Create100 ms360 ms14-52 sec Destroy70 ms200 ms3-38 sec

IEEE Fox Valley SubsectionKate Keahey Enforcement Capabilities Unix accountVServerVMware CPU usage (sec)Via setrlimit()Not at present, but could be added Not enforced CPU usage (%)Not enforcedLimited: no VServer can starve another Not in VMware Workstation Disk space usageDynamically (per-user quotas) Dynamically (per context quotas) Statically (virtual disks) Memory usageNoNot at present, but could be added Statically Network usageNoDynamically

IEEE Fox Valley SubsectionKate Keahey Virtual is the New Real! l Virtual machines are a very interesting option for the Grid u Excellent usability potential: l Configurability, enhanced security, state management, replication, enforcement… l Even potential as distribution tool! u Excellent potential for optimizations u Performance, resource usage, access to specialized hardware, etc. are not so bad, especially with new technologies like Xen u Some maturity issues l Do benefits outweigh challenges?

IEEE Fox Valley SubsectionKate Keahey How does it work in practice? l Recent project: combining VMs and Grids to create a platform for bioinformatics applications l Some of the conclusions: u Use of virtual machines can significantly broaden the resource base u Saves installation time l EMBOSS installation: ~45 minutes l Deploying a 2GB VM image: ~6.5 minutes l Peace of mind: priceless! u Enforcement capabilities l Depend on the implementation but are generally better than what we have now l SC04 poster: u Quality of Life in the Grids: VMs meet Bioinformatics Applications, T. Freeman and D. Galron

IEEE Fox Valley SubsectionKate Keahey How can VWs change the Grid? l Challenges to the established Grid model u Security challenges u Networking challenges u And many, many others… l Issue of responsibility u Who vets a workspace? u Who is responsible for its good behavior? l The role of VOs is going to grow u VO might take on additional responsibilities l Administers and maintains VMs, certification authority, could potentially stop suspect VMs, is to blame if something happens… u Should the VO be a legal entity? l Do VOs have the resources to do that? u Are VOs going to become too heavyweight? l What are the trade-offs and a healthy balance?

IEEE Fox Valley SubsectionKate Keahey Virtual Playgrounds l Define a virtual Grid in terms of requirements u Virtual workspaces u Potentially networking requirements u Other services l Provide mechanisms to create a Grid l Provide services for the deployment of such virtual playgrounds on real resources l Ephemeric Grids built for a special purpose: u Family is getting together to decide when to spend Xmas u Scientists getting up a Grid for the purposes of a specific experiment run u A game tournament u A scientific simulation that gets discarded or interrrupted but can potentially be restored later l Towards a true utility computing model

IEEE Fox Valley SubsectionKate Keahey Conclusions l Addressing QoS and QoL is critical for the utility computing model of Grids u Unglamorous but necessary tasks u Combating complexity, improving scalability u Without it flexibly moving between resources on the Grid is very hard l Current technological advances make this model ever closer to reality u A breakthrough is required in terms of usability u Virtual machines fit the bill l Virtual is the new Real! l To find out more: