Highlights
AssessGrid is software!
Methods and algorithms elaborated in the projects are put into action in software for Risk Management. The project released its first prototype in fall 2007. The second prototype was delivered during summer 2008. Final result of the project was available in February 2009.
As it is intended for reuse in other projects, the project also provides separately the Negotiation Manager for WS-Agreement protocol.
All the source code is released as Open Source under Apache V2 license.
Web portal of the 2nd prototype
The AssessGrid portal offers the possibility to design and negotiate SLAs for jobs running in a Computational Grid. The portal offers features to create and edit applications or workflows. Once a job definition has been created, it can be inserted in an SLA which is used for the negotiation with Grid brokers and Grid providers.
Within the design phase, users can specify arguments of the application, target resources, as well as input and output files. Input/Output files can be stored on any file server available in the Internet – the executing Grid provider transfers the files without any need of user interaction.
Since in the AssessGrid testbed all providers are using the planning-based scheduler OpenCCS, the execution time of the application must be specified. All this information will be used by the Grid provider to schedule the execution on the correct number of resources.
Workflow jobs
The 2nd prototype enables to design workflow jobs consisting of several tasks to be performed. The workflow editor in the portal enables to define dependencies of tasks and create arbitrary workflows (loops and conditionals are not yet considered). Data transfers between several sub-tasks are performed automatically without any interaction of the user.
SLA Negotiation
Once the desired application definition has been stored on the portal, the user can start the SLA negotiation. The first step is to define an SLA request by setting price and penalty fee as requested for this application. Since time constraints are crucial, the user can specify the latest completion time of the job (here defined as 7th October 2008 – 18:54). In the example, the user has specified a maximum Probability of Failure (PoF) of 1% implying that an SLA fulfilment is very important for his business. The lower this figure, the most likely the job will succeed, but the higher the price.
The SLA request is sent to several providers at once in order to get different quotes for SLA provisioning.
In the example below, both quotes have the penalty fee as requested in the SLA request. The prices for executing the job differ for provider_2 and provider_3. The PoF published by the provider may be inaccurate (on purpose or due to bad estimation). That’s why the user can ask the broker to adjust the PoF – an independent 3rd party opinion supports that users know an accurate PoF estimation. In the example, the user only requested the broker for an independent PoF estimation of provider_2’s SLA quote.
By clicking on “Detail” in the offer overview, the user can take a detailed look at the SLA. In AssessGrid SLAs are defined according to the WS-Agreement specification specification from the GRAAP group - here is an example of such an SLA. If the user is satisfied with one SLA offer, he can accept it which initiates the contract conclusion with the provider.
Monitoring
SLAs which have been signed by users and providers can be monitored in the portal. The portal provides an overview of the status and key information of all SLAs signed. The user can archive SLAs or group SLAs according to different characteristics in order to reduce and organize the view.
For each SLA detailed monitoring information is available. The monitoring overview shows the main contract data as well as the current state. If the SLA provisioning has been successful, the user can download the output files directly from the portal.
