Chapter 2. Related Works
2.2 Economic Models
The Grid Economy takes the concept model generated in human economy as a referral.
Based on this concept model, many Economic Models are used as job scheduling strategies.
Economic Models are divided into two categories, the price-based-model and non-price-based-model. Under the non-price-based-model, users share the resources together to reach their goals. However, under price-based-model, money system is existed and the users pay money according as different needs. Economic Models have various transaction systems as shown in Figure 2.3[5, 10, 17, 26].
Figure 2.3 Economic Models [10, 26]
The non-price based economy models are the Game theory and the Community/Coalition/
Bartering Models. The Game theory takes self-regard as the principles, which means users take the best plans that are most beneficial and reasonable for them. The Community/Coalition/Bartering Model, however, takes all knowable resources into account and makes use of them. It’s the resource sharing between the communities. There are many price-based-model but none of them have been considered the best one even thought these economy models have been broadly discussed and used in resource distribution and management. We’re going to introduce all the price-based-model in below.
1. The commodity Market Model: The resource provider offers competitive resource price and announce service information. The resource price may be statically or floated adjusted, which means users purchase from the published resource price only, therefore, there is no communication and coordination between the user and the resource provider.
Non-Price based
2. The Posted Price Model: similar to the commodity market model. Under this model, the resource provider sets up the lower resource price and special premium condition, such as the special offer time period or great deal purchase policy, to attract certain users and raise the utility rate of resource. In this model, the user doesn’t need to communicate with the resource provider as we mentioned in the Commodity Market Model.
3. The Bargaining Model: The resource provider negotiates the resource price and using time with the user under this model. The transaction is made once the agreement which could obtain the maximum benefit has been reached between them.
4. The Tendering/Contract-Net model: The user asks many resource providers to appraise the resources and choose a resource provider that offers the lowest expense as the transaction partner according to the deadline and the budget.
5. The Auction Model: There are One-to-Many and Many-to-Many models in Auction.
Under the One-to-Many model, once the resource broker starts the initial bidding, other user brokers would participate in the auction and start bidding. The English auction, the Dutch auction, the first-price Sealed-bid auction and the Vickrey auction (second-price auction) are counted in these kinds of auction models.
z The English Auction：The resource provider accepts many users to participate the auction. The user made the highest bidding wins the auction. After the auction, the user acquires the right to use the resource. Therefore, under this model, the resource broker has to use the strategy to make the appropriate price according to the user’s deadline and budget.
z The First-price sealed-bid auction：Users bid without knowing the auction price.
The one with the highest bidding obtains the right to use the resource. Therefore, the best strategy for each user is bidding the price lower the real price of the
resource. However, they still have to wait until the auction is over to know if they acquire the right to use the resource.
z The Vickrey (Second-price sealed-bid) auction[32]：Similar to the First-price sealed-bid auction, users send out their price under the situation they don’t know others prices. When the auction is over, the user with the highest bidding acquires the right to use the resource. However, the amount the user has to pay is the second high price.
z The Dutch Auction：Opposite to the English auction, the resource provider makes an initial resource price. If certain user thinks it is a reasonable price, he/she will bid and acquire the right to use the resource. If no user bid to purchase, resource providers would ask again when they drop the price next time. During the auction, these actions would be repeated until there is a user willing to bid and acquire the right to use the resource. If there is no user makes bidding before the auction time, the auction would be end. The economics models above have the same behavior that the user with the highest bidding obtains the right to use the resource.
In figure 2.3, the double auction in Many-to-Many model is the auction model in most common use. Under this model, users and resource providers are in opposing positions. There are two double auctions, the continuous double auction (CDA) and the periodic double auction (PDA). Under the CDA model, users can bid the prices anytime. However, users bid the prices in fixed time under the PDA model. If the user misses the bidding time, he/she could join the auction in the next auction time.
There is also the Proportional Resource Sharing Model in the Many-to-Many model. The resources allocated to each user are in the direct proportion with the prices they bid. For example, if certain user needs more resources to computing the job, he/she must bid more
amount of the price to obtain higher proportion of the resource [14].
Nowadays, various discrete computing systems take different strategies to allocate the resources. For example, Nimrod-G uses the commodity market model, the posted price model, the bargaining model and the monopoly/oligopoly model to formulate job scheduling algorithm; Condor [15] and SETI@Home [28] use the community/coalition/bartering mode;
Mariposa uses the bargaining model and the tendering/contract-net model [7].
Resource providers and users may choose more than one market economy model in order to reach their individual maximum economic utility. Sometimes, they would also combine different models. In this study, we use the First-price sealed-bid auction model in An Auction Model combined with the A Bid-based Proportional Resource Sharing Model to establish the transaction model. Each auction period, users would bid the appropriate price to acquire the resource proportion. Resource providers allocate different proportion of resources to users by using the proportion share model according to their bidding prices. If users wishe to obtain more resources, they have to bid higher prices to reach their goals.
There are many factors in making the resource price, for example, the peak or off-peak time; the longer or shorter time for the user to use the resources; the frequency and the loyalty of the user; the past consuming history; using the recourses on the weekdays or weekends.
Since these factors could be the standard to make the resource price, it does increase much elasticity.
Moreover, budget, deadline and resource costs are the standards that are most frequently used for selecting the strategies. Except these three variables, there are other variables which could be taken into account for formulating more detailed algorithm to reach the goal. For example, setting the priority of the users, the network bandwidth of the resources, even the reliability of the resources are the variables to be considered. However, the algorithm would
become more complicated if we consider more variables [8].