Introduction
Cloud Exchange (CEx) serves as a market maker, bringing service providers and users together. The University of Melbourne proposed it under Intercloud architecture (Cloudbus). It supports brokering and exchanging cloud resources for scaling applications across multiple clouds. It aggregates the infrastructure demands from application brokers and evaluates them against the available supply. It supports the trading of cloud services based on competitive economic models such as commodity markets and auctions.

Global exchange of cloud resources
Source: https://snscourseware.org/snsctnew/files/1583815568.pdf
Now we will talk about various entities of the Global exchange of cloud resources.
Introduction to Cloud Computing
Entities of the Global exchange of cloud resources
Now we will talk about the various entities of the global exchange of cloud resources.
Market directory
A market directory is an extensive database of resources, providers, and participants using the resources. Participants can use the market directory to find providers or customers with suitable offers.
Auctioneers
Auctioneers clear bids and ask from market participants regularly. Auctioneers sit between providers and customers and grant the resources available in the Global exchange of cloud resources to the highest bidding customer.
Brokers
Brokers mediate between consumers and providers by buying capacity from the provider and sub-leasing these to the consumers. They must select consumers whose apps will provide the most utility. Brokers may also communicate with resource providers and other brokers to acquire or trade resource shares. To make decisions, these brokers are equipped with a negotiating module informed by the present conditions of the resources and the current demand.
Service-level agreements(SLAs)
The service level agreement (SLA) highlights the details of the service to be provided in terms of metrics that have been agreed upon by all parties, as well as penalties for meeting and failing to meet the expectations.
The consumer participates in the utility market via a resource management proxy that chooses a set of brokers based on their offering.SLAs are formed between the consumer and the brokers, which bind the latter to offer the guaranteed resources. After that, the customer either runs their environment on the leased resources or uses the provider's interfaces to scale their applications.
Providers
A provider has a price-setting mechanism that determines the current price for their source based on market conditions, user demand, and the current degree of utilization of the resource.
Based on an initial estimate of utility, an admission-control mechanism at a provider's end selects the auctions to participate in or to negotiate with the brokers.
Resource management system
The resource management system provides functionalities such as advance reservations that enable guaranteed provisioning of resource capacity.