> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ionq.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Platform Systems

> An overview of some of the systems that make up the IonQ Quantum Cloud Platform

## Queue Manager

Jobs are managed through a *[fair-share](https://en.wikipedia.org/wiki/Fair-share_scheduling) style*, weighted scheduling system. When a job is submitted, queue manager places it in the appropriate *allocation group* based on its parent organization. As jobs are pulled from the queue to be sent to the QPU, the queue manager cycles through each of those groups over a set duration for each.

<Frame caption="Pictured: The Queue Manager places a new job in the appropriate group, then the QPU dynamically distributes available time across groups in order for a set amount of time.">
  <img src="https://mintcdn.com/ionq/KP8cXNscCAA57Ku7/user-manual/media/fair-share-trans.png?fit=max&auto=format&n=KP8cXNscCAA57Ku7&q=85&s=3948d8859f67e97ae52efb6128870147" alt="Fair share" width="2105" height="1096" data-path="user-manual/media/fair-share-trans.png" />
</Frame>

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## Reservations

Reservations are a period of *exclusive access* to the QPU during a pre-scheduled block of time. These are offered to support large runs of jobs or for timing-sensitive hybrid runs. During this period, the [Queue Manager](#queue-manager) modifies its allocation groups so that it will only retrieve jobs from the organization specified in the reservation configuration.

Reservations are typically scheduled for blocks no-shorter than 1 hour, only available to customers with an existing contract, and can be scheduled by contacting [support@ionq.co](mailto:support@ionq.co).

<Info>
  Braket customers can also make reservations directly through the Braket console. [Learn more](https://docs.aws.amazon.com/braket/latest/developerguide/braket-reservations.html)
</Info>

***

## **Learning More**

*This list is not exhaustive and our systems evolve constantly. If you have additional questions about our software stack or Platform systems, do not hesitate to reach out [in Slack](https://join.slack.com/t/ionqcommunity/shared_invite/zt-2ohj4fkvb-ErVKebhkwaP7S~lt2Gq0_w) or via [support@ionq.co](mailto:support@ionq.co) .*