  Financial exchanges are increasingly moving their operations to the public
cloud. This migration presents challenges because of the extreme networking
requirements of an exchange. Exchanges require a low latency multicast service
to disseminate market information to all market participants (MPs)
simultaneously. Fair or simultaneous delivery of data is necessary for fair
competition in the market as MPs often compete on how fast they can react to a
piece of information. Furthermore, exchanges need a mechanism for scalable
order submission by MPs, which at times show a bursty behavior. Bursty order
submission can lead to excessive packet losses, and naive remedies may increase
orders latency. The lack of switch multicast in the cloud, varying latency
between VMs, and limited control over the underlying network fabric make it
difficult for a cloud tenant to realize an exchange's requirements.
  We design and implement Jasper, a first of its kind scalable cloud-hosted
financial exchange. Jasper consists of two major components: (i) a low latency
overlay multicast service, and (ii) a scalable order submission mechanism. The
multicast service minimizes latency and its variance in the cloud and achieves
simultaneous delivery of data. For order submission, Jasper implements a
special priority queue, FancyPQ, that helps achieve high throughput for an
exchange and keeps the latency of orders low during periods of bursts. Further,
Jasper leverages confidential computing capabilities to define a security
boundary between an exchange and market participants. Jasper achieves better
scalability and 50% lower latency than the multicast service provided by AWS.
FancyPQ increases the throughput of exchange by up to 150% and lowers the
latency of orders by up to 99.9% during periods of bursts.
