Spin Server Usage Example

The following diagram (see next page) shows the exchange of messages over time between a participant and Cboe’s Multicast Top feed and Spin Server.

At time 1, the participant has no state of the book and desires to become current. The participant caches the received Multicast Top messages (sequences 310172 and 310173) for later use. Since the participant has no book, they cannot yet be applied.

At time 5, the participant has successfully logged into the Spin Server and has cached another message, sequence 310174.

At time 7, the participant receives a Spin Image Available message which indicates that the spin server is capable of giving them a spin of all symbols as of sequence 310169. The participant does not have all messages cached after 310169 (they are missing 310170 and 310171), so this spin is not useful to the participant.

At time 10, the participant receives a Spin Image Available message which is useful since it would be a spin of all orders up to and including sequence 310175 and the participant has all messages after 310175 cached.

At time 11, the participant sends a Spin Request for all messages up to and including 310175 and continues to cache Multicast Top messages received.

At time 14, the Spin Server acknowledges the Spin Request and indicates that three symbols will be sent.

At time 24, the spin server indicates that it has finished sending all open orders. The participant must then apply the cached messages from sequence number 310176 through current.

Note: Spin Servers are available for each unit. Participants may need to employ multiple Spin Servers depending upon their architecture.