Exchange Host Failure and Recovery
Exchange host failure and host disconnect (discussed earlier in this chapter) are two separate and distinct events. A host disconnect refers to any disruption in network connectivity between the TFX Gateway and the exchange host, whereas an exchange host failure involves the actual failure of one or more of the trading engines that make up the exchange host.
In the event that the TFX exchange host (or trading engine) fails, all electronic traders on all ISVs lose their ability to trade on the exchange host (or trading engine). However, these traders remain electronically connected to the exchange.
When the exchange host (or trading engine) fails, it deletes all GTD orders but continues to maintain GTC orders.
Shutting Down the TFX Gateway
Shutting down the TFX Gateway during a TFX exchange host failure causes price problems. During the day, the TFX Gateway keeps a record of products’ Open, High, and Low prices. If the TFX Gateway is shut down and restarted during a TFX exchange host failure, these prices are calculated from the point the exchange comes back online. Thus, a product’s Open, High, and Low prices for the day can be incorrect if a new price was established while the TT Gateway was disconnected.
When the exchange host (or trading engine) recovers, the following items occur:
- The TFX Gateway receives a message that the TFX exchange host (trading engine) is again available.
- Due to the large number of traders and ISVs attempting to reconnect to the TFX exchange host, it may take some time before the TFX Gateway finds a connection.
- Orders: When a trader reconnects, the Order Router re-requests all Order Book information. The exchange deletes GTD orders. The TFX Gateway places most GTD orders on hold until traders resubmit them. However, GTD order information may not be available if the Order Router crashes before writing the GTD orders to the Order Router log. In this case, GTD orders are deleted from both the exchange and the TFX Gateway.
- Spreads: The exchange host automatically recreates any spreads that use GTC orders. The exchange host deletes any spread that does not include GTC orders.
- Prices: The Price Server renews its product subscriptions and begins broadcasting product data.