Redundant TT Gateways
Setting up Redundant TT Gateways
When operating redundant TT Gateways set up for manual failover, you must:
- Assign each TT Gateway a unique exchange-flavor. The license file must reflect these exchange names. For information on how TT licenses exchange names, refer to Licensing Client and Server Applications.
- Enter all trader logins into the Windows User Authentication System on the each of the TT Gateways (or a Domain Controller). For information on entering logins, refer to Login Security.
- Set up appropriate risk parameters on all TT Gateways
- Perform any additional tasks as documented in the disaster recovery chapter in the SAM specific to the relevant TT Gateway.
The following subsections discuss the affect of manually failing over using unique exchange-flavors.
In a redundant environment in which each TT Gateway uses a unique exchange-flavor, when a TT Gateway fails, all traders that use the TT Gateway immediately lose their connections and experience the following:
- Orders: To update Order Book information, a trader must log into another active TT Gateway. Orders cannot be submitted via the failed TT Gateway. The exchange can pull orders or put them on hold.
- Fills: Traders stop receiving fill information from the exchange. Depending upon the exchange, if fills occur they can be dropped and unrecoverable.
- Synthetic Orders: The TT Gateway retains synthetic orders (and their status) submitted before the TT Gateway failure. Additional synthetic orders cannot be submitted via the TT Gateway. Whether the working order components of synthetic orders remain active in the market depends upon the exchange. Updated order information is not available until the TT Gateway connects to the exchange.
- Prices: Current prices do not update.
At the time of failure, TT recommends that traders document their positions. This information is useful for recovery and failover purposes.
Manually Failing Over
In a manual failover scenario, the only disruption that occurs is the loss of connection and trading privileges for the amount of time it takes to log into the alternative TT Gateway. Depending on the type of TT Gateway used, certain problems can occur (such as missing fills, held or canceled orders, etc.).
During a manual failover between TT Gateways:
- On certain TT Gateways (i.e., TT LIFFE Connect Gateways), traders must wait at least thirty seconds before failing over.
- Before logging into a different TT Gateway of the same type, the trader should close out of and then reopen X_TRADER®.
- The trader must log into another TT Gateway of the same type. For instance, if a TT CME Gateway fails, the trader must log into another TT CME Gateway.
- The trader must reopen his workspace when he logs into an alternative TT Gateway.
When X_TRADER® is logged into a TT Gateway and the TT Gateway fails, X_TRADER® retries its login until the TT Gateway comes back online or until you close X_TRADER® thus breaking the connection. If the trader does not log out of the failed TT Gateway, and is still logged into both TT Gateways when the failed gateway comes back online, his Fill Window and Order Book can start to behave erratically:
For these reasons, the trader must log out and log back into X_TRADER® as soon as the he is able to do so.
Post Failover Behavior
After a trader performs a manual failover, the TT system exhibits the following behavior:
- Fills: X_TRADER® begins accepting fills again. Whether previous fills are accessible to the trader depends upon the exchange on which the trader trades.
- Orders: The exchange on which the trader trades determines the behavior of orders.
- Synthetic Orders: The trader can access any working order components of his synthetic orders. These working orders appear as regular limit orders. The trader has no access to synthetic orders that have not yet been submitted to the exchange (i.e., ones that the failed TT Gateway stores).
- Prices: Prices become current after traders log in and re-subscribe to specific products by opening their grids and workspaces.
Failed Login Attempts
Traders can encounter difficulties logging into alternate TT Gateways on certain exchanges (e.g., TT LIFFE Connect Gateways). Refer to the disaster recovery chapter in the SAM for the specific TT Gateway.
These types of login problems usually are the result of the exchange continuing to recognize the ID as logged in.
Opening a New Workspace
After logging into a new TT Gateway, a trader must open a new workspace. If a trader has not already configured a workspace for that particular gateway, he will receive a Workspace Conversion dialog box. By clicking on the needed exchange name and then Convert, the trader can use a workspace originally associated with a different exchange name.
A trader is logged into a TT LIFFE Futures Gateway with an exchange name of LIFFE. This trader has a saved workspace associated with LIFFE, called “BigMoney.” While he is trading, the TT Gateway fails, and the trader is forced to log into another TT LIFFE Futures Gateway. This gateway is on the same network with an exchange name of LIFFE-A. After logging in, the trader goes to open the saved workspace, “BigMoney.”
Because “BigMoney” is associated with LIFFE, not LIFFE-A, the trader will be prompted with the Workspace Conversion dialog box.
The trader clicks to select LIFFE-A, and then he clicks Convert. The trader now sees his “BigMoney” workspace and continues trading.
Unless the trader plans to log into LIFFE-A from then on, he should not save his workspace while in LIFFE-A. If the trader saves his workspace, it overwrites the settings, and he receives the same Workspace Conversion dialog box the next time he logs into LIFFE.
Gateway Recovery in a Redundant Environment
For information on what tasks the TT Gateway performs when it is restarted, refer to Gateway Software Recovery.
TT Gateways that suffer hardware failure are unable to go back online until the situation is rectified via replacement of the affected components. When you replace or correct failed hardware and restart the TT Gateway, recovery processes are identical to those listed above in Gateway Software Recovery.