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Simulated Heartbeats

Overview

If you notice problems in an application's heartbeat, you can avoid frequent or unintentional disconnects by simulating heartbeats on the machine that is experiencing the heartbeat problem. Simulated heartbeats lead the receiving application to believe that the source is active and error-free. However, this technique causes slower disconnects when applications actually need to disconnect (e.g., a TT MISS Gateway becomes locked and traders need to do a hot failover).

Example Simulated Heartbeats

If an application crashes completely, Guardian identifies this state, and does not simulate heartbeats. Thus, simulating heartbeats is useful only when an application is too busy to generate heartbeats by itself.

When you configure Guardian or Guard Server to simulate heartbeats, TT recommends that you do not use a value greater than five (5).

Simulating Heartbeats

To simulate heartbeats, in aconfig_local.xml, you must set the parameter HB-Generate to a value equal to the number of heartbeats you want to simulate when an application is too busy to generate heartbeats by itself.

To simulate heartbeats:

  1. On the Desktop, double click AConfig Utility.

    The AConfig Utility window appears.

  2. Navigate to AConfigCoreGuardappDebug, where app is either Guardian or GuardServer.
  3. Click HB-Generate.
  4. Click the Value cell.

    You may need to click the cell a second time before being able to edit its values.

  5. Type the number of heartbeats you want the program to simulate in the event of a hung program.

    TT recommends that you do not use a value greater than five (5).

  6. Click Apply.

    The AConfig Utility writes all changes to aconfig_local.xml.

  7. On the File menu, click Exit.

    Heartbeat logging is now on. However, due to the manner in which Guardian and Guard Server send heartbeats, a log file is generated only when another TT application is running (i.e., X_TRADER® or a TT Gateway component such as the Price or Order Server).