You can configure the amount of time between system checks for failed servers with the heartbeat interval setting.
When these settings are modified to provide short failover times, there are some system-tuning issues to be aware of. First, Java is not a real-time environment. It is possible for threads to be delayed if the JVM is experiencing long garbage collection times. Threads might also be delayed if the machine hosting the JVM is heavily loaded (due to the JVM itself or other processes running on the machine). If threads are delayed, heartbeats might not be sent on time. In the worst case, they might be delayed by the required failover time. If threads are delayed, false failure detections occur. The system must be tuned and sized to ensure that false failure detections do not happen in production. Adequate load testing is the best way to ensure this.