public Long getUptime() {
      return uptime;
    }
Gets the amount of time in milliseconds that the JVM process with the GemFire service has
been running.

@return a long value indicating the number of milliseconds that the GemFire service JVM has
        been running.
@see java.lang.management.RuntimeMXBean#getUptime()
geode-core/src/main/java/org/apache/geode/distributed/AbstractLauncher.java