long calculateInitialDelay() {
    long initDelay = initialDelayIndex.getAndIncrement();
    initDelay =
        TimeUnit.MILLISECONDS.toNanos(initDelay * INITIAL_DELAY_MULTIPLIER_IN_MILLISECONDS)
            + pingIntervalNanos;
    return initDelay;
  }
At each registration of new endpoint increase counter for calculation of initial delay offset
geode-core/src/main/java/org/apache/geode/cache/client/internal/LiveServerPinger.java