@Override
  protected void profileRemoved(Profile profile) {
    if (profile instanceof GatewaySenderProfile) {
      GatewaySenderProfile sp = (GatewaySenderProfile) profile;
      if (!sp.isParallel) {// SerialGatewaySender
        // if there is a primary sender, then don't volunteer for primary
        if (advisePrimaryGatewaySender() != null) {
          return;
        }
        if (!sender.isPrimary()) {// IF this sender is not primary
          if (!adviseEldestGatewaySender()) {// AND this is not the eldest sender
            if (logger.isDebugEnabled()) {
              logger.debug(
                  "Sender {} is not the eldest in the system. Giving preference to eldest sender to become primary...",
                  sender);
            }
            return;
          }
          launchLockObtainingVolunteerThread();
        }
      }
    }
  }
When the sender profile is removed, then check for the primary members if they are not
available then this secondary sender should volunteer for primary
geode-core/src/main/java/org/apache/geode/internal/cache/wan/GatewaySenderAdvisor.java