public void checkSenderIds() {
    if (illegalGatewaySenderIds != null) {
      if (!gatewaySenderIdsDifferWarningMessage) {
        gatewaySenderIdsDifferWarningMessage = true;
        logger.warn(
            "Region {} has {} gateway sender IDs. Another member has the same region with {} gateway sender IDs. For the same region, across all members, gateway sender ids should be same.",
            region.getName(), region.getGatewaySenderIds(), illegalGatewaySenderIds);
      }
    } else {
      if (gatewaySenderIdsDifferWarningMessage) {
        gatewaySenderIdsDifferWarningMessage = false;
        logger.warn(
            "Region {} now has the same gateway sender IDs on all members. The previous problem with them being different has been corrected.",
            region.getName());
      }
    }
    if (illegalAsyncEventQueueIds != null) {
      if (!asyncQueueIdsDifferWarningMessage) {
        asyncQueueIdsDifferWarningMessage = true;
        logger.warn(
            "Region {} has {} AsyncEvent queue IDs. Another member has the same region with {} AsyncEvent queue IDs. For the same region, across all members, AsyncEvent queue IDs should be same.",
            region.getName(), region.getVisibleAsyncEventQueueIds(), illegalAsyncEventQueueIds);
      }
    } else {
      if (asyncQueueIdsDifferWarningMessage) {
        asyncQueueIdsDifferWarningMessage = false;
        logger.warn(
            "Region {} now has the same AsyncEvent queue IDs on all members. The previous problem with them being different has been corrected.",
            region.getName());
      }
    }
  }
Needs to be called if this region's gateways or asyncEventIds change.
geode-core/src/main/java/org/apache/geode/internal/cache/SenderIdMonitor.java