router: Avoid duplicate alerts when router state changes (#3904)

When both routers of VPC is in MASTER state
then multiple alerts are sent equally to the number of tiers in the VPC.
If the VPC has 3 tiers then 6 alerts will be sent. This is not good
if VPC has more than 10 networks in it.

Instead of checking the router status for all the tiers in the VPC,
just check the status of the router for one tier in a VPC so that
multiple duplicate alerts can be avoided

Author: ravening

server/src/main/java/com/cloud/network/router/VirtualNetworkApplianceManagerImpl.java

@@ -1075,7 +1075,9 @@ private void checkDuplicateMaster(final List<DomainRouterVO> routers) {
             for (final DomainRouterVO router : routers) {
                 final List<Long> routerGuestNtwkIds = _routerDao.getRouterNetworks(router.getId());
 
-                for (final Long routerGuestNtwkId : routerGuestNtwkIds) {
+                final Long vpcId = router.getVpcId();
+                if (vpcId != null || routerGuestNtwkIds.size() > 0) {
+                    Long routerGuestNtwkId = vpcId != null ? vpcId : routerGuestNtwkIds.get(0);
                     if (router.getRedundantState() == RedundantState.MASTER) {
                         if (networkRouterMaps.containsKey(routerGuestNtwkId)) {
                             final DomainRouterVO dupRouter = networkRouterMaps.get(routerGuestNtwkId);
@@ -1084,7 +1086,6 @@ private void checkDuplicateMaster(final List<DomainRouterVO> routers) {
                             final String context = "Virtual router (name: " + router.getHostName() + ", id: " + router.getId() + " and router (name: " + dupRouter.getHostName()
                                     + ", id: " + router.getId() + ") are both in MASTER state! If the problem persist, restart both of routers. ";
                             _alertMgr.sendAlert(AlertManager.AlertType.ALERT_TYPE_DOMAIN_ROUTER, router.getDataCenterId(), router.getPodIdToDeployIn(), title, context);
-                            _alertMgr.sendAlert(AlertManager.AlertType.ALERT_TYPE_DOMAIN_ROUTER, dupRouter.getDataCenterId(), dupRouter.getPodIdToDeployIn(), title, context);
                             s_logger.warn(context);
                         } else {
                             networkRouterMaps.put(routerGuestNtwkId, router);
@@ -1168,8 +1169,14 @@ protected void runInContext() {
 
                 updateSite2SiteVpnConnectionState(routers);
 
-                List<NetworkVO> networks = _networkDao.listVpcNetworks();
-                s_logger.debug("Found " + networks.size() + " VPC networks to update Redundant State. ");
+                List<NetworkVO> networks = new ArrayList<>();
+                for (Vpc vpc : _vpcDao.listAll()) {
+                    List<NetworkVO> vpcNetworks = _networkDao.listByVpc(vpc.getId());
+                    if (vpcNetworks.size() > 0) {
+                        networks.add(vpcNetworks.get(0));
+                    }
+                }
+                s_logger.debug("Found " + networks.size() + " VPC's to update Redundant State. ");
                 pushToUpdateQueue(networks);
 
                 networks = _networkDao.listRedundantNetworks();