add auto invalidation of dns cache

src/server/server.ts

@@ -179,6 +179,15 @@ export default class Server {
     });
   }
 
+  /**
+   * Invalidates the DNS cache for the server.
+   */
+  public invalidateDns() {
+    this.dnsInfo = {
+      hasResolved: false,
+    };
+  }
+
   /**
    * Returns the name of the server.
    *

src/server/serverManager.ts

@@ -23,6 +23,13 @@ export default class ServerManager {
     cron.schedule(Config.pinger.pingCron, () => {
       this.pingServers();
     });
+
+    cron.schedule(Config.pinger.dnsInvalidationCron, () => {
+      logger.info("Invalidating DNS cache for all servers");
+      for (const server of this.servers) {
+        server.invalidateDns();
+      }
+    });
   }
 
   /**