2021-07-29 13:50:49.554 ERROR 6 --- [gistrationTask1] o.s.s.s.TaskUtils$LoggingErrorHandler    : Unexpected error occurred in scheduled task

java.lang.IllegalArgumentException: small-apps-bck: small-apps-bck: System error
    at de.codecentric.boot.admin.client.registration.DefaultApplicationFactory.getLocalHost(DefaultApplicationFactory.java:186) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    at de.codecentric.boot.admin.client.registration.DefaultApplicationFactory.getServiceHost(DefaultApplicationFactory.java:168) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    at de.codecentric.boot.admin.client.registration.DefaultApplicationFactory.getServiceBaseUrl(DefaultApplicationFactory.java:103) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    at de.codecentric.boot.admin.client.registration.ServletApplicationFactory.getServiceUrl(ServletApplicationFactory.java:63) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    at de.codecentric.boot.admin.client.registration.ServletApplicationFactory.getManagementBaseUrl(ServletApplicationFactory.java:76) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    at de.codecentric.boot.admin.client.registration.DefaultApplicationFactory.getHealthUrl(DefaultApplicationFactory.java:154) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    at de.codecentric.boot.admin.client.registration.DefaultApplicationFactory.createApplication(DefaultApplicationFactory.java:80) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    at de.codecentric.boot.admin.client.registration.DefaultApplicationRegistrator.register(DefaultApplicationRegistrator.java:56) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-5.3.8.jar!/:5.3.8]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_202]
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [na:1.8.0_202]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_202]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [na:1.8.0_202]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_202]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_202]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_202]
Caused by: java.net.UnknownHostException: small-apps-bck: small-apps-bck: System error
    at java.net.InetAddress.getLocalHost(InetAddress.java:1506) ~[na:1.8.0_202]
    at de.codecentric.boot.admin.client.registration.DefaultApplicationFactory.getLocalHost(DefaultApplicationFactory.java:183) ~[spring-boot-admin-client-2.4.3.jar!/:2.4.3]
    ... 15 common frames omitted
Caused by: java.net.UnknownHostException: small-apps-bck: System error
    at java.net.Inet4AddressImpl.lookupAllHostAddr(Native Method) ~[na:1.8.0_202]
    at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:929) ~[na:1.8.0_202]
    at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1324) ~[na:1.8.0_202]
    at java.net.InetAddress.getLocalHost(InetAddress.java:1501) ~[na:1.8.0_202]
    ... 16 common frames omitted