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Edge service settings in the UAG admin console shows 'Horizon destination server' as down.
The root cause of the issue is the inability of the UAG server to establish a connection with the backend connection server. This could be due to an SSLHandshakeException, DNS or network issues, or certificate-related problems, for instance - thumbprint mismatch, SSL handshake failure, or issues with the certificate chaining for the cert used for the Connection server URL.
Before applying the suggested resolution, it is important to note any potential impacts, risks, or implications. Users should be aware that resolving the issue may require downtime or affect the availability of the Horizon destination server.
Within the UAG Logs, which can be gathered as a bundle from the support settings section of the admin portal. the esmanager.log contains logging related to the Edge Services including horizon and you can search for log lines related to the keyword "view.ViewEdgeService[healthCheckBroker]” here: Reference: Collecting Logs from the Unified Access Gateway ApplianceDepending on the scenario, users may need to verify the thumbprint, check certificate chaining, or resolve DNS or network issues. The article provides sample log entries for two scenarios and outlines the steps to fix each one. Scenario 1: UAG cannot connect to the Backend Connection Server due to an SSL certificate issue. [nioEventLoopGroup-4-1]ERROR client.HttpClient[exceptionCaught: 286][]: Exception caught while communication to backend: javax.net.ssl.SSLHandshakeException: General SSLEngine problem [Monitoring]ERROR view.ViewEdgeService[healthCheckBroker: 266][]: Exception message:io.netty.handler.codec.DecoderException: javax.net.ssl.SSLHandshakeException: General SSLEngine problem To resolve this issue: Verify if the thumbprint matches with the cert used for the connection server URL Ensure the address used in the UAG configuration matches the connection server certificate and URL.Verify a full certificate chain is presentVerify any certificate revocation list is reachable.Please see Troubleshooting SSL certificate Issues with the VMware Horizon Server or Console (2082408) for additional troubleshooting steps. Scenario 2: UAG could not establish a connection with the backend connection server as it couldn’t resolve the connection server URL either due to DNS or network issues. [nioEventLoopGroup-4-1]ERROR client.HttpClient[lambda$send$4: 209][]: unable to connect to connectionserver.domain.com:8443, reason=java.net.UnknownHostException: connectionserver.domain.com: Name or service not known [Monitoring]ERROR view.ViewEdgeService[healthCheckBroker: 266][]: Exception message:java.net UnknownHostException: horizonserver.org.com : Name or service not known. 07:29:03,882[nioEventLoopGroup-7-1]ERROR view.ViewEdgeService[onFailure: 165][]: Failed to resolve hostname address in proxyDestinationUrl: To resolve this issue: Check your IP, subnet, gateway and DNS settings are configured correctly or as you would expect.Check basic device interconnectivity utilizing ping or curl on the UAG console to the Backend horizon Server : curl -v -k https://brokerfqdnorip:443/ nslookup brokerhostname Ensure no firewall is blocking DNS or network traffic.Please see Unified Access Gateway(UAG): Troubleshooting DNS Connectivity Issues with Horizon View Servers (50120424) for detailed additional troubleshooting steps.
Unified Access Gateway(UAG): UAG Gateway Error Messages in Horizon View Administrator Portal Dashboard (90749)