Unable to resolve host googleads.googleapis.com

[金子冴]

Hello.

We are trying to use Google Ads API with Client Library of Java.

But it returns exception `java.net.UnknownHostException`.

The total error message is the following.

```

05-Apr-2022 16:51:35.365 WARNING [grpc-default-executor-138] io.grpc.internal.ManagedChannelImpl$NameResolverListener.handleErrorInSyncContext [Channel<83>: (googleads.googleapis.com:443)] Failed to resolve name. status=Status{code=UNAVAILABLE, description=Unable to resolve host googleads.googleapis.com, cause=java.net.UnknownHostException: host: unknown error
    at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
    at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928)
    at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323)
    at java.net.InetAddress.getAllByName0(InetAddress.java:1276)
    at java.net.InetAddress.getAllByName(InetAddress.java:1192)
    at java.net.InetAddress.getAllByName(InetAddress.java:1126)
    at java.net.InetAddress.getByName(InetAddress.java:1076)
    at io.grpc.internal.ProxyDetectorImpl.detectProxy(ProxyDetectorImpl.java:260)
    at io.grpc.internal.ProxyDetectorImpl.proxyFor(ProxyDetectorImpl.java:200)
    at io.grpc.internal.DnsNameResolver.detectProxy(DnsNameResolver.java:269)
    at io.grpc.internal.DnsNameResolver.access$600(DnsNameResolver.java:66)
    at io.grpc.internal.DnsNameResolver$Resolve.run(DnsNameResolver.java:310)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

```

We already testes the following points.

- Our application is running on the instance of Amazon EC2. We can success (no packet loss) to send ping to the domain, and dig command also returns `NOERROR`. The EC2 instance can identify the domain.

```

sh-4.2$ dig googleads.googleapis.com

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.37.rc1.47.amzn1 <<>> googleads.googleapis.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 17952
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;googleads.googleapis.com.      IN      A

;; ANSWER SECTION:
googleads.googleapis.com. 94    IN      A       142.250.196.106

;; Query time: 1 msec
;; SERVER: 172.31.0.2#53(172.31.0.2)
;; WHEN: Fri Apr  8 10:04:28 2022
;; MSG SIZE  rcvd: 58

sh-4.2$ ping googleads.googleapis.com
PING googleads.googleapis.com (142.250.196.106) 56(84) bytes of data.
64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=1 ttl=105 time=2.38 ms
64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=2 ttl=105 time=2.32 ms
64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=3 ttl=105 time=2.35 ms
64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=4 ttl=105 time=2.36 ms
64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=5 ttl=105 time=2.43 ms
64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=6 ttl=105 time=2.39 ms
64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=7 ttl=105 time=2.98 ms
^C64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=8 ttl=105 time=2.32 ms
64 bytes from nrt12s35-in-f10.1e100.net (142.250.196.106): icmp_seq=9 ttl=105 time=2.41 ms
^C
--- googleads.googleapis.com ping statistics ---
9 packets transmitted, 9 received, 0% packet loss, time 8011ms
rtt min/avg/max/mdev = 2.322/2.441/2.983/0.204 ms
sh-4.2$

```

- On our application, we tried to get the IP address of the domain by `InetAddress#getByName` method. We could resolve the domain, it means only the name resolve method in Client Library is facing trouble for resolving the domain name.

```

# The result of `InetAddress#getByName`

10:42:47:558 Host name:googleads.googleapis.com # `InetAddress#getHostName`

10:42:47:559 Host Address:142.250.196.106  # `InetAddress# getHostAddress`

```

We are using Client Library like this.

```

<dependency>
            <groupId>com.google.api-ads</groupId>
            <artifactId>google-ads</artifactId>
            <version>17.0.1</version>
</dependency>

```

```

        # Create `googleAdsClient` and `op` (KeywordPlanOperation) before here

        try (KeywordPlanServiceClient client = googleAdsClient.getLatestVersion().createKeywordPlanServiceClient()) {
            // Adds the keyword plan.
            MutateKeywordPlansResponse response
                    = client.mutateKeywordPlans(String.valueOf(customerId), Arrays.asList(op));
            // Displays the results.
            return response.getResults(0).getResourceName();
        }

```

We want to know what configurations is lacked.

Thank you for sharing information.

[Google Ads API Forum Advisor]

Hi,

Thank you for reaching out to our API support team.

You appear to be encountering a client library related error. That said, I would recommend that you reach out to the Java client library owners via this link, for further insight and guidance.

Best regards,

Peter Laurence Google Ads API Team

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