问题描述
当涉及到 dynamo DB 时，这可能是一个非常愚蠢的问题。
好吧，总结一下我在我的项目中设置了一个 dynamoDB 的问题。
（仅供参考，我还没有设置本地 dynamodb，我正在尝试在实验室环境中连接到我的远程数据库）
其配置如下：
AmazonDynamoDBClientBuilder amazonDynamoDB = AmazonDynamoDBClientBuilder.standard();
if (DYNAMO_DB_MODE_REMOTE.equals("remote")) {
amazonDynamoDB.setRegion(amazonAWSRegion);
amazonDynamoDB.setCredentials(new InstanceProfileCredentialsProvider(false));
} else {
amazonDynamoDB.setEndpointConfiguration(new AwsClientBuilder.EndpointConfiguration(amazonDynamoDBEndpoint,amazonAWSRegion));
amazonDynamoDB.setCredentials(new AWsstaticCredentialsProvider(new BasicAWSCredentials(amazonAWSAccessKey,amazonAWSSecretKey)));
}
我在上面这段代码中遇到的问题如下：
com.amazonaws.SdkClientException: Failed to connect to service endpoint:
at com.amazonaws.internal.EC2ResourceFetcher.doReadResource(EC2ResourceFetcher.java:100)
at com.amazonaws.internal.InstanceMetadataServiceResourceFetcher.getToken(InstanceMetadataServiceResourceFetcher.java:91)
at com.amazonaws.internal.InstanceMetadataServiceResourceFetcher.readResource(InstanceMetadataServiceResourceFetcher.java:69)
at com.amazonaws.internal.EC2ResourceFetcher.readResource(EC2ResourceFetcher.java:66)
at com.amazonaws.auth.InstanceMetadataServiceCredentialsFetcher.getCredentialsEndpoint(InstanceMetadataServiceCredentialsFetcher.java:58)
at com.amazonaws.auth.InstanceMetadataServiceCredentialsFetcher.getCredentialsResponse(InstanceMetadataServiceCredentialsFetcher.java:46)
at com.amazonaws.auth.BaseCredentialsFetcher.fetchCredentials(BaseCredentialsFetcher.java:112)
at com.amazonaws.auth.BaseCredentialsFetcher.getCredentials(BaseCredentialsFetcher.java:68)
at com.amazonaws.auth.InstanceProfileCredentialsProvider.getCredentials(InstanceProfileCredentialsProvider.java:166)
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.getCredentialsFromContext(AmazonHttpClient.java:1251)
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.runBeforeRequestHandlers(AmazonHttpClient.java:827)
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.doExecute(AmazonHttpClient.java:777)
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.executeWithTimer(AmazonHttpClient.java:764)
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.execute(AmazonHttpClient.java:738)
at com.amazonaws.http.AmazonHttpClient$RequestExecutor.access$500(AmazonHttpClient.java:698)
at com.amazonaws.http.AmazonHttpClient$RequestExecutionBuilderImpl.execute(AmazonHttpClient.java:680)
at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:544)
at com.amazonaws.http.AmazonHttpClient.execute(AmazonHttpClient.java:524)
at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.doInvoke(AmazonDynamoDBClient.java:5110)
at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.invoke(AmazonDynamoDBClient.java:5077)
at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.executeUpdateItem(AmazonDynamoDBClient.java:4696)
at com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient.updateItem(AmazonDynamoDBClient.java:4662)
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$SaveObjectHandler.doUpdateItem(DynamoDBMapper.java:870)
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$2.executeLowLevelRequest(DynamoDBMapper.java:610)
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper$SaveObjectHandler.execute(DynamoDBMapper.java:749)
at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper.save(DynamoDBMapper.java:639)
at com.amazonaws.services.dynamodbv2.datamodeling.AbstractDynamoDBMapper.save(AbstractDynamoDBMapper.java:123)
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Caused by: java.net.socketException: Network is unreachable: connect
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
at java.net.socksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.socket.connect(Socket.java:589)
at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:463)
at sun.net.www.http.HttpClient.openServer(HttpClient.java:558)
at sun.net.www.http.HttpClient.<init>(HttpClient.java:242)
at sun.net.www.http.HttpClient.New(HttpClient.java:339)
at sun.net.www.http.HttpClient.New(HttpClient.java:357)
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1202)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1181)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1032)
at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:966)
at com.amazonaws.internal.ConnectionUtils.connectToEndpoint(ConnectionUtils.java:52)
at com.amazonaws.internal.EC2ResourceFetcher.doReadResource(EC2ResourceFetcher.java:80)
... 66 common frames omitted
amazonDynamoDB.setCredentials(new InstanceProfileCredentialsProvider(false));
来自 DynamoDB 配置，不知何故，解决了这个问题！
但是我一开始不明白哪里出了问题。
有人可以帮我吗？提前致谢！
解决方法
问题是您的本地机器没有实例配置文件。
如果您希望从本地计算机使用 AWS 服务，则必须使用在本地检索信息的凭证提供程序。我建议使用 DefaultAWSCredentialsProviderChain，它会查找本地配置（在 $HOME/.aws 中或通过环境变量或系统属性），并且还支持实例配置文件（以防您在 EC2 实例上运行）。
这就是删除 amazonDynamoDB.setCredentials(new InstanceProfileCredentialsProvider(false)); 起作用的原因