“No common protection layer between client and ser

Question

I'm trying to communicate programmatically to a Hadoop cluster which is kerberized (CDH 5.3/HDFS 2.5.0).

I have a valid Kerberos token on the client side. But I'm getting an error as below, "No common protection layer between client and server".

What does this error mean and are there any ways to fix or work around it?

Is this something related to HDFS-5688? The ticket seems to imply that the property "hadoop.rpc.protection" must be set, presumably to "authentication" (also per e.g. this).

Would this need to be set on all servers in the cluster and then the cluster bounced? I don't have easy access to the cluster so I need to understand whether 'hadoop.rpc.protection' is the actual cause. It seems that 'authentication' should be the value used by default, at least according to the core-default.xml documentation.

java.io.IOException: Failed on local exception: java.io.IOException: Couldn't setup connection for principal1/[e-mail] to server2.acme.net/10.XX.XXX.XXX:8020; Host Details : local host is: “some-host.acme.net/168.XX.XXX.XX”; destination host is: “server2.acme.net”:8020;

    at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:764)

    at org.apache.hadoop.ipc.Client.call(Client.java:1415)

    at org.apache.hadoop.ipc.Client.call(Client.java:1364)

    at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:206)

    at com.sun.proxy.$Proxy24.getFileInfo(Unknown Source)

    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

    at java.lang.reflect.Method.invoke(Method.java:498)

    at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:187)

    at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)

    at com.sun.proxy.$Proxy24.getFileInfo(Unknown Source)

    at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:707)

    at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1785)

    at org.apache.hadoop.hdfs.DistributedFileSystem$17.doCall(DistributedFileSystem.java:1068)

    at org.apache.hadoop.hdfs.DistributedFileSystem$17.doCall(DistributedFileSystem.java:1064)

    at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)

    at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:1064)

    at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1398)

    ... 11 more

Caused by: java.io.IOException: Couldn't setup connection for principal1/[e-mail] to server2.acme.net/10.XX.XXX.XXX:8020;

    at org.apache.hadoop.ipc.Client$Connection$1.run(Client.java:671)

    at java.security.AccessController.doPrivileged(Native Method)

    at javax.security.auth.Subject.doAs(Subject.java:422)

    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)

    at org.apache.hadoop.ipc.Client$Connection.handleSaslConnectionFailure(Client.java:642)

    at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:725)

    at org.apache.hadoop.ipc.Client$Connection.access$2800(Client.java:367)

    at org.apache.hadoop.ipc.Client.getConnection(Client.java:1463)

    at org.apache.hadoop.ipc.Client.call(Client.java:1382)

    ... 31 more

Caused by: javax.security.sasl.SaslException: No common protection layer between client and server

    at com.sun.security.sasl.gsskerb.GssKrb5Client.doFinalHandshake(GssKrb5Client.java:251)

    at com.sun.security.sasl.gsskerb.GssKrb5Client.evaluateChallenge(GssKrb5Client.java:186)

    at org.apache.hadoop.security.SaslRpcClient.saslEvaluateToken(SaslRpcClient.java:483)

    at org.apache.hadoop.security.SaslRpcClient.saslConnect(SaslRpcClient.java:427)

    at org.apache.hadoop.ipc.Client$Connection.setupSaslConnection(Client.java:552)

    at org.apache.hadoop.ipc.Client$Connection.access$1800(Client.java:367)

    at org.apache.hadoop.ipc.Client$Connection$2.run(Client.java:717)

    at org.apache.hadoop.ipc.Client$Connection$2.run(Client.java:713)

    at java.security.AccessController.doPrivileged(Native Method)

    at javax.security.auth.Subject.doAs(Subject.java:422)

    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1614)

    at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:712)

    ... 34 more

Answer 1

To fix the "No common protection between client and server" error which is coming from SASL, I needed to set "hadoop.rpc.protection" to the same value as the one set on the serverside in the cluster. It happened to be "privacy" in this case.

Additionally, the cluster is configured for HA so I had to pick the right hostname to use in the HDFS URI ("fs.defaultFS") and in the "dfs.namenode.kerberos.principal" property:

Configuration config = new Configuration();
config.set("fs.defaultFS", "hdfs://host1.acme.com:8020");
config.set("hadoop.security.authentication", "kerberos");
config.set("hadoop.rpc.protection", "privacy");
// Need this or we get the error "Server has invalid Kerberos principal":
config.set("dfs.namenode.kerberos.principal",  
    "hdfs/[e-mail]");