They way this is supposed to work is the following in a secure cluster. 1) The user that is running TezClient/DAGClient needs to be Kerberos authenticated. This allows the process running DAGClient/TezClient to contact the RM and get tokens to communicate with the AM.
2) The TezClient/DAGClient uses the tokens obtained from the RM and populates it into the current user UGI (ie the use who is running TezClient/DAGClient). The RPC to the AM will try to authenticate the current user using the tokens just added to the current users UGI. In a non-secure environment, no tokens are needed. So I am guessing that your are running in a secure env. Given the above info, what is happening in your case. Whichever user the client is running under, it looks like it can authenticate to the RM to get the app report. So it should have gotten tokens to access the AM. Its not clear what you mean by user “subroto” being privileged and the real user not considered by Tez. It looks like you are running the client as user “subroto”. Who is “subroto” and who is the real user? Does this happen always or occasionally. There is a known race condition in YARN where the client gets tokens before the AM gets the key to validate the tokens. You can turn on debug logging and see the SASL negotiation logs to get more info on whats happening. You may add a debug log in getAMProxy() to verify that token were obtained from the RM and added to the UGI. It may help if you describe your scenario. What are you trying to achieve by impersonation and how are you trying to do that. We recently added ACLs in case that works for your scenario. *From:* Subroto Sanyal [mailto:[email protected]] *Sent:* Sunday, August 31, 2014 8:59 PM *To:* [email protected] *Subject:* Re: Tez with secured hadoop Hi Bikas, In the method: org.apache.tez.client.TezClientUtils.getAMProxy(Configuration, String, int, Token) a UGI is getting created with name of the current user. I think in this process it ignores all the security things and making the authentication mode as "SIMPLE". I have piece of code which tries to create a TezClient and it keeps throwing the exception: [anonymous] WARN [2014-08-28 03:37:50.181] [MrPlanRunnerV2] (UserGroupInformation.java:1551) - PriviledgedActionException as:subroto (auth:SIMPLE) cause:java.io.IOException: org.apache.hadoop.security.AccessControlException: Client cannot authenticate via:[TOKEN, KERBEROS] [anonymous] INFO [2014-08-28 03:37:50.182] [MrPlanRunnerV2] (TezClient.java:539) - Failed to retrieve AM Status via proxy com.google.protobuf.ServiceException: java.io.IOException: Failed on local exception: java.io.IOException: org.apache.hadoop.security.AccessControlException: Client cannot authenticate via:[TOKEN, KERBEROS]; Host Details : local host is: "domU-12-31-39-0F-74-32/10.193.119.192"; destination host is: "domU-12-31-39-0C-7D-37":59431; at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:216) at com.sun.proxy.$Proxy111.getAMStatus(Unknown Source) at org.apache.tez.client.TezClient.getAppMasterStatus(TezClient.java:532) at org.apache.tez.client.TezClient.waitTillReady(TezClient.java:607) at subroto.tez.TezClusterSession$2.run(TezClusterSession.java:180) I m trying to achieve impersonation. Here user "subroto" is privileged user and the real user is not at all considered by the Tez Code. Request some suggestion on this. On Tue, Aug 19, 2014 at 11:18 PM, Bikas Saha <[email protected]> wrote: There is nothing special that you need to do if you are already running secure Map Reduce jobs. The client needs to run in a Kerberized authenticated context. After that if you are using the built-in library of inputs/outputs etc then they should be taking care of all the access credentials for you when using the 0.5 API. I If you are using 0.4 API to write your job then you may need to use additional APIs for passing credentials to the application. Look for credentials in https://github.com/apache/tez/blob/branch-0.4.0-incubating/tez-mapreduce-examples/src/main/java/org/apache/tez/mapreduce/examples/FilterLinesByWord.java and also *public* *synchronized* DAG *addURIsForCredentials(*Collection*<* URI*>* uris*)* The second method is a shortcut if you are using HDFS files for input. It obtains credentials for you from a collection of HDFS input URIs. Bikas *From:* Subroto Sanyal [mailto:[email protected]] *Sent:* Tuesday, August 19, 2014 3:30 AM *To:* [email protected] *Subject:* Tez with secured hadoop hi Tez works on secure hadoop cluster since tez-0.3. Is there any documentation available about configuring TezClient to make it work? -- Cheers, *Subroto Sanyal* CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You. -- Cheers, *Subroto Sanyal* -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
