At

This preview shows page 385 - 387 out of 395 pages.

at org.apache.hadoop.hdfs.server.namenode.FSImage.recoverTransitionRead(FSImage.java:212) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFSImage(FSNamesystem.java:1020) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.loadFromDisk(FSNamesystem.java:739) at org.apache.hadoop.hdfs.server.namenode.NameNode.loadNamesystem(NameNode.java:537) at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:596) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:765) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:749) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1441) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1507) This is due to a potential issue where an EC2 instance can have multiple sets of fully qualified domain names when launching EMR clusters in a VPC, which makes use of both an AWS-provided DNS server and a custom user-provided DNS server. If the user-provided DNS server does not provide any pointer (PTR) records for any A records used to designate nodes in an EMR cluster, clusters will fail starting up when configured in this way. The solution is to add 1 PTR record for every A record that is created when an EC2 instance is launched in any of the subnets in the VPC. AWS GovCloud (US-West) Errors The AWS GovCloud (US-West) region differs from other regions in its security, configuration, and default settings. As a result, use the following checklist to troubleshoot Amazon EMR errors that are specific to the AWS GovCloud (US-West) region before using more general troubleshooting recommendations. 379
Image of page 385
Amazon EMR Management Guide Other Issues Verify that your IAM roles are correctly configured. For more information, see Configure IAM Service Roles for Amazon EMR Permissions to AWS Services and Resources (p. 177) . Ensure that your VPC configuration has correctly configured DNS resolution/hostname support, Internet Gateway, and DHCP Option Set parameters. For more information, see VPC Errors (p. 377) . If these steps do not solve the problem, continue with the steps for troubleshooting common Amazon EMR errors. For more information, see Common Errors in Amazon EMR (p. 364) . Other Issues Do you not see the cluster you expect in the Cluster List page or in results returned from ListClusters API? Check the following: The cluster age is less than two months. Amazon EMR preserves metadata information about completed clusters for your reference, at no charge, for two months. The console does not provide a way to delete completed clusters from the console; these are automatically removed for you after two months. You have permissions to view the cluster. You are viewing the correct region. Troubleshoot a Lake Formation Cluster (Beta) This section walks you through the process of troubleshooting common issues when using Amazon EMR with AWS Lake Formation.
Image of page 386
Image of page 387

You've reached the end of your free preview.

Want to read all 395 pages?

  • Spring '12
  • LauraParker
  • Amazon Web Services, Amazon Elastic Compute Cloud

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask ( soon) You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors