373 EC2 is Out of Capacity p 374 Cluster Terminates With NOSLAVELEFT and Core

373 ec2 is out of capacity p 374 cluster terminates

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Instance Type Not Supported (p. 373) EC2 is Out of Capacity (p. 374) Cluster Terminates With NO_SLAVE_LEFT and Core Nodes FAILED_BY_MASTER Usually, this happens because termination protection is disabled, and all core nodes exceed disk storage capacity as specified by a maximum utilization threshold in the yarn-site configuration classification, which corresponds to the yarn-site.xml file. This value is 90% by default. When disk utilization for a core node exceeds the utilization threshold, the YARN NodeManager health service reports the node as UNHEALTHY . While it's in this state, Amazon EMR blacklists the node and does not allocate YARN containers to it. If the node remains unhealthy for 45 minutes, Amazon EMR marks the associated Amazon EC2 instance for termination as FAILED_BY_MASTER . When all Amazon EC2 instances associated with core nodes are marked for termination, the cluster terminates with the status NO_SLAVE_LEFT because there are no resources to execute jobs. Exceeding disk utilization on one core node might lead to a chain reaction. If a single node exceeds the disk utilization threshold because of HDFS, other nodes are likely to be near the threshold as well. The first node exceeds the disk utilization threshold, so Amazon EMR blacklists it. This increases the burden of disk utilization for remaining nodes because they begin to replicate HDFS data among themselves that they lost on the blacklisted node. Each node subsequently goes UNHEALTHY in the same way, and the cluster eventually terminates. Best Practices and Recommendations Configure Cluster Hardware with Adequate Storage When you create a cluster, make sure that there are enough core nodes and that each has an adequate instance store and EBS storage volumes for HDFS. For more information, see Calculating the Required HDFS Capacity of a Cluster (p. 135) . You can also add core instances to existing instance groups manually or by using auto-scaling. The new instances have the same storage configuration as other instances in the instance group. For more information, see Scaling Cluster Resources (p. 328) . Enable Termination Protection Enable termination protection. This way, if a core node is blacklisted, you can connect to the associated Amazon EC2 instance using SSH to troubleshoot and recover data. If you enable termination protection, be aware that Amazon EMR does not replace the Amazon EC2 instance with a new instance. For more information, see Using Termination Protection (p. 88) . Create an Alarm for the MRUnhealthyNodes CloudWatch Metric This metric reports the number of nodes reporting an UNHEALTHY status. It's equivalent to the YARN metric mapred.resourcemanager.NoOfUnhealthyNodes . You can set up a notification for this alarm 368
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Amazon EMR Management Guide Resource Errors to warn you of unhealthy nodes before the 45-minute timeout is reached. For more information, see Monitor Metrics with CloudWatch (p. 296) .
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  • Spring '12
  • LauraParker
  • Amazon Web Services, Amazon Elastic Compute Cloud

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