A company uses an Amazon EMR cluster with 50 nodes to process operational data and make the data available for data analysts. These jobs run nightly use Apache Hive with the Apache Jez framework as…

Task nodes in an Amazon EMR cluster are primarily for compute and do not store HDFS data. Adding task nodes would increase processing power but would not address a storage capacity issue that prevents HDFS replication.

The error message 'File could only be replicated to 0 nodes instead of 1' strongly suggests that HDFS DataNodes lack the capacity (most often disk space) to store data replicas. In Amazon EMR, core nodes are responsible for both data processing and storing data in HDFS. Therefore, monitoring the `HDFSUtilization` metric and adding more core nodes when it crosses a threshold directly increases HDFS storage capacity, resolving the replication failure.

The `MemoryAllocatedMB` metric tracks memory usage, not disk space. While memory issues can cause job failures, they would manifest as out-of-memory errors rather than HDFS replication failures due to lack of nodes to store data. Task nodes do not store HDFS data.

The `MemoryAllocatedMB` metric tracks memory usage. Although core nodes store HDFS data, memory issues are distinct from the HDFS replication failure, which points to a lack of available storage nodes for data blocks, not a memory-related problem.