Health diagnostics analyzes the health status of services and nodes in an E-MapReduce (EMR) cluster. When a cluster fails or behaves unexpectedly, run a diagnostic to identify issues across services such as Hive, Hadoop Distributed File System (HDFS), YARN, and ZooKeeper. The diagnostic report shows the cluster status, issues found, root causes, and remediation suggestions.
Prerequisites
Before you begin, make sure that you have:
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A cluster of one of the following types: DataLake, Dataflow, OLAP, DataServing, or custom. Health diagnostics is not supported for other cluster types. For more information, see Create a cluster
Run health diagnostics
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Log on to the EMR console. In the left-side navigation pane, click EMR on ECS.
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In the top navigation bar, select the region where your cluster resides and select a resource group.
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On the EMR on ECS page, find the cluster and click its name in the Cluster ID/Name column.
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Click the Monitoring and Diagnostics tab, then click the Health Diagnostics subtab.
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Click Initiate Diagnostics. In the dialog box that appears, set the Time Range parameter, then click Start.
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After the diagnostic completes, find the report in the list and click View Report in the Actions column.
Diagnostic report contents
The report provides the following information:
| Section | Description |
|---|---|
| Cluster status | Overall health status of the cluster |
| Issues detected | List of issues found across services and nodes |
| Root causes | The underlying cause of each issue |
| Remediation suggestions | Recommended steps to resolve each issue |
What's next
After reviewing the diagnostic report, follow the remediation suggestions in the report to resolve issues found in the cluster's services or nodes.
If the diagnostic does not identify the root cause, consider checking external factors such as resource quotas, network configuration, or underlying infrastructure status, as these may affect cluster health without being detectable by the diagnostic.