This NodeManager health test checks that the number of file descriptors used does not rise above some percentage of the NodeManager file descriptor limit. A failure of this health test may indicate a bug in either Hadoop or Cloudera Manager. Contact Cloudera support. This test can be configured using the File Descriptor Monitoring Thresholds NodeManager monitoring setting.

Short Name: File Descriptors

This NodeManager health test checks that the NodeManager is not spending too much time performing Java garbage collection. It checks that no more than some percentage of recent time is spent performing Java garbage collection. A failure of this health test may indicate a capacity planning problem or misconfiguration of the NodeManager. This test can be configured using the Garbage Collection Duration Thresholds and Garbage Collection Duration Monitoring Period NodeManager monitoring settings.

Short Name: GC Duration

This NodeManager health test factors in the health of the host upon which the NodeManager is running. A failure of this test means that the host running the NodeManager is experiencing some problem. See that host's status page for more details.This test can be enabled or disabled using the NodeManager Host Health Test NodeManager monitoring setting.

Short Name: Host Health

This NodeManager health test checks that the filesystem containing the log directory of this NodeManager has sufficient free space. This test can be configured using the Log Directory Free Space Monitoring Absolute Thresholds and Log Directory Free Space Monitoring Percentage Thresholds NodeManager monitoring settings.

Short Name: Log Directory Free Space

This NodeManager health test checks that the Cloudera Manager Agent on the NodeManager host is heart beating correctly and that the process associated with the NodeManager role is in the state expected by Cloudera Manager. A failure of this health test may indicate a problem with the NodeManager process, a lack of connectivity to the Cloudera Manager Agent on the NodeManager host, or a problem with the Cloudera Manager Agent. This test can fail either because the NodeManager has crashed or because the NodeManager will not start or stop in a timely fashion. Check the NodeManager logs for more details. If the test fails because of problems communicating with the Cloudera Manager Agent on the NodeManager host, check the status of the Cloudera Manager Agent by running /etc/init.d/cloudera-scm-agent status on the NodeManager host, or look in the Cloudera Manager Agent logs on the NodeManager host for more details. This test can be enabled or disabled using the NodeManager Process Health Test NodeManager monitoring setting.

Short Name: Process Status

This is a NodeManager health test that checks whether the ResourceManager considers the NodeManager alive. A failure of this health test may indicate that the NodeManager is having trouble communicating with the ResourceManager. Look in the NodeManager logs for more details. This test may return an unknown result if the Service Monitor is not able to communicate with the ResourceManager web server. Check the status of the ResourceManager web server and the Service Monitor logs if this test is returning an unknown result. This test can be enabled or disabled using the NodeManager Connectivity Health Check NodeManager monitoring setting. The NodeManager Connectivity Tolerance at Startup NodeManager monitoring setting and the Health Check Startup Tolerance ResourceManager monitoring setting can be used to control the test's tolerance windows around NodeManager and ResourceManager restarts respectively.

Short Name: ResourceManager Connectivity

This NodeManager health test checks that the NodeManager has not recently exited unexpectedly. The test returns "Bad" health if the number of unexpected exits goes above a critical threshold. For example, if this test is configured with a critical threshold of 1, this test would return "Good" health if there have been no unexpected exits recently. If there has been 1 or more unexpected exits recently, this test would return "Bad" health. This test can be configured using the Unexpected Exits Thresholds and Unexpected Exits Monitoring Period NodeManager monitoring settings.

Short Name: Unexpected Exits

This NodeManager health test checks that the web server of the NodeManager is responding quickly to requests by the Cloudera Manager Agent, and that the Cloudera Manager Agent can collect metrics from the web server. A failure of this health test may indicate a problem with the web server of the NodeManager, a misconfiguration of the NodeManager or a problem with the Cloudera Manager Agent. Consult the Cloudera Manager Agent logs and the logs of the NodeManager for more detail. If the test's failure message indicates a communication problem, this means that the Cloudera Manager Agent's HTTP requests to the NodeManager's web server are failing or timing out. These requests are completely local to the NodeManager's host, and so should never fail under normal conditions. If the test's failure message indicates an unexpected response, then the NodeManager's web server responded to the Cloudera Manager Agent's request, but the Cloudera Manager Agent could not interpret the response for some reason. This test can be configured using the Web Metric Collection NodeManager monitoring setting.

Short Name: Web Server Status