Host Monitor Health Tests

This Host Monitor health test checks that the number of file descriptors used does not rise above some percentage of the Host Monitor 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 Host Monitor monitoring setting.

Short Name: File Descriptors

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

Short Name: Host Health

This Host Monitor health test checks that no messages are being dropped by the host stage of the Host Monitor pipeline. A failure of this health test indicates a problem with the Host Monitor. This may indicate a configuration problem or a bug in the Host Monitor. This test can be configured using the Host Monitor Host Pipeline Monitoring Time Period monitoring setting.

Short Name: Host Pipeline

This Host Monitor health test checks that the filesystem containing the log directory of this Host Monitor 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 Host Monitor monitoring settings.

Short Name: Log Directory Free Space

This Host Monitor health test checks that the Host Monitor threads are not experiencing long scheduling pauses. The test uses a pause monitoring thread in the Host Monitor that tracks scheduling delay by noting if it is run on its requested schedule. If the thread is not run on its requested schedule, the delay is noted and considered pause time. The health test checks that no more than some percentage of recent time is spent paused. A failure of this health test may indicate that the Host Monitor is not getting enough CPU resources, or that it is spending too much time doing garbage collection. Inspect the Host Monitor logs for any pause monitor output and check garbage collection metrics exposed by the Host Monitor. This test can be configured using the Pause Duration Thresholds and Pause Duration Monitoring Period Host Monitor monitoring settings.

Short Name: Pause Duration

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

Short Name: Process Status

This is a Host Monitor health test that checks that the filesystem containing the data storage directory of this Host Monitor has sufficient free space. This test can be configured using the Storage Directory Free Space Monitoring Absolute Thresholds and Storage Directory Free Space Monitoring Percentage Thresholds Host Monitor monitoring settings.

Short Name: Storage Directory Free Space

This Host Monitor health test checks that the Host Monitor 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 Host Monitor monitoring settings.

Short Name: Unexpected Exits

This health test checks that the role's web server is responding quickly to requests by the Cloudera Manager Agent, and that the Cloudera Manager Agent can collect metrics from the web server. Failure of this health test may indicate a problem with the web server of the Host Monitor, a misconfiguration of the Host Monitor or a problem with the Cloudera Manager Agent. Consult the Cloudera Manager Agent logs and the logs of the Host Monitor for more detail. If the test's failure message indicates a communication problem, the Cloudera Manager Agent's HTTP requests to the Host Monitor's web server are failing or timing out. If the test's failure message indicates an unexpected response, the Host Monitor's web server responded to the Cloudera Manager Agent's request, but the response could not be interpreted for some reason. This test can be configured using the Web Metric Collection Host Monitor monitoring setting.

Short Name: Web Server Status