TaskTracker Health Tests

This is a TaskTracker health test that checks that the JobTracker has not blacklisted the TaskTracker. A failure of this health test indicates that the JobTracker has blacklisted the TaskTracker because of the failure rate of tasks on the TaskTracker is significantly higher than the average cluster failure rate. Check the TaskTracker logs for more details. This test can be enabled or disabled using the TaskTracker Blacklisted Health Test TaskTracker monitoring setting.

Short Name: Blacklisted Status

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

Short Name: File Descriptors

This TaskTracker health test checks that the TaskTracker 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 TaskTracker. This test can be configured using the Garbage Collection Duration Thresholds and Garbage Collection Duration Monitoring Period TaskTracker monitoring settings.

Short Name: GC Duration

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

Short Name: Host Health

This is a TaskTracker health test that checks whether the JobTracker considers the TaskTracker alive. A failure of this health test may indicate that the TaskTracker is having trouble communicating with the JobTracker. Look in the TaskTracker logs for more details. This test can be enabled or disabled using the TaskTracker Connectivity Health Test TaskTracker monitoring setting. The TaskTracker Connectivity Tolerance at Startup TaskTracker monitoring setting and the Health Check Startup Tolerance JobTracker monitoring setting can be used to control the test's tolerance windows around TaskTracker and JobTracker restarts respectively.

Short Name: JobTracker Connectivity

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

Short Name: Log Directory Free Space

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

Short Name: Process Status

This TaskTracker health test checks that the TaskTracker 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 TaskTracker 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 TaskTracker, a misconfiguration of the TaskTracker or a problem with the Cloudera Manager Agent. Consult the Cloudera Manager Agent logs and the logs of the TaskTracker for more detail. If the test's failure message indicates a communication problem, the Cloudera Manager Agent's HTTP requests to the TaskTracker's web server are failing or timing out. If the test's failure message indicates an unexpected response, the TaskTracker'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 TaskTracker monitoring setting.

Short Name: Web Server Status