ZooKeeper Server Health Tests

This is a ZooKeeper Server role-level health test that checks that a moving average of the ZooKeeper Server's connection count does not exceed some value. A failure of this health test indicates a high connection load on the ZooKeeper Server. This test can be configured using the ZooKeeper Server Connection Count Thresholds and ZooKeeper Server Connection Count Monitoring Period ZooKeeper Server monitoring settings.

Short Name: Connection Count.

This is a ZooKeeper Server health test that checks that the filesystem containing the data directory of this ZooKeeper Server has sufficient free space. The data directory contains the database snapshots of the ZooKeeper Server. This test can be configured using the Data Directory Free Space Monitoring Absolute Thresholds and Data Directory Free Space Monitoring Percentage Thresholds ZooKeeper Server monitoring settings.

Short Name: Data Directory Free Space

This is a ZooKeeper Server health test that checks that the filesystem containing the data log directory of this ZooKeeper Server has sufficient free space. The data log directory contains the transaction logs of the ZooKeeper Server. This test can be configured using the Data Log Directory Free Space Monitoring Absolute Thresholds and Data Log Directory Free Space Monitoring Percentage Thresholds ZooKeeper Server monitoring settings.

Short Name: Data Log Directory Free Space

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

Short Name: File Descriptors

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

Short Name: GC Duration

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

Short Name: Host Health

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

Short Name: Log Directory Free Space

This is a ZooKeeper server health test that checks that the ratio of the maximum request latency to the maximum client-negotiable session timeout does not exceed some value. Note that the maximum client-negotiable timeout need not be the actual session timeout used by a client but is the upper bound of such client session timeouts. As a result, this test being in "Good" health does not preclude clients from experiencing timeouts based on the particular session timeout value they have negotiated with the server. A failure of this health test likely indicates a high load on the ZooKeeper Server. This test can be configured using the Maximum Latency Monitoring Thresholds ZooKeeper Server monitoring setting.

Short Name: Maximum Request Latency

This is a ZooKeeper Server role-level health test that checks that a moving average of the size of the ZooKeeper Server's outstanding requests does not exceed some value. Outstanding requests are the number of queued requests in the server. It increases when the server is under load and is receiving more sustained requests than it can process. A failure of this health test indicates a high connection load on the ZooKeeper Server. This test can be configured using the ZooKeeper Server Outstanding Requests Thresholds and ZooKeeper Server Outstanding Requests Monitoring Period ZooKeeper Server monitoring settings.

Short Name: Outstanding Requests.

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

Short Name: Process Status

This is a ZooKeeper server role-level health test to verify that the server is part of a quorum. This check is disabled if the ZooKeeper Server is in standalone mode. The test returns "Concerning" health as long as the quorum membership status for the ZooKeeper Server was determined within the detection window and it is in leader election. The test returns "Bad" health if the ZooKeeper Server is not part of a quorum or the quorum status of the ZooKeeper Server could not be determined for the entire detection window. A failure of this health test may indicate a communication problem between this ZooKeeper Server and the rest of its peers or between the Cloudera Manager Service Monitor and the ZooKeeper Server. Check the ZooKeeper Server and Cloudera Manager Service Monitor logs for additional information. This test can be enabled or disabled using the Enable the Quorum Membership Check ZooKeeper Server monitoring setting. In addition, the Quorum Membership Detection Window setting can be used to adjust the time that the Cloudera Manager Service Monitor has to detect the ZooKeeper Server quorum membership status before this health test fails.

Short Name: Quorum Membership.

This Server health test checks that the Server 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 Server monitoring settings.

Short Name: Unexpected Exits