Master Health Checks

Master File Descriptors

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

Short Name: File Descriptors

Property Name Description Template Name Default Value Unit
File Descriptor Monitoring Thresholds The health check thresholds of the number of file descriptors used. Specified as a percentage of file descriptor limit. master_fd_thresholds critical:70.000000, warning:50.000000 PERCENT

Master GC Duration

This Master health check checks that the Master 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 check may indicate a capacity planning problem or misconfiguration of the Master. This test can be configured using the HBase Master Garbage Collection Duration Thresholds and HBase Master Garbage Collection Duration Monitoring Period Master monitoring settings.

Short Name: GC Duration

Property Name Description Template Name Default Value Unit
HBase Master Garbage Collection Duration Monitoring Period The period to review when computing the moving average of garbage collection time. master_gc_duration_window 5 MINUTES
HBase Master Garbage Collection Duration Thresholds The health check thresholds for the weighted average time spent in Java garbage collection. Specified as a percentage of elapsed wall clock time. See HBase Master Garbage Collection Duration Monitoring Period. master_gc_duration_thresholds critical:60.000000, warning:30.000000 PERCENT

Master HBase Master Canary

This is an HBase Master health check that checks that a client can connect to and get basic information from the Master in a reasonable amount of time. The check returns "Bad" health if the connection to or basic queries of the Master fail. The check returns "Concerning" health if the connection attempt or queries do not complete in a reasonable time. A failure of this health check may indicate that the Master is failing to satisfy basic client requests correctly or in a timely fashion. Check the status of the Master, and look in the Master logs for more details. This test can be enabled or disabled using the HBase Master Canary Health Check HBase Master monitoring setting.

Short Name: HBase Master Canary

Property Name Description Template Name Default Value Unit
HBase Master Canary Health Check Enables the health check that a client can connect to the HBase Master master_canary_health_enabled true no unit

Master Host Health

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

Short Name: Host Health

Property Name Description Template Name Default Value Unit
HBase Master Host Health Check When computing the overall HBase Master health, consider the host's health. master_host_health_enabled true no unit

Master Log Directory Free Space

This Master health check checks that the filesystem containing the log directory of this Master 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 Master monitoring settings.

Short Name: Log Directory Free Space

Property Name Description Template Name Default Value Unit
Log Directory Free Space Monitoring Absolute Thresholds The health check thresholds for monitoring of free space on the filesystem that contains this role's log directory. log_directory_free_space_absolute_thresholds critical:5368709120.000000, warning:10737418240.000000 BYTES
Log Directory Free Space Monitoring Percentage Thresholds The health check thresholds for monitoring of free space on the filesystem that contains this role's log directory. Specified as a percentage of the capacity on that filesystem. This setting is not used if a Log Directory Free Space Monitoring Absolute Thresholds setting is configured. log_directory_free_space_percentage_thresholds critical:never, warning:never PERCENT

Master Process Status

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

Short Name: Process Status

Property Name Description Template Name Default Value Unit
HBase Master Process Health Check Enables the health check that the HBase Master's process state is consistent with the role configuration master_scm_health_enabled true no unit
Healthy HBase Region Servers Monitoring Thresholds The health check thresholds of the overall HBase Region Servers health. The check returns "Concerning" health if the percentage of "Healthy" HBase Region Servers falls below the warning threshold. The check is unhealthy if the total percentage of "Healthy" and "Concerning" HBase Region Servers falls below the critical threshold. hbase_regionservers_healthy_thresholds critical:90.000000, warning:95.000000 PERCENT

Master Unexpected Exits

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

Short Name: Unexpected Exits

Property Name Description Template Name Default Value Unit
Unexpected Exits Monitoring Period The period to review when computing unexpected exits. unexpected_exits_window 5 MINUTES
Unexpected Exits Thresholds The health check thresholds for unexpected exits encountered within a recent period specified by the unexpected_exits_window configuration for the role. unexpected_exits_thresholds critical:any, warning:never no unit

Master Web Server Status

This Master health check checks that the web server of the Master 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 check may indicate a problem with the web server of the Master, a misconfiguration of the Master or a problem with the Cloudera Manager agent. Consult the Cloudera Manager agent logs and the logs of the Master 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 Master's web server are failing or timing out. These requests are completely local to the Master's host, and so should never fail under normal conditions. If the test's failure message indicates an unexpected response, then the Master'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 Master monitoring setting.

Short Name: Web Server Status

Property Name Description Template Name Default Value Unit
Web Metric Collection Enables the health check that the Cloudera Manager Agent can successfully contact and gather metrics from the web server. master_web_metric_collection_enabled true no unit