This is the documentation for Cloudera Manager 4.8.5.
Documentation for other versions is available at Cloudera Documentation.

Configuring Monitoring Settings

There are several types of monitoring settings you can configure in Cloudera Manager:

  • For a service or role for which monitoring is provided, you can enable and disable selected health checks and events, configure how those health checks factor into the overall health of the service, and modify thresholds for the status of certain health checks. Cloudera Manager supports this type of monitoring configuration for HDFS, MapReduce, HBase, Impala, ZooKeeper, and Flume. For hosts you can disable or enable selected health checks, modify thresholds, and enable or disable health alerts.
  • For the Cloudera Management Services you can configure monitoring settings for the monitoring roles — enable and disable health checks on the monitoring processes as well as configuring some general settings related to events and alerts (specifically with the Event Server and Alert Publisher). Each of the Cloudera Management Services has its own parameters that can be modified in order to specify how much data is retained by that service. For some monitoring functions, the amount of retained data can grow very large, so it may become necessary to adjust the limits.

This section covers the following topics:

For general information about modifying configuration settings, see Modifying Configuration Settings.

Configuring Activity Monitoring

The Activity Monitor monitors the MapReduce jobs running on your cluster. This also includes the higher-level activities, such as Pig, Hive, and Oozie workflows that eventually run as MapReduce tasks. Currently the Activity Monitor does not support MapReduce v2 (YARN).

You can monitor for slow-running jobs or jobs that fail, and alert on these events. To detect jobs that are running too slowly, you must configure a set of activity duration rules that specify what jobs to monitor, and what the limits on duration are for those jobs. A "slow activity" event occurs when a job exceeds the duration limit configured for it in an activity duration rule. Activity duration rules are not defined by default; you must configure these rules if you want to see events for jobs that exceed the duration defined by these rules.

To configure Activity Monitor settings for MapReduce:

  1. Click the Services tab.
  2. Select the MapReduce service instance.
  3. Select Configuration > View and Edit.
  4. Click the Monitoring category at the bottom of the left-hand Category panel.
  5. Click Service-Wide.
  6. Specify one or more activity duration rules.
  7. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Activity Duration Rules

An activity duration rule is a regular expression (used to match an activity name (Job ID)) combined with a run time limit which the job should not exceed. You can add as many rules as you like, one per line, in the Activity Duration Rules property.

The format of each rule is regex=number where the regex is a regular expression to match against the activity name, and number is the job duration limit, in minutes. When a new activity starts, each regex expression is tested against the name of the activity for a match.

The list of rules is tested in order, and the first match found is used. For example, if the rule set is:

foo=10
bar=20

Any activity named "foo" would be marked slow if it ran for more than 10 minutes. Any activity named "bar" would be marked slow if it ran for more than 20 minutes.

Since full Java regular expressions can be used, if the rule set is:

foo.*=10
bar=20

In this case, any activity with a name that starts with "foo" (for example, fool, food, foot) will match the first rule (see http://download.oracle.com/javase/tutorial/essential/regex/).

If there is no match for an activity, then that activity will not be monitored for job duration. However, you can add a "catch-all" as the last rule which will always match any name:

foo.*=10
bar=20
baz=30
.*=60

In this case, any job that runs longer than 60 minutes will be marked slow and will generate an event.

Configuring Health Monitoring

The initial health monitoring configuration is handled during the installation and configuration of your cluster, and most monitoring parameters have default settings. However, you can set or modify these at any time.

To configure a service monitoring setting:

  1. Click the Services tab, and select the service instance you want to modify. (This can be any of the services for which monitoring is provided, or the Cloudera Manager management service.)
  2. Select Configuration > View and Edit.
  3. Click the Monitoring category at the bottom of the left-hand Category panel.
  4. Under the Monitoring category, select the category of properties you want to change (these are organized as service-wide or by role).
  5. Configure the property.
  6. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

To configure a host monitoring setting:

  1. Click the Hosts tab.
  2. To modify the settings for an individual host, select the host.
  3. Select Configuration > View and Edit.
  4. Click the Monitoring category at the bottom of the left-hand Category panel.
  5. Configure the property.
  6. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Depending on the service or role you select, and the configuration category, you can enable or disable health checks, determine when health checks cause alerts, or determine whether specific health checks are used in computing the overall health of a role or service. In most cases you can disable these "roll-up" health checks separately from the individual health checks.

As a rule, a health check whose result is considered "Concerning" or "Bad" will be forwarded as an event to the Event Server. That includes health checks whose results are based on configured Warning or Critical thresholds, as well pass-fail type health checks. An event will also be published when the Health Check result returns to normal.

You can control when an individual health check will be forwarded as an event or an alert by modifying the threshold values for the relevant health test.

Configuring Directory Monitoring

Cloudera Manager can perform threshold-based monitoring of free space in the various directories on the hosts its monitors — such as log directories or checkpoint directories (for the Secondary NameNode).

These thresholds can be set in one of two ways — as absolute thresholds (in terms of MiB and GiB, and so on) or as percentages of space. As with other threshold properties, you can set values that will trigger events at both the Warning and Critical levels.

If you set both thresholds, the Absolute Threshold setting will be used.

These thresholds are set under the Monitoring category of the Configuration page for each service.

Configuring Impala Query Monitoring

You can configure the visibility of the Impala query results and the size of the storage allocated to Impala query results.

Configuring Query Visibility

To configure whether admin and non-admin users can view all queries, only that user's queries, or no queries:

  1. Click the Services tab.
  2. Select the Impala service instance.
  3. Select Configuration > View and Edit.
  4. Click the Monitoring category at the bottom of the left-hand Category panel.
  5. Click Service-Wide.
  6. Set the Query List Settings properties for admin and non-admin users.
  7. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Configuring Impala Query Store and Runtime Profile Maximum Size

The query store stores enough information to make the query searchable through the filter language. The query profile stores the information on the details page.
  1. Click the Services tab.
  2. Select a Cloudera Management service instance.
  3. Select Configuration > View and Edit.
  4. Click the Service Monitor (Default) > Advanced category at the bottom of the left-hand Category panel.
  5. Set the Impala Query Store Maximum Size property. The default is 25MiB. If specifying a larger cache size, the overall Java heap size should be increased accordingly.
  6. Set the Impala Runtime Profile Maximum Size property. The default is 25MiB. If specifying a larger cache size, the overall Java heap size should be increased accordingly.
  7. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.
  8. Restart the Service Monitor.

Configuring Alerts

Enabling Activity Monitor Alerts

You can enable alerts when an activity runs too slowly or fails.

  1. Click the Services tab.
  2. Select the MapReduce service instance.
  3. Select Configuration > View and Edit.
  4. Click the Monitoring category at the bottom of the left-hand Category panel.
  5. Click Service-Wide.
  6. Check the Alert on Slow Activities or Alert on Activity Failure checkboxes.
  7. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Enabling Configuration Change Alerts

Configuration change alerts can be set service wide, and/or on specific roles for the service.
  1. Click a service, role, or host.
  2. Select Configuration > View and Edit.
  3. Click the Monitoring category at the bottom of the left-hand Category panel.
  4. Check the Enable Configuration Change Alerts checkbox.
  5. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Enabling HBase Alerts

  1. Click the Services tab.
  2. Select the HBase service instance.
  3. Select Configuration > View and Edit.
  4. Click the Monitoring category at the bottom of the left-hand Category panel.
  5. Click Service-Wide.
  6. Set one of the region or Hbck alerts:
    • Hbck Region Error Count
    • Hbck Error Count
    • Hbck Alert Error Codes
    • Hbck Slow Run
    • Region Health Canary Slow Run
    • Canary Unhealthy Region Count
    • Canary Unhealthy Region Percentage
  7. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Configuring Health Alerts

Enabling Health Alerts

You can enable alerts when the health of a service or role crosses a threshold.

  1. Click the Services tab, and select the service instance you want to modify.
  2. Select Configuration > View and Edit.
  3. Click the Monitoring category at the bottom of the left-hand Category panel.
  4. Check the Enable Health Alerts for this Role checkbox.
  5. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Modifying the Heath Threshold

You can configure the threshold when a health alert is raised.

  1. Click the Services tab.
  2. Select a Cloudera Management service instance.
  3. Select Configuration > View and Edit.
  4. Select Event Server.
  5. Click the Health Alert Threshold value, and choose Bad or Concerning radio button.
  6. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Configuring Alerts Transitioning Out of Alerting Health Threshold

You can configure an alert when a service or role instances transition from an alerting to a non-alerting health threshold.

  1. Click the Services tab.
  2. Select a Cloudera Management service instance.
  3. Select Configuration > View and Edit.
  4. Check the Alert on Transitions out of Alerting Health checkbox.
  5. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

Configuring Log Alerts

You can configure an alert when a daemon emits a log message that matches a specified regular expression. See Configuring Log Events.

Configuring Alert Delivery

You can configure alerts to be delivered by email or sent as SNMP traps. These configurations are set under the Alert Publisher role of the Cloudera Manager management service. See Configuring Alert Delivery.

If you want to add to or modify the list of alert recipient email addresses, you can do this starting at the Administration > Alerts page. You can also send a test alert e-mail from this page.

  Note: If alerting is enabled for events, you will be able to search for and view alerts in the Events tab, even if you do not have email notification configured.

Configuring Log Events

You can enable or disable the forwarding of selected log events to the Event Server. This is enabled by default, and is a service-wide setting (Enable Log Event Capture) for each service for which monitoring is provided. You can enable and disable event capture for CDH services or for the Cloudera management services.

To enable or disable log event capture:

  1. Click the Services tab, and select the service instance you want to modify.
  2. Select Configuration > View and Edit.
  3. Click the Monitoring category at the bottom of the left-hand Category panel.
  4. Under Service-Wide > Events and Alerts, modify the Enable Log Event Capture setting.
  5. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

You can also modify the rules that determine how log messages are turned into events. Editing these rules is not recommended.

For each role, there are rules that govern how its log messages are turned into events by the custom log4j appender for the role. These are defined in the Rules to Extract Events from Log Files property for each HDFS, MapReduce and HBase role, and for ZooKeeper, Flume agent, and monitoring roles as well.

To configure which log messages become events:

  1. Click the Services tab, and select the service instance you want to modify.
  2. Click the Monitoring category at the bottom of the left-hand Category panel.
  3. Select the role group for the Role for which you want to configure log events, or search for "Rules to Extract Events from Log Files". Note that for some roles there may be more than one role group, and you may need to modify all of them. The easiest way to ensure that you have found all occurrences of the property to need to modify is to search for the property by name; Cloudera Manager will show all copies of the property that match the search filter.
  4. Edit these rules as needed.
  5. Click Save Changes to commit the changes. You can add a note that will be included with the change in the Configuration History.

A number of useful rules are defined by default, based on Cloudera's experience supporting Hadoop clusters. For example:

  • The line {"rate": 10, "threshold":"FATAL"}, means log entries with severity FATAL should be forwarded as events, up to 10 a minute.
  • The line {"rate": 0, "exceptiontype": "java.io.EOFException"}, means log entries with the exception java.io.EOFException should always be forwarded as an event.

The syntax for these rules is defined in the Description field for this property: the syntax lets you create rules that identify log messages based on log4j severity, message content matching, and/or the exception type. These rules must result in valid JSON. You can also specify that the event should generate an alert (by setting "alert":true in the rule). If you specify a content match, the entire content must match — if you want to match on a partial string, you must provide wildcards as appropriate to allow matching the entire string.

  Note: Editing these rules is not recommended. Cloudera Manager provides a default set of rules that should be sufficient for most users.