ClusterControl Documentation
Use the menu below or the search below to learn everything you need to know about ClusterControl Settings

Settings for the cluster including general settings, mail notifications and thresholds. CMON Settings General Settings

  • Cluster Name
    • Cluster name. This name will appear in the database cluster list and database cluster summary.
  • Staging Area
    • The staging area is a directory (created automatically) to store intermediate data, such as dump files, binaries, packages used in installations, upgrades or scaling. The staging area is automatically cleaned, but should be big enough to hold dump files of your entire database.
  • Sudo
    • Sudo command password (if SSH User* is not root) if running as sudoers. Change in CMON configuration file under sudo.
  • SSH User
    • Read-only. The user that can SSH from the ClusterControl Server to the other nodes without password. Change in CMON configuration file under os_user or osuser.
  • SSH Identity
    • Read-only. Change in CMON configuration file under ssh_identity.
  • History
    • Number of days you would like to keep historic data. Ensure you have enough disk space on the ClusterControl server if you want to store historic data.
  • Log Interval
    • How many minutes between automatic MySQL error log retrieval. Email Notification Settings

Configures email notifications for alarms generated for your database cluster.

  • Send email to
    • Recipient email address.
  • Send digests at
    • Send a digested (summary) email at this time every day for the selected recipient.
  • Time-zone
    • Timezone for the selected recipient.
  • Daily limit for non-digest email as
    • The maximum number of non-digest email notification should be sent per day for the selected recipient. -1 for unlimited.
  • Alarm/Event Category
    Event Description
    Network Network related messages, e.g host unreachable, SSH issues.
    CmonDatabase Internal CMON database related messages.
    Mail Mail system related messages.
    Cluster Cluster related messages, e.g cluster failed.
    ClusterConfiguration Cluster configuration messages, e.g software configuration messages.
    ClusterRecovery Recovery messages like cluster or node recovery failures.
    Node Message related to nodes, e.g node disconnected, missing GRANT, failed to start HAProxy, failed to start NDB cluster nodes.
    Host Host related messages, e.g CPU/disk/RAM/swap alarms.
    DbHealth Database health related messages, e.g memory usage of mysql servers, connections.
    DbPerformance Alarms for long running transactions and deadlocks
    SoftwareInstallation Software installation related messages.
    Backup Messages about backups.
    Unknown Other uncategorized messages.
  • Select how you want alarms/events to be delivered
    Action Description
    Ignore Ignore if an alarm raised.
    Deliver Send notification immediately via email once an alarm raised.
    Digest Send a summary of alarms raised everyday at Send digests at Runtime Configuration

Summarizes the active ClusterControl Controller (CMON) runtime configuration parameters and displays the versions of ClusterControl Controller and ClusterControl UI packages. All parameters listed here are loaded directly from cmon.cmon_configuration table, displayed by the current cluster ID. You can filter out the variables by using the Search field on top of the table. Each parameter has the Current Value (the active value loaded into ClusterControl) and also the Default Value (if undefined, ClusterControl will use this value) as well as description of the parameter.

Some configuration parameters can be modified directly from the UI like swap_warning (Settings > Thresholds > Swap Warning) and backup_subdir (Backup > Settings > Default Backup Subdirectory). Some parameters have to be set inside CMON configuration file for the respective cluster ID.

Thus, there are two ways to modify the value of any parameter:

  1. Change the value directly from the UI if exists. This will save it into cmon database. No cmon restart requires.
  2. Append the parameter line inside CMON configuration file for the respective cluster at /etc/cmon.d/cmon_X.cnf (where X is the cluster ID). This requires cmon restart to get it loaded into cmon database.

As a side note, the settings that are set through UI will always take precedence.


You can also run cmon --help-config to get the details of supported parameters. Thresholds

Provides thresholds for warnings and critical event. Thresholds specify the threshold level at which an alarm will be triggered and notification will be sent via email to the list of recipients configured in the Email Notification Settings. Set your alarm thresholds for:

  • CPU, RAM, disk space and swap utilization
  • MySQL server memory utilization
  • DataMemory, IndexMemory, tablespace, redo log and buffer utilization (MySQL Cluster)
Level Description
Warning Sets your warning threshold in percentage for specific event.
Critical Sets your critical threshold in percentage for specific event. Graphs

Manages graph settings and data capturing. On each database node, ClusterControl records up to 82 MySQL counters every db_stats_collection_interval defined in CMON configuration file. The default is 30 seconds.

You can choose to view up to 20 counters in 2 or 3 columns layout on this page. The settings configured here affects ClusterControl > Performance > Overview page. Query Monitor

Manages how ClusterControl should perform query monitoring. It determines the output of:

  • ClusterControl > Overview > Cluster-Wide Queries
  • ClusterControl > Query Monitoring > Top Queries
  • ClusterControl > Query Monitoring > Query Outliers

Changes happened in this page does not require the CMON service to restart.

  • MySQL Local Query Override
    • Choose whether you want ClusterControl to override the local MySQL query sampling:
      • Yes - The local MySQL configuration settings inside my.cnf for long_query_time and log_queries_not_using_indexes will be used.
      • No - ClusterControl uses Long Query Time and Log queries not using indexes will be used across all MySQL Servers.
  • Long Query Time
    • Collects queries taking longer than Long Query Time seconds:
      • 0 - All queries.
      • 0.1 - Only queries taking more than 0.1 seconds will be accounted.