Automated configuration

In the performance monitoring tool, sensors can be configured on nodes that are part of an IBM Storage Scale cluster through an IBM Storage Scale based configuration mechanism. However, this requires the execution of the mmchconfig release=LATEST command.

The automated configuration method allows the sensor configuration to be stored as part of the IBM Storage Scale configuration. Automated configuration is available for the sensor configuration files, /opt/IBM/zimon/ZIMonSensors.cfg, and partly for the collector configuration files, /opt/IBM/zimon/ZIMonCollector.cfg. Only the peers section for federation is available for the collector configuration files. In this setup, the /opt/IBM/zimon/ZIMonSensors.cfg configuration file on each IBM Storage Scale node is maintained by IBM Storage Scale. As a result, the file must not be edited manually because whenever IBM Storage Scale needs to update a configuration parameter, the file is regenerated and any manual modifications are overwritten. Before using the automated configuration, an initial configuration needs to be stored within IBM Storage Scale. You can store this initial configuration by using the mmperfmon config generate command as shown:

prompt# mmperfmon config generate \
--collectors collector1.domain.com,collector2.domain.com,...

The mmperfmon config generate command uses a template configuration file for generating the automated configuration. The default location for that template configuration is /opt/IBM/zimon/defaults/ZIMonSensors.cfg.

The template configuration includes the initial settings for all the sensors and may be modified prior to invoking the mmperfmon config generate command. This file also includes a parameter called colCandidates. This parameter specifies the number of collectors that each sensor must report its data to. This may be of interest for high-availability setups, where each metric must be sent to two collectors in case one collector becomes unavailable. The colCandidates parameter is used to automatically configure federation between the specified collectors. For more information, see Configuring multiple collectors.

Once the configuration file is stored within IBM Storage Scale, it can be activated as follows:
prompt# mmchnode --perfmon –N nodeclass1,nodeclass2,…
Note: Any previously existing configuration file is overwritten. Configuration changes result in a new version of the configuration file, which is then propagated through the IBM Storage Scale cluster at the file level.

To deactivate the performance monitoring tool, the same command is used but with the --noperfmon switch supplied instead. Configuration parameters can be changed with the following command where parami is of the form sensorname.sensorattribute:
prompt mmperfmon config update param1=value1 param2=value2 …

Sensors that collect per cluster metrics such as GPFSDiskCap, GPFSFilesetQuota, GPFSFileset, and GPFSPool must only run on a single node in the cluster for the following reasons:
  1. They typically impose some overhead.
  2. The data reported is the same, independent of the node the sensor is running on
Other sensors such, as the cluster export services sensors, must also only run on a specific set of nodes. For all these sensors, the restrict function is especially intended.

Some sensors, such as VFS, are not enabled by default even though they have associated predefined queries with the mmperfmon query command. To enable VFS sensors, use the mmfsadm vfsstats enable command on the node. To enable a sensor, set the period value to an integer greater than 0 and restart the sensors on that node by using the systemctl restart pmsensors command.

Removing an automated configuration

When upgrading the performance monitoring tool, it is important to note how the previous version was configured and if the configuration mechanism is to be changed. If the configuration mechanism is to be changed, it is important to verify that the installed versions of both IBM Storage Scale and the performance monitoring tool support the new configuration method. However, if you want to use the manual configuration method, then take care of the following:

  1. None of the nodes in the cluster must be designated perfmon nodes. If the nodes in the cluster are designated as perfmon nodes then run mmchnode --noperfmon –N all command.
  2. Delete the centrally stored configuration information by issuing mmperfmon config delete --all command.
  3. Manual configuration is no longer actively supported.

The /opt/IBM/zimon/ZIMonSensors.cfg file is then maintained manually. This mode is useful if sensors are to be installed on non-IBM Storage Scale nodes or if you want to have a cluster with multiple levels of IBM Storage Scale running.