Configure equal system service distribution among management hosts

Set the Balanced slot allocation policy

By default, system services are started on one management host until all the CPU slots on the host are used, then another host is selected and services are started on that one until all the CPU slots on that host are used, and so on. This can cause some management hosts to be overloaded while other hosts remain idle.

You can, however, configure the system so that system services are evenly distributed on management hosts. You do this by configuring the Balanced slot allocation policy on the ManagementHosts resource group.

When the Balanced slot allocation policy is enabled, hosts are selected according to the number of free CPU slots on the host. Since the number of free CPU slots on a host decreases with each allocation, the same host will not be reselected unless it has the highest number of free CPU slots.

  1. Select Consumers > Consumers & Plans > Resource Plan.

    The Resource Plan window is displayed.

  2. Select the ManagementHosts resource group.

    Resource Plan settings for this host group are displayed.

  3. Select Time Intervals and Settings > Show Advanced Settings from the drop-down menu.

    The slot allocation policy is displayed.

  4. Click Slot allocation policy to expand and select Balanced. Use free slots from the host with the highest number of free slots.

    You are given an information message because the Balanced slot allocation policy will not affect any system services that have already been started. Only system services that are started from this moment on will be allocated using the Balanced slot allocation policy.

Apply the Balanced slot allocation policy to current allocations

When you change the slot allocation policy, the new policy is only applicable to allocations requests made after the policy was changed.

In some cases, you may want to apply the policy immediately so that system services are redistributed equally among management hosts. You can do this by stopping and restarting the system services. Note that restarting services will affect cluster operations. Refer to the table below for details.

The following is a list of out-of-box services and the effect on your cluster during service restart:


Out-of-box services

Effect of restarting it

ServiceDirector

Services cannot be registered with Service Director.

WEBGUI

The Platform Management Console is temporarily unavailable. Users that are currently connected to the Platform Management Console will need to log on again.

WebServiceGateway

New clients cannot connect to the cluster through the Web Services API.

RS

Package deployment is not available.

purger

No data is purged from the database.

plc

Data is pending to be collected.

derbydb

Data cannot be stored in the Derby database.

SD

New client applications cannot connect to Symphony.

SOAM commands cannot be run.


  1. View how services are allocated among management hosts and make a note of which services you want to redistribute among management hosts.
    egosh service list -l
  2. Restart system services so that slots are allocated from management hosts according to the new allocation policy.

    To restart all system services in the cluster:

    egosh service stop all
    egosh service start all

    To restart each service individually, replace service_name with the name of the service:

    egosh service stop service_name
    egosh service start service_name

    For example, to restart Service Director:

    egosh service stop ServiceDirector
    egosh service start ServiceDirector
  3. View redistribution of services among management hosts.
    egosh service list
  4. For each application in your cluster, disable and enable it to restart the session manager.
    Important:

    When you disable an application, workload is terminated.

    soamcontrol app disable myapp -s
    soamcontrol app enable myapp
  5. View redistribution of session managers among management hosts.
    soamview app