Increase Capacity Manually

1 Description

This instruction describes how to increase the capacity of the Call Session Control Function (CSCF) cluster, that is, to scale out, by adding a Virtual Machine (VM) to it.

This document always refers to horizontal scaling, where the scalability of the system is provided by multiple instances to distribute the load in parallel for having the capacity needed. Vertical scaling is not considered in this document.

The scaling function does not require a license.

Note:: Even though the PL-3 and PL-4 Virtual Machines (VMs) are considered to be part of the scaling domain, they cannot be scaled in.

2 Procedure

2.1 Increase Capacity Manually

Prerequisites

This instruction references the following documents:
- CSCF Health Check
- Ericsson Command-Line Interface User Guide
No tools are required.
The following conditions must apply:
- The procedure must only be performed by support personnel with experience of Cloud and the CSCF.
- No other upgrade or maintenance activity must be performed during the procedure.
- Before starting these procedures, the user performing the operations must have access to the System Controller (SC) nodes.
- Signaling Manager Command-Line Interface (CLI) or Graphical User Interface (GUI) must be closed before the start of the Scaling Operations. Manual updates of the configurations during Scaling Operations are not allowed.
- A Virtual Infrastructure Manager (VIM) is available.
- An Ericsson Command-Line Interface (ECLI) session in Exec mode is in progress.

Steps

Prepare for scaling, see Section 2.2 Prepare for Scaling.
Increase capacity, see Section 2.3 Configure Scale-Out.

2.2 Prepare for Scaling

Steps

Connect to one of the SC nodes:
ssh <user>@<system management IP address>
Check the operational state of the scaling feature:
SC-1: ~ # cmw-configuration --status SCALING

The following is an example output:
Disable
If the result is Enable, scaling is prepared. Exit this procedure.
If the result is Disable, enable scaling functionality:
SC-1: ~ # cmw-configuration --enable SCALING
Before any scaling-related activities are performed, create a system backup. See Create Backup.

2.3 Configure Scale-Out

Steps

Make sure that the scaling feature is enabled and a system backup is created.
Before any scaling-related activities are performed, create a system backup. See Create Backup.
Check that the cluster is in a healthy state, see CSCF Health Check.
Create VMs that must have the same number of Virtual CPUs (vCPUs), the same amount of RAM, and the same number of ports as the other Payload (PL) VMs in the cluster. See the VIM documentation for how to create VMs.
Launch the new VMs in the VIM. The new VMs automatically PXE boot from the System Controller (SC) node VMs.
Navigate to the CrM Managed Object (MO), for example:
>dn ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1

Verify that the scale-out process has started:

(CrM=1)>show -r

The following is an example output:

CrM=1
   autoRoleAssignment=ENABLED
   ComputeResourceRole=PL-3
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=Default-Role"
      uses="ManagedElement=1,Equipment=1,ComputeResource=PL-3"
   ComputeResourceRole=PL-4
      adminState=UNLOCKED
      instantiationState=INSTANTIATING
      operationalState=DISABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=Default-Role"
      uses="ManagedElement=1,Equipment=1,ComputeResource=PL-4"
   Role=SYSTEM
      isProvidedBy
      scalability=NON_SCALABLE
   Role=Default-Role
      isProvidedBy
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-3"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-4"
      scalability=SCALABLE

Continue to check the progress of the scale-out process until it ends. Also make sure that the added node has joined the cluster:
(CrM=1)>show -m ComputeResourceRole -p \ instantiationState,operationalState

The following example output shows the final result:
ComputeResourceRole=PL-3 instantiationState=INSTANTIATED operationalState=ENABLED ComputeResourceRole=PL-4 instantiationState=INSTANTIATED operationalState=ENABLED
This example shows that instantiationState has changed to INSTANTIATED for node PL-4. It means that PL-4 is added to the cluster.

The example also shows that operationalState has changed to ENABLED for node PL-4. It means that node PL-4 has joined the cluster.
Perform a health check, see CSCF Health Check.

1	Description
2	Procedure
2.1	Increase Capacity Manually
2.2	Prepare for Scaling
2.3	Configure Scale-Out