Decrease Capacity Manually

1 Description

This instruction describes how to decrease the Call Session Control Function (CSCF) cluster capacity by performing a graceful scale-in operation, which removes a Virtual Machine (VM) from the cluster.

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 Decrease 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

Select an action based on the type of scale-in:
- Decrease capacity through graceful scale-in, see Section 2.2 Configure Graceful Scale-In.
- Decrease capacity through forceful scale-in, see Section 2.3 Configure Forceful Scale-In.

2.2 Configure Graceful Scale-In

Steps

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.
Navigate to the CrM MO, for example:
>dn ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1

Verify that the VM to be scaled in is scalable:

(CrM=1)>show -r

The following is an example output:

CrM=1
   autoRoleAssignment=ENABLED
   ComputeResourceRole=PL-5
      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-5"
   ComputeResourceRole=PL-7
      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-7"
   ComputeResourceRole=PL-4
      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-4"
   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=SC-2
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=SYSTEM"
      uses="ManagedElement=1,Equipment=1,ComputeResource=SC-2"
   ComputeResourceRole=SC-1
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=SYSTEM"
      uses="ManagedElement=1,Equipment=1,ComputeResource=SC-1"
   ComputeResourceRole=PL-6
      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-6"
   Role=SYSTEM
      isProvidedBy
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=SC-1"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=SC-2"
      scalability=NON_SCALABLE
   Role=Default-Role
      isProvidedBy
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-6"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-3"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-4"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-5"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-7"
      scalability=SCALABLE

Retrieve the Universally Unique Identifier (UUID) for the VM to be scaled in, for example:
(CrM=1)>show ManagedElement=1,Equipment=1,\ ComputeResource=PL-8

The following is an example output:
ComputeResource=PL-8 macAddress "fa:16:3e:b7:d3:a3" "fa:16:3e:27:cb:90" "fa:16:3e:24:73:4a" uuid="a4dcda89-cf95-4bf6-81bd-99d47fde9eef"
Navigate to the ComputeResourceRole MO for the VM to be scaled in, for example:
(CrM=1)>ComputeResourceRole=PL-8
Enter Config mode:
(ComputeResourceRole=PL-8)>configure
Prepare the scale-in operation:
(config-ComputeResourceRole=PL-8)>no provides
Navigate to the CrM MO:
(config-ComputeResourceRole=PL-8)>up
Perform the scale-in:
(config-CrM=1)>commit

Note:
To cancel the scale-in, run abort.

Verify that the scale-in process has started:

(CrM=1)>show -r

The following is an example output:

ComputeResourceRole=PL-8
      adminState=SHUTTINGDOWN
      instantiationState=UNINSTANTIATING
      operationalState=ENABLED
      uses="ManagedElement=1,Equipment=1,ComputeResource=PL-8"

If a failure occurs during the scale-in, see CSCF Troubleshooting Guideline.

Verify that the VM is scaled in:

(CrM=1)>show -r

The following is an example output showing that the VM ComputeResourceRole=PL-8 is no longer running:

CrM=1
   autoRoleAssignment=ENABLED
   ComputeResourceRole=PL-3
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=SYSTEM"
      uses="ManagedElement=1,Equipment=1,ComputeResource=PL-3"
   ComputeResourceRole=PL-4
      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-4"
   ComputeResourceRole=SC-1
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=SYSTEM"
      uses="ManagedElement=1,Equipment=1,ComputeResource=SC-1"
   ComputeResourceRole=SC-2
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=SYSTEM"
      uses="ManagedElement=1,Equipment=1,ComputeResource=SC-2"
   ComputeResourceRole=PL-5
      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-5"
   ComputeResourceRole=PL-6
      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-6"
   ComputeResourceRole=PL-7
      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-7"
   Role=Default-Role
      isProvidedBy
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-4"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-5"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-6"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-7"
      scalability=SCALABLE
   Role=SYSTEM
      isProvidedBy
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-3"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=SC-1"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=SC-2"
      scalability=NON_SCALABLE

Remove the VM with the UUID that is retrieved in Step 5 from the VIM. See the VIM documentation.
Check that the cluster is in a healthy state, see CSCF Health Check.

2.3 Configure Forceful Scale-In

Steps

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.
Remove one of the scalable VMs from the VIM.
Note:
Do not delete any of the VMs named SC-1, SC-2, PL-3, or PL-4.
Navigate to the CrM MO, for example:
>dn ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1

Identify the ComputeResourceRole where the adminState is LOCKED and operationalState is DISABLED:

(CrM=1)>show -r

The following is an example output:

ComputeResourceRole=PL-8
      adminState=LOCKED
      instantiationState=INSTANTIATED
      operationalState=DISABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=Default-Role"
      uses="ManagedElement=1,Equipment=1,ComputeResource=PL-8"

Enter Config mode:
(ComputeResourceRole=PL-8)>configure
Prepare the scale-in operation:
(config-ComputeResourceRole=PL-8)>no provides
Navigate to the CrM MO:
(config-ComputeResourceRole=PL-8)>up
Perform the scale-in:
(config-CrM=1)>commit

Verify that the scale-in process has started:

(CrM=1)>show -r

The following is an example output:

ComputeResourceRole=PL-8
      adminState=LOCKED
      instantiationState=INSTANTIATED
      operationalState=DISABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=Default-Role"
      uses="ManagedElement=1,Equipment=1,ComputeResource=PL-8"

If a failure occurs during the scale-in, see CSCF Troubleshooting Guideline.

Verify that the VM is scaled in:

(CrM=1)>show -r

The following is an example output showing that the VM ComputeResourceRole=PL-8 is no longer running:

CrM=1
   autoRoleAssignment=ENABLED
   ComputeResourceRole=PL-3
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=SYSTEM"
      uses="ManagedElement=1,Equipment=1,ComputeResource=PL-3"
   ComputeResourceRole=PL-4
      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-4"
   ComputeResourceRole=SC-1
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=SYSTEM"
      uses="ManagedElement=1,Equipment=1,ComputeResource=SC-1"
   ComputeResourceRole=SC-2
      adminState=UNLOCKED
      instantiationState=INSTANTIATED
      operationalState=ENABLED
      provides="ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,Role=SYSTEM"
      uses="ManagedElement=1,Equipment=1,ComputeResource=SC-2"
   ComputeResourceRole=PL-5
      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-5"
   ComputeResourceRole=PL-6
      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-6"
   ComputeResourceRole=PL-7
      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-7"
   Role=Default-Role
      isProvidedBy
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-4"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-5"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-6"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-7"
      scalability=SCALABLE
   Role=SYSTEM
      isProvidedBy
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=PL-3"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=SC-1"
         "ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1,ComputeResourceRole=SC-2"
      scalability=NON_SCALABLE

Check that the cluster is in a healthy state, see CSCF Health Check.

1	Description
2	Procedure
2.1	Decrease Capacity Manually
2.2	Configure Graceful Scale-In
2.3	Configure Forceful Scale-In