Manually Scale In Cluster

MTAS

1	Description
2	Procedure
2.1	Manually Scale In Cluster
2.2	Prepare for Scaling
2.3	Configure Graceful Scale-In
2.4	Configure Forceful Scale-In

1 Description

This instruction describes how to decrease the MTAS cluster capacity by performing either a graceful or forceful 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 Manually Scale In Cluster

Prerequisites

This instruction references the following documents:
No tools are required.
The following conditions must apply:
- The procedure must only be performed by support personnel with experience of Cloud and MTAS.
- 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.
- Scaling must only be performed after site-specific initial configuration is applied on the node. For more details, see MTAS Hardening Guide.
- 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.
Select action based on the type of scale-in:
- Decrease capacity through graceful scale-in, see Section 2.3 Configure Graceful Scale-In.
- Decrease capacity through forceful scale-in, see Section 2.4 Configure Forceful Scale-In.

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 Graceful Scale-In

Steps

Make sure that the scaling feature is enabled and a system backup is created. See Section 2.2 Prepare for Scaling.
Check that the cluster is in a healthy state, see MTAS 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, for example:

(CrM=1)>show -r

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, for example:
(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, for example:
(CrM=1)>show -r
If a failure occurs during the scale-in, see MTAS 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. Refer to the VIM documentation.
Perform a health check, refer to MTAS Health Check.

2.4 Configure Forceful Scale-In

Steps

Check that the cluster is in a healthy state, see MTAS 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, for example:

(CrM=1)>show -r

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, for example:
(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 scaling-in process has started, for example:

(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, refer to MTAS 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

Perform a health check, refer to MTAS Health Check.