Contents

1   Description

This instruction describes how to increase the capacity of the MTAS 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.

2   Procedure

2.1   Manually Scale Out Cluster

Prerequisites

• This instruction references the following documents:
  • Create Backup
  • MTAS Hardening Guide
  • MTAS 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 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

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

2.2   Prepare for Scaling

Steps

1. Connect to one of the SC nodes:

   ssh <user>@<system management IP address>

2. Check the operational state of the scaling feature:

   SC-1: ~ # cmw-configuration --status SCALING

   The following is an example output:

   Disable

3. If the result is Enable, scaling is prepared. Exit this procedure.
4. If the result is Disable, enable scaling functionality:

   SC-1: ~ # cmw-configuration --enable SCALING

5. Before any scaling-related activities are performed, create a system backup. See Create Backup.

2.3   Configure Scale-Out

Steps

1. Make sure that the scaling feature is enabled and a system backup is created.
2. Check that the cluster is in a healthy state, see MTAS Health Check.
3. 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. Refer to the VIM documentation for how to create VMs.
4. Launch the new VMs in the VIM. The new VMs automatically PXE boot from the System Controller (SC) node VMs.
5. Navigate to the CrM Managed Object (MO), for example:

   >dn ManagedElement=1,SystemFunctions=1,SysM=1,CrM=1

6. 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

7. 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.

8. Do a SmallRestart:
   1. Run the SmallRestart command:

      >ManagedElement=1,MtasFunction=MtasFunction,\
      mtasFunctionSmallRestart

   2. Exit from the ECLI:

      >exit

9. Perform a health check, see MTAS Health Check.