Sizing and scalability considerations

The sizing baselines specified in this topic are based on the performance lab benchmark test results performed in BMC’s test labs. You may use these baselines as a reference for your on-premises BMC Helix Service Management deployment.

Concurrent user requirements

Sizing requirements are measured in groups of T-shirt sizes such as Small, Medium, and Large. Each group has a considered maximum load of the following users:

• Concurrent users—represent the number of users who are logged in and actively working on a system across each of the following applications that are hosted on a single deployment of BMC Helix Service Management:
  • BMC Helix ITSM
  • BMC Helix ITSM: Smart IT
  • BMC Helix Dashboards
  • BMC Digital Workplace
  • BMC Digital Workplace Catalog
  • BMC Live Chat
• Resilient concurrent users—are the maximum number of users that the deployment should handle from a single failure without service interruption if pods in the deployment become unavailable.

In real-world deployments, concurrent users might not be the only factor that drives the categorization of a system in the Small, Medium, or Large category. For example, if you have a high number of integrations that create a high number of system transactions, you must increase your sizing to accommodate the additional load from integrations.

The following table lists the concurrent user guidelines for a deployment size:

Considerations when building a Kubernetes cluster

There are several considerations when building a Kubernetes cluster regarding sizing before considering the application requirements. The application requirements are meant to be included in addition to your other resource requirements. This could include but not be limited to:

• Kubernetes control plane nodes
• Host operating system requirements of worker nodes
• Kubernetes management software requirements
• Additional software (for example: monitoring software) that is deployed on the cluster

It is important to refer to your distributors and vendors to make sure additional requirements are also included in any cluster planning.

Kubernetes cluster requirements

For a successful deployment and operation of BMC Helix Service Management, make sure that specific hardware resources are available to all applications.

The following table lists the minimum amount of available compute resource requirements for the Service Management applications with BMC Helix Platform Common Services:  

Kubernetes quotas

Set up quotas on the cluster namespaces to enforce maximum scheduled requests and limits. If you schedule additional workloads beyond the configured quotas, the Kubernetes cluster might prevent the scheduling and affect operations in the namespace.

The following table lists the recommended settings:

Use the BMC Helix Platform itsmcompact deployment size with BMC Helix Service Management Compact size. You can use the BMC Helix Platform itsmsmall size with BMC Helix Service Management Small, Medium, and Large sizes. Use the BMC Helix Platform itsmxlarge size with BMC Helix Service Management Extra Large size.

Kubernetes node requirements

Make sure that your cluster maintains a minimum number of worker nodes to provide a high availability environment for the application data lakes. 

To support the loss of worker nodes in your cluster, you must provide extra worker nodes with resources equal to your largest worker node. As a result, if one worker node goes down, you will still maintain the minimum number of resources required to recover the application.

For example, if you have four worker nodes of 10 vCPU and 50 GB RAM, you will need a 5th worker node of 10 vCPU and 50 GB RAM to recover an application without having any impact due to the loss of a worker node. 

Database resource requirements

The following table lists the BMC Helix Innovation Suite database resource requirements:

Persistent volume requirements

High performance of Kubernetes Persistent Volume Disk is essential for the overall system performance. Persistent Volume Disk requires block storage. BMC supports a Bring-Your-Own-Storage model for Kubernetes Persistent Volumes. 

The following tables lists the disk requirements:

We recommend that you use solid-state drive (SSD) with the following specifications:

Multi-instance deployments

BMC Helix Service Management supports multi-instance deployments. You can deploy new instances of BMC Helix Service Management in multiple namespaces that utilize the same BMC Helix Platform.
For multi-instance deployments, consider the following points:

• Load profile requirements are the combined requirements of BMC Helix Service Management and BMC Helix Platform Common Services load profiles. 
  If your requirements exceed a combined load profile, contact BMC Support to confirm the required cluster resources.

• Disk space requirements are increased by approximately 250 GB times the number of instances connecting to the BMC Helix Platform.
  This number might vary depending on the individual instances. 
• Cluster resource requirements are in addition to the BMC Helix Service Management namespace and BMC Helix Platform namespace quota.
• Database requirements are the combined requirements based on the deployment size.

BMC Helix ITSM Insights resource requirements

BMC Helix ITSM Insights provides native AI Service Management capabilities with the BMC Helix Platform. BMC Helix ITSM Insights uses Natural Language Processing (NLP) and AI clustering algorithms to deliver use cases such as proactive problem management and real-time incident correlation.

Installation of ITSM Insights is optional. You must add the resource requirements listed in the table below to the overall infrastructure sizing requirements of your BMC Helix Service Management deployment. Sizing for ITSM Insights is based on data volumes rather than concurrent users.

The following table lists the additional ITSM Insights resource requirements:

CPU requirements

The CPU speed must be 2.4 GHz or higher.

Worker and master node disk requirements

Kubernetes master and worker nodes require a free disk space allocation of 150 GB each for container images.

Pod specifications

The BMC Helix Service Management Pod Specification spreadsheet provides detailed information for sizing your environment. Cluster architects can use the information to help determine the node sizes and cluster width.

When reviewing the specification spreadsheet, check the large replica counts to ensure that your cluster width is sufficient.

Disaster recovery requirement

If you enable disaster recovery, you will need an additional processor, memory, and disk space to operate successfully. The following guidance is based on using the default disaster recovery configurations. Any modification to these settings might impact the amount of disk storage that is necessary and must be recalculated.   
The following tables list the additional resources required in the Kubernetes cluster (per data center):  

The following tables list the additional recommendations to add to the namespace quotas (per data center):  

Sizing guidelines to upgrade BMC Helix Platform Common Services

When you upgrade to BMC Helix Platform Common Services version, consider the following additional resource requirements:

Sizing considerations for migrating from Open Distro to OpenSearch

If you are upgrading BMC Helix Platform Common Services version from 23.2.02 or 23.4.00 to 24.1.00 and 24.2, consider the following additional resource requirements for migrating from Open Distro to OpenSearch.

For the Elasticsearch data migration from Open Distro to OpenSearch to be successful, in addition to the resources listed in this topic, the following processor, memory, and disk space are required: 

You can reclaim the resources after the upgrade.

Sizing considerations for migrating from PostgreSQL database 12.9 to 15.x

If you are upgrading BMC Helix Platform Common Services version from 23.2.02, 23.4.00, or 24.1.00 to 24.2, consider the following additional resource requirements for migrating PostgreSQL database.

To migrate data from PostgreSQL database 12.9 to 15.x you must run the  PostgreSQL migration utility.

For the migration to be successful, in addition to the resources listed in this topic, the following processor, memory, and storage are required : 

You can reclaim the resources after the upgrade.