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:

Deployment size	Resilient concurrent users	Maximum concurrent users
Compact	Not applicable	200
Small	200	400
Medium	400	800
Large	800	1,800
Extra large	1,250	2,500

 The following table lists the supported deployment sizes for BMC Helix ITSM Insights, including the number of concurrent users and the incidents per day that each size can handle:

Deployment size	Concurrent users	Incidents per day
Compact	10	1,000
Small	25	5,000
Medium	50	10,000
Large	100	15,000
Extra large	200	20,000

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, with and without BMC Helix ITSM Insights, 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:   

Deployment size	vCPU (Core)	RAM (GB)
Compact	33	118
Small	47	197
Medium	48	255
Large	60	272
Extra large	79	440

Kubernetes cluster requirements with BMC Helix ITSM Insights

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

Installation of BMC Helix ITSM Insights is optional. However, if installed, make sure that the following requirements are met. These requirements are based on data volumes rather than concurrent users.

The following table lists additional ITSM Insights resource requirements, in addition to those in the Kubernetes cluster requirements section:

Deployment size	vCPU (Core)	RAM (GB)
Compact	3	36
Small	10	64
Medium	28	85
Large	33	78
Extra large	28	91

BMC HelixGPT requirements

If you plan to deploy BMC HelixGPT, ensure that your Kubernetes cluster includes the following additional resource allocations. These requirements are separate from the overall Kubernetes cluster sizing recommendations and must be accounted for to support BMC HelixGPT services.

Deployment size	vCPU (Core)	RAM (GB)
Compact	6	19
Small	12	37
Medium	12	37
Large	12	37
Extra large	12	37

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:

BMC Helix Service Management namespace quotas
Deployment size	vCPU requests (milli core)	vCPU limits (milli core)	Memory requests (GB)	Memory limits (GB)
Compact	11,780	109,500	65	243
Small	21,240	194,650	131	435
Medium	21,710	233,650	188	535
Large	34,010	253,750	205	558
Extra large	50,210	278,750	314	678
BMC Helix Platform namespace quotas
Deployment size	vCPU requests (milli core)	vCPU limits (milli core)	Memory requests (GB)	Memory limits (GB)
itsmcompact	20,240	62,350	53	110
itsmsmall	25,610	87,700	67	133
itsmxlarge	28,130	99,750	126	252

Kubernetes quotas with BMC Helix ITSM Insights

The following table lists the additional recommended settings for environments with BMC Helix ITSM Insights, in addition to those in the Kubernetes quotas section:

BMC Helix Service Management namespace quotas
Deployment size	vCPU requests (milli core)	vCPU limits (milli core)	Memory requests (GB)	Memory limits (GB)
Compact	2,000	2,500	6	2
Small	1,500	6,000	6	6
Medium	20,600	7,000	27	31
Large	24,400	9,000	20	20
Extra large	16,000	5,000	12	24
BMC Helix Platform namespace quotas
Deployment size	vCPU requests (milli core)	vCPU limits (milli core)	Memory requests (GB)	Memory limits (GB)
itsmcompact	1,800	5,800	30	75
itsmsmall	8,010	16,150	58	146
itsmxlarge	11,700	26,100	79	170

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 six worker nodes of 10 vCPU and 50 GB RAM, you will need a 7th 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. 

Deployment size	Minimum worker nodes
Compact	4
Small	6
Medium	6
Large	6
Extra large	6

For details regarding the specifications of the pod, refer to the Pod Specifications section.

Database resource requirements

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

Deployment Size	vCPU (Core)	RAM (GB)
Compact (100 users maximum)	10	20
Compact (200 users maximum)	10	24
Small	12	32
Medium	40	64
Large	64	80
Extra large	80	160

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:

Deployment size	Block storage (GB)
	BMC Helix Service Management	BMC Helix Service Management + BMC Helix ITSM Insights
Compact	1,372	1,402
Small	1,696	1,726
Medium	1,696	1,726
Large	1,696	1,726
Extra large	2,446	2,566

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

Specification	Deployment size
	Compact	Small	Medium	Large	Extra large
Average latency	< 100ms	< 100ms	< 100ms	< 100ms	< 100ms
Write throughput	20 MB/s	150 MB/s	165 MB/s	200 MB/s	200 MB/s
Read throughput	100 MB/s	800 MB/s	1 GB/s	1.2 GB/s	1.2 GB/s
IOPS Write	1K	3K	3.2K	3.5K	3.5K
IOPS Read	3K	10K	11K	12K	12K

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.

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

To determine the appropriate pod specifications for your environment, refer to the following Pod specification spreadsheets:

• BMC Helix Service Management without ITSM Insights – Provides sizing details for BMC Helix Service Management environments without BMC Helix ITSM Insights.
• BMC Helix Service Management with ITSM Insights – Provides sizing details for BMC Helix Service Management environments with BMC Helix ITSM Insights.

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.

BMC Helix Logging (EFK) stack requirements

Use BMC Helix Logging to collect, store, and view logs by using Elasticsearch, Fluent Bit, and Kibana (EFK). Deploying the BMC Helix Logging stack comes with additional hardware requirements that the Kubernetes cluster must be able to provide as well as the expected namespace quotas. For more information, Preparing to collect logs from external log sources. The following table shows the additional stack requirements to allow BMC Helix Logging deployment:

Deployment size	vCPU (Core)	RAM (GB)	PVC (GB) (with 3 days retention)
Compact	1	10	70
Small	1	11	100
Medium	1	11	100
Large	1	11	100
Extra large	2	11	100

BMC Helix Logging (EFK) stack quota requirements

The following table shows the additional stack quota requirements to allow BMC Helix Logging deployment:

Deployment size	vCPU requests (milli core)	vCPU limits (milli core)	Memory requests (GB)	Memory limits (GB)
Compact	180	8,500	6	15
Small	180	11,500	7	18
Medium	180	11,500	7	18
Large	180	11,500	7	18
Extra large	450	16,500	7	18

FluentBit Daemonset

The Helix logging stack utilizes FluentBit collectors as a daemonset to access logs on the worker nodes. Requirements for the collectors are in addition to the previous requirements and depend on the number of worker nodes that are in the cluster. Use the table below to determine the size of the pod in your deployment and multiply the requirements by the number of pods in your cluster. The cluster will additionally require the value of requests calculated.

Deployment size	vCPU requests (milli core)	vCPU limits (milli core)	Memory requests (GB)	Memory limits (GB)
Compact	100	200	0.128	0.256
Small	100	200	0.128	0.256
Medium	100	200	0.128	0.256
Large	100	200	0.128	0.256
Extra large	100	200	0.128	0.256

​​For example, to get the total quota value, multiply your worker node count by a value in FluentBit Daemonset table, and add a value in the BMC Helix Logging (EFK) stack quota requirements table.

Assume that you have 4 worker nodes in your compact-sized cluster. Your total CPU requests quota calculation will be:
4 * 100 + 180 = 580 (Millicore)

Similarly, you can do the calculation for memory requests. 

BMC Helix EFK Logging requirements

Parameters	Compact	Small	Medium	Large	Extra large
Number of days for retention	7	7	7	7	7

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):  

Category	vCPU	RAM (GB)	PVC (GB)
Compact	5	10	200
Small	9	16	400
Medium	9	16	400
Large	9	16	400
Extra large	9	16	1000

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

BMC Helix Service Management Namespace Quotas (DR Additions)
Category	vCPU requests (milli core)	vCPU limits (milli core)	Memory requests (GB)	Memory limits (GB)
Compact	5,100	12,200	10	26
Small	8,400	25,400	16	53
Medium	8,400	25,400	16	53
Large	8,400	25,400	16	53
Extra large	8,400	25,400	16	53

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 PostgreSQL database 15.x to 17.x

If you are upgrading BMC Helix Platform Common Services version from 25.1.00 to 25.2.00, consider the following additional resource requirements for migrating the PostgreSQL database.

To migrate data from PostgreSQL database 15.x to 17.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.

Kubernetes quotas requirements

The following table lists additional quota requirements for Postgres 15.x to 17.x migration:

Category	vCPU (milli core) requests	MEM (Gi) requests	vCPU (milli core) limits	MEM (Gi) limits
Compact	2,000	5.5	9,000	14.5
Small	2,000	5.5	9,000	14.5
Medium	2,000	5.5	9,000	14.5
Large	2,000	5.5	9,000	14.5
Extra Large	2,000	5.5	9,000	20.5

Kubernetes cluster requirements

The following table lists additional Kubernetes cluster hardware requirements for Postgres 15.x to 17.x migration:

Category	vCPU (Core)	RAM (GB)	PVC (GB)
Compact	2	5.5	90
Small	2	5.5	90
Medium	2	5.5	90
Large	2	5.5	90
Extra Large	2	5.5	90

Additional Kubernetes quotas requirements during upgrade

To ensure that the upgrade completes successfully, allocate the following additional resources, in addition to those in the Kubernetes quotas section. 

The following table shows the additional resources to allocate during the upgrade, based on deployment size:

Additional BMC Helix Platform Common Services namespace quotas during upgrade
Deployment size	vCPU requests (milli core)	vCPU limits (milli core)	Memory requests (GB)	Memory limits (GB)
Compact	130	4,600	12	25
Small	130	6,100	12	25
Medium	130	6,100	12	25
Large	130	6,100	12	25
Extra large	310	12,100	12	25

You can reclaim the resources after the upgrade.