When you install a Custom Hive, you choose a Windows machine in your environment to host it. That machine runs the Synthetic Monitoring Scouts assigned to the Hive.
Because Scouts use the machine’s CPU and memory, make sure the machine has enough resources to support the expected workload. If the machine does not have enough resources, Scout runs may be delayed or fail to finish before the next scheduled run.
Custom Hive resource requirements depend mainly on the Scout types you run and how many Scouts run at the same time:
- EUC Scouts usually require the most resources because they launch a real browser session during the test using Chrome and
chromedriver. - Infrastructure Scouts and Application Scouts, such as HTTP/S, DNS, Ping, Traceroute, Site Load, Teams, and Exchange Scouts, usually use fewer resources.
When sizing a Custom Hive, treat EUC Scout concurrency as the main factor. The number of EUC Scouts running at the same time usually has a greater impact on host performance than the total number of lighter Scouts.
Use this article to choose a baseline host setup, understand what affects Custom Hive performance, and know when to add resources or adjust the Scout workload.
The following recommendations summarize the sizing guidance in this article. The sections below explain how to apply them.
- Use a dedicated Windows machine with at least 4 vCPU, 8 GB RAM, and a standard SSD.
- Run Custom Hive build 1238 or newer.
- Add antivirus or EDR exclusions for the Custom Hive installation directory and
sb-runner.exe. - Account for the number of EUC Scouts that can run at the same time, because EUC Scouts usually require the most CPU and memory.
- Keep Scout intervals at the default 5-minute interval unless you have confirmed that the Custom Hive can handle the additional workload.
- Monitor Processor Queue Length, Scout queueing, and other host performance signals, not only CPU usage.
Recommended Host Setup
Use the following setup as the baseline for a dedicated Windows-based Custom Hive host.
| Resource | Recommendation | Notes |
|---|---|---|
| Operating system | Windows | Custom Hives run on Windows machines. |
| vCPU | 4 vCPU minimum | Required when the Custom Hive runs EUC Scouts. |
| RAM | 8 GB | Validated with a mixed Scout workload of about 100 Scouts on a dedicated Custom Hive host. |
| Disk | Standard SSD | The Custom Hive is not disk-heavy, but low-latency storage can help when Scout runs start processes. |
| Custom Hive build | 1238 or newer | Earlier builds might leave orphaned chrome.exe processes after EUC Scout runs, which can increase CPU and memory usage over time. |
This setup is a baseline, not a fixed limit. You might need more resources if the Custom Hive runs many Scouts, runs several EUC Scouts at the same time, or uses shorter Scout intervals.
Do not use a 2 vCPU machine for a Custom Hive that runs EUC Scouts. When EUC Scout runs overlap with other Scout runs, a 2 vCPU machine can cause scheduling delays even when CPU usage does not appear high. For signals that can help identify CPU scheduling issues, see Monitor Custom Hive health.
After you choose a host size, see Install and Configure Custom Hives for installation steps.
Tested Baseline Workload
The 4 vCPU / 8 GB RAM baseline was validated with the following workload at the default 5-minute Scout interval.
| Scout type | Count in validated test |
|---|---|
| EUC Scouts, Citrix StoreFront via Workspace App | 3 concurrent |
| DNS Scouts | About 10 |
| Microsoft Teams Scout | 1 |
| Microsoft Exchange Online Scout | 1 |
| Site Load Scouts | About 5 |
| HTTP/S Scouts | About 90 |
During this test, the host remained stable. Memory usage stayed at approximately 4 GB out of 8 GB available. CPU usage increased briefly during EUC Scout runs and then recovered quickly. Other Scout runs did not queue.
This tested configuration shows that a 4 vCPU / 8 GB RAM Custom Hive host can support several EUC Scouts together with a larger number of lighter Scouts. The Scout counts in this section describe the tested configuration. They are not a guaranteed maximum or a hard limit.
As you add or change Scouts, monitor the Custom Hive carefully. EUC Scout concurrency is the main variable to watch.
Recommended Host Configuration
After you choose the host size, configure the Windows machine to reduce avoidable performance issues. The following recommendations help reduce process-spawn overhead and prevent known issues with older Custom Hive builds.
Add Antivirus and EDR Exclusions
Process creation is part of Scout execution. Real-time antivirus or EDR tools, including Windows Defender or equivalent tools, can inspect each process start and increase CPU time during Scout runs.
To help reduce process-spawn overhead during Scout execution, add exclusions for the following:
- The Custom Hive installation directory. The default path is:
C:\Program Files\Scoutbees Custom Hive\ - The
sb-runner.exeprocess.
Keep the Custom Hive Updated
Run Custom Hive build 1238 or newer.
Earlier builds might leave orphaned chrome.exe renderer processes after EUC Scout runs. These processes can accumulate over time and gradually consume CPU and memory.
If the number of chrome.exe processes grows steadily over several hours or days, upgrade the Custom Hive to build 1238 or newer.
You can check the process count in Task Manager or by using Get-Process.
To get notified when a new Custom Hive version is released, follow the Hives Release Notes page.
Manage Scout Density and Intervals
The two main factors that affect Custom Hive load are EUC Scout concurrency and Scout interval.
- EUC Scout concurrency: EUC Scouts use the most host resources. As you add EUC Scouts, monitor Processor Queue Length and Scout queueing. If these signals increase, add vCPU before increasing the workload further.
- Scout interval: The default interval is 5 minutes. Shorter intervals increase load because Scouts run more often. Do not reduce the interval unless you have confirmed that the Custom Hive has enough available capacity.
Monitor Custom Hive Health
CPU usage alone does not always show whether a Custom Hive is properly sized. A host can show moderate CPU usage while still experiencing scheduling contention.
Use the following signals to identify possible capacity or configuration issues.
| Signal | What it means | What to do |
|---|---|---|
| Processor Queue Length is sustained above 60, and especially above 100 | The machine is spending more time scheduling threads. Scout latency can increase even when CPU usage looks moderate. | Add vCPU. This is the main signal that the host is undersized for the current EUC and lighter Scout overlap. |
| Elevated kernel time or page-fault rate during Scout runs | Antivirus or EDR scanning might be affecting process creation. | Add the recommended antivirus or EDR exclusions for the Custom Hive installation directory and sb-runner.exe. |
chrome.exe process count grows steadily over several hours or days |
Older Custom Hive builds might leave orphaned Chrome renderer processes. | Upgrade the Custom Hive to build 1238 or newer. |
| Infrastructure Scout or Application Scout queueing (tests not completing within their configured interval) | EUC Scouts might be saturating CPU during their runs, or the host might not have enough vCPU for the workload. | Reduce EUC Scout concurrency, increase Scout intervals, or add vCPU. |
Plan for Larger Workloads
If you plan to run significantly more EUC Scouts than the tested workload, or if you want to use shorter Scout intervals, treat the change as a scaling exercise rather than a one-time configuration change.
Follow these guidelines:
- Add vCPU before adding RAM. CPU is usually the limiting resource for EUC Scout workloads.
- Add EUC Scouts in small increments.
- Monitor Processor Queue Length over a full day, not only during a short test window. This helps capture peak overlap between Scout runs.
- Check the monitoring signals before adding more Scout density.
- If Scout queueing appears, reduce EUC Scout concurrency, increase Scout intervals, or add vCPU.
The tested 4 vCPU / 8 GB RAM baseline is a starting point. Larger EUC workloads may require additional vCPU depending on concurrency, Scout intervals, and host activity.