Discovery resource utilization
Summarize
Summary of Discovery resource utilization
This document outlines the network bandwidth and CPU resource utilization associated with ServiceNow Discovery operations across various operating systems and device types. It provides detailed metrics on data transfer volumes for different discovery scenarios, helping customers understand the impact of Discovery activities on their infrastructure.
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Bandwidth Consumption Details
Network traffic generated by Discovery probes and patterns varies significantly by operating system and device type. The provided data breaks down bandwidth consumption into four segments of data flow:
- MID Server to Instance
- Instance to MID Server
- MID Server to Target device
- Target device to MID Server
The total bandwidth consumption for typical discovery runs differs, with Windows Server 2012 and EMC Storage devices showing higher bandwidth usage (up to approximately 6.8 MB), while devices such as Cisco UCS Switch and F5 Load Balancer consume less bandwidth.
For three-tier applications (UI, application, and data layers), initial discovery consumes significantly more bandwidth (up to 17.9 MB total) compared to subsequent discovery runs (around 3.4 MB), reflecting lower data transfer needs once initial data is collected.
Discovery bandwidth for pattern-based scans over different operating system types also varies, with Windows Server and Solaris devices generally requiring more data transfer during creation and updates, whereas other devices like HP-UX and L3 Switch show lower consumption.
Note: The measurements are taken with base operating configurations; actual results may vary based on local system settings.
CPU Usage Considerations
CPU consumption during Discovery depends on a combination of factors including operating system, hardware chipset, and workload characteristics. Customers should monitor their specific environments to assess the performance impact of Discovery operations. Identifying unique system builds and observing Discovery’s CPU usage can help in optimizing and balancing resource utilization.
Practical Implications for ServiceNow Customers
- Understanding bandwidth requirements helps plan network capacity and avoid performance bottlenecks during Discovery runs.
- Awareness of higher bandwidth consumption during initial discovery supports scheduling and resource allocation strategies.
- Monitoring CPU impact enables proactive tuning and ensures Discovery operations do not adversely affect system performance.
- Variation across device types and operating systems underscores the importance of environment-specific testing and performance analysis.
Standard transactions on Windows and UNIX generate various amounts of network traffic, depending on what is being discovered.
These tables show the bandwidth consumption for each data flow segment of a typical discovery using probes and patterns over different operating systems.
| Device Type | MID > Instance | Instance > MID | MID > Target | Target > MID | Total |
|---|---|---|---|---|---|
| Windows 2016 | 0.104966 | 0.101271 | 0.77739 | 2.364353 | 3.34798 |
| Windows 2012 | 0.126327 | 0.07928 | 1.177146 | 3.70751 | 5.089804 |
| Windows 2008 | 0.141816 | 0.104674 | 1.032673 | 3.594784 | 4.873947 |
| Windows 10 | 0.091466 | 0.075601 | 0.642313 | 2.221103 | 3.030483 |
| Linux CentOS | 0.164232 | 0.111376 | 0.148742 | 0.690117 | 1.114467 |
| Mac OSX | 0.103707 | 0.068302 | 0.021681 | 0.461365 | 0.655055 |
| HP-UX | 0.120358 | 0.106676 | 0.042669 | 0.101149 | 0.370852 |
| Solaris | 0.130551 | 0.099414 | 0.060243 | 0.346605 | 0.636813 |
| Cisco UCS Switch | 0.029655 | 0.027465 | 0.094918 | 0.097444 | 0.249492 |
| F5 Load Balancer | 0.043935 | 0.03689 | 0.017179 | 0.012132 | 0.110136 |
| A10 Load Balancer | 0.046631 | 0.032266 | 0.018313 | 0.03182 | 0.12903 |
| EMC Storage | 0.4776 | 0.373828 | 1.215954 | 4.741926 | 6.809308 |
The following table shows the bandwidth comparison between an initial discovery for three-tier applications and for each subsequent discovery. Bandwidth is broken up into the three tiers: UI (Apache), application (Websphere), and data (Oracle). This measures the total data transfer for each discovery run once for a device class.
| Device Type | MID > Instance | Instance > MID | MID > Target | Target > MID | Total |
|---|---|---|---|---|---|
| Three-tier application - Initial discovery | 0.712829 | 0.678862 | 7.084678 | 9.430181 | 17.90655 |
| F5 Load Balancer | 0.017179 | 0.012132 | |||
| Apache on Linux | 0.540161 | 1.107108 | |||
| Websphere on Linux | 0.729403 | 1.165112 | |||
| Oracle on Windows | 5.797935 | 7.145829 | |||
| Three-tier application - subsequent discovery | 0.150882 | 0.107409 | 2.536535 | 0.560122 | 3.354948 |
| F5 load balancer | 0.001347 | 0.012132 | |||
| Apache on Linux | 0.136366 | 0.79392 | |||
| Websphere on Linux | 0.341042 | 0.11365 | |||
| Oracle on Windows | 2.05778 | 0.354948 |
This table shows discovery of different OS types using patterns. This measures, in megabytes, the total amount of data created and the total amount of data in subsequent scans for each device.
| Device | MID > Instance | Instance > MID | MID > Target | Target > MID | Total | |
|---|---|---|---|---|---|---|
| Linux | Create | 0.39 | 0.486 | 0.098 | 0.273 | 1.247 |
| Update | 0.382 | 0.499 | 0.093 | 0.264 | 1.238 | |
| Windows Server | Create | 0.289 | 0.316 | 5.628 | 8.508 | 14.741 |
| Update | 0.273 | 0.306 | 5.621 | 8.458 | 14.658 | |
| Solaris | Create | 1.222 | 1.4 | 0.383 | 0.917 | 3.922 |
| Update | 1.24 | 1.42 | .399 | .675 | 3.734 | |
| HP-UX | Create | 0.176 | 0.222 | 0.063 | 0.13 | 0.591 |
| Update | 0.178 | 0.247 | 0.062 | 0.128 | 0.615 | |
| Citrix Netscaler | Create | 0.424 | 1.919 | 0.019 | 0.042 | 2.404 |
| Update | 0.355 | 0.619 | 0.016 | 0.041 | 1.031 | |
| F5 | Create | 0.087 | 0.135 | 0.026 | 0.047 | 0.295 |
| Update | 0.132 | 0.171 | 0.026 | 0.047 | 0.376 | |
| L3 Switch | Create | 0.172 | 0.125 | 0.282 | 0.478 | 1.057 |
| Update | 0.178 | 0.126 | 0.282 | 0.479 | 1.065 |
CPU Usage examples
Examples from CPU Usage will vary among the matrix of thousands of combinations of Operating Systems, chip sets and specific loads for each system.
Your mix of these variables will determine your unique level of CPU consumption.
You can identify unique builds using internal templates and discover them by watching the performance impact, or lack of performance impact that your Discovery tool has on your system.