This section describes how to size an OpenShift-based container ecosystem cluster by using a sample cloud-native application. The following table shows a cloud-native inventory management application with a customized quotation generation system workload. Estimated memory, CPU core, I/O bandwidth, and storage requirements are indicative of resource requirements at times of peak load.
Table 5. Estimated workload resource requirements by application type
Application type |
Number of pods |
Maximum memory (GB) |
CPU cores |
Typical IOPS: Kb/s @ block size (KB) |
Persistent storage (GB) |
Apache web application |
150 |
0.5 |
0.5 |
10 @ 0.5 |
1 |
Python-based application |
50 |
0.4 |
0.5 |
55 @ 0.5 |
1 |
JavaScript runtime |
220 |
1 |
1 |
80 @ 2.0 |
1 |
Database |
100 |
16 |
2 |
60 @ 8.0 |
15 |
Java-based tools |
110 |
1.2 |
1 |
25 @ 1.0 |
1.5 |
The overall resource requirements are: 630 pods, 630 CPU cores, 2,047 GB RAM,
1.9 TB storage, and 130 Gbps aggregate network bandwidth.
Our calculations using the workload information from Table 5 take into account the following considerations:
Certain cluster design considerations apply to estimating the required number of compute nodes used. This section outlines these considerations.
The following table shows the available configurations:
Table 6. Calculated compute node alternate configurations based on Table 5 data
Compute node type (PowerEdge R640) |
Required node quantity |
Total CPU cores |
Total RAM (GB) |
Intel Gold 4208 CPU, 192 GB RAM, |
40 |
640 |
7,680 |
Intel Gold 6226 CPU, 384 GB RAM, |
27 |
648 |
10,368 |
Intel Gold 6252 CPU, 768 GB RAM, |
14 |
672 |
10,752 |
Our minimum recommended control-plane node configuration is a PowerEdge R640 server with dual Intel Gold 6226 CPUs and 192 GB RAM. As the Red Hat resource requirements show, this node is large enough for a 250-node cluster and higher. Dell Technologies recommends that you do not scale beyond 200 nodes, so the proposed reference design is adequate for nearly all deployments. The following table shows the sizing recommendations:
Table 7. Control-plane node sizing guide
Number of compute nodes |
CPU cores* |
Memory (GB) |
25 |
4 |
16 |
100 |
8 |
32 |
200 |
16 |
64 |
*Does not include provisioning of at least four cores per node for infrastructure I/O handling