Chapter 10. Optimizing routing The OpenShift Container Platform HAProxy router can be scaled or configured to optimize performance. 10.1. Baseline Ingress Controller (router) performance The OpenShift Container Platform Ingress Controller, or router, is the ingress point for ingress traffic for applications and services that are configured using routes and ingresses. When evaluating a single HAProxy router performance in terms of HTTP requests handled per second, the performance varies depending on many factors. In particular: HTTP keep-alive/close mode Route type TLS session resumption client support Number of concurrent connections per target route Number of target routes Back end server page size Underlying infrastructure (network/SDN solution, CPU, and so on) While performance in your specific environment will vary, Red Hat lab tests on a public cloud instance of size 4 vCPU/16GB RAM. A single HAProxy router handling 100 routes terminated by backends serving 1kB static pages is able to handle the following number of transactions per second. In HTTP keep-alive mode scenarios: Encryption LoadBalancerService HostNetwork none 21515 29622 edge 16743 22913 passthrough 36786 53295 re-encrypt 21583 25198 In HTTP close (no keep-alive) scenarios: Encryption LoadBalancerService HostNetwork none 5719 8273 edge 2729 4069 passthrough 4121 5344 re-encrypt 2320 2941 The default Ingress Controller configuration was used with the spec.tuningOptions.threadCount field set to 4 . Two different endpoint publishing strategies were tested: Load Balancer Service and Host Network. TLS session resumption was used for encrypted routes. With HTTP keep-alive, a single HAProxy router is capable of saturating a 1 Gbit NIC at page sizes as small as 8 kB. When running on bare metal with modern processors, you can expect roughly twice the performance of the public cloud instance above. This overhead is introduced by the virtualization layer in place on public clouds and holds mostly true for private cloud-based virtualization as well. The following table is a guide to how many applications to use behind the router: Number of applications Application type 5-10 static file/web server or caching proxy 100-1000 applications generating dynamic content In general, HAProxy can support routes for up to 1000 applications, depending on the technology in use. Ingress Controller performance might be limited by the capabilities and performance of the applications behind it, such as language or static versus dynamic content. Ingress, or router, sharding should be used to serve more routes towards applications and help horizontally scale the routing tier. For more information on Ingress sharding, see Configuring Ingress Controller sharding by using route labels and Configuring Ingress Controller sharding by using namespace labels . For more information on tuningOptions, see Ingress Controller configuration parameters . You can modify the Ingress Controller deployment using the information provided in Setting Ingress Controller thread count for threads and Ingress Controller configuration parameters for timeouts, and other tuning configurations in the Ingress Controller specification.

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