k6

Scripts to benchmark Object Cache Pro and Relay against various plugins.

Setup

Make sure k6 is installed. All tests can be run locally using k6 run or in the cloud using k6 cloud.

Metrics

When Object Cache Pro is installed, custom metrics for WordPress, Redis and Relay are automatically collected. For other plugins, use the k6-metrics.php as a must-use plugin to capture more metrics.

Tests

k6-wp.js

Fetches all WordPress sitemaps and iterates through URLs sequentially for reproducible runs.

k6 run k6-wp.js --env SITE_URL=https://example.com
k6 run k6-wp.js --vus=100 --duration=10m --env SITE_URL=https://example.com

Variable	Required	Description
SITEMAP_URL	No	Custom sitemap URL (default: {SITE_URL}/wp-sitemap.xml).
PROFILE	No	Named benchmark profile (see Profiles). Omit to use the site's default configuration.

Environment variables

Variable	Required	Description
SITE_URL	Yes	Base URL of the site, without trailing slash
BYPASS_CACHE	No	When set, sends cookies that bypass full-page caches
PROJECT_ID	No	k6 Cloud project ID
K6_SECRET	No	Secret token for the reset endpoint. When set, setup() flushes the object cache, transients, and WooCommerce sessions before the run. Must match K6_SECRET in wp-config-benchmark.php.

Profiles

Profiles select which object cache drop-in and client to use for a run, applied via HTTP request headers. Omitting PROFILE uses the site's PHP configuration unchanged.

k6 run k6-wp.js --env SITE_URL=https://example.com --env PROFILE=ocp-relay

Available profiles

Base

Profile	Drop-in	Client
none	WordPress built-in memory cache	—
ocp-relay	Object Cache Pro	Relay
ocp-phpredis	Object Cache Pro	PhpRedis
roc-phpredis	Redis Object Cache	PhpRedis
roc-relay	Redis Object Cache	Relay

Capture profiles — use with har-replay.js + the capture mu-plugin (stubs/k6-capture.php) to record one Redis command trace (corpus) per configuration. Each flips exactly one capture-time knob — one that changes which commands run, so it can't be reproduced at replay and needs its own corpus. All capture under PhpRedis (Relay's client-side cache would drop round-trips and record an incomplete stream).

Profile	knob vs baseline	command-stream effect
capture-baseline	—	plain keys, single alloptions GET, no prefetch
capture-hfe	group_flush=atomic	groups-as-hashes + hash-field-expiry: every GET→HGET, sets become HFE field writes — changes reads, not just flushes
capture-prefetch	prefetch=true	batched key preload pipeline at request start (warm the site first)

Benchmark profiles — direct A/B comparisons against the live site (k6-wp.js).

Profile	knob	value
split-off	split_alloptions	false
split-on	split_alloptions	true
prefetch-off	prefetch	false
prefetch-on	prefetch	true
client-phpredis	client	phpredis
client-relay	client	relay
client-relay-adaptive	client	relay + relay.adaptive on
php-lz4	serializer + compression	php + lz4
php-zstd	serializer + compression	php + zstd
igbinary-lz4	serializer + compression	igbinary + lz4
igbinary-zstd	serializer + compression	igbinary + zstd

Profiles are defined in lib/profiles.js. See __data/README.md for all supported headers.