From 6fa622c11315908f5c8104b59adb892d56e84413 Mon Sep 17 00:00:00 2001 From: Trevor Emerick Date: Wed, 8 Jul 2026 23:14:02 -0400 Subject: [PATCH] docs: add PHP SSI operational guidance to README Document disk quota, runtime network, and startup delay considerations for PHP single-step APM instrumentation. Co-authored-by: Cursor --- README.md | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/README.md b/README.md index 4127bf2c..7ed5825c 100644 --- a/README.md +++ b/README.md @@ -96,6 +96,12 @@ Download and import the [relevant libraries][6] to send data. To learn more, che | `DD_TRACE_PHP_VERSION` | Pin the PHP tracer version installed by SSI. Defaults to `1.19.2`. | | `DD_WAIT_TRACE_AGENT` | Use this option to delay the startup of the application until the Trace Agent is ready. This option is especially useful for Golang apps. | +**PHP SSI notes:** + +- **Disk quota:** PHP apps using SSI typically need `disk_quota: 2048M` (or higher) in `manifest.yml`. The default 1 GB is often not enough to stage `php_buildpack`'s runtime plus the tracer installed at container start. +- **Runtime network:** Unlike other SSI runtimes, PHP downloads `datadog-setup.php` from GitHub on each container start. Outbound access to `github.com` is required unless you provide an alternate install path. +- **Startup delay:** The PHP tracer is installed when `.profile.d` scripts run. Web processes and sidecars may contend on a lock during install, which can add up to 120 seconds to startup on the first process start. + ### Log collection **Enable log collection**