Make composer operations with Drupal way faster and easier on RAM

tl;dr: Run composer require zaporylie/composer-drupal-optimizations:^1.0 in your Drupal codebase to halve Composer's RAM usage and make operations like require and update 3-4x faster.

A few weeks ago, I noticed Drupal VM's PHP 5.6 automated test suite started failing on the step that runs composer require drupal/drush. (PSA: PHP 5.6 is officially dead. Don't use it anymore. If you're still using it, upgrade to a supported version ASAP!). This was the error message I was getting from Travis CI:

PHP Fatal error:  Allowed memory size of 2147483648 bytes exhausted (tried to allocate 32 bytes) in phar:///usr/bin/composer/src/Composer/DependencyResolver/RuleWatchNode.php on line 40

I ran the test suite locally, and didn't have the same issue (locally I have PHP's CLI memory limit set to -1 so it never runs out of RAM unless I do insane-crazy things.

So then I ran the same test but with PHP's memory_limit set to 2G—yeah, that's two gigabytes of RAM—and it failed! So I ran the command again using Composer's --profile option and -vv to see exactly what was happening:

# Run PHP 5.6 in a container.
$ docker run --rm -it drupaldocker/php-dev:5.6-cli /bin/bash
# php -v     
PHP 5.6.36 (cli) (built: Jun 20 2018 23:33:51)

# composer create-project drupal-composer/drupal-project:8.x-dev composer-test --prefer-dist --no-interaction

# Install Devel module.
# cd composer-test
# composer require drupal/devel:^1.2 -vv --profile
Do not run Composer as root/super user! See for details
[126.7MB/5.04s] ./composer.json has been updated
[129.6MB/6.08s] > pre-update-cmd: DrupalProject\composer\ScriptHandler::checkComposerVersion
[131.5MB/6.10s] Loading composer repositories with package information
[131.9MB/6.52s] Updating dependencies (including require-dev)
[2054.4MB/58.32s] Dependency resolution completed in 3.713 seconds
[2054.9MB/61.89s] Analyzed 18867 packages to resolve dependencies
[2054.9MB/61.89s] Analyzed 1577311 rules to resolve dependencies
[2056.9MB/62.68s] Dependency resolution completed in 0.002 seconds
[2055.5MB/62.69s] Package operations: 1 install, 0 updates, 0 removals
[2055.5MB/62.69s] Installs: drupal/devel:1.2.0
[2055.5MB/62.70s] Patching is disabled. Skipping.
[2055.5MB/62.80s]   - Installing drupal/devel (1.2.0): [2055.6MB/62.83s] [2055.6MB/63.02s] Downloading (0%)[2055.6MB/63.02s]                   [2[2055.6MB/63.04s] Downloading (5%)[2[2055.6MB/63.06s] Downloading (15%)[[2055.7MB/63.08s] Downloading (30%)[[2055.7MB/63.10s] Downloading (40%)[[2055.8MB/63.12s] Downloading (55%)[[2055.8MB/63.14s] Downloading (65%)[[2055.9MB/63.15s] Downloading (75%)[[2055.9MB/63.15s] Downloading (80%)[[2055.9MB/63.17s] Downloading (90%)[[2056.0MB/63.18s] Downloading (100%)[2055.5MB/63.19s]
[2055.5MB/63.19s]  Extracting archive[2055.6MB/63.57s]     REASON: Required by the root package: Install command rule (install drupal/devel 1.x-dev|install drupal/devel 1.2.0)
[2055.6MB/63.57s] No patches found for drupal/devel.
[731.5MB/71.30s] Writing lock file
[731.5MB/71.30s] Generating autoload files
[731.8MB/73.01s] > post-update-cmd: DrupalProject\composer\ScriptHandler::createRequiredFiles
[731.6MB/78.82s] Memory usage: 731.61MB (peak: 2057.24MB), time: 78.82s

So... when it started looking through Drupal's full stack of dependencies—some 18,867 packages and 1,577,311 rules—it gobbled up over 2 GB of RAM. No wonder it failed when memory_limit was 2G!

That seems pretty insane, so I started digging a bit more, and found that the PHP 7.1 and 7.2 builds were not failing; they peaked around 1.2 GB of RAM usage (yet another reason you should be running PHP 7.x—it uses way less RAM for so many different operations!).

Then I found a really neat package which had some outlandish promises: composer-drupal-optimizations mentioned in the README:

Before: 876 MB RAM, 17s; After: 250 MB RAM, 5s

I went ahead and added the package to a fresh new Drupal project with:

composer require zaporylie/composer-drupal-optimizations:^1.0

(Note that this operations still uses the same huge amount of memory and time, because the package to optimize things is being installed!)

And then I ran all the tests on PHP 5.6, 7.1, and 7.2 again. Instead of spelling out the gory details (they're all documented in this issue in the Drupal VM issue queue), here is a table of the amazing results:

PHP Version Before After Difference
5.6 2057.24 MB 540.02 MB -1.5 GB
7.1 1124.52 MB 426.64 MB -800 MB
7.2 1190.94 MB 423.93 MB -767 MB

You don't have to be on ancient-and-unsupported PHP 5.6 to benefit from the speedup afforded by ignoring unused/really old Symfony packages!

Next Steps

You should immediately add this package to your Drupal site (if you're using Composer to manage it) if you run Drupal 8.5 or later. And if you use a newer version of Acquia BLT, you're already covered! I'm hoping this package will be added upstream to drupal-project as well (there's sort-of an issue for that), and maybe even something could be done on the Drupal level.

Requiring over 1 GB of RAM to do even a simple composer require for a barebones Drupal site is kind-of insane, IMO.


Thanks for this! I was running into issues with my basic cheap 1GB RAM VPS a few months ago. My current solution was to create swap space on the hdd just so composer could function and update.

This will definitely speed things up, as even with the 10k drives on the VPS, it still takes nearly 1 full minute to run composer without making any changes!

I'm so excited to implement this!

Now you have me wanting a jelly donut! There goes a New Years Resolution 🤪

Thanks @geerlingguy, this produces amazing results and we have immediately integrated into our D8 project template @lakedrops as well which is built on top of the project template over at GitHub.

Thanks for sharing. Waiting for Composer isn't anyones favorite pasttime. We will zaporylie/composer-drupal-optimizations to all our Drupal projects.


We did try this, and spent some time afterwards wondering why our pipelines broke. It turns out this will break fresh installs (at least those that uses ).

Drupal project has bunch of files in the root of web/ directory, but for whatever reason when this composer package is required, those files will not be generated.