README

Run wp-cron on all public sites in a multisite network (REST API based).

"You could have done this with a simple cron job. Why use this plugin?"

I have a cluster of WordPress sites. I did run a shell script calling wp cli, but the race condition was a problem. I needed a way to run wp-cron on all sites without overlapping. This plugin was created to solve that problem.

🚀 Quick Start

1. Download all-sites-cron.zip
2. Upload via Network > Plugins > Add New > Upload Plugin
3. Network Activate the plugin.
4. Disable WordPress default cron in wp-config.php:

   define( 'DISABLE_WP_CRON', true );

Also available via Composer:

composer require soderlind/all-sites-cron

Updates

• Plugin updates are handled automatically via GitHub. No need to manually download and install updates.

🏗 Architecture (v2.0.0)

The plugin is organised as a thin orchestrator (all-sites-cron.php) backed by five focused classes under src/:

All classes live in the Soderlind\Multisite\AllSitesCron namespace and are autoloaded via Composer PSR-4.

🔧 Configuration

The plugin exposes a REST API route that triggers cron across your network.

JSON usage:

https://example.com/wp-json/all-sites-cron/v1/run

GitHub Actions plain text (add ?ga=1):

https://example.com/wp-json/all-sites-cron/v1/run?ga=1

Deferred mode (add ?defer=1 - responds immediately, processes in background):

https://example.com/wp-json/all-sites-cron/v1/run?defer=1

🚀 Redis Queue Support: If Redis is available, deferred mode automatically uses Redis for job queuing (more reliable and scalable). See Redis Queue documentation or Quick Start.

Combine parameters (GitHub Actions + Deferred):

https://example.com/wp-json/all-sites-cron/v1/run?ga=1&defer=1

Adding ?ga=1 outputs results in GitHub Actions compatible format:

• Success: ::notice::Running wp-cron on X sites
• Error: ::error::Error message

Example GitHub Action success notice

⏰ Trigger Options

1. (Preferred) Use a service like cron-job.org, pingdom.com, or easycron.com to call the endpoint every 5 minutes.

2. System Crontab (every 5 minutes):

*/5 * * * * curl -s https://example.com/wp-json/all-sites-cron/v1/run

1. GitHub Actions every 5 minutes. (5 minutes is the shortest interval in GitHub Actions):

name: All Sites Cron Job
on:
  schedule:
    - cron: '*/5 * * * *'

env:
  CRON_ENDPOINT: 'https://example.com/wp-json/all-sites-cron/v1/run?ga=1&defer=1'

jobs:
  trigger_cron:
    runs-on: ubuntu-latest
    timeout-minutes: 5
    steps:
      - run: |
          curl -X GET ${{ env.CRON_ENDPOINT }} \
            --connect-timeout 10 \
            --max-time 30 \
            --retry 3 \
            --retry-delay 5 \
            --silent \
            --show-error \
            --fail

Note: Using defer=1 is recommended for GitHub Actions to prevent timeout errors on large networks.

🔒 Authentication (Optional)

By default the REST endpoints are public (backward-compatible). To require a shared-secret token:

1. Define the token in wp-config.php:

   define( 'ALL_SITES_CRON_AUTH_TOKEN', 'your-long-random-secret' );

   Or store it as a site option: update_site_option( 'all_sites_cron_auth_token', 'your-secret' );

2. Pass the token with requests:

   # Bearer header (preferred)
   curl -H "Authorization: Bearer your-long-random-secret" \
     https://example.com/wp-json/all-sites-cron/v1/run
   
   # Query parameter
   curl "https://example.com/wp-json/all-sites-cron/v1/run?token=your-long-random-secret"

When no token is configured the endpoints remain open.

Customization

Filters

Below is a complete list of filters provided by the plugin (including Redis + legacy aliases) that let you tune execution, performance, and infrastructure behavior.

Notes:

• https_local_ssl_verify is a WordPress core filter, not defined by this plugin; we simply honor it when dispatching non‑blocking HTTP requests. See core docs for broader usage.
• Legacy dss_cron_* filters are still applied first internally (for backward compatibility) via the get_filter() helper, then the newer all_sites_cron_* version. Migrate to the new names; legacy ones will be removed in a future major release.

Examples

Rate limiting:

add_filter( 'all_sites_cron_rate_limit_seconds', fn( $seconds ) => 120 ); // 2 minutes between runs

Limit total sites:

add_filter( 'all_sites_cron_number_of_sites', fn( $max ) => 500 ); // Cap total processed sites

Batch size:

add_filter( 'all_sites_cron_batch_size', fn( $batch ) => 25 ); // Smaller batches to reduce memory

Request timeout:

add_filter( 'all_sites_cron_request_timeout', fn( $timeout ) => 0.05 ); // 50ms per site dispatch

all_sites_cron_require_auth

Control whether authentication is required for REST endpoints.

• Type: bool
• Default: true when a token is configured, false otherwise
• New in: v2.0.0

// Force authentication even without a stored token
add_filter( 'all_sites_cron_require_auth', '__return_true' );

https_local_ssl_verify

Redis connection:

add_filter( 'all_sites_cron_redis_host', fn() => 'redis.internal' );
add_filter( 'all_sites_cron_redis_port', fn() => 6380 );
add_filter( 'all_sites_cron_redis_db', fn() => 2 );

Custom queue key:

add_filter( 'all_sites_cron_redis_queue_key', fn() => 'network_cron:jobs' );

Enable SSL verification (core filter):

add_filter( 'https_local_ssl_verify', '__return_true' );

Filter Usage Examples

Large Network Configuration (1000+ sites):

// Process more sites in smaller batches
add_filter( 'all_sites_cron_number_of_sites', fn() => 2000 );
add_filter( 'all_sites_cron_batch_size', fn() => 25 );
add_filter( 'all_sites_cron_rate_limit_seconds', fn() => 180 ); // 3 minutes

Small Network Configuration (< 100 sites):

// Faster processing with larger batches
add_filter( 'all_sites_cron_batch_size', fn() => 100 );
add_filter( 'all_sites_cron_rate_limit_seconds', fn() => 30 ); // 30 seconds

Development/Testing Configuration:

// More aggressive settings for testing
add_filter( 'all_sites_cron_rate_limit_seconds', fn() => 10 ); // 10 seconds
add_filter( 'all_sites_cron_batch_size', fn() => 5 );
add_filter( 'all_sites_cron_request_timeout', fn() => 0.1 );

Legacy Filters (Deprecated)

Legacy aliases still applied (old → new):

Migration tip:

// Old:
add_filter( 'dss_cron_number_of_sites', fn() => 300 );
// New:
add_filter( 'all_sites_cron_number_of_sites', fn() => 300 );

Using the Incoming Filter Parameter

All filter callbacks receive the current value as the first parameter. You can modify relative to the incoming value instead of hard‑coding:

// Increase existing rate limit by 30 seconds (but cap at 300):
add_filter( 'all_sites_cron_rate_limit_seconds', fn( $seconds ) => min( $seconds + 30, 300 ) );

// Halve the batch size dynamically (never less than 10):
add_filter( 'all_sites_cron_batch_size', fn( $batch ) => max( 10, (int) floor( $batch / 2 ) ) );

// Scale the max sites based on environment variable:
add_filter( 'all_sites_cron_number_of_sites', fn( $current ) => getenv( 'ASC_MAX_SITES' ) ? (int) getenv( 'ASC_MAX_SITES' ) : $current );

// Add a safety floor for the request timeout (never below 0.01):
add_filter( 'all_sites_cron_request_timeout', fn( $timeout ) => max( 0.01, $timeout ) );

// Dynamically choose Redis queue key per environment (prefix existing):
add_filter( 'all_sites_cron_redis_queue_key', fn( $key ) => 'prod_' . $key );

Interpreting Rate Limiting

If called again before the cooldown finishes the API returns HTTP 429 with JSON:

{
  "success": false,
  "error": "rate_limited",
  "message": "Rate limited. Try again in 37 seconds.",
  "retry_after": 37,
  "cooldown": 60,
  "last_run_gmt": 1696071234,
  "timestamp": "2025-09-30 12:35:23"
}

Headers include: Retry-After: <seconds>.

Benefits of REST mode

• No rewrite rules to flush: activation is simpler and avoids edge cases with 404s or delayed availability.
• No unexpected 301 canonical/trailing‑slash redirects: direct, cache‑friendly 200 responses.
• Versioned, discoverable endpoint (/wp-json/all-sites-cron/v1/run) integrates with the WP REST index and tooling.
• Consistent structured JSON by default plus optional GitHub Actions text via ?ga=1.
• Proper HTTP status codes (e.g. 429 for rate limiting, 400 for invalid context) instead of a blanket 200.
• Easy extensibility: future endpoints (status, logs, defer mode, auth) can be added under the same namespace without new rewrites.
• Reduced theme / front‑end interference: bypasses template loading and front‑end filters tied to template_redirect.
• Better compatibility with CDNs and monitoring: REST semantics and headers are predictable and cache‑aware.
• Straightforward integration in external systems (CI/CD, orchestration) that already speak JSON.
• Built‑in argument handling and potential for schema/permission hardening via permission_callback.
• Clean separation of concerns: routing (REST) vs. execution logic (cron dispatcher) improves maintainability.
• Clear place to implement enhancements (rate limiting, future defer/background mode, auth tokens, metrics) with minimal risk.
• Easier automated testing using WP REST API test utilities (no need to simulate front‑end rewrite resolution).
• Avoids canonical redirect filter hacks previously needed to suppress 301s on /dss-cron.
• Safer for multi‑environment deployments (no dependency on rewrite flush timing during deploy pipelines).

Copyright and License

All Sites Cron is copyright 2024–2025 Per Soderlind

All Sites Cron is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

All Sites Cron is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with the Extension. If not, see http://www.gnu.org/licenses/.

Migration Note

The plugin was renamed from "DSS Cron" (slug: dss-cron) to "All Sites Cron" (slug: all-sites-cron). The old REST namespace dss-cron/v1 is still registered for backward compatibility, but you should migrate your automation scripts to use all-sites-cron/v1. Legacy WordPress filters like dss_cron_number_of_sites continue to work; new code should use the all_sites_cron_* equivalents.