Better Multisite Cron (WordPress mu-plugin)

WordPress's built-in wp-cron.php doesn't scale on large multisites — it only handles one site per request. This plugin runs cron across all sites sequentially via WP-CLI, with time limits, error emails, and grouped log output.

• Requires WP-CLI and WordPress Multisite
• Sends error emails when jobs fail
• Runs cron for last_updated blogs first (customizable order)
• Limits the overall time cron is running (--max_seconds)
• Compact log files by default, verbose with --log_verbose

Usage

wp multisite-cron run [--max_seconds=900] [--log_verbose] [--overtime_is_error] ...

Example

You could have two crontab entries:

• One running every 30 min for max 15 min, caring about active blogs first.
• Another running daily for 10 hours doing everything else, sending an email if time was not enough.

# trigger every 30 mins, run for max 15 min (900s). don't treat overtime as error.
*/30 * * * * cd /srv/www/current && wp multisite-cron run --log_errors_to_file='/srv/www/logs/better-cron.log' --max_seconds=900 > /dev/null 2>&1

# trigger daily at midnight, run for 10 hrs, treat overtime as error (sends email).
0 0 * * * cd /srv/www/current && wp multisite-cron run --log_errors_to_file='/srv/www/logs/better-cron.log' --max_seconds=36000 --overtime_is_error > /dev/null 2>&1

Options

Option	Default	Description
always_add_blog_ids	'1'	Comma-separated blog IDs to always include and prioritize.
debug	false	More verbose CLI output.
email_to	network admin_email	Email address for error notifications.
include_archived	false	Run cron for archived blogs?
limit_last_updated_months	null	Only include blogs updated in the last X months.
limit	null	Limit to X blogs. null = no limit.
log_errors_to_file	false	Absolute path to error log file.
log_success_to_file	false	Absolute path to success log file.
log_verbose	false	Include args, query and per-blog cmd/response in log files.
log_max_size	20971520 (20 MB)	Max log file size in bytes before erroring.
max_seconds	0	Stop starting new blogs after X seconds. 0 = no limit.
order_by	'last_updated DESC, blog_id ASC'	SQL ORDER BY for blog processing order.
overtime_is_error	false	Treat overtime as an error (triggers email).
send_error_email	true	Send an email when errors occur?
skip_all_plugins	false	CLI only. Pass --skip-plugins to sub-commands.
skip_all_themes	false	CLI only. Pass --skip-themes to sub-commands.

Log output

Blog tasks are grouped: blogs with identical state (same job_names, over_time, etc.) are merged into a single entry with a blog_ids array. This keeps logs compact on large multisites.

Default (compact) — no args/query_all_blogs, no per-blog cmd/response/site_url/issue:

{
  "2026-03-17 17:30:02": {
    "error_count": 0,
    "duration_all_seconds": 900.3,
    "blog_tasks": [
      {
        "over_time": 0,
        "job_names": ["wp_queue_connections_databaseconnection", "scoped_notify_process_queue"],
        "duration_blog_seconds": 0.96,
        "blog_ids": ["1"]
      },
      {
        "over_time": 0,
        "job_names": ["do_pings"],
        "duration_blog_seconds": 2.13,
        "blog_ids": ["1235"]
      },
      {
        "over_time": 0,
        "job_names": [],
        "blog_ids": ["6129", "3967", "...3855 more"]
      },
      {
        "over_time": 1,
        "job_names": [],
        "blog_ids": ["4938", "1416", "...124 more"]
      }
    ]
  }
}

(blog_ids truncated for readability — actual output contains all IDs)

--log_verbose — same structure, but includes args, query_all_blogs at the top level, and cmd, response, site_url, issue per blog task. Less grouping happens since per-blog fields differ.

Todos

• Add a log-table?
• Add tests
• Make it usable via backend (not just WP-CLI)