Performance Optimization

Baseline: main 23.0+. Complements skills bitrix-caching, bitrix-sessions, and bitrix-database.

Composite Site

Technology caching static HTML while loading dynamic blocks via AJAX. Kernel entry points: \Bitrix\Main\Composite\Engine, \Bitrix\Main\Composite\Responder.

1. Mark dynamic zones: <div data-dynamic="true">...</div> or frame mode APIs.
2. Enable in Admin → Settings → Composite Site (Autocomposite or Composite mode).
3. Configure NGINX to serve composite cache pool directly.
4. Clear component cache before enabling.

Modes:

• Autocomposite — kernel auto-detects static/dynamic.
• Composite — manual zone configuration.

NGINX: point try_files to the composite cache pool directory (BitrixVM: Configure nginx to use composite cache).

Do not put personalized data in static zone (cart, user name, permissions).

Query Optimization

• Limit ORM select fields.
• Use indexes matching filter/order columns.
• Avoid N+1 — fetchCollection() with relations.
• Batch operations instead of per-row updates.
• Enable ORM query cache where appropriate.
• Use SqlTracker in dev to find slow queries (skill bitrix-database).

Replication and Clustering

• MySQL master-slave for read scaling.
• Extra connections via .settings.php connections and \Bitrix\Main\Data\ConnectionPool (Application::getConnectionPool() / Application::getConnection('name')).
• Read-only analytics queries → separate connection.

Sharding

Horizontal partitioning for very large tables (enterprise scenarios). Kernel support varies by edition.

Hot/Cold Sessions

Related to separated session mode (bitrix-sessions):

• Hot data (kernel $_SESSION['BX']) → encrypted cookies.
• Cold data → Redis/DB backend.
• Reduces storage round-trips on every hit.

Checklist

• Composite tested with all dynamic blocks (cart, auth, personal).
• NGINX composite cache configured in production.
• Slow queries identified and indexed.
• Session backend matches load (Redis for high-traffic).
• File cache replaced with Redis/Memcached in production.