Developing a Caching Module for 1C-Bitrix on Redis

When your Bitrix site slows down, the /bitrix/cache/ folder balloons to 40GB, and database locks under load, the standard file cache is no longer viable. A Redis-based caching module addresses these issues head-on. On one project with a catalog of 500,000 items, the file cache grew to 40GB, and read operations were blocking the database. Switching to a Redis backend achieved a 98% hit rate, reduced latency by 90%, and enabled atomic tag invalidation. With over 10 years of Bitrix development experience and 40+ similar projects, we design robust caching solutions tailored to your architecture. Contact us for a free analysis and a turnkey proposal.

Why Redis outperforms file cache

File cache doesn't scale across multiple servers, read/write operations are locked at the filesystem level, and tag invalidation is a blocking operation. Redis executes queries in memory, with 90% lower response time. Atomic operations (Sets, Lists) make invalidation instantaneous. In practice, a Redis module achieves a 98% hit rate, while file cache rarely exceeds 85%. Load testing with 1,000 concurrent requests showed Redis handling all requests in 120 ms versus 450 ms for file cache.

CacheManager architecture

The central CacheManager class implements the strategy pattern. The backend is selected in module settings:

$cache = \Vendor\Cache\CacheManager::getInstance();

// Standard get-or-set
$result = $cache->remember('catalog_section_12', 3600, function() {
    return CIBlockSection::GetList(/* ... */)->Fetch();
}, ['iblock_12', 'catalog']);
// → Data from cache or result of callable on miss

// Explicit tag invalidation
$cache->invalidateTag('iblock_12');
// → All keys tagged with iblock_12 are cleared

Redis backend: atomic tag invalidation

Tags are implemented via Redis Sets. Invalidation is atomic with no filesystem locks:

class RedisCacheBackend implements CacheBackendInterface
{
    private \Redis $redis;

    public function get(string $key): mixed
    {
        $data = $this->redis->get($key);
        return $data !== false ? unserialize($data) : null;
    }

    public function set(string $key, mixed $value, int $ttl, array $tags = []): void
    {
        $serialized = serialize($value);
        $this->redis->setEx($key, $ttl, $serialized);

        // Tags stored as Redis Sets
        foreach ($tags as $tag) {
            $this->redis->sAdd("tag:{$tag}", $key);
            $this->redis->expire("tag:{$tag}", $ttl + 3600);
        }
    }

    public function invalidateTag(string $tag): void
    {
        $keys = $this->redis->sMembers("tag:{$tag}");
        if ($keys) {
            $this->redis->del(...$keys);
        }
        $this->redis->del("tag:{$tag}");
    }
}

Four caching strategies

We apply four strategies depending on data type:

• TTL cache — classic time-to-live for rarely changing data: site settings, regions, shipping.
• Event invalidation — reset on Bitrix events (OnAfterIBlockElementAdd, OnAfterIBlockElementUpdate, etc.).
• Stale-while-revalidate — serve stale cache instantly, trigger background regeneration via an agent. Eliminates thundering herd on miss.
• Request-scoped — in-memory array for a single HTTP request, avoiding repeated DB queries.

Want to determine the optimal strategy for your project? Contact us for a consultation.

Cache warmup to prevent spikes

After cache flush, the first request hits the database. Under high load, this causes a spike. A warmup agent solves this:

// Registered warmup tasks
$cache->registerWarmup('catalog_menu', function() {
    return CIBlockElement::GetList(/* full catalog */);
}, ['iblock_main_catalog'], 7200);

// Agent runs hourly and refreshes cache before TTL expires
\Vendor\Cache\WarmupAgent::run();

Monitoring and statistics

Table b_vendor_cache_stat stores aggregate stats per key:

• key_prefix, hits, misses, avg_ttl, last_hit_at

Admin interface includes:

• Hit rate by key category
• Top "cold" keys (>20% misses)
• Cache size per backend
• Manual invalidation by tag or key
• Log of recent invalidation operations

How to integrate with existing components?

Standard components use $APPLICATION->IncludeComponent() with CACHE_TYPE parameter. The module intercepts this mechanism and redirects to Redis:

// In init.php after module inclusion
\Vendor\Cache\BitrixCacheBridge::install();
// → Overrides \Bitrix\Main\Data\Cache::createInstance()
//   returning Redis backend instead of file

The bridge makes the swap transparent—components continue working without code changes.

Process: from audit to deployment

1. Analysis — study current architecture, measure performance (XDebug, MySQL slow log), identify bottlenecks.
2. Design — design module schema: select strategies, design tag structure, coordinate with you.
3. Implementation — write CacheManager code, backends, agents, bridge.
4. Testing — load testing with JMeter (1,000 virtual users) and metric collection.
5. Deployment — install on staging and production, monitor for one week.

What's included

Timeline and cost

Total: 10–12 working days. Code warranty: 1 year. Development cost is calculated individually. For projects with a PHP server cluster—additional Redis Cluster or Sentinel setup: +1–2 days.

Learn more about Redis and caching principles.

Assess your site's current performance: we offer a free caching audit in 2 days. Order a caching module to keep your site fast and stable under any load—contact us for a consultation!

1C-Bitrix Module Development and Setup

The main trap of Bitrix is init.php. You add an OnBeforeIBlockElementUpdate handler there, then another one — a year later the file is 2000 lines, and on every hit all that code executes. We move business logic into full-fledged modules with D7 ORM, custom tables, and administrative interface. The module can be disabled, transferred to another project, covered with tests — none of that is possible with init.php. Our team has 10+ years of Bitrix experience, certified specialists, and a 6-month code guarantee. Request a consultation — we'll explain how to migrate legacy code to a modular architecture.

Why is init.php the worst place for business logic?

Init.php does not support class autoloading, lacks an isolated namespace, cannot be unit tested, and cannot be disabled without editing the file itself. Every handler written there runs on every request, even if not needed. In a module, you register handlers through EventManager, and they only execute when the event occurs. Performance difference: up to 3x with 10+ handlers.

Standard Modules: Typical Problems and Solutions

Information blocks. IBlock architecture is the first thing we review on any project. A classic mistake: one catalog infoblock with 80 properties, 30 of which are multiple. The b_iblock_element_property table swells to millions of rows, and CIBlockElement::GetList with filtering on three properties does a full scan. We move reference data to Highload-blocks, eliminate multiple properties where possible, and design the structure for 5x growth.

e-Store (sale). Cart business rules are a separate story. We set discount priorities to prevent two campaigns from giving 60% instead of 30%, connect payment handlers, and write custom validation via OnSaleOrderBeforeSaved.

Search. The built-in search module with morphology works up to 10–15 thousand elements. Beyond that — Elasticsearch. We configure it via the Bitrix search module API, indexing through CSearchFullText or custom indexers.

Highload-blocks for dictionaries, logs, user data — instead of bloated IBlocks. Direct queries via Bitrix\Highloadblock\HighloadBlockTable, custom tables instead of the EAV structure of standard infoblocks. A million records — no degradation.

Mail events. Configuration is not just templates in b_event_message. The key is SPF, DKIM, DMARC on the DNS, otherwise transactional emails go to spam. We check deliverability and set up bounce handling.

How to Design Infoblocks for Performance?

We use Highload-blocks for reference data (colors, sizes, manufacturers) that are not involved in complex queries. For SKUs — a separate infoblock with linking via IBLOCK_ELEMENT_PROPERTY. Enable INDEX_PROPERTY for frequently filtered properties. Tagged caching: when an element changes, only the related cache is cleared. Highload-blocks process up to 10x faster than infoblocks with multiple properties on volumes of 100,000 records.

Custom Module Development

Each module follows the structure /local/modules/vendor.modulename/:

• install/index.php — setup class, create tables via $DB->RunSQLBatch()
• lib/ — D7 ORM classes, extending Bitrix\Main\ORM\Data\DataManager
• admin/ — administrative pages using CAdminList, CAdminForm
• include.php — autoloading, event handler registration via EventManager::getInstance()->registerEventHandler()
• REST API endpoints via \Bitrix\Rest\RestManager

The module registers in the system, appears in the "Installed Solutions" list, and has its own settings at /bitrix/admin/settings.php?mid=vendor.modulename. It can be enabled, disabled, and updated through UpdateSystem or custom migration mechanics.

Examples of implemented tasks:

• Campaign management — visual condition builder via CAdminCalendar, timers via agents (CAgent::AddAgent), analytics linked to the sale module
• Cost calculator — React widget on the frontend, REST API in the module, formulas stored in a Highload-block
• Booking system — real-time calendar, locking via $DB->StartTransaction() / $DB->Commit() on concurrent requests, integration with channel manager via webhook

Components and Composite Cache

Component customization via result_modifier.php and component_epilog.php, not by editing template.php of the standard template. This way core updates are painless.

Composite cache ("Composite Site" technology) — the server sends ready HTML, bypassing PHP routing. Dynamic areas (cart, authorization) are loaded via CBitrixComponent::setFrameMode(true) and AJAX. TTFB drops to 30–50 ms. But there are caveats: not all components are compatible, $APPLICATION->ShowPanel() breaks composite, and careful markup of <div id="bx-composite-..."> is required.

What to Check Before Installing a Marketplace Module?

Before installing a module from the marketplace, an audit is mandatory. We check: SQL queries without prepared statements (hello SQL injection), direct use of $_REQUEST without filtering, use of outdated kernel API instead of D7, conflicts with the composite cache module. A module with no updates for over a year and a few dozen installations is likely a problem on the next PHP update. A typical case: a module calls CIBlockElement::GetList with no cache reset — the site crashes with 5000 elements.

Migration to D7

When upgrading PHP or switching to a new edition — refactor outdated calls:

• CIBlockElement::GetList() → Bitrix\Iblock\Elements\ElementTable::getList()
• CSaleOrder::GetList() → Bitrix\Sale\Order::getList()
• CModule::IncludeModule() → Bitrix\Main\Loader::includeModule() Testing on staging, rollback via git on issues.

According to official 1C-Bitrix documentation, D7 ORM is the recommended tool for working with data, providing type safety and automatic query generation.

Comparison: Init.php vs Module

Module Development Scope and Cost

What is included in module development?

• Technical specification and architectural plan
• Code following PSR-4 and Bitrix code style
• Unit tests (PHPUnit) for business logic
• Integration tests for events and REST API
• Installation, configuration, and API documentation
• Repository and documentation access
• Administrator training for module usage
• 6-month warranty support

Estimated timelines and complexity:

Cost is calculated individually — contact us for a project estimate.

Module Testing

Unit tests via PHPUnit cover business logic: discount calculation, validation, document generation. Mocks for Bitrix\Main\Application::getConnection() allow tests to be DB-independent. Integration tests verify event handlers on a real database — OnAfterIBlockElementAdd, OnSaleOrderSaved, etc. REST API endpoints are tested via curl or PHPUnit HTTP client. Critical for modules working with b_sale_order, b_catalog_price — where errors cost money.

Compatibility is checked on PHP 7.4, 8.0, 8.1, 8.2 and editions: Standard, Small Business, Business. We check conflicts with popular marketplace modules — they often intercept the same events. Load testing: measurements on 10K, 100K, 1M records, profiling via Xdebug for memory leaks and N+1 queries.

Practical Examples

Campaign module for an electronics chain. The built-in sale module discounts did not cover scenarios like "2+1", a gift with purchase over a certain amount, or combined conditions. We built a visual builder: marketers create rules via drag-and-drop without development tickets. Campaign calendar, auto-deactivation via agents, analytics linked to b_sale_order — conversion, average check, usage count. Time to launch a new campaign dropped from two days to half an hour.

Calculator for builders. Parameters (area, materials, number of floors) → formula → preliminary estimate → lead to CRM via CRest::call('crm.lead.add'). Regional coefficients and seasonal markups from a Highload-block, material prices from 1C exchange. The number of target leads increased by a third: clients see a breakdown before calling a manager.

Booking for a hotel chain. Real-time availability via AJAX requests to a custom table vendor_booking_slots, seasonal tariff calculation, synchronization with Booking.com via channel manager API. Room locking on concurrent booking via SELECT ... FOR UPDATE in transactions. Timezones handled via \DateTimeZone — a guest from Vladivostok and a manager from Moscow see the same picture.

We will evaluate your project within one day. Write to us — we'll tell you what is included in turnkey development. Contact us for a consultation on your project. Order a custom module development — get a ready solution with documentation and support.