Performance Optimization in Sitecore

Caching Strategies

Implementing caching properly in Sitecore significantly improves performance. The following caching techniques should be used:

 HTML Caching

Ø  Store rendered HTML output to reduce processing time.

Ø  Enable caching on Sitecore renderings (Caching tab in Sitecore Experience Editor).

Ø  Configure vary by parameters to cache different versions of content.

Data Caching

Ø  Use Sitecore’s Data Cache to store frequently accessed database queries.

Ø  Implement custom memory caches using .NET MemoryCache for high-frequency data.

Ø  Leverage pre-fetch caching to load important content in advance.

Output Caching

Ø  Store entire page outputs in the cache for quick retrieval.

Ø  Configure Sitecore Output Cache settings at the item level.

Ø  Set cache expiration rules to balance freshness and performance.

 

Load Balancing & Database Optimization

Load Balancing in Sitecore

Ø  Use multiple Sitecore Content Delivery (CD) servers to distribute traffic.

Ø  Implement Sitecore Session State in Redis or SQL Server for scalability.

Ø  Enable Sticky Sessions in load balancer configurations.

Database Optimization

Ø  Index frequently accessed fields in Sitecore databases.

Ø  Use Sitecore Content Search API instead of querying the database directly.

Ø  Enable database sharding for large-scale implementations.

Ø  Perform regular database cleanup to remove unused or outdated content.

1.1 HTML Caching: Storing Rendered Output

HTML caching stores the rendered output of components so that Sitecore doesn’t have to regenerate them every time a user requests a page.

How to Enable HTML Caching for Components

1. Go to Sitecore Content Editor → Presentation → Renderings.
2. Select the rendering you want to cache.
3. Under Caching, enable:
• Vary by Data
• Vary by Device
• Vary by Parameters

<rendering id="{RENDERING-ID}" cacheable="true" varyByData="true" varyByDevice="true" varyByParameters="true" />

Best Practices:

Use HTML caching for static content blocks, footers, headers, and reusable UI elements.

Avoid caching personalized components or real-time content.

 

Data Caching: Reducing Database Calls

Data caching helps store frequently accessed data to reduce database queries.

How to Implement Data Caching in Sitecore Use Sitecore Caching API to store and retrieve objects efficiently.

var cachedData = Sitecore.Caching.CacheManager.GetNamedCache("MyCustomCache");

if (cachedData == null)

{

    cachedData = GetDataFromDatabase();

    Sitecore.Caching.CacheManager.GetNamedCache("MyCustomCache").Set("DataKey", cachedData, DateTime.Now.AddMinutes(10));

}

 

Best Practices:

• Cache frequently accessed lists, dropdown values, and configurations.
• Set cache expiration times based on content volatility.

 

Output Caching: Reducing Processing Overhead

Output caching stores entire rendered pages to serve them faster.

 

How to Enable Output Caching in Sitecore

1. Navigate to System → Settings → Caching.
2. Enable full-page output caching in the web.config file:

<sitecore>

  <cacheManager>

    <cache name="HtmlCache" enabled="true" />

  </cacheManager>

</sitecore>

 

Best Practices:

• Use output caching for static landing pages and content that doesn’t change frequently.
• Avoid full-page caching for user-authenticated pages or personalized experiences.

 

Use Sitecore’s Data Cache

Sitecore provides built-in caching mechanisms that help store frequently accessed database queries. Utilizing Sitecore’s Data Cache can significantly improve system performance.

Implementation:

• Enable Sitecore’s database caching in Sitecore.config under caching settings.
• Utilize Sitecore's DataCache API to store and retrieve data efficiently.
• Monitor cache performance using the Sitecore Caching admin page (/sitecore/admin/cache.aspx).

Example Usage:

var cache = Sitecore.Caching.CacheManager.GetNamedInstance("customDataCache", 10000);

string cachedValue = cache.GetString("key");

if (cachedValue == null)

{

    cachedValue = GetDataFromDatabase(); // Fetch from database

    cache.SetString("key", cachedValue);

}

 

 

2. Implement Custom Memory Caches Using .NET MemoryCache

For frequently accessed, non-Sitecore content or custom data structures, using the built-in .NET MemoryCache class efficiently reduces repeated database calls.

Implementation:

• Use MemoryCache to store non-Sitecore data such as API responses, configuration settings, or frequently used computations.
• Define expiration policies such as absolute expiration (fixed time) or sliding expiration (time since last access).

Example Usage:

using System;

using System.Runtime.Caching;

 

public class CustomCacheHelper

{

    private static readonly MemoryCache _cache = MemoryCache.Default;

 

    public static string GetData(string key)

    {

        return _cache.Get(key) as string;

    }

 

    public static void SetData(string key, string value, int expirationMinutes = 10)

    {

        var policy = new CacheItemPolicy { AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(expirationMinutes) };

        _cache.Set(key, value, policy);

    }

}

 

// Usage:

string data = CustomCacheHelper.GetData("key");

if (data == null)

{

    data = GetDataFromDatabase();

    CustomCacheHelper.SetData("key", data);

}

 

 

3. Leverage Pre-Fetch Caching

Pre-fetch caching allows important content to be loaded into the cache in advance, reducing the risk of slow responses when users request the data.

Implementation:

• Identify critical content (e.g., homepage, navigation menus, featured products).
• Use scheduled tasks or Sitecore jobs to refresh cache data periodically.
• Load content into the cache at startup to ensure quick access.

 

 

Example Usage:

public class PrefetchCache

{

    private static readonly MemoryCache _cache = MemoryCache.Default;

 

    public static void PreloadData()

    {

        var policy = new CacheItemPolicy { AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(30) };

        _cache.Set("homePageData", GetHomePageData(), policy);

        _cache.Set("navigationData", GetNavigationData(), policy);

    }

}

 

// Call during application start:

PrefetchCache.PreloadData();

 

 

Optimization Tips

1. Cache Dependencies – Set up cache dependencies so that updates to Sitecore items automatically invalidate related cache entries.
2. Use HTML and Output Caching – Store rendered components and pages in the cache for performance improvements.
3. Monitor Cache Usage - Regularly analyze cache hit ratios in Sitecore's admin interface and adjust cache sizes accordingly.
4. Implement Redis Cache - Sitecore supports Redis as an external provider for distributed caching in scaled environments.

 

 

2. Load Balancing in Sitecore

A single server can only handle so much traffic before it crashes or slows down. Load balancing distributes traffic across multiple servers, ensuring high availability and reliability.

2.1 Configuring Load Balancing in Sitecore

1. Set Up Multiple Content Delivery (CD) Servers:
• Deploy multiple CD instances to distribute user traffic.
• Use a Load Balancer (Azure Traffic Manager, AWS ELB, or Nginx).
2. Use Sitecore’s Load Balancing Configuration:
• Modify the scvariable_Web.config file:

<sitecore>

  <settings>

    <setting name="ContentDelivery.RemoteEvents.Enabled" value="true" />

  </settings>

</sitecore>

Best Practices:

• Use sticky sessions if session management is required.
• Ensure CD servers don’t contain Content Management (CM) roles.

 

3. Database Optimization in Sitecore

Databases are often Sitecore's biggest performance bottleneck. Poor indexing, unoptimized queries, and bloated data slow down Sitecore’s experience database (xDB) and the Master/Web Databases.

 

SQL Indexing for Faster Queries

Sitecore databases should be indexed appropriately to speed up data retrieval.

 Steps to Optimize Indexing:

1. Identify slow queries using SQL Profiler.
2. Add non-clustered indexes on frequently queried fields.
3. Schedule database maintenance to rebuild indexes periodically.

Best Practices:

Regularly clean EventQueue and History tables.

Enable SQL Database Partitioning for large datasets.

 

3.2 Cleanup Unused Items in Sitecore Databases

Over time, Sitecore databases accumulate obsolete versions, orphaned items, and outdated analytics data.

How to Clean Up Sitecore Databases

• Run the Database Cleanup Tool in the Control Panel → Administration → Cleanup.
• Set up automatic cleanup scripts to remove unused versions:

DELETE FROM VersionedFields WHERE ItemId NOT IN (SELECT ID FROM Items);

Best Practices:

• Keep only necessary versions of items (limit to 5 versions max).
• Schedule xDB data purges every 30 days to remove old analytics data.

 

Optimize Content Delivery by Using Sitecore CDNs

A Content Delivery Network (CDN) improves page load speeds by caching and serving assets from geographically distributed servers.

How to Use CDN with Sitecore Media Library

1. Enable Media Library Caching.
2. Configure Azure CDN or Cloudflare to serve static assets.
3. Modify MediaRequestHandler to allow CDN requests:

<sitecore>

  <mediaLibrary>

    <enableMediaCache>true</enableMediaCache>

  </mediaLibrary>

</sitecore>

Best Practices:

• Serve CSS, JS, and images from a CDN to reduce server load.
• Use lazy loading for images to improve initial page render time.