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Varnish

Description

Fast loading times are a key factor in business success. If page rendering takes too long, you are likely to experience a high bounce rate—the share of visitors to your web application who leave after viewing only the initial page. Long page load times can be a primary cause of this. This places significant demands on your web application, particularly in the mobile sector. One solution to this problem is Varnish Cache, which stores entire web pages—or parts of them—in memory and serves them directly. This relieves the load on your application servers, which would otherwise have to execute application scripts to generate the page and interact with other services (such as the database). You can significantly reduce response and load times and downsize your application and database servers, resulting in additional cost savings. Varnish Cache offers flexible options for selectively invalidating cached content, which forces the application servers to regenerate it. This gives you control over which content is served unchanged and for how long. How Varnish Cache is integrated into your setup depends on the software you use. Many e-commerce solutions, including OXID eShop and Shopware, support the use of Varnish Cache. Another important aspect is the ability to continue serving web pages even if application servers or other critical services responsible for generating content fail. As long as the cached content remains valid, your website visitors continue to be served without noticing the outage. What we aim to achieve with this service:

  • Integration of Varnish Cache servers into your setup
  • Enabling speed optimization within your setup
  • Offering high-performance, cost-effective setup options
  • Enabling service continuity during outages (application servers and other services)

What you can expect from our service

  • High availability of the caching solution
  • Scalability
  • A configuration snippet that sets up and verifies the connection between Varnish Cache instances, load balancers, and application servers
  • Full customer control over configuration
  • Ability for the customer to clear the cache

Optional service features

  • Varnish Plus (based on individual agreement)

Service requests

  • Restarting the Varnish Cache service
  • Clearing the cache
  • Deploying a new configuration (without service interruption)

Standard Configurations

We offer two distinct standard hosting solutions that differ in performance and availability. If these options do not meet your requirements, or if you would like assistance with setup, please contact our consulting team to develop a solution tailored to your specific needs.

Single-Server Setup

This option is particularly suitable for development and testing systems, as it offers excellent value for money. It involves the installation and operation of a single Varnish Cache instance.

Redundant Setup (Our Best Practice)

For production environments, we recommend a setup consisting of multiple Varnish Cache instances (servers) with an upstream load balancer. This ensures that traffic is routed to an active Varnish Cache server or, alternatively, directly to an application server if no Varnish Cache server is available. Since all Varnish Cache instances maintain identical cache content, the specific instance selected does not matter (applies to Varnish Plus only). If all Varnish Cache instances fail to respond simultaneously, the request is forwarded directly to an application server. We offer an optional "SLA Premium" service for this configuration. Under the terms of the SLA, the service is considered available if it responds to a request; the content of the response is not a determining factor.

Our "Trending" tool provides access to Varnish Cache-specific historical data—such as

  • Backend connections,
  • ESI,
  • Fetch,
  • Hit rates,
  • Total backend connections,
  • Total fetch,
  • Total hit rates,

allowing you to monitor and optimize Varnish Cache usage.

External Access

There is no external access to the Varnish Cache service. Cache content can be purged from servers within the setup, provided they have been authorized to do so.

Optional Features/Configurations

If you have further questions about the capabilities, configuration, or usage of Varnish Cache, please contact our consulting team. We would be happy to arrange a consultation with you.

Managed Cloud Instance Sizes

Upon request, we can provide a quote for larger or smaller managed cloud instances tailored to your performance requirements. High-performance storage options are also available.

FAQ

Can Varnish caches be located in different availability zones?

Yes, that is possible.

What happens if the RAM allocated for the cache runs out of space?

First, the Varnish cache will attempt to delete content that is no longer valid. If that is insufficient, it will delete content that has not been accessed for the longest time.

Can all Varnish cache instances fail simultaneously?

We distribute the instances across different hardware to achieve greater redundancy of the components used.

Do multiple Varnish instances synchronize with each other automatically?

If you are interested in Varnish HA, please contact our consulting team.

Important Notes

We offer Varnish as a managed service. You can find further information and details about our managed services on our website.