Definition and Purpose:
SiteSpect's bypass mode is a feature that allows traffic to bypass the SiteSpect infrastructure entirely by routing traffic directly to your origin servers. This mode can be activated by your team (for maintenance or troubleshooting purposes) or automatically invoked (for SiteSpect Cloud deployments) in the rare event that SiteSpect's services need to be temporarily disabled without disrupting your website's availability.
Note: with most on-premises deployments, SiteSpect sits behind one or more load balancers that health checks the engines and will fail over to the origin in the event the engines report ill health. The details are client and/or environment-specific.
Additionally, in some cases, SiteSpect will leverage a DNS failover via Akamai Global Traffic Management (GTM).
Activation Process:
When bypass mode is activated, DNS settings are updated so that the value of the CNAME record, which normally points to SiteSpect, instead points to the client’s failover address (configured at SiteSpect). This could be the origin server or a CDN based on the traffic flow design. This process ensures that all incoming traffic bypasses SiteSpect and is instead handled by the origin infrastructure directly. In other words, bypass mode cuts SiteSpect out of the flow of traffic completely.
Impact on Active Campaigns:
During bypass mode, all active campaigns in SiteSpect are effectively paused. Users visiting the website will not be served any variations or tests managed by SiteSpect, as the traffic no longer flows through SiteSpect’s systems. The website functions as if SiteSpect is not in place, with no A/B tests, personalizations, or other modifications applied.
Use Cases:
- Maintenance:
For SiteSpect Cloud, upgrades and maintenance are performed seamlessly without any disruption to traffic or campaigns and don’t require bypass mode. For on-premises customers, bypass mode is leveraged for upgrades or maintenance to the SiteSpect platform, ensuring that traffic is unaffected while changes are being made. Bypass mode can be a useful tool for your team during scheduled maintenance or updates to your environment. - Troubleshooting:
If issues arise that are suspected to be related to SiteSpect, bypass mode can be enabled to determine if SiteSpect is the cause. This helps isolate problems by removing SiteSpect from the traffic flow. - Health Checks:
For SiteSpect Cloud deployments, bypass mode will be triggered automatically if health checks fail. This can occur for a number of reasons. For example: network issues between SiteSpect and the client origin, web server issues at client origin, or, typically, the health check target has been moved or deleted (inaccessible). - Slow-Origin Bypass:
There is another way that bypass mode is invoked automatically. This is called a 'slow-origin' bypass. It happens when open connections to your origin accumulate beyond a certain pre-defined threshold.
Every domain configuration at SiteSpect is served by nine Points of Presence (a.k.a. PoPs), one in each of SiteSpect’s data centers. If the number of open connections on a single PoP surpasses our threshold, that one PoP is bypassed according to the slow-origin protocol (please see below).
If the number of open connections surpasses our threshold on two or more POPs at the same time, the entire domain is bypassed according to the slow-origin protocol, and the client will receive an email alert at the start and end of the bypass.
An alert is not sent when a single POP is bypassed, since the other POPs continue to serve traffic for your site.
This state of bypass allows the open connections to clear.
The Slow-Origin Protocol:
The first time that a domain is placed in a slow-origin bypass, it remains bypassed for five minutes, then the bypass is automatically removed. If the situation recurs, the second bypass will last for a duration of 30 minutes. A third instance will result in an 1 hour of bypass. In the event of a fourth instance, the domain will remain in bypass until manually removed.
Reverting Back to Routing Mode:
Once the reason for enabling bypass mode has been addressed, the bypass can be removed, which reverts DNS records to route traffic back through SiteSpect. At this point, all active campaigns and tests will resume as normal and users will be automatically allocated to their prior campaign assignments.
When bypass is initiated automatically, the bypass is also ended automatically; our systems are designed to restore traffic once it evaluates as healthy. For example, if your health check target is renamed or removed, the domain will automatically enter the bypass state. Once the health check is restored, the domain will automatically come out of bypass and begin processing traffic again.
Bypass mode is an essential feature for ensuring the stability and performance of your website in rare scenarios where issues arise with SiteSpect or its integration; it allows you to temporarily suspend SiteSpect's influence on your website, letting traffic flow directly to your origin servers without any modifications. This feature is particularly valuable for diagnosing and resolving issues without disrupting the user experience.