The following article contains commonly asked questions and points of consideration to help develop the requirements for migrating analytics connectors from client-side tags to server-side connectors using EventStream. 


It is important to note that migrating from client-side to server-side could result in some minor differences in the data being sent to the analytics platform due to the delivery method and features available for each method. 

Testing and Validation

A new property will need to be set up for testing and should be identical to or as close to the production property as possible in order to validate the server-side data. Important and varied reports currently produced out of the client-side analytics implementation should be used as benchmarks for validation against the testing property. The testing property should have the same filters as the production property, as differences can cause issues during validation. It is also helpful to identify core metrics, defined as the most business-critical or project use case relevant fields, for validation. These values should be validated first and any issues addressed before beginning the server-side migration. Tealium will configure the server-side connectors to send data to those properties, making data validation easier.

Client-side Generated Data Points

Sending data directly to analytics vendors through client-side network requests automatically provides those vendors with certain data points (ex: IP addresses, browser user agents, third-party cookies, etc.). Those data points will need to be present in the server-side payload in order to be sent in the final API request.

Considerations Before Migrating

Here are some considerations unique to the Google Analytics EventStream connector that should be reviewed before beginning a migration:

  • Attribution Considerations: Client ID
    • Option 1: Google Analytics Cookie Matching Service tag
      Tealium has a Google Analytics Cookie Matching Service tag, which returns the _ga cookie, similar to how the Google Analytics tag sets the same cookie. From this _ga cookie, the Google Client ID can be parsed for use server-side. If the cookie sync is unsuccessful, the Tealium Visitor ID would be returned for use as the Client ID.
    • Option 2: Tealium Visitor ID
      If it’s only important that the Client ID is a unique value per device and browser (not that it originates from Google), the tealium_visitor_id can be passed as the Client ID. This option does not require a cookie sync tag.
    • Option 3: Run GA Tag Client-Side Once Per Session
      A Google Analytics tag can run once per session with the setting “Allow Advertising Features” enabled. This setup ensures a valid Client ID is created.
  • The referrer value: This value should only be sent to Google Analytics if the referrer is not the host domain.
  • Page View Events and Link Events: These events are simple to recreate as server-side events and should replicate 1:1. They will work similarly to the client-side events.
  • IP Address: As shared above exposing the user’s IP address can provide a more accurate representation of where the calls are coming from in Google Analytics. If you are interested in enabling IP address collection server-side, please reach out to your Customer Success Manager.

Validating Google Analytics:
There are a few helpful tools that can be used to validate Google Analytics client-side network calls that Tealium recommends:

Commonly Asked Questions

How does server-side analytics tracking work in Tealium?

Moving Google Analytics server-side will involve removing client-side libraries from the page entirely. Code that was handled by a specific piece of the vendor's library will need to be converted into Tealium compatible code, if applicable.

What will be different from the current client-side experience?
Depending on the vendor, removing client-side code can cause a variance in attribution. While Tealium aims to minimize this variance as much as possible, it is not guaranteed to be identical. Below is an example of a difference that could alter the attribution:

Google ID is assigned in a cookie via Google Analytics (gtag.js). Without the client-side library, this value cannot be used. Instead, Tealium will use its Anonymous ID for the Google Analytics ID. Tealium can conditionally set the Google ID if it already exists in a cookie, and can assign a new ID later if the cookie gets deleted.

It is important to keep in mind that when reviewing reporting for a client-side to server-side migration, a 3%-7% reporting variance is considered standard. This statistic is based on averages and may not align exactly with a unique implementation. If questions arise regarding the differences in the vendor's reporting, please contact a vendor representative.

Why do variances in reporting occur?

Traffic variances may occur for a few reasons including:

  • The vendor's tag code takes longer to load than the Tealium Collect Tag code, so the event is captured by our server instead of by the vendor's code depending on how quickly the visitor navigates away from the page.
  • Server-side requests through the API connection could time out in scenarios where a client-side request would be successful.
  • Server-side data collection may lose cached page navigation data because using a web browser’s back button or reloading a cached page does not generate additional server requests or responses. This condition may limit pathing data available for analytics reports.

Is there any way to limit the attribution changes?
Enabling the exposure of a user’s IP Address is required. The IP address provides greater accuracy and prevents Google Analytics from interpreting users as originating from the same place (i.e. the Tealium IP Address).

If you are interested in enabling IP address collection server-side, please reach out to your Customer Success Manager.


Does this change how data is validated?
Moving analytics server-side will limit the ability to verify the requests since the requests will not show in vendor validation tools (ex: Google Tag Assistant) and are no longer visible from the browser. Connector actions can be validated using the Trace Tool found within the Tealium Tools Chrome extension.

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