README.md

Argos

Argos checks critical gTag settings and log errors to the console, GA4, and BigQuery

Background

It is common to encounter problems when moving from client-side tagging to server-side tagging because of the many nuaces and complexities involved. In particular, it is common to find issues with with the Google Tag, or gTag, which can cause potentially large discrepancies with reporting, bidding, audiences in Google and other marketing platforms.

It is often difficult to know what settings and parameters are causing these issues. Argos monitors a few of the most important settings so any that are incorrect are spotted quickly. The common configuation settings the tag checks are:

• domain & region settings
• gTag measurement IDs
• consent & privacy settings

For more details on these see Explanation of Settings in Detail below.

Why Argos?

Argos is a many-eyed, all-seeing giant in Greek mythology. This tag watches over your gTag settings in production and allows you to monitor them through GA4, BigQuery, and/or Cloud Logging.

Implementation

Prerequisites

• Server Side Google Tag Manager
• If logging to GA4: admin access to a GA4 Account
• If logging to BigQuery: read/write access to a BigQuery dataset

Tag Set-up

1. Download the crictial_gtag_monitoring.tpl template to your local machine. Make sure the file is saved with the extension .tpl.
2. Open Google Tag Manager and select your server-side container.
3. Click on templates -> then the new button in the tag templates section. Click the three dots in the top right hand corner and import.
4. Select the template from your machine.
5. Optionally edit the permissions to specific which projects and tables in BigQuery and tags using this template will be able to access. You can use a * if you would like the template to be able to access any database, though you will need to ensure access settings are configured correctly (see below).
6. Press save.
7. Go to the tags page and press new.
8. Configure the tag by adding expected settings. For an explanation of each setting see the next section.
9. Choose what actions you'd like the tag to take. If selecting the GA4, BigQuery, or Cloud Logging actions follow the additional instructions below to set these up.
10. Add a triggering condition. We recommend firing on all pages or all events while doing testing to make sure you catch all potential errors.
11. Save

Explanation of Settings in Detail

Setting	What is it?	What will happen if this is incorrect	Example Input
Expected Domains	A comma-separate list of the domains on which your gTag is installed.	If the gTag is called from an incorrect domain it's very likely that attribution will not work correctly because cookies are not shared across domains. sGTM should always be called from the same domain (including subdomains) as the client-side container	example.co.uk, example.de, example.fr
Expected Countries	A list of countries where you expect traffic to come from.	Google treats data differently in different regions. If traffic is coming from unexpected regions it could suggest issues with the client-side gTag set-up or your region-specific settings in sGTM. This list should be a comma-searated list of ISO-3166-1 alpha-2 formatted country codes	GB, DE, FR
Expected GA Measurment IDs	Comma-separated list of the GA Measurement IDs you expect to see firing on your site.	Having the incorrect GA4 measurement IDs may mean data is routed incorrectly or you have unexpected tags on your website.	G-B7Q2YVVMBE, G-H6334KDAH
Expected DMA parameter value	The gTag sets the DMA parameter based on where it thinks the user is. DMA = 1 is expected for EEA traffic and 0 for non-EEA traffic. Different data controls are applied to EEA traffic.	If you are seeing DMA = 1 coming from non-EEA countries you will likely find significant data discrepancies in your Google account because user data will not be joined as expected	Choose 1, 0, or both from the dropdown
Expected GCS Values	The GCS parameter relates to consent mode. G111 means all consent is granted and G100 means all consent is denied but cookieless pings have been implemented. Comma-separated list of the GCS values you expect to see from your tag. Allowed values are: G100, G101, G110, and G111	Seeing unexpected GCS parameters means consent mode is implemented incorrectly.	For basic consent mode you might add: G101,G110, G111. For advanced consent mode you might add G100, G101, G110, G111.

Here is an example of how you may configure the tag. It is expect traffic from three websites in GB, DE, and FR with three gTags. DMA is set to "Any" because traffic is expected from both inside and outside the EEA. The expected GCS paramters don't include G100 which means we should not be seeing pings when consent is denied.

GA4 Setup

If you have selected "Send error event to GA4" follow these additional instructions.

In GA4 you will need set up this event and custom dimesion:

1. Go to your GA4 property > admin > data display > events
2. Create a new event e.g. "sgtm_argos_error"
3. If using the custom dimesion go to admin > data display > custom dimensions
4. Create a custom dimension e.g. "argos_error"

When selected you will see additional inputs appear in the tag template:

1. Add the measurment ID for the GA4 account where you want to send the data
2. Add a name for the event which you set up above
3. Choose if you want to also send the error message as a custom dimension. If you do, add the name of the custom dimension you set up above
4. Save or continuing configuring the tag with other settings.

You can check the event is working by launching preview mode in sGTM and triggering the tag with incorrect settings. In GA4 Debug you should see an event appear as shown below:

BigQuery Setup

If the server-side container is deployed to App Engine or Cloud Run, then Google Tag Manager will use the service account attached to the instance for connecting to BigQuery.

If the server-side container is deployed in a different Cloud provider to Google Cloud, please follow these additional instructions to attach a Google Cloud service account to the deployment.

This service account needs to have permission to access the BigQuery data.

1. Open the IAM Service Accounts page in the Google project that contains the sGTM container and find the account used for the sGTM deployment in Cloud Run.
2. Click the pencil to edit the permissions and assign the BigQuery Data Editor role (docs).
3. Go to BigQuery.
4. Within the relevant project create a new dataset, taking note of the name you use.
5. Within the dataset, create a new table again taking note of the name you use.
6. Create a table with two columns for the following: request string, and error message. The type for both should be strings. It doesn't matter what the columns are called.
7. Optionally add a timestamp column if you'd like one for easier troubleshooting. The type should be timestamp. Again, the name doesn't matter.
8. Save.

Once the BigQuery setup is complete you can add relevant settings in the tag:

1. In the tag tick "Log error to BigQuery". A new section with additional inputs will appear below
2. Add the settings for the cloud project, dataset ID and table ID
3. Add the column names for each of the columns making sure they exactly match what you created above. If adding a timestamp tick "Insert timestamp column" and add the column name in the input that appears
4. Save or continuing configuring the tag with other settings.

You can check the event is working by launching preview mode in sGTM and triggering the tag with incorrect settings. In BigQuery you should see events logged. You will also see success or error messages logger in sGTM preview mode.

Google Cloud Logging Setup

By default sGTM logs to Cloud Logging unless logging has been disabled. Logging must be enabled for this feature to work.

By ticking "Log request and error to Cloud Logging", the tag will log the request and error to the console and preppend a custom message to the beginning to allow you to filter logs accordingly. Add this message in the Custom Cloud Logging Message input field

Follow the console logging instructions to filter out the logs coming from the Argos tag using the custom message you've set up.

Note: logging all events can be very expensive, especially for servers with a significant amount of traffic. It is possible to choose to only log specific messages by following the instructions linked in the previous paragraph.

Note: this will mean that the tag logs twice in preview mode if you have also selected "Log to console in preview mode when there is an error".

Disclaimer

Copyright 2024 Google LLC. This solution, including any related sample code or data, is made available on an “as is,” “as available,” and “with all faults” basis, solely for illustrative purposes, and without warranty or representation of any kind. This solution is experimental, unsupported and provided solely for your convenience. Your use of it is subject to your agreements with Google, as applicable, and may constitute a beta feature as defined under those agreements. To the extent that you make any data available to Google in connection with your use of the solution, you represent and warrant that you have all necessary and appropriate rights, consents and permissions to permit Google to use and process that data. By using any portion of this solution, you acknowledge, assume and accept all risks, known and unknown, associated with its usage, including with respect to your deployment of any portion of this solution in your systems, or usage in connection with your business, if at all.