Sitecore Analytics cookie id does not match in MongoDB Contacts table records

Question

I have Sitecore 8.2 installed in my local environment. I was investigating that is analytics/xDB working correctly in my setup. I opened my site with a browser and saved the cookie SC_ANALYTICS_GLOBAL_COOKIE value for myself and the browser a few pages. I waited that the session ends so that Sitecore flushed the data to MongoDB. I checked the interactions table in MongoDb and I can find the record where I visited the pages. What I noticed also is that the id of ContactId in that record does not match the one that I took from the cookie in the browser, although the Pages that were visited are correct. I did this a few times to make sure. Also, the Contacts table didn't have the same value.

Looking at the Sitecore documentation I understood that the cookie SC_ANALYTICS_GLOBAL_COOKIE value should be the same as ContactId. How come in my case it isn't?

Answer 1

You need to parse contact id from cookie value to Guid first and then convert it to ToBase64String.

Something like:

// Id of the Contact in the format xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
string contactId = "50638e2f-43b2-46ee-806d-665f4fb08954";
    
var guid = Guid.Parse(contactId);
var bytes = guid.ToByteArray();

string encodedId = Convert.ToBase64String(bytes);

You will receive encodedId in a form similar to L45jULJD7kaAbWZfT7CJVA==.

Then you can query MongoDB using:

db.getCollection('Contacts').find({_id:new BinData(3, 'L45jULJD7kaAbWZfT7CJVA==')})

Code copied from and more details: https://jonathanrobbins.co.uk/2017/04/30/how-to-find-sitecore-contacts-in-xdb-mongodb/