Mysterious document field 'synchronizedOn'

Hi,

We are using latest CBL on Anroid + sync gateway 3.1.3 and coucbase server enterprise 7.13. We migrated from sync gateway version 2.8 to 3.1.3 in last February.

By accident we discovered an attribute called synchronizedOn with null value in some of our documents. We don’t create or update this attribute in our app nor in our back end services that access couchbase server.

We are wondering where does this attribute come from? We didn’t find any reference to this attribute in the documentation

• Which couchbase component sets this field in the documents?
• When is it set?
• Could it possibly cause document update errors?
• Can we delete this field without causing errors?

Here is an example of a document with this field:
{
“plapp”: {
“channels”: [
“9822d92b-fcc8-11e9-b065-0a5802b030ad”
],
“code”: “0001”,
“documentType”: “Storage”,
“label”: “0001 Regalfach”,
“storageId”: “fbstrg-0000976966-0001”,
“synchronizedOn”: null,
“technicalAgencyId”: “9822d92b-fcc8-11e9-b065-0a5802b030ad”
}
},

Regards,
Faris Ahmed

I searched in all the sync gateway code repositories and I do not find any reference to synchronizedOn, so I assume it is an application property.