Pull only delta data from integration

[Shusovit Dutta]

I have to pull some data which are updated in a 3rd party tool. But need to make sure I am not pulling all the records everyday. I should pull only the data which has been updated on that day on the 3rd party tool. How can i achieve this delta data pull. 
Also what if SN is down and the scheduled job to pull data for that day does not run. How can I make sure that I pull it from the last scheduled job execution date till the latest updated data in 3rd party tool.

In short I need to make sure I pull only the delta data and not the full list of data every time also taking into the consideration the fact that if SN is down or something happens where system could not pull for a particular day, i should have a setup to pull from that day onwards.

[Sandeep Rajput]

@Shusovit Dutta In order to pull the delta data, both provider (3rd party tool) and consumer (ServiceNow in your case) need to implement an integration model where the consumer can exchange the last sync timestamp with the provider to receive only the data which added/updated after the shared timestamp. The provider will take this last sync timestamp as an input to their API call and will only share data added/updated after it.

The consumer (ServiceNow) need to update the value of last sync timestamp each time it fetches the delta successfully. With this model, even if the consumer/provider is out of service for some time, they will only receive delta data.

Hope this answers your question.