I am trying to work with a 3rd party service api . One of the methods they have brings in all records which takes a lot of time , about 9 mins ( i tried this using chrome app "Advanced Rest Client"). Resetting the HttpRequest timeout to 120 secs (which is the max) in Salesforce doesn't really help here. Any other suggestions ?
One pattern to address this is to separate the request from the responses. You make the request specifying a callback URL and get an immediate response. Then the 3rd party service calls back (perhaps multiple times) as results are available over the next few minutes.
But that requires that the 3rd party service to be designed to support this pattern. Though the slower a service is, the more likely it is to support this pattern.