Bloomberg Session timeout?

Question

As informed by the example in the Bloomberg APIv3, i need to start a Bloomberg session to open a service, then i need to use the service to create a request.

My question is, if my program sent a request, got the answer, and then after a while it might need to send another request. In this situation, how do i determine whether the Session/Service is still good to use to send the request, or do i need to start another session?

Does it cost much to start a session? Dose it bother Bloomberg's server if i start and stop a session quite often？

BTW, when i'm retrieving historical data, what's the proper size of data to ask for within a single request?

Thanks a lot for your kind help!

Answer 1

There are many questions here. The following answers are just my opinion, your best bet is to ask bloomberg themselves from a "Help Help" in your terminal session. Tell the person at the other end that you want your question to go to the API team.

Q: How do I determine if the session is still good? A: I don't know of any other way than using is and seeing if an exception occurs. However I have had sessions stay open for many hours perfectly happily.

Q: Does it cost much to start a session? A: Bloomberg don't give any guidance on this, but compared with the overhead of fetching data it doesn't seem much.

Q: What is the proper size of data to ask for? A: I believe if you ask for a lot bloomberg will break the request up for optimal transport, so you should ask for as much as you can in one request, as it will be more efficient. Beware of stepping over your data limits though.