Fiori oData Queries timeout errors

Dear All

We have extended the Fiori oData services to fit in our scenarios. Some of these services keep failing out giving Timeout errors.

The HTTP Connection Timeout in Gateway Server is kept high, so that it does not cause any timeout.

So the suspect is the queries are timing out in ECC itself. How do we check this, are there TCodes to confirm this?

I am assuming somewhere RFC timeout might be happening, before ECC returns the data back to Gateway. Or SQL timeouts in ECC

What are the options we have to investigate this issue and resolve (Assume the oData query is already optimized in ECC)

Appreciate if someone can help.

Thanks

Sandip