Internal Api Error.UNEXPECTED INTERNAL API ERROR

[Veer]

I am running a script to fetch the keyword stats like average monthly
search volume etc. I am calling for one keyword each time, I am
running the api call in a loop for 1.3 million keywords, but after
sometime api call stops and below error shows

[message:protected] =>
InternalApiError.UNEXPECTED_INTERNAL_API_ERROR @

Please help me out.

[AdWords API Advisor]

Hi Veer,

It appears that there are some occasional internal timeouts that are
leading to this error. The appropriate response is to wait for a few
seconds and then try your request again.

As an aside, requesting the STATS for one keyword at a time is very
inefficient, and we recommend that you batch multiple keywords into
one request. This allows your application to run faster and should
reduce the occurrence of these errors. The
RelatedToKeywordSearchParameter can contain up to 2500 keywords when
requesting STATS.

Best,
- Eric Koleda, AdWords API Team