Sudden spike in inbound bytes

I was watching the real time data on Google Analytics and I noticed that page views suddenly dropped by 50% for a small period of time. The drop occurred at 6.28PM.

When I noticed this, I went into the Datadog dashboard and immediately saw the following:

frontend

That spike occurred at roughly the exact same moment. The graph above is haproxy.frontend.bytes.in_rate, which Datadog defines as “Rate of bytes in on frontend hosts.”

It jumped from 18 bytes per second to 53 bytes per second.

Does anyone know what might have caused this or how I could further debug these kind of spikes?

Thanks,
Wayne