I checked the peppy duts, there were no jobs around 4/20/2017 20:00:00 

what should I check then? 

another failure https://uberchromegw.corp.google.com/i/chromeos/builders/veyron_speedy-paladin/builds/5058

Both those boards are on the same shard, chromeos-server14.mtv.corp.google.com. That makes is very suspiciously either a shard rpc or other shard-specific issue

https://uberchromegw.corp.google.com/i/chromeos/builders/veyron_mighty-paladin/builds/5063

All of the three are on server14, might be relate to the slow apache?

chromeos-server14.mtv.corp.google.com   board:veyron_mighty, board:veyron_speedy, board:peppy

Something went down on the shard for a two hour stretch:
    https://viceroy.corp.google.com/chromeos/machines?duration=1d&hostname=chromeos-server14&refresh=-1&status=Running&topstreams=12&utc_end=1492790704.42

Whatever it was, it doesn't behave like any of our known
problems, although I won't rule out a new symptom for something
we're already tracking.

assumed one off