For master build 19114 (https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8941157531302551888), it looks like many of the child failures are directly or indirectly related to provisioning failures:

wolf-paladin: https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8941156373422364720
Notice repeated provision failure for AutoUpdate.double (https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/suiteDetails?cidbBuildId=2744433)

This pattern also happens on:
wizpig-paladin - https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8941156373805053360
winky-paladin - https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8941156374283792608

Other failures from this master run look like machines can't connect which seems related, for example:
veyron_minnie-paladin - https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8941156384256716480 (if I an looking at the test failure logs correct, e.g. https://pantheon.corp.google.com/storage/browser/chromeos-autotest-results/216675663-chromeos-test/chromeos4-row9-rack9-host19/)