Wait for caches to sync before running node sync

[bowei]

There can be a race condition where the queue somehow triggers
before the caches are able to sync.

Improve logging around the event for better debugging in the future.

[bowei]

/assign @rramkumar1

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[bowei]

/assign @freehan

[rramkumar1]

/lgtm

[k8s-ci-robot]

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