-- A failure that repeats is told apart from one that just happened (novox/hq 04-ISSUES/065).
--
-- A node re-applies what it holds on a steady interval and reports each time (novox/hq ADR 0010),
-- which is right for a failure that goes away by itself -- the overlay not up yet, a registry
-- briefly unreachable -- and makes a failure that will never go away look exactly the same: one
-- row, replaced, saying "failed" at a fresh time. Nothing distinguished "failed once, will succeed
-- when its dependency arrives" from "failed identically for ever", and nothing escalated the second.
--
-- Still one row per node. What is added is how long the CURRENT failure has been the same one:
-- when it first appeared, and how many reports in a row have said it. A report that says something
-- different starts the count again; a clean apply clears it.

alter table node_report
    add column failing_since timestamptz,
    add column failures      int not null default 0;