private Optional<String> shouldPark(Node node, NodeList allNodes) {
        if (NodeFailer.hasHardwareIssue(node, allNodes))
            return Optional.of("has hardware issues");
        if (node.type().isHost() && node.status().failCount() >= maxAllowedFailures)
            return Optional.of("has failed too many times");
        if (node.status().wantToDeprovision())
            return Optional.of("want to deprovision");
        if (node.status().wantToRetire())
            return Optional.of("want to retire");
        return Optional.empty();
    }
Returns whether the node should be parked instead of recycled
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/FailedExpirer.java