@Ignore
    @Test
    public void testReadingAndAppendingToExistingData() {
        String dataDir = dataDir("QuestMetricsDbExistingData");
        if ( ! new File(dataDir).exists()) {
            System.out.println("No existing data to check");
            return;
        }
        IOUtils.createDirectory(dataDir + "/metrics");
        ManualClock clock = new ManualClock("2020-10-01T00:00:00");
        clock.advance(Duration.ofSeconds(9)); // Adjust to last data written
        QuestMetricsDb db = new QuestMetricsDb(dataDir, clock);

        List<NodeTimeseries> timeseries = db.getNodeTimeseries(Duration.ofSeconds(9), Set.of("host1"));
        assertFalse("Could read existing data", timeseries.isEmpty());
        assertEquals(10, timeseries.get(0).size());

        System.out.println("Existing data read:");
        for (var snapshot : timeseries.get(0).asList())
            System.out.println("  " + snapshot);

        clock.advance(Duration.ofSeconds(1));
        db.addNodeMetrics(nodeTimeseries(2, Duration.ofSeconds(1), clock, "host1"));
        System.out.println("New data written and read:");
        timeseries = db.getNodeTimeseries(Duration.ofSeconds(2), Set.of("host1"));
        for (var snapshot : timeseries.get(0).asList())
            System.out.println("  " + snapshot);
    }
To manually test that we can read existing data
node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/QuestMetricsDbTest.java