private void ensureTablesExist() {
        if (nodeTable.exists())
            ensureNodeTableIsUpdated();
        else
            createNodeTable();

        if (clusterTable.exists())
            ensureClusterTableIsUpdated();
        else
            createClusterTable();
    }
An implementation of the metrics Db backed by Quest:
This provides local persistent storage of metrics with fast, multi-threaded lookup and write,
suitable for production.

@author bratseth
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/QuestMetricsDb.java