test.java

public void testArchivedSetting() throws IOException {
        if (runningAgainstOldCluster) {
            String updateSettingsRequestBody = "{\"persistent\": {\"cluster.routing.allocation.disk.watermark.high\": 0.99}}";
            client().performRequest("PUT", "/_cluster/settings", emptyMap(),
                new StringEntity(updateSettingsRequestBody, ContentType.APPLICATION_JSON));
        }

        Map<?, ?> r = toMap(client().performRequest("GET", "/_cluster/settings", singletonMap("flat_settings", "true")));
        r = (Map<?, ?>) r.get("persistent");
        // The restart will have moved the setting to "archived"
        assertEquals("0.99", r.get((runningAgainstOldCluster ? "" : "archived.") + "cluster.routing.allocation.disk.watermark.high"));

        if (false == runningAgainstOldCluster) {
            // We should be able to update another setting
            String updateSettingsRequestBody = "{\"persistent\": {\"cluster.routing.allocation.enable\": \"all\"}}";
            client().performRequest("PUT", "/_cluster/settings", emptyMap(),
                new StringEntity(updateSettingsRequestBody, ContentType.APPLICATION_JSON));
            // And lets read it back just for good measure
            r = toMap(client().performRequest("GET", "/_cluster/settings", singletonMap("flat_settings", "true")));
            r = (Map<?, ?>) r.get("transient");
            assertEquals("all", r.get("cluster.routing.allocation.enable"));
        }
    }