Case Studies & War Stories

Production Patterns

Pattern 1: Auto-Refresh Dashboard

From the real Host Health Monitor — polls every 30 seconds:

import { queryExecutionClient } from "@dynatrace-sdk/client-query";

export function useDql(query: string) {
  const [data, setData] = useState([]);
  const [loading, setLoading] = useState(true);

  const run = useCallback(() => {
    queryExecutionClient
      .queryExecute({ body: { query, requestTimeoutMilliseconds: 30000, maxResultRecords: 1000 } })
      .then((res) => { setData(res.result?.records ?? []); setLoading(false); })
      .catch(() => setLoading(false));
  }, [query]);

  useEffect(() => {
    run();
    const id = setInterval(run, 30_000);
    return () => clearInterval(id);
  }, [run]);

  return { data, loading };
}

Pattern 2: SLO Status Cards

const SloStatus = () => {
  const { data, loading } = useDql(
    `fetch dt.davis.slo | fields slo.name, slo.status, slo.target, slo.evaluatedPercentage | limit 5`
  );
  if (loading) return <ProgressCircle />;
  return (
    <Flex gap={12} flexWrap="wrap">
      {data.map((s: any, i: number) => {
        const pct = s["slo.evaluatedPercentage"];
        const ok = pct >= s["slo.target"];
        return (
          <Flex key={i} flexDirection="column" alignItems="center" padding={12}
            style={{ background: "var(--dt-colors-surface-default)", borderRadius: 8 }}>
            <Text>{s["slo.name"]}</Text>
            <Heading level={3} style={{ color: ok ? "var(--dt-colors-charts-categorical-color-06)"
              : "var(--dt-colors-charts-categorical-color-12)" }}>
              {Number(pct).toFixed(2)}%
            </Heading>
          </Flex>
        );
      })}
    </Flex>
  );
};

Pattern 3: Problem List

const ProblemList = () => {
  const { data, loading } = useDql(
    `fetch events, from:now()-7d | filter event.kind == "DAVIS_PROBLEM"
     | fields timestamp, display_id, event.name, event.status
     | sort timestamp desc | limit 10`
  );
  if (loading) return <ProgressCircle />;
  if (!data.length) return <Text>No problems in the last 7 days ✓</Text>;
  return (
    <Flex flexDirection="column" gap={4}>
      {data.map((p: any, i: number) => (
        <Flex key={i} gap={8} padding={8}
          style={{ background: "var(--dt-colors-surface-default)", borderRadius: 4 }}>
          <Text style={{ fontFamily: "monospace" }}>{p.display_id}</Text>
          <Text style={{ flex: 1 }}>{p["event.name"]}</Text>
          <Text style={{ color: p["event.status"] === "ACTIVE"
            ? "var(--dt-colors-charts-categorical-color-12)" : undefined }}>
            {p["event.status"]}
          </Text>
        </Flex>
      ))}
    </Flex>
  );
};

What Was Covered

Module  Skill                          What You Can Build
──────  ─────────────────────────────  ──────────────────────────────────
00-03   Foundations                     Scaffold, build, deploy, run DOOM
04-07   Data and UI                     Query Grail, render tables and charts
08-11   Advanced                        App Functions, intents, workflows, deploy
12-14   Boss Level                      Multi-tab production apps