Question

或者我做错了什么。我有一项服务可以统计收到的请求。请求具有平台，执行请求的客户端应用程序版本以及其他标签。重新启动服务后（这种情况很少发生在更新中，因此会重置指标）。

因此，我想计算最近时间范围内每个平台的查询百分比，然后执行以下操作：

SELECT SUM("received")  as "received"
FROM (
  SELECT NON_NEGATIVE_DIFFERENCE(MAX("received")) as "received"
  FROM  "http_metrics"
  WHERE time >= now() - 4h GROUP BY time(1s)
) GROUP BY "platform";

哪个返回：

...
tags: platform=ios
time                 received
----                 --------
1970-01-01T00:00:00Z 581

tags: platform=unknown
time                 received
----                 --------
1970-01-01T00:00:00Z 12310

tags: platform=web
time                 received
----                 --------
1970-01-01T00:00:00Z 6196

并在不分组的情况下进行相同操作：

SELECT SUM("received")  as "received"
FROM (
  SELECT NON_NEGATIVE_DIFFERENCE(MAX("received")) as "received"
  FROM  "http_metrics"
  WHERE time >= now() - 4h GROUP BY time(1s)
);

哪个返回：

time                 received
----                 --------
1970-01-01T00:00:00Z 8274

这显然是不正确的，因为“未知”平台接收的请求不能超过所有请求。但是我什至不知道哪个是不正确的，全部不正确的，平台不完整的或两者都不是？

如何正确计算请求总数和平台总数？

Answer 1

好吧，所以问题是，由于我的测量还具有其他标签，例如服务器和应用程序版本，并且每个标签都有单独的计数器，因此它们都变得交错，可以在图形上看到，该图表应该平滑且累积的，但是非常尖刻：

但是当我们添加GROUP BY *

SELECT "received" FROM  "http_metrics"  WHERE $timeFilter GROUP BY *;

它分为许多独立的平滑序列：

现在，这是有区别的，因此我们可以创建子查询进行汇总。

总计：

SELECT SUM("received") as "received" FROM (
    SELECT NON_NEGATIVE_DIFFERENCE(MAX("received")) as "received"
    FROM "http_metrics"
    WHERE time >= now() - 6h
    GROUP BY time(1s), *
) WHERE  time >= now() - 6h;

time                           received
----                           --------
2018-07-17T01:07:46.184292033Z 1367

分组：

SELECT SUM("received") as "received" FROM (
    SELECT NON_NEGATIVE_DIFFERENCE(MAX("received")) as "received"
    FROM "http_metrics"
    WHERE time >= now() - 6h
    GROUP BY time(1s), *
) WHERE  time >= now() - 6h
GROUP BY "platform";

... I'm not going to bore you with response, but sum matches total sum.

所以，我想这个故事应该是这样的：每次您要区分具有某些标签的柜台时，都需要GROUP BY *

总和小于InfluxDB测量中标记的总和？

1 个答案: