如何计算interval的值 - Nightingale

SQL变量

字段名	含义	使用场景
database	数据库	无
table	表名
time_field	时间戳的字段
query	查询条件	日志原文
from	开始时间
to	结束时间
aggregation	聚合算法	时序图
field	聚合的字段	时序图
limit	分页参数	日志原文
offset	分页参数	日志原文
interval	直方图的时间粒度	直方图

日志原文

直方图

# 如何计算interval的值
max := 60 // 最多60个柱子
interval := ($to-$from) / max
interval = interval - interval%10
if interval <= 0 {
	interval = 60
}

SELECT count() as cnt,
	FLOOR(UNIX_TIMESTAMP($time_field) / $interval) * $interval AS __ts__ 
		FROM $table
	WHERE $time_field BETWEEN FROM_UNIXTIME($from) AND FROM_UNIXTIME($to)
	GROUP BY __ts__;

{
	"database":"$database",
	"sql":"$sql",
	"keys:": {
		"valueKey":"cnt",
		"timeKey":"__ts__"
	}
}

日志原文

SELECT * from $table
	WHERE $time_field BETWEEN FROM_UNIXTIME($from) AND FROM_UNIXTIME($to)
	ORDER by $time_filed
	LIMIT $limit OFFSET $offset;

{
	"database":"$database",
	"sql":"$sql"
}

时序图

日志行数

SELECT COUNT() AS cnt, DATE_FORMAT(date, '%Y-%m-%d %H:%i:00') AS __ts__ 
	FROM nginx_access_log
	WHERE $time_field BETWEEN FROM_UNIXTIME($from) AND FROM_UNIXTIME($to)
	GROUP BY __ts__

{
	"database":"$database",
	"sql":"$sql",
	"keys:": {
		"valueKey":"cnt",
		"timeKey":"__ts__"
	}
}

max/min/avg/sum

SELECT $aggregation($field) AS series, DATE_FORMAT(date, '%Y-%m-%d %H:%i:00') AS __ts__ 
	FROM nginx_access_log
	WHERE $time_field BETWEEN FROM_UNIXTIME($from) AND FROM_UNIXTIME($to)
	GROUP BY __ts__

{
	"database":"$database",
	"sql":"$sql",
	"keys:": {
		"valueKey":"series",
		"timeKey":"__ts__"
	}
}

分位值

SELECT percentile($field, 0.95) AS series, DATE_FORMAT(date, '%Y-%m-%d %H:%i:00') AS __ts__ 
	FROM nginx_access_log
	WHERE $time_field BETWEEN FROM_UNIXTIME($from) AND FROM_UNIXTIME($to)
	GROUP BY __ts__

{
	"database":"$database",
	"sql":"$sql",
	"keys:": {
		"valueKey":"series",
		"timeKey":"__ts__"
	}
}