Misthios/grafana-zabbix
1
0
Fork 0
Code Issues Pull Requests Actions 1 Packages Projects Releases Wiki Activity

Fix to consolidate avg accuracy (#753)

Browse Source 
* The interval must fit exactly n times to the time range and query made so that the resulting avg will be exact

* Add interval fix also to trend query
This commit is contained in:
Tommi Palomäki
2020-05-15 14:08:12 +03:00
committed by GitHub
parent 77e39da60c
commit 1ae4b86ca9
2 changed files with 16 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
src/datasource-zabbix/zabbix/connectors/sql/mysql.js
View File

@@ -3,26 +3,24 @@
*/
function historyQuery(itemids, table, timeFrom, timeTill, intervalSec, aggFunction) {
let time_expression = `clock DIV ${intervalSec} * ${intervalSec}`;
let query = `
SELECT CAST(itemid AS CHAR) AS metric, ${time_expression} AS time_sec, ${aggFunction}(value) AS value
SELECT CAST(itemid AS CHAR) AS metric, MIN(clock) AS time_sec, ${aggFunction}(value) AS value
FROM ${table}
WHERE itemid IN (${itemids})
AND clock > ${timeFrom} AND clock < ${timeTill}
GROUP BY ${time_expression}, metric
GROUP BY (clock-${timeFrom}) DIV ${intervalSec}, metric
ORDER BY time_sec ASC
`;
return query;
}
function trendsQuery(itemids, table, timeFrom, timeTill, intervalSec, aggFunction, valueColumn) {
let time_expression = `clock DIV ${intervalSec} * ${intervalSec}`;
let query = `
SELECT CAST(itemid AS CHAR) AS metric, ${time_expression} AS time_sec, ${aggFunction}(${valueColumn}) AS value
SELECT CAST(itemid AS CHAR) AS metric, MIN(clock) AS time_sec, ${aggFunction}(${valueColumn}) AS value
FROM ${table}
WHERE itemid IN (${itemids})
AND clock > ${timeFrom} AND clock < ${timeTill}
GROUP BY ${time_expression}, metric
GROUP BY (clock-${timeFrom}) DIV ${intervalSec}, metric
ORDER BY time_sec ASC
`;
return query;

12
src/datasource-zabbix/zabbix/connectors/sql/sqlConnector.js
View File

@@ -43,6 +43,12 @@ export class SQLConnector extends DBConnector {
let {intervalMs, consolidateBy} = options;
let intervalSec = Math.ceil(intervalMs / 1000);
// The interval must match the time range exactly n times, otherwise
// the resulting first and last data points will yield invalid values in the
// calculated average value in downsampleSeries - when using consolidateBy(avg)
let numOfIntervals = Math.ceil((timeTill - timeFrom) / intervalSec);
intervalSec = (timeTill - timeFrom) / numOfIntervals;
consolidateBy = consolidateBy || 'avg';
let aggFunction = dbConnector.consolidateByFunc[consolidateBy];
@@ -66,6 +72,12 @@ export class SQLConnector extends DBConnector {
let { intervalMs, consolidateBy } = options;
let intervalSec = Math.ceil(intervalMs / 1000);
// The interval must match the time range exactly n times, otherwise
// the resulting first and last data points will yield invalid values in the
// calculated average value in downsampleSeries - when using consolidateBy(avg)
let numOfIntervals = Math.ceil((timeTill - timeFrom) / intervalSec);
intervalSec = (timeTill - timeFrom) / numOfIntervals;
consolidateBy = consolidateBy || 'avg';
let aggFunction = dbConnector.consolidateByFunc[consolidateBy];