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

docs: update db connection docs

Browse Source
This commit is contained in:
Alexander Zobnin
2017-10-22 11:06:48 +03:00
parent c8205b30c3
commit 538589b99b
4 changed files with 56 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
docs/sources/img/installation-postgres_ds_config.png Normal file
View File

@@ -0,0 +1,3 @@
version https://git-lfs.github.com/spec/v1
oid sha256:d7dae33170bf09b353f886bc1a8cbc4307d80858c514199f08f1b9e01bc01e81
size 260406

14
docs/sources/installation/configuration-sql.md
View File

@@ -1,5 +1,7 @@
# SQL Data Source Configuration
## MySQL
In order to use _Direct DB Connection_ feature you should configure SQL data source first.
![Configure MySQL data source](../img/installation-mysql_ds_config.png)
@@ -7,7 +9,7 @@ In order to use _Direct DB Connection_ feature you should configure SQL data sou
Select _MySQL_ data source type and provide your database host address and port (3306 is default for MySQL). Fill
database name (usually, `zabbix`) and specify credentials.
## Security notes
### Security notes
As you can see in _User Permission_ note, Grafana doesn't restrict any queries to the database. So you should be careful
and create a special user with limited access to Zabbix database. Grafana-Zabbix plugin uses only `SELECT` queries to
@@ -20,3 +22,13 @@ Also, all queries are invoked by grafana-server, so you can restrict connection
```sql
GRANT SELECT ON zabbix.* TO 'grafana'@'grafana-host' identified by 'password';
```
## PostgreSQL
Select _PostgreSQL_ data source type and provide your database host address and port (5432 is default). Fill
database name (usually, `zabbix`) and specify credentials.
![Configure PostgreSQL data source](../img/installation-postgres_ds_config.png)
### Security notes
Make sure you use read-only user for Zabbix database.

2
docs/sources/installation/configuration.md
View File

@@ -65,7 +65,7 @@ Read [how to configure](/installation/configuration-sql) SQL data source in Graf
#### Supported databases
Now only **MySQL** is supported by Grafana.
**MySQL** and **PostgreSQL** are supported by Grafana.
### Alerting

48
docs/sources/reference/direct-db-connection.md
View File

@@ -22,12 +22,26 @@ and `trend.get` API calls.
Below is an example query for getting history in the Grafana-Zabbix Plugin:
**MySQL**:
```sql
SELECT itemid AS metric, clock AS time_sec, {aggFunc}(value) as value
FROM {historyTable}
WHERE itemid IN ({itemids})
AND clock > {timeFrom} AND clock < {timeTill}
GROUP BY time_sec DIV {intervalSec}, metric
FROM {historyTable}
WHERE itemid IN ({itemids})
AND clock > {timeFrom} AND clock < {timeTill}
GROUP BY time_sec DIV {intervalSec}, metric
ORDER BY time_sec ASC
```
**PostgreSQL**:
```sql
SELECT to_char(itemid, 'FM99999999999999999999') AS metric,
clock / {intervalSec} * {intervalSec} AS time,
{aggFunc}(value) AS value
FROM {historyTable}
WHERE itemid IN ({itemids})
AND clock > {timeFrom} AND clock < {timeTill}
GROUP BY 1, 2
ORDER BY time ASC
```
where `{aggFunc}` is one of `[AVG, MIN, MAX, SUM, COUNT]` aggregation functions, `{historyTable}` is a history table,
@@ -36,18 +50,34 @@ where `{aggFunc}` is one of `[AVG, MIN, MAX, SUM, COUNT]` aggregation functions,
When getting trends, the plugin additionally queries a particular value column (`value_avg`, `value_min` or `value_max`) which
depends on `consolidateBy` function value:
**MySQL**:
```sql
SELECT itemid AS metric, clock AS time_sec, {aggFunc}({valueColumn}) as value
FROM {trendsTable}
WHERE itemid IN ({itemids})
AND clock > {timeFrom} AND clock < {timeTill}
GROUP BY time_sec DIV {intervalSec}, metric
FROM {trendsTable}
WHERE itemid IN ({itemids})
AND clock > {timeFrom} AND clock < {timeTill}
GROUP BY time_sec DIV {intervalSec}, metric
ORDER BY time_sec ASC
```
**PostgreSQL**:
```sql
SELECT to_char(itemid, 'FM99999999999999999999') AS metric,
clock / {intervalSec} * {intervalSec} AS time,
{aggFunc}({valueColumn}) AS value
FROM {trendsTable}
WHERE itemid IN ({itemids})
AND clock > {timeFrom} AND clock < {timeTill}
GROUP BY 1, 2
ORDER BY time ASC
```
**Note**: these queries may be changed in future, so look into sources for actual query structure.
As you can see, the Grafana-Zabbix plugin uses aggregation by a given time interval. This interval is provided by Grafana and depends on the panel width in pixels. Thus, Grafana displays the data in the proper resolution.
## Functions usage with Direct DB Connection
There's only one function that directly affects the backend data. This function is `consolidateBy`. Other functions work on the client side and transform data that comes from the backend. So you should clearly understand that this is pre-aggregated data (by AVG, MAX, MIN, etc).
For example, say you want to group values by 1 hour interval and `max` function. If you just apply `groupBy(10m, max)` function, your result will be wrong, because you would transform data aggregated by default `AVG` function. You should use `consolidateBy(max)` coupled with `groupBy(10m, max)` in order to get a precise result.
For example, say you want to group values by 1 hour interval and `max` function. If you just apply `groupBy(10m, max)` function, your result will be wrong, because you would transform data aggregated by default `AVG` function. You should use `consolidateBy(max)` coupled with `groupBy(10m, max)` in order to get a precise result.