Monitoring of Kafka cluster and nodes
You can monitor the status of the Kafka cluster in the control panel:
- look up information about using the cluster node in the form of graphs in the control panel;
- watch cluster status;
- get disk fill notifications.
Cluster and database node metrics can also be export in Prometheus format.
View the status of the node cluster
- В control panels go to Cloud platform → Databases.
- Open the cluster page → tab Monitoring.
- In the block Monitoring of cluster servers see what's available node cluster metrics.
Cluster node metrics in the control panel
View cluster status
- В control panels go to Cloud platform → Databases.
- Look at the status in the cluster row → column Status.
Disk fullness notifications
If the cluster disk is 80% full, a notification will automatically be sent to the account's email.
If the cluster disk is 95% or more full, the cluster will go into status DISK_FULL and will be read-only. To make the cluster read-write, disk cleanup or scale the cluster and select a configuration with a larger disk size.
Clear the disk
Open a transaction transaction_read_only = no and delete unnecessary data using one of the queries:
-
DROP TABLE— deletes the structure (data, privileges, indexes, constraints, triggers). Use when completely deleting a table with data and structure:BEGIN;
SET transaction_read_only = no;
DROP TABLE table_name;
COMMIT; -
TRUNCATE TABLE— deletes the contents of the table, but the structure is preserved. Works fasterDROP TABLE. Use when deleting all rows of a table while preserving the table structure:BEGIN;
SET transaction_read_only = no;
TRUNCATE TABLE table_name;
COMMIT; -
DELETE— use to delete specific strings.
We do not recommend using the query DELETE FROM table WHERE ... to clean up the disk. This query can create oversized samples on large tables and place them on disk. The remaining free disk space may run out completely, causing problems with Kafka and the need to restore it manually.
Export metrics in Prometheus format
You can export metrics in the format Prometheus and then configure monitoring and alerts for Kafka clusters yourself. Historical information for clusters is not available — metrics are only requested in real time.
To export metrics, you need to get a monitoring token. The token gives access to metrics of all clusters in one project pool.
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В control panels go to Cloud platform → Databases.
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Open the cluster page → tab Monitoring.
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In the block Metrics in Prometheus format click Manage tokens.
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Click Create.
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Enter the name of the token.
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Click Create. The token will be generated automatically.
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Add to the Prometheus configuration file:
scrape_configs:
- job_name: get-metrics-from-dbaas
scrape_interval: 1m
static_configs:
- targets:
- '<pool>.dbaas.selcloud.ru'
scheme: https
authorization:
type: Bearer
credentials: <monitoring_token>Specify:
<pool>— the pool in which the token operates, e.g.ru-3. The address (URL) depends on the region and pool, you can look in the URL list;<monitoring_token>— monitoring token value.
-
The source of the metrics will appear at
http://<localhost>:9090/targets.Specify
<localhost>— IP address where Prometheus is installed. -
See what's available Prometheus metrics.
Metrics in Prometheus format
Metrics in Prometheus format are provided for all clusters. A specific cluster can be found by the database cluster identifier in the label ds_id.