Monitoring of cluster, nodes and MySQL semi-sync databases

Last update: June 04 2025

Monitoring of cluster, nodes and MySQL semi-sync databases

In cloud databases MySQL semi-sync you can monitor the state of the cluster.

To assess the overall health of the cluster , look at the status of the cluster.

For more detailed analysis, some metrics can be viewed as graphs in the dashboard:

• node cluster metrics;
• database metrics.

The full set of available metrics can be exported in Prometheus format.

You can find out when you are about to run out of disk space by using the disk fullness notification.

View cluster status⁠

1. In the Control panel, on the top menu, click Products and select Cloud Databases.

2. Open the Active tab.

3. In the cluster row, look at the status.

   ACTIVE	The cluster is available
   CREATING	A cluster is created
   UPDATING	Changes are applied to the cluster
   RESIZING	The cluster is scalable
   ERROR	There was an error, create a ticket
   DISK FULL	The disk is full and the cluster is read-only. To make the cluster read-write, scale the cluster and select a configuration with a larger disk size
   DEGRADED	Some nodes in the cluster are unavailable
   DELETING	The cluster is being deleted

View the status of the node cluster⁠

1. In the Control panel, on the top menu, click Products and select Cloud Databases.
2. Open the Active tab.
3. Open the cluster page → Monitoring tab.
4. In the Cluster Monitoring block, click Cluster Nodes.
5. In the Server field, select the node whose metrics you want to view.
6. Look at the available metrics of the node cluster.

Cluster node metrics in the control panel⁠

vCPU	How many percent of the node cluster cores are utilized
CPU iowait	How much percent of the processor's time was spent waiting for I/O
Memory	Memory utilization excluding cache and operating system buffers in percent or gigabytes
Disk	Used disk space in percent or gigabytes. The file system reserves 4% of the disk space for service needs, so the space occupied is greater than the actual space used by this 4%
Network load	The number of bits or packets sent and received over the network interface
Disk, read and write speed	Data read speed in B/s and data write speed in KB/s
Disk, number of IOPS	Number of read and write operations per second
OOM	Number of processes that ended with an Out of Memory error due to lack of RAM
Load Average	The average value of system load over a period of time. Indicates how many processes are processed by the cluster cores.The indicator is presented in the form of three values — for one minute, five minutes and 15 minutes. These values should not be greater than the number of cores on the node

View the status of the databases⁠

1. In the Control panel, on the top menu, click Products and select Cloud Databases.
2. Open the Active tab.
3. Open the cluster page → Monitoring tab.
4. In the Cluster Monitoring block, click Cluster.
5. In the Server field, select the node whose metrics you want to view.
6. Take a look at the available database metrics.

Database metrics in the dashboard⁠

Threads	The number of threads (tracks) inside MySQL: Cached — number of tracks in the cache; Connected — number of open connections; Running — number of running tracks
Inquiries	The number of requests of a particular type per second: DELETE; INSERT; SELECT; UPDATE.
Slow queries	Number of slow queries per second. Slow queries are defined by the long_query_time parameter. You can change the value of the long_query_time parameter
Cache hit	Percentage of requests entering the cache
Database size	Total size of the selected database in bytes
Temporary file size	Total size of temporary files in bytes
Size of binlog files	Total size of binlog files in bytes

Export metrics in Prometheus format⁠

Historical information for clusters is not available — metrics are requested only in real time. The list of all metrics that are supported in cloud databases and their description can be viewed in the Metrics table in Prometheus format.

1. Get a token.
2. Get the metrics in Prometheus format.

1. Get a token⁠

The token gives access to the metrics of all project clusters in a single pool.

1. In the Control panel, on the top menu, click Products and select Cloud Databases.

2. Open the Active tab.

3. Open the cluster page → Monitoring tab.

4. In the Tokens for Prometheus block, click Create token. The token will be generated automatically.

5. Copy the token. To do this, click in the token line.

2. Get metrics in Prometheus format⁠

Configuration file

1. Add the scrape_configs block 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> — pool in which the token is active, for example ru-3. Address (URL) depends on the region and pool, you can look in the URL list;
   • <monitoring_token> — The monitoring token that you received earlier.

2. Open a page in your browser where Prometheus-formatted metrics will be available:

   http://<ip_address>:9090/targets

   Specify <ip_address> — the IP address where Prometheus is installed.

3. Independently configure monitoring and alerts for database clusters.

CLI

1. Open the CLI.

2. To get metrics, submit a request:

   curl -L "https://<pool>.dbaas.selcloud.ru/metrics" -H "Authorization: Bearer <monitoring_token>"

   Specify:

   • <pool> — pool in which the token is active, for example ru-3. Address (URL) depends on the region and pool, you can look in the URL list;
   • <monitoring_token> — The monitoring token you received earlier.

   Available metrics in Prometheus format will appear in the response.

3. Independently configure monitoring and alerts for database clusters.

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 ds_id label.

Infrastructure level metrics

dbaas_memory_percent	Memory utilization excluding cache and operating system buffers (RAM) in percent
dbaas_memory_bytes	Occupied memory excluding cache and operating system buffers (RAM) in bytes
dbaas_oom_count	Number of processes that terminated with an Out of Memory error due to lack of RAM
dbaas_cpu	Percent vCPU utilization on database cluster nodes
dbaas_cpu_iowait	I/O waiting time in percent
dbaas_disk_percent	Percentage of disk space occupied. The file system reserves 4% of disk space for service needs, so the occupied space is larger than the actual space used by this 4%
dbaas_disk_bytes	Occupied disk space in bytes. The file system reserves 4% of disk space for service needs, so the occupied space is larger than the actual space used by this 4%
dbaas_disk_read_iops	Number of read operations per second
dbaas_disk_write_iops	Number of recording operations per second
dbaas_disk_read_bytes	Disk read speed in bytes per second
dbaas_disk_write_bytes	Data write speed to disk in bytes per second
dbaas_node_load1	The average value of system load in one minute. Shows how many processes are processed by the cluster cores
dbaas_node_load5	The average system utilization over five minutes. Shows how many processes are processed by the cluster cores
dbaas_node_load15	The average value of system load over 15 minutes. Shows how many processes are processed by the cluster cores
dbaas_network_receive_bytes	Number of bytes received through the network interface
dbaas_network_transmit_bytes	Number of bytes sent through the network interface
dbaas_network_receive_packets	Number of packets received through the network interface per second
dbaas_network_transmit_packets	Number of packets sent through the network interface per second
dbaas_role	Role of the node: 0 — role unknown; 1 — master; 2 — replica

Application level metrics

dbaas_threads_cached	Number of threads (tracks) in the cache
dbaas_threads_connected	Number of open connections to the cluster
dbaas_threads_running	Number of running threads (tracks)
dbaas_commands_total_select	Number of SELECT queries in MySQL per second
dbaas_commands_total_insert	Number of INSERT queries in MySQL per second
dbaas_commands_total_update	Number of UPDATE queries in MySQL per second
dbaas_commands_total_delete	Number of DELETE queries in MySQL per second
dbaas_slow_queries	The number of slow queries per second. Slow queries are defined by the long_query_time parameter
dbaas_innodb_buffer_pool_hit_ratio	Percentage of requests entering the cache
dbaas_mysql_tmp_size_bytes	MySQL temporary files size in bytes
dbaas_mysql_total_binlogs_size_bytes	Total size of binlog files in bytes
dbaas_databases_size_bytes	The total size of the database in bytes. You can use the datname label, which is the name of the database. The metric is absent if there is no data in the database

Disk fullness notifications⁠

If the cluster disk is 80% full, a notification will appear in the dashboard and will be sent to the Account Owner's email and those users subscribed to the "Services and Services" notification category.

If the cluster disk is 95% full or more, the cluster will enter DISK_FULL status and will be read-only. To make the cluster read-write , scale the cluster and select a configuration with a larger disk size.