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Monitor Azure Database for MySQL - Flexible Server

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APPLIES TO: Azure Database for MySQL - Flexible Server

Azure Database for MySQL flexible server provides monitoring of servers through Azure Monitor. Monitoring data about your servers helps you troubleshoot and optimize for your workload.

In this article, you learn about the various metrics available and Server logs for your flexible server that give insight into the behavior of your server.

Note

This article contains references to the term slave, a term that Microsoft no longer uses. When the term is removed from the software, we'll remove it from this article.

Metrics

Metrics are numerical values that describe some aspect of the resources of your server at a particular time. Monitoring your server's resources helps you troubleshoot and optimize your workload by allowing you to monitor what matters the most to you. Monitoring the right metrics helps you keep the performance, reliability, and availability of your server and applications.

Azure Database for MySQL flexible server provides various metrics to understand how your workload is performing and based on this data, you can understand the impact on your server and application.

All Azure metrics have a one-minute frequency, and each metric provides 30 days of history. You can configure alerts on the metrics. For step-by-step guidance, see How to set up alerts. Other tasks include setting up automated actions, performing advanced analytics, and archiving history. For more information, see the Azure Metrics Overview.

Troubleshooting Metrics

Sometimes, you might run into issues with creating, customizing, or interpreting charts in Azure metrics explorer. The situation of a Chart showing no data could arise due to various factors. These might include the Microsoft Insights resource provider not being registered for your subscription, or you lacking adequate access rights to your Azure Database for MySQL - Flexible Server. Other possibilities could be that your resource didn't generate metrics within the chosen time frame, or the selected time range exceeds 30 days.

Several reasons that follow can cause this behavior:

  • Microsoft.Insights resource provider isn’t registered: Exploring metrics requires Microsoft.Insights resource provider registered in your subscription. Register your server manually by following steps described in Azure resource providers and types.
  • Insufficient access rights to your resource: Ensure that you have sufficient permissions for your Azure Database for MySQL - Flexible Server from which you’re exploring metrics. Your resource didn’t emit metrics during the selected time range: Change the time of the chart to a wider range. In Azure, Azure role-based access control (Azure RBAC) controls access to metrics. You must be a member of monitoring reader, monitoring contributor, or contributor to explore metrics for any resource.
  • Your resource didn’t emit metrics during the selected time range: This could be due to several reasons. One possibility is that your resource didn’t generate metrics within the chosen time frame. Change the time of the chart to a wider range to see if this resolves the issue. For more detailed information on troubleshooting this issue, refer to the Azure Monitor metrics troubleshooting guide.
  • Time range greater than 30 days: Verify that the difference between start- and end- dates in the time picker doesn’t exceed the 30-day interval. For more detailed information on troubleshooting metrics, refer to the Azure Monitor metrics troubleshooting guide.
  • Dashed Line Indication: In Azure Monitor, the presence of a dashed line signifies a gap in data, or a "null value", between two points of known time grain data. This is a deliberate design that helps in the detection of missing data points. If your chart displays dashed lines, it indicates missing data and you can refer to the documentation for further information.

For more detailed information on troubleshooting metrics, refer to the Azure Monitor metrics troubleshooting guide.

List of metrics

These metrics are available for Azure Database for MySQL flexible server:

Metric display name Metric Unit Description
Host CPU percent cpu_percent Percent Host CPU percent is total utilization of CPU to process all the tasks on your server over a selected period. This metric includes workload of your Azure Database for MySQL flexible server instance and Azure MySQL process. High CPU percent can help you find if your database server has more workload than it can handle. This metric is equivalent to total CPU utilization similar to utilization of CPU on any virtual machine.
CPU Credit Consumed cpu_credits_consumed Count This is for Burstable Tier Only CPU credit is calculated based on workload. See B-series burstable virtual machine sizes for more information.
CPU Credit Remaining cpu_credits_remaining Count This is for Burstable Tier Only CPU remaining is calculated based on workload. See B-series burstable virtual machine sizes for more information.
Host Network In network_bytes_ingress Bytes Total sum of incoming network traffic on the server for a selected period. This metric includes traffic to your database and to Azure Database for MySQL flexible server features like monitoring, logs etc.
Host Network out network_bytes_egress Bytes Total sum of outgoing network traffic on the server for a selected period. This metric includes traffic from your database and from Azure Database for MySQL flexible server features like monitoring, logs etc.
Active Connections active_connection Count The number of active connections to the server. Active connections are the total number of threads connected to your server, which also includes threads from azure_superuser.
Storage IO percent io_consumption_percent Percent The percentage of IO in use over selected period. IO percent is for both read and write IOPS.
Storage IO Count storage_io_count Count The total count of I/O operations (both read and write) utilized by server per minute.
Host Memory Percent memory_percent Percent The total percentage of memory in use on the server, including memory utilization from both database workload and other Azure MySQL processes. This metric provides evaluation of the server's memory utilization, excluding reusable memory like buffer and cache.
Available Memory Bytes available_memory_bytes Bytes This metric represents the amount of memory that is currently available for use on the server.
Total connections total_connections Count The number of client connections to your Azure Database for MySQL flexible server instance. Total Connections is sum of connections by clients using TCP/IP protocol over a selected period.
Aborted Connections aborted_connections Count Total number of failed attempts to connect to your Azure Database for MySQL flexible server instance, for example, failed connection due to bad credentials. For more information on aborted connections, you can refer to this documentation.
Queries queries Count Total number of queries executed per minute on your server. Total count of queries per minute on your server from your database workload and Azure MySQL processes.
Slow_queries slow_queries Count The total count of slow queries on your server in the selected time range.

Storage Breakdown Metrics

Metric display name Metric Unit Description
Storage Limit storage_limit Bytes The maximum storage size configured for this server.
Storage Percent storage_percent Percent The percentage of storage used out of the server's maximum storage available.
Storage Used storage_used Bytes The amount of storage in use. The storage used by the service may include the database files, transaction logs, and the server logs.
Data Storage Used data_storage_used Bytes The amount of storage used for storing database files.
ibdata1 Storage Used ibdata1_storage_used Bytes The amount of storage used for storing system tablespace (ibdata1) file.
Binlog Storage Used binlog_storage_used Bytes The amount of storage used for storing binary log files.
Other Storage Used other_storage_used Bytes The amount of storage used for other components and metadata files.
Backup Storage Used backup_storage_used Bytes The amount of backup storage used.

Replication metrics

Metric display name Metric Unit Description
Replication Lag replication_lag Seconds Replication lag is the number of seconds the replica is behind in replaying the transactions received from the source server. This metric is calculated from "Seconds_behind_Master" from the command "SHOW SLAVE STATUS" and is available for replica servers only. For more information, see "Monitor replication latency"
Replica IO Status replica_io_running State Replica IO Status indicates the state of replication I/O thread. Metric value is 1 if the I/O thread is running and 0 if not.
Replica SQL Status replica_sql_running State Replica SQL Status indicates the state of replication SQL thread. Metric value is 1 if the SQL thread is running and 0 if not.
HA IO Status ha_io_running State HA IO Status indicates the state of HA replication. Metric value is 1 if the I/O thread is running and 0 if not.
HA SQL Status ha_sql_running State HA SQL Status indicates the state of HA replication. Metric value is 1 if the SQL thread is running and 0 if not.
HA Replication Lag ha_replication_lag Seconds HA Replication lag is the number of seconds the HA Standby server is behind in replaying the transactions received from the source server. This metric is calculated from "Seconds_behind_Master" from the command "SHOW SLAVE STATUS" and is available for HA standby servers only.

Note

For read replicas in Azure Database for MySQL flexible server, value of Slave_IO_Running/Replica_IO_Running from MySQL command "SHOW SLAVE STATUS" or "SHOW REPLICA STATUS" will be denoted as "NO" and should be ignored because Azure Database for MySQL flexible server's implementation of replicas does not rely on establishing a connection to communicate with the source server. For genuine status of I/O thread of your read replicas kindly refer to Replica IO Status from Metrics under Monitoring blade.

Enhanced metrics

DML statistics

Metric display name Metric Unit Description
Com_select Com_select Count The total count of select statements that have been executed on your server in the selected time range.
Com_update Com_update Count The total count of update statements that have been executed on your server in the selected time range.
Com_insert Com_insert Count The total count of insert statements that have been executed on your server in the selected time range.
Com_delete Com_delete Count The total count of delete statements that have been executed on your server in the selected time range.

DDL statistics

Metric display name Metric Unit Description
Com_create_db Com_create_db Count The total count of create database statements that have been executed on your server in the selected time range.
Com_drop_db Com_drop_db Count The total count of drop database statements that have been executed on your server in the selected time range.
Com_create_table Com_create_table Count The total count of create table statements that have been executed on your server in the selected time range.
Com_drop_table Com_drop_table Count The total count of drop table statements that have been executed on your server in the selected time range.
Com_Alter Com_Alter Count The total count of alter table statements that have been executed on your server in the selected time range.

Innodb metrics

Metric display name Metric Unit Description
InnoDB Row Lock Time innodb_row_lock_time Milliseconds InnoDB row lock time measures the duration of time in milliseconds for InnoDB row-level locks.
InnoDB Row Lock Waits innodb_row_lock_waits Count InnoDB row lock waits metric counts the number of times a query had to wait for an InnoDB row-level lock.
Innodb_buffer_pool_reads Innodb_buffer_pool_reads Count The total count of logical reads that InnoDB engine couldn't satisfy from the Innodb buffer pool, and had to be fetched from the disk.
Innodb_buffer_pool_read_requests Innodb_buffer_pool_read_requests Count The total count of logical read requests to read from the Innodb Buffer pool.
Innodb_buffer_pool_pages_free Innodb_buffer_pool_pages_free Count The total count of free pages in InnoDB buffer pool.
Innodb_buffer_pool_pages_data Innodb_buffer_pool_pages_data Count The total count of pages in the InnoDB buffer pool containing data. The number includes both dirty and clean pages.
Innodb_buffer_pool_pages_dirty Innodb_buffer_pool_pages_dirty Count The total count of pages in the InnoDB buffer pool containing dirty pages.

Server logs

In Azure Database for MySQL flexible server, users can configure and download server logs to assist with troubleshooting efforts. With this feature enabled, an Azure Database for MySQL flexible server instance starts capturing events of the selected log type and writes them to a file. You can then use the Azure portal and Azure CLI to download the files to work with them. The server logs feature is disabled by default. For information about how to enable server logs, see How to enable and download server logs for Azure Database for MySQL flexible server.

Server logs support slow query logs and error logs for enabling and downloading. To perform a historical analysis of your data, in the Azure portal, on the Diagnostics settings pane for your server, add a diagnostic setting to send the logs to Log Analytics workspace, Azure Storage, or event hubs. For more information, see Set up diagnostics.

Server logs retention

When logging is enabled for an Azure Database for MySQL flexible server instance, logs are available up to seven days from their creation. If the total size of the available logs exceeds 7 GB, then the oldest files are deleted until space is available. The 7-GB storage limit for server logs is available free of cost and can't be extended. Logs are rotated every 24 hours or 500 MB, whichever comes first.

Next steps