Merge pull request #205171 from code-sidd/Metric_Update_FS

updating metrics doc flex server

Author: BCS2022

articles/mysql/flexible-server/concepts-monitoring.md

@@ -17,6 +17,9 @@ Azure Database for MySQL Flexible Server provides monitoring of servers through
 
 In this article, you will learn about the various metrics available 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.
+
 ## Available metrics
 
 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. For example, in flexible server, you can monitor **Host CPU percent**, **Active Connections**, **IO percent**, and **Host Memory Percent** to identify when there is a performance impact. From there, you may have to optimize your workload, scale vertically by changing compute tiers, or scaling horizontally by using read replica.
@@ -28,20 +31,20 @@ These metrics are available for Azure Database for MySQL:
 
 |Metric display name|Metric|Unit|Description|
 |---|---|---|---|
-|Host CPU percent|cpu_percent|Percent|The percentage of CPU utilization on the server, including CPU utilization from both customer workload and Azure MySQL processes|
-|Host Network In |network_bytes_ingress|Bytes|Incoming network traffic on the server, including traffic from both customer database and Azure MySQL features like replication, monitoring, logs etc.|
-|Host Network out|network_bytes_egress|Bytes|Outgoing network traffic on the server, including traffic from both customer database and Azure MySQL features like replication, monitoring, logs etc.|
-|Replication Lag|replication_lag|Seconds|The time since the last replayed transaction. This metric is available for replica servers only.|
-|Active Connections|active_connection|Count|The number of active connections to the server.|
+|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 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.|
+|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 MySQL 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 MySQL features like monitoring, logs etc.|
+|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](../single-server/how-to-troubleshoot-replication-latency.md)"|
+|Active Connections|active_connection|Count|The number of active connections to the server. Active connections are the total number of [threads connected](https://dev.mysql.com/doc/refman/8.0/en/server-status-variables.html#statvar_Threads_connected) to your server, which also includes threads from [azure_superuser](../single-server/how-to-create-users.md).|
 |Backup Storage Used|backup_storage_used|Bytes|The amount of backup storage used.|
-|IO percent|io_consumption_percent|Percent|The percentage of IO in use.|
-|Host Memory Percent|memory_percent|Percent|The percentage of memory in use on the server, including memory utilization from both customer workload and Azure MySQL processes|
+|IO percent|io_consumption_percent|Percent|The percentage of IO in use over selected period. IO percent is for both read and write IOPS.|
+|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 shows total consumption of memory of underlying host similar to consumption of memory on any virtual machine.|
 |Storage Limit|storage_limit|Bytes|The maximum storage for this server.|
 |Storage Percent|storage_percent|Percent|The percentage of storage used out of the server's maximum.|
 |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.|
-|Total connections|total_connections|Count|The number of total connections to the server|
-|Aborted Connections|aborted_connections|Count|The number of failed attempts to connect to the MySQL, for example, failed connection due to bad credentials.|
-|Queries|queries|Count|The number of queries per second|
+|Total connections|total_connections|Count|The number of client connections to your Azure Database for MySQL Flexible server. 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 MySQL server, for example, failed connection due to bad credentials. For more information on aborted connections, you can refer to this [documentation](https://dev.mysql.com/doc/refman/5.7/en/communication-errors.html).|
+|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.|
 
 ## Next steps
 - See [How to set up alerts](./how-to-alert-on-metric.md) for guidance on creating an alert on a metric.