Update README.md

README.md

@@ -196,6 +196,7 @@ dotnet add package MagicOnion
 - [HTTPS (TLS)](#https-tls)
 - [Deployment](#deployment)
 - Integrations
+    - [Metrics](#metrics)
     - [Swagger](#swagger)
 - Advanced
     - [MagicOnionOption](#magiconionoption)
@@ -1206,6 +1207,31 @@ MagicOnion is also supported in Docker containers and running on Kubernetes.
 See [docs/articles/deployment/](docs/articles/deployment/) for information on deploying to Amazon Web Service and other cloud services.
 
 ## Integrations
+
+### Metrics
+MagicOnion server supports metrics related to StreamingHub using System.Diagnostics.Metrics. 
+
+- see: https://learn.microsoft.com/en-us/dotnet/core/diagnostics/metrics
+
+#### Meter: MagicOnion.Server
+
+|Metric|Unit|Tags|
+|--|--|--|
+|magiconion.server.streaminghub.connections|`{connection}`|`rpc.system`, `rpc.service`|
+|magiconion.server.streaminghub.method_duration|`ms`|`rpc.system`, `rpc.service`, `rpc.method`|
+|magiconion.server.streaminghub.method_completed|`{request}`|`rpc.system`, `rpc.service`, `rpc.method`, `magiconion.streaminghub.is_error`|
+|magiconion.server.streaminghub.exceptions|`{exception}`|`rpc.system`, `rpc.service`, `rpc.method`, `error.type`|
+
+##### Tags
+|Tag name|Value|
+|--|--|
+|rpc.system|`magiconion`|
+|rpc.service|StreamingHub interface name (e.g. `IGreeterService`)|
+|rpc.method|StreamingHub method name (e.g. `HelloAsync`)|
+|magiconion.streaminghub.is_error|Whether a StreamingHub method call succeeded or failed.  (e.g. `true` or `false`)|
+|error.type|Thrown exception type (e.g. `System.InvalidOperationException`)|
+
+
 ### Swagger
 MagicOnion has built-in HTTP/1.1 JSON Gateway and [Swagger](http://swagger.io/) integration for Unary operation. It can execute and debug RPC-API easily.