Application monitoring and diagnostics

[ennishol]

Hello,

To assess an application's performance effectively, one often needs to delve into questions such as:

• Is there a connection pool available for a client (HTTP, DB, Kafka, etc.), and what is its size?
• How many clients are connected to the server http_server_active_requests
• How many connections are opened to a remote server?
• What does the client configuration look like? is compression enabled? does it keep connections open for reuse?
• What are the latencies for requests and responses?
• How large is the connection wait queue, for example, mongodb_driver_pool_waitqueuesize, or in the context of Kafka, what is the consumer lag?

Many other typical questions about an application must be answered to get initial diagnostic data quickly. And of course, there are tons of metrics available and also configuration files and documentation about configurations default values.

I'm curious whether Quarkus might offer a summary of the most important diagnostics through an endpoint in the dev-ui, or perhaps even something suited for production environments.