Services

Services in the sidebar lists the request/reply services built with NATS Micro, the service framework in the NATS clients (Go, JavaScript, Python, Rust and others), that answer on the current connection. Natscope asks them on $SRV.INFO, as nats micro ls does, and on $SRV.STATS for their statistics, every 5 seconds, and waits up to 2 seconds for the answers. Answers that aren't valid service replies are left out.

Try it with the demo service that ships with the NATS CLI: nats micro serve demo.

The list

The list on the left shows each service with its instances and versions, and, when statistics are available, its request rate, error share and health:

• Healthy: fewer than 1% of the requests failed.
• Degraded: more than 1% failed.
• Failing: more than 10% failed.
• Idle: no requests.

Rates and health cover the time between the last two refreshes, so they appear after the second one. The header counts services, instances and failing services. Auto-refresh asks again every 5 seconds; Refresh asks at once. Filter the list by service name, description, endpoint name or subject.

Each service has its own address, such as /services/orders, so Back and bookmarks work.

A service

Click a service to see:

• Its request rate, error share and average time for the last window. Hover them for the totals since the instances started.
• Endpoints: the subject each one listens on, its queue group, metadata, and its rate, errors and average time. An endpoint whose name matches a unary method of a Protobuf service in your schema sources shows that method. An endpoint without a queue group is answered by every instance.
• Last errors: the last error of each endpoint, with the instance and version that reported it.
• Instances: each running copy with its version, rate, errors, start time, how long it took to answer (RTT) and metadata. Raw JSON shows its $SRV.INFO and $SRV.STATS replies, including any custom statistics the service adds.

Call opens Request / Reply with the endpoint subject filled in. When the endpoint matches a Protobuf method, its request and reply types are selected too. An endpoint subject with wildcards needs its tokens filled in there.

Permissions

Finding services needs permission to publish to $SRV.INFO and to receive the answers on a reply inbox. Statistics need permission to publish to $SRV.STATS. Many accounts do not grant these, so the page tells you what is missing instead of failing:

• No access to services: the page names the missing permission and stops refreshing. Check again retries once the permission has been granted. If your account receives replies on a private inbox, set its prefix in the connection settings instead.
• Statistics are hidden: services and endpoints are listed without the statistics columns. Auto-refresh stops asking for statistics; Refresh checks the permission again.
• No services found: you have access, but nothing answered within 2 seconds. Services in other accounts are not visible from this connection.