| Apache SkyWalking Rust Agent |
| ========== |
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| <img src="http://skywalking.apache.org/assets/logo.svg" alt="Sky Walking logo" height="90px" align="right" /> |
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| [](https://twitter.com/AsfSkyWalking) |
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| [**SkyWalking**](https://github.com/apache/skywalking) Rust Agent provides observability capability for Rust App and Library, |
| including tracing, metrics, topology map for distributed system and alert. |
| It uses SkyWalking native formats and core concepts to keep best compatibility and performance. |
| |
| # Concepts |
| All concepts are from the official SkyWalking definitions. |
| ## Span |
| Span is an important and common concept in distributed tracing system. Learn Span from Google Dapper Paper. |
| For better performance, we extend the span into 3 kinds. |
| |
| 1. EntrySpan EntrySpan represents a service provider, also the endpoint of server side. As an APM system, we are targeting the application servers. So almost all the services and MQ-consumer are EntrySpan(s). |
| 2. LocalSpan LocalSpan represents a normal Java method, which does not relate to remote service, neither a MQ producer/consumer nor a service(e.g. HTTP service) provider/consumer. |
| 3. ExitSpan ExitSpan represents a client of service or MQ-producer, as named as LeafSpan at early age of SkyWalking. e.g. accessing DB by JDBC, reading Redis/Memcached are cataloged an ExitSpan. |
| |
| Tag and Log are similar attributes of the span. |
| - Tag is a key:value pair to indicate the attribute with a string value. |
| - Log is heavier than tag, with one timestamp and multiple key:value pairs. Log represents an event, typically an error happens. |
| |
| ## TracingContext |
| TracingContext is the context of the tracing process. Span should only be created through context, and be archived into the |
| context after the span finished. |
| |
| # Example |
| |
| ```rust |
| use skywalking_rust::context::trace_context::TracingContext; |
| use skywalking_rust::reporter::grpc::Reporter; |
| use tokio; |
| |
| async fn handle_request(reporter: ContextReporter) { |
| let mut ctx = TracingContext::default("svc", "ins"); |
| { |
| // Generate an Entry Span when a request |
| // is received. An Entry Span is generated only once per context. |
| let span = ctx.create_entry_span("operation1").unwrap(); |
| |
| // Something... |
| |
| { |
| // Generates an Exit Span when executing an RPC. |
| let span2 = ctx.create_exit_span("operation2").unwrap(); |
| |
| // Something... |
| |
| ctx.finalize_span(span2); |
| } |
| |
| ctx.finalize_span(span); |
| } |
| reporter.send(context).await; |
| } |
| |
| #[tokio::main] |
| async fn main() { |
| let tx = Reporter::start("http://0.0.0.0:11800").await; |
| |
| // Start server... |
| } |
| ``` |
| |
| # License |
| Apache 2.0 |
