* Implement mechanism to apply custom api path to the sleuth server baseUrl.
This comes in handy when another monitoring tool is being used, for instance new relic, which doesn't not require path in its tracing api.
* Fix up documentation on the ZipkinProperties
* Update the main documentation for api path
* Add missing comma
# Modules
* New modules: `spring-cloud-sleuth-autoconfigure`, `spring-cloud-sleuth-api`, `spring-cloud-sleuth-instrumentation`
`spring-cloud-sleuth-core` removed and changed to `spring-cloud-sleuth-instrumentation` & `spring-cloud-sleuth-api`
* Removed `spring-cloud-starter-sleuth-otel`
To add OpenTelemetry support you need to add `spring-cloud-starter-sleuth` (adds Brave by default), exclude Brave and add `spring-cloud-sleuth-otel` dependency
* Except for the tests, `spring-cloud-sleuth-autoconfigure` is the only module that can have access to `@Configuration`, `@ConfigurationProperties` classes.
Tests have been added to ensure such separation.
## Package moving
* `org.springframework.cloud.sleuth.api` -> `org.springframework.cloud.sleuth`
* `org.springframework.cloud.sleuth.brave.autoconfig` -> `org.springframework.cloud.sleuth.autoconfig.brave`
* `org.springframework.cloud.sleuth.otel.autoconfig` -> `org.springframework.cloud.sleuth.autoconfig.otel`
* `org.springframework.cloud.sleuth` -> `org.springframework.cloud.sleuth`
* Instrumentation: `org.springframework.cloud.sleuth.annotation` -> `org.springframework.cloud.sleuth.instrument.annotation`
* All the autoconfiguration classes were moved under `org.springframework.cloud/sleuth.autoconfig` package
## Global class modifications
* Any class registered as a bean is now public
## Classes
* `RateLimitingSampler` constructor changed
* Merged a lot of auto configuration classes into one (e.g. `BraveAutoConfiguration` now imports various other configurations)
* Renamed `TraceBraveAutoConfiguration` to `BraveAutoConfiguration`
* Renamed `TraceOtelAutoConfiguration` to `OtelAutoConfiguration`
* Removed all `NoOp` implementations of the API
Spring Cloud Sleuth currently is an autoconfiguration over Brave. It also consists of various instrumentation mechanisms for libraries that are not supported by Brave (e.g. Spring Cloud Circuitbreaker).
We would like to abstract Brave so that Spring Cloud Sleuth becomes an autoconfiguration for any tracer implementation that is compatible with Spring Cloud Sleuth. That way Spring Cloud Sleuth in its core module would consist of an API and various tracer implementations would implement that API which would also allow automatic instrumentation of libraries that are supported by Spring Cloud Sleuth.
## OpenTelemetry Support
Thanks to doing this abstraction we are able to support new tracer implementations, not only Brave. We've decided to add support for the OpenTelemetry SDK as the second one. If in the future if we decide to add new tracers then it will be just a matter of adding a new module that bridges to the Spring Cloud Sleuth one. Thanks to abstraction of tests as well we will be easily able to plug that tracer mechanism into our current suite of tests.
- adds Spring Cloud Function instrumentation
- adds Operators to manually provide instrumentation for Fluxes
- introduces Manual instrumentation mode for Reactor
TODO: Documentation (will add it soon)
related gh-1684
The AsyncZipkinSpanHandler calls 'check' once on startup to let someone
know an error that may affect tracing up front. Before, this didn't
include the endpoint so it is less obvious what could be the problem.
Ex people goof the URL (don't add /api/v2/spans or it is added twice)
There was emmense work to prepare for decoupling of spring-cloud-sleuth-core
from Zipkin. This included complete test conversion and deprecations between
2.2.x and 3.0.x.
This moves all Zipkin related code to spring-cloud-sleuth-zipkin, making the
primary data recording tool `SpanHandler` as opposed to `Reporter<zipkin2.Span>`
For example, Wavefront and soon Stackdriver can implement `SpanHandler` and
skip conversion into the Zipkin model first. `SpanHandler` also includes
begin and end hooks which allow data extensions to be developed.
see https://github.com/wavefrontHQ/wavefront-spring-boot
I noticed we deleted many things without deprecation in 3.x and figured
deprecation was the right way. However, this doesn't work for auto-config
properties. This replaces deprecation with a TODO note to hide all the
types so that 4.x won't require guessing if someone externally is using
them directly or not.
`SpanHandler` is the base type for the now deprecated `FinishedSpanHandler`.
Notable, it can not just handle things at the end of a recording, but also the
beginning.
For example, this permits set-once baggage without the HTTP abstraction:
```java
static final BaggageField EPOCH_SECONDS = BaggageField.create("epoch_seconds");
static final class RootOnlyBaggage extends SpanHandler {
@Override
public boolean begin(TraceContext context, MutableSpan span, @Nullable TraceContext parent) {
if (EPOCH_SECONDS.getValue(context) == null) { // only set at the first span
long epochSeconds = System.currentTimeMillis() / 1000;
EPOCH_SECONDS.updateValue(context, String.valueOf(epochSeconds));
}
return true;
}
@Override public boolean end(TraceContext context, MutableSpan span, Cause cause) {
Tags.BAGGAGE_FIELD.tag(EPOCH_SECONDS, context, span);
return true;
}
}
```
As the parent is available, it can also facilitate advanced tasks like counting
children, or summarizing entire local roots.
See https://github.com/openzipkin/brave/tree/master/brave/src/test/java/brave/features/handler
and https://github.com/openzipkin/brave/blob/master/brave/src/main/java/brave/handler/SpanHandler.java for more
Types like Properties and AutoConfiguration and internal utilities are
routinely marked public when they needn't be. This causes toil as we
have to preserve signatures even if they were made public by accident.
This deprecates the mass of types marked public to give some hope of
less undifferentiated toil in the future. Ideally, future change will
consider greatly if a type should be public or not as doing so haunts
maintainers.
Before, spring-cloud-sleuth-zipkin had to import `SamplerAutoConfiguration`
directly to unwind a sampler ordering problem caused by `TraceAutoConfiguration`
defining the default `Sampler` bean.
This fixes that by moving the default `Sampler` to where it belongs
(`SamplerAutoConfiguration`) and having `TraceAutoConfiguration` import
the sampling configuration directly as opposed to relying on auto-configuration
ordering. Finally it removes the mistake of setting `SamplerAutoConfiguration`
as auto-configuration in the first place.
The name `SamplerAutoConfiguration` was left alone because changing it would
interfere with 3rd party code that formerly imported it to correct this issue
in their non-zipkin setups.
Fixes#1618
This moves code and properties under org.springframework.cloud.sleuth.baggage
Properties are now under "spring.sleuth.baggage"
Those coming from 2.x should migrate with the following:
* spring.sleuth.baggage-keys -> `BaggagePropagationCustomizer`
* spring.sleuth.local-keys -> spring.sleuth.baggage.local-fields
* spring.sleuth.propagation-keys -> spring.sleuth.baggage.remote-fields
* spring.sleuth.propagation.tag.whitelisted-keys -> spring.sleuth.baggage.tag-fields
* spring.sleuth.log.slf4j.whitelisted-mdc-keys -> spring.sleuth.baggage.correlation-fields
* spring.sleuth.log.slf4j.enabled -> spring.sleuth.baggage.correlation-enabled
Those using MDC should know that for performance reasons, we no longer
set the following fields: `parentId` `spanExportable`.
We also do not set fields to "dirty" by default. Doing this by default
raised the overhead substantially, especially in reactive applications.
Those who want sleuth to override manual `MDC.put` operations as
described in #1416, or with to add back `parentId` `spanExportable` need
to define their own bean:
Ex. this is the former setup:
```java
@Bean CorrelationScopeDecorator oldConfig(List<String> myFieldNames) {
CorrelationScopeDecorator.Builder builder = MDCScopeDecorator.newBuilder().clear()
.add(SingleCorrelationField.create(BaggageFields.TRACE_ID))
.add(SingleCorrelationField.create(BaggageFields.PARENT_ID))
.add(SingleCorrelationField.create(BaggageFields.SPAN_ID))
.add(SingleCorrelationField.newBuilder(BaggageFields.SAMPLED)
.name("spanExportable").build());
// Set all fields dirty, so that any changes made by MDC directly are reverted.
for (String name : myFieldNames) {
builder.add(SingleCorrelationField.newBuilder(BaggageField.create(name))
.dirty().build());
}
return builder.build();
}
```
without this change we're reusing the same broker for application logic and sending spans to zipkin
with this change we're adding a property to allow providing a different set of addresses for brokers to send spans to Zipkin
fixes gh-1210
