@Scheduled doesn't work out of the box

[innokenty]

I have a spring-boot project with tracer added (more details below). Configuration is just the default one, just the trace name is configured. I'm trying to get my trace value in a @Scheduled method, but I get IllegalStateException: X-Flow-ID has not been started.

Question: how is it supposed to work? I think the documentation on this is missing.

Description

• I'm running on spring-boot:1.4.6.
• I have only tracer-spring-boot-starter:0.16.0 in dependencies.
• I have configured only this single property for tracer: tracer.traces.X-Flow-ID=flow-id
• I have a @Scheduled method inside of which I'm calling tracer.get("X-Flow-ID").getValue() on an @Autowired Tracer tracer field.
• Autowiring works, but I get the following exception:

java.lang.IllegalStateException: X-Flow-ID has not been started
	at org.zalando.tracer.DefaultTracer.getAndCheckValue(DefaultTracer.java:102) ~[tracer-core-0.16.0.jar:na]
	at org.zalando.tracer.DefaultTracer.access$000(DefaultTracer.java:15) ~[tracer-core-0.16.0.jar:na]
	at org.zalando.tracer.DefaultTracer$1.getValue(DefaultTracer.java:68) ~[tracer-core-0.16.0.jar:na]

Question

I didn't really find any docs of what a "support for scheduling" means. I'm sure I'm doing something wrong, but can you point out what's missing? I was expecting that the trace will be already initialized and I can just get it's value (and send in an outgoing request).

[whiskeysierra]

That sounds like the correct setup to me. Can you compare your setup to this test? Maybe there is an obvious difference somewhere? Do you register a custom TaskScheduler or something? Maybe you can put some breakpoints in the SchedulingAutoConfiguration to see whether it's executed correctly.

[innokenty]

It works on an empty project indeed. I think the scheduler configuration doesn't work properly in this case. Not sure why, but I think the conditional taskScheduler bean is simply not created. In my log I see only:

org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler - Initializing ExecutorService  'taskScheduler'

ANd no more relevant mentions of taskScheduler.

How is this supposed to work, if a bean with this name and type is already present?

[innokenty]

Turned out the problem was that my project already had a TaskScheduler bean configured (see below). And that's why tracer's autoconfiguration was not running, since it's conditional.

@Configuration
public class TaskSchedulerConfig {
    @Bean
    public ThreadPoolTaskScheduler taskScheduler() {
        return new ThreadPoolTaskScheduler();
    }
}

Maybe it would a great idea to somehow make this configuration not conditional, but make it extend whatever schedulers there are already in the context?

And if someone stumbles upon that thread some day: check if you already have a taskScheduler bean defined, guys! It ain't gonna work!!

[Sam-Kruglov]

Just got the same error. Had to copy paste bean definition from org.zalando.tracer.spring.TracerAutoConfiguration.AsyncAutoConfiguration#taskExecutor without condition. Worked, thanks

[Sam-Kruglov]

@whiskeysierra it doesn't make sense to have both @Primary and @ConditionalOnMissingBean

[whiskeysierra]

2.x is drastically different and has no support for async/scheduled anymore. That responsibility can be delegates https://github.com/opentracing-contrib/java-spring-cloud/blob/master/instrument-starters/opentracing-spring-cloud-core/src/main/java/io/opentracing/contrib/spring/cloud/scheduled/ScheduledAutoConfiguration.java