问题
I use Spring Cloud Feign and Sleuth with a Zipkin server. My problem is that when I enable Sleuth, then any simple request takes at least 600ms. Note that for tests purposes, I've set the sampler percentage of Sleuth at 1.
Can I do something to improve that?
Here some log of a request which takes 25ms without Sleuth and 700ms with Sleuth. (user calls /teams which calls /cities):
13:46:46.064 [http-nio-8080-exec-3] DEBUG o.s.c.s.instrument.web.TraceFilter - Received a request to uri [/teams] that should not be sampled [false]
13:46:46.064 [http-nio-8080-exec-3] DEBUG o.s.c.s.instrument.web.TraceFilter - No parent span present - creating a new span
13:46:46.065 [http-nio-8080-exec-3] DEBUG o.s.web.servlet.DispatcherServlet - DispatcherServlet with name 'dispatcherServlet' processing GET request for [/teams]
13:46:46.078 [http-nio-8080-exec-3] DEBUG o.s.c.s.i.w.TraceHandlerInterceptor - Handling span [Trace: 99b8ae8aa88157a6, Span: 99b8ae8aa88157a6, Parent: null, exportable:true]
13:46:46.078 [http-nio-8080-exec-3] DEBUG o.s.c.s.i.w.TraceHandlerInterceptor - Adding a method tag with value [getTeams] to a span [Trace: 99b8ae8aa88157a6, Span: 99b8ae8aa88157a6, Parent: null, exportable:true]
13:46:46.078 [http-nio-8080-exec-3] DEBUG o.s.c.s.i.w.TraceHandlerInterceptor - Adding a class tag with value [TeamService] to a span [Trace: 99b8ae8aa88157a6, Span: 99b8ae8aa88157a6, Parent: null, exportable:true]
13:46:46.083 [hystrix-cities-2] DEBUG o.s.c.s.i.h.SleuthHystrixConcurrencyStrategy$HystrixTraceCallable - Continuing span [Trace: 99b8ae8aa88157a6, Span: 99b8ae8aa88157a6, Parent: null, exportable:true]
13:46:46.084 [hystrix-cities-2] DEBUG o.s.c.s.i.w.c.feign.TraceFeignClient - Created new Feign span [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true]
13:46:46.084 [hystrix-cities-2] DEBUG o.s.c.s.i.w.c.feign.TraceFeignClient - The modified request equals GET http://localhost:8080/cities HTTP/1.1
X-B3-ParentSpanId: 99b8ae8aa88157a6
X-B3-Sampled: 1
X-B3-TraceId: 99b8ae8aa88157a6
X-Span-Name: http:/cities
X-B3-SpanId: 4cea0c5e2e662ea3
13:46:46.101 [http-nio-8080-exec-5] DEBUG o.s.c.s.instrument.web.TraceFilter - Received a request to uri [/cities] that should not be sampled [false]
13:46:46.101 [http-nio-8080-exec-5] DEBUG o.s.c.s.instrument.web.TraceFilter - Found a parent span [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true] in the request
13:46:46.101 [http-nio-8080-exec-5] DEBUG o.s.c.s.instrument.web.TraceFilter - Parent span is [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true]
13:46:46.101 [http-nio-8080-exec-5] DEBUG o.s.b.w.f.OrderedRequestContextFilter - Bound request context to thread: org.apache.catalina.connector.RequestFacade@36324069
13:46:46.101 [http-nio-8080-exec-5] DEBUG o.s.web.servlet.DispatcherServlet - DispatcherServlet with name 'dispatcherServlet' processing GET request for [/cities]
13:46:46.105 [http-nio-8080-exec-5] DEBUG o.s.c.s.i.w.TraceHandlerInterceptor - Handling span [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true]
13:46:46.105 [http-nio-8080-exec-5] DEBUG o.s.c.s.i.w.TraceHandlerInterceptor - Adding a method tag with value [getCities] to a span [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true]
13:46:46.105 [http-nio-8080-exec-5] DEBUG o.s.c.s.i.w.TraceHandlerInterceptor - Adding a class tag with value [cityService] to a span [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true]
13:46:46.106 [http-nio-8080-exec-5] DEBUG o.s.w.s.m.m.a.RequestResponseBodyMethodProcessor - Written [com.citymanager.entity.City@320dc277] as "application/json" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@33bb3f86]
13:46:46.107 [http-nio-8080-exec-5] DEBUG o.s.c.s.instrument.web.TraceFilter - Trying to send the parent span [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true] to Zipkin
13:46:46.107 [http-nio-8080-exec-5] DEBUG o.s.c.s.z.ServerPropertiesEndpointLocator - Span will contain serviceName [city-manager]
13:46:46.109 [hystrix-cities-2] DEBUG o.s.c.s.i.w.c.feign.TraceFeignClient - Closing Feign span and logging CR [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true]
13:46:46.109 [hystrix-cities-2] DEBUG o.s.c.s.i.w.c.feign.TraceFeignClient - Closing Feign span [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true]
13:46:46.109 [hystrix-cities-2] DEBUG o.s.c.s.z.ServerPropertiesEndpointLocator - Span will contain serviceName [city-manager]
13:46:46.459 [http-nio-8080-exec-5] DEBUG o.s.c.s.instrument.web.TraceFilter - Closing the span [Trace: 99b8ae8aa88157a6, Span: 4cea0c5e2e662ea3, Parent: 99b8ae8aa88157a6, exportable:true] since the response was successful
13:46:46.464 [hystrix-cities-2] DEBUG o.s.w.c.HttpMessageConverterExtractor - Reading [class com.citymanager.entity.City] as "application/json;charset=UTF-8" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@33bb3f86]
13:46:46.465 [hystrix-cities-2] DEBUG o.s.c.s.i.h.SleuthHystrixConcurrencyStrategy$HystrixTraceCallable - Detaching span since it was continued [Trace: 99b8ae8aa88157a6, Span: 99b8ae8aa88157a6, Parent: null, exportable:true]
13:46:46.466 [http-nio-8080-exec-3] DEBUG o.s.w.s.m.m.a.RequestResponseBodyMethodProcessor - Written [com.citymanager.entity.Team@3c35ed9b] as "application/json" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter@33bb3f86]
13:46:46.466 [http-nio-8080-exec-3] DEBUG o.s.web.servlet.DispatcherServlet - Successfully completed request
13:46:46.467 [http-nio-8080-exec-3] DEBUG o.s.c.s.instrument.web.TraceFilter - Closing the span [Trace: 99b8ae8aa88157a6, Span: 99b8ae8aa88157a6, Parent: null, exportable:true] since the response was successful
13:46:46.467 [http-nio-8080-exec-3] DEBUG o.s.c.s.z.ServerPropertiesEndpointLocator - Span will contain serviceName [city-manager]
13:46:46.857 [AsyncReporter(org.springframework.cloud.sleuth.zipkin.RestTemplateSender@42519b72)] DEBUG o.s.web.client.RestTemplate - Created POST request for "http://localhost:9411/api/v1/spans"
13:46:46.857 [AsyncReporter(org.springframework.cloud.sleuth.zipkin.RestTemplateSender@42519b72)] DEBUG o.s.web.client.RestTemplate - Setting request Accept header to [text/plain, application/json, application/*+json, */*]
13:46:46.857 [AsyncReporter(org.springframework.cloud.sleuth.zipkin.RestTemplateSender@42519b72)] DEBUG o.s.web.client.RestTemplate - Writing [[B@1aecb2f4] as "application/json" using [org.springframework.http.converter.ByteArrayHttpMessageConverter@4414cc2d]
13:46:46.885 [AsyncReporter(org.springframework.cloud.sleuth.zipkin.RestTemplateSender@42519b72)] DEBUG o.s.web.client.RestTemplate - POST request for "http://localhost:9411/api/v1/spans" resulted in 202 (null)
回答1:
It seems like you are using Sleuth with Zipkin via HTTP. You can try the Sleuth with Zipkin via Spring Cloud Stream approach. I haven't done the benchmark myself, but it should improve the performance in theory.
Please see the documentation at: https://cloud.spring.io/spring-cloud-sleuth/spring-cloud-sleuth.html#_sleuth_with_zipkin_via_spring_cloud_stream
回答2:
I wonder what kind of a benchmarking method you have picked. Which version of Sleuth are you using? Also is this one single benchmark that you're doing? Is it on your computer? Has the JVM gotten heated up? Are there any other processes executed? Doing benchmarking is not that easy... You can use tools like JMH to do it better.
BTW try turning off the DEBUG logging level and check the results again.
We are performing benchmark tests of Sleuth and from what we see when adding Sleuth the latency gets increased by around 20 ms. Definitely not 600 ms.
来源：https://stackoverflow.com/questions/43937265/enabling-sleuth-slows-requests-down-a-lot