Tagged: Restful Toggle Comment Threads | Keyboard Shortcuts
-
Wang
-
Wang
Chaos Engineering
Chaos Engineering is a great idea — build an automated solution/tool to randomly attempt to break a system in some way; ultimately to learn how the system behaves in such situations. Then you can use your newfound knowledge to find ways to make the system more fault tolerant during these failure conditions in the future.
From :https://medium.com/better-programming/chaos-engineering-chaos-testing-your-http-micro-services-acc99d145515- Chaos engineering in Azure: https://azure.microsoft.com/en-us/blog/inside-azure-search-chaos-engineering/
- Chaos engineering in Netflix: https://netflixtechblog.com/tagged/chaos-engineering
- Netflix chaos monkey: https://github.com/Netflix/chaosmonkey
-
Wang
-
Wang
Guarantee service availability in kubernetes
A good service not only provide good functionalities, but also ensure the availability and uptime.
We reinforce our service from QoS, QPS, Throttling, Scaling, Throughput, Monitoring.
Qos
There’re 3 kinds of QoS in kubernetes: Guaranteed, Burstable, BestEffort. We usually use Guaranteed, Burstable for different services.
#Guaranteed resources: requests: cpu: 1000m memory: 4Gi limits: cpu: 1000m memory: 4Gi #Burstable resources: requests: cpu: 1000m memory: 4Gi limits: cpu: 6000m memory: 8GiQPS
We did lots of stress test on APIs by Gatling before we release them, we mainly care about mean response time, std deviation, mean requests/sec, error rate (API Testing Report), during testing we monitor server metrics by Datadog to find out bottlenecks.
We usually test APIs in two scenarios: internal, external. External testing result is much lower than internal testing because of network latency, network bandwidth and son on.
Internal testing result
================================================================================ ---- Global Information -------------------------------------------------------- > request count 246000 (OK=246000 KO=0 ) > min response time 16 (OK=16 KO=- ) > max response time 5891 (OK=5891 KO=- ) > mean response time 86 (OK=86 KO=- ) > std deviation 345 (OK=345 KO=- ) > response time 50th percentile 30 (OK=30 KO=- ) > response time 75th percentile 40 (OK=40 KO=- ) > response time 95th percentile 88 (OK=88 KO=- ) > response time 99th percentile 1940 (OK=1940 KO=- ) > mean requests/sec 817.276 (OK=817.276 KO=- ) ---- Response Time Distraaibution ------------------------------------------------ > t < 800 ms 240565 ( 98%) > 800 ms < t < 1200 ms 1110 ( 0%) > t > 1200 ms 4325 ( 2%) > failed 0 ( 0%) ================================================================================
External testing result
================================================================================ ---- Global Information -------------------------------------------------------- > request count 33000 (OK=32999 KO=1 ) > min response time 477 (OK=477 KO=60001 ) > max response time 60001 (OK=41751 KO=60001 ) > mean response time 600 (OK=599 KO=60001 ) > std deviation 584 (OK=484 KO=0 ) > response time 50th percentile 497 (OK=497 KO=60001 ) > response time 75th percentile 506 (OK=506 KO=60001 ) > response time 95th percentile 1366 (OK=1366 KO=60001 ) > response time 99th percentile 2125 (OK=2122 KO=60001 ) > mean requests/sec 109.635 (OK=109.631 KO=0.003 ) ---- Response Time Distribution ------------------------------------------------ > t < 800 ms 29826 ( 90%) > 800 ms < t < 1200 ms 1166 ( 4%) > t > 1200 ms 2007 ( 6%) > failed 1 ( 0%) ---- Errors -------------------------------------------------------------------- > i.g.h.c.i.RequestTimeoutException: Request timeout after 60000 1 (100.0%) ms ================================================================================
Throttling
We throttle API by Nginx limit, we configured ingress like this:
annotations: nginx.ingress.kubernetes.io/limit-connections: '30' nginx.ingress.kubernetes.io/limit-rps: '60'
And it will generate Nginx configuration dynamically like this:
limit_conn_zone $limit_ZGVsaXZlcnktY2RuYV9kc2QtYXBpLWNkbmEtZ2F0ZXdheQ zone=xxx_conn:5m; limit_req_zone $limit_ZGVsaXZlcnktY2RuYV9kc2QtYXBpLWNkbmEtZ2F0ZXdheQ zone=xxx_rps:5m rate=60r/s; server { server_name xxx.xxx ; listen 80; location ~* "^/xxx/?(?<baseuri>.*)" { ... ... limit_conn xxx_conn 30; limit_req zone=xxx_rps burst=300 nodelay; ... ... }Scaling
We use HPA in kubernetes to ensure auto (Auto scaling in kubernetes), you could check HPA status in server:
[xxx@xxx ~]$ kubectl get hpa -n test-ns NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE api-demo Deployment/api-demo 39%/30%, 0%/30% 3 10 3 126d [xxx@xxx ~]$ kubectl get pod -n test-ns NAME READY STATUS RESTARTS AGE api-demo-76b9954f57-6hvzx 1/1 Running 0 126d api-demo-76b9954f57-mllsx 1/1 Running 0 126d api-demo-76b9954f57-s22k8 1/1 Running 0 126d
Throughput & Monitoring
We integrated Datadog for monitoring(Monitoring by Datadog), we could check detail API metrics from various dashboards.
Also we could calculate throughout from user, request, request time.
-
Wang
Nginx ingress in kubernetes
There are 3 ways to expose your service: NodePort, LoadBalancer, Ingress, next I will introduce about how to use ingress.
1.Deploy ingress controller
You need deploy ingress controller at first which will start nginx pods, then nginx will bind domains and listen to the requests.
I built a common ingress chart for different service, I only need change values-<service>.yaml and deploy script if any changes.
Another key point is that you must be clear about ingress-class, different service use different ingress-class, it will be quite messy if you mistake them.
args: - /nginx-ingress-controller - --default-backend-service=$(POD_NAMESPACE)/default-http-backend - --configmap=$(POD_NAMESPACE)/nginx-configuration - --tcp-services-configmap=$(POD_NAMESPACE)/tcp-services - --udp-services-configmap=$(POD_NAMESPACE)/udp-services - --ingress-class={{ .Values.server.namespace }} - --sort-backends=true2.Configure service ingress
Next we need configure service ingress which will append nginx server configuration dynamically.
I also built a service chart which include environment configurations, Jenkins & Helm will use different values-<env>.yaml when execute pipeline deployment.
Ingress example:
apiVersion: extensions/v1beta1 kind: Ingress metadata: name: {{ .Values.app.name }}{{ .Values.deploy.subfix }} namespace: {{ .Values.app.namespace }} annotations: kubernetes.io/ingress.class: "{{ .Values.ingress.class }}" kubernetes.io/tls-acme: "true" nginx.ingress.kubernetes.io/enable-cors: "false" nginx.ingress.kubernetes.io/rewrite-target: / nginx.ingress.kubernetes.io/proxy-body-size: 10m spec: rules: - host: {{ .Values.ingress.hostname }} http: paths: - path: {{ .Values.ingress.path }} backend: serviceName: {{ .Values.app.name }}{{ .Values.deploy.subfix }} servicePort: {{ .Values.container.port }} -
Wang
[Gatling] Customize your scripts based on scenario
Sometimes record function may not fulfill your requirement, in this case you need write scala script yourself according to gatling document.
Below is a simple sample to test two APIs: employee & health check
package me.hongmeng.stress.test import io.gatling.core.Predef._ import io.gatling.http.Predef._ class SimpleSimulation extends Simulation { val hostname = "http://localhost:8080" val httpProtocol = http .baseURL(hostname) .inferHtmlResources() .acceptHeader("*/*") .contentTypeHeader("application/json") .userAgentHeader("Gatling/2.3.1") val headers = Map("accept-encoding" -> "gzip, deflate", "cache-control" -> "no-cache") val employeeScenario = scenario("create_experiment_simulation") .exec( http("employee") .post("/v1/employees") .headers(headers) .body( StringBody("{"name": "xiaowang","major": "software"}") ) ) val healthScenario = scenario("health_simulation") .exec( http("health_check") .get("/actuator/health") .headers(headers) ) setUp( employeeScenario.inject(atOnceUsers(10)), healthScenario.inject(atOnceUsers(10)) ).protocols(httpProtocol) } -
Wang
[Gatling] Know about stress test tool
Gatling is kind of stress test tool to test your app’s performance, for detail infos, please refer to official document.
Next I will summurize how to install gatling on your Macbook.
1.Download gatling
wget https://repo1.maven.org/maven2/io/gatling/highcharts/gatling-charts-highcharts-bundle/2.3.1/gatling-charts-highcharts-bundle-2.3.1-bundle.zip
2.Unzip & Enter
unzip gatling-charts-highcharts-bundle-2.3.1-bundle.zip & cd gatling-charts-highcharts-bundle-2.3.1-bundle
3.Start record function
bin/record.sh
After starting record script, you could see the UI as below:
Please configure the proxy port and click Start button. Then you could set your browser proxy and surf the target URL, gatling will capture the content as below:
If you finished and wanna save the result, please click Stop & Save button, gatling will generate a new scala script which save all your behaviors just now, and the script will be under user-files/simulations/
xxx@xxx 2.3.1 $ ll user-files/simulations/ total 328 drwxr-xr-x@ 4 1154257814 80 136 Aug 13 11:30 . drwxr-xr-x@ 5 1154257814 80 170 Mar 6 22:59 .. -rw-r--r-- 1 1154257814 80 166657 Aug 13 11:54 RecordedSimulation.scala drwxr-xr-x@ 4 1154257814 80 136 Mar 6 22:59 computerdatabase
If you wanna change the generated file location, please modify outputFolder in conf/recorder.conf
hongmeng.wang@X0621 2.3.1 $ cat conf/recorder.conf recorder { core { className=RecordedSimulation encoding=utf-8 harFilePath="" headless=false mode=Proxy outputFolder="/usr/local/Cellar/gatling/2.3.1/user-files/simulations" package="" ... ... -
Wang
[Spring Boot2] Access log trace
If I wanna trace access logs, I usually configured in nginx and tomcat, only print business logs in java api.
In this case you need check both nginx logs and api logs in monitor tools like kinaba, it’s a little bit inconvenience, so I wanna also add request access logs in api side.
Generally we can create a new interceptor which extends OncePerRequestFilter, it will intercept all the requests and you can define your own logic inside. But it maybe a little complex in POST request, if you intercept and handle POST request body, when the request arrived controller, the request body will be null, because you have read the stream in your interceptor, so you have to create another request wrapper which extends HttpServletRequestWrapper, then pass the request wrapper to the filter chain.
Actually we can make it in more easily way according to spring boot’s component: spring-boot-starter-actuator. actuator component contains lots of useful endpoints like health check/shutdown hook/metrics and so on. There are also a class named HttpTraceRepository, which will record recent access logs. Specific documentation please go to Spring Boot Actuator.
I extended HttpTraceRepository and combined with Aspectj, which will print both request and parameters to log, and extract it into framework module, any project could include it very easily.
Printed logs as below:
2018-05-03 06:56:10,651 - [http-nio-8080-exec-6] - [INFO ] - [xxx.xxx.xxx.api.framework.aop.LogHttpTraceRepository.around(line:47)] - RequestParam:[1,null,null], ResponseEntity:{"timestamp":1525330570651,"status":200,"error":null,"exception":null,"message":"success","path":null,"method":null,"data":{"experimentId":1,"results":[]}} 2018-05-03 06:56:10,654 - [http-nio-8080-exec-6] - [INFO ] - [xxx.xxx.xxx.api.framework.aop.LogHttpTraceRepository.add(line:32)] - GET http://localhost:8080/v1/employees?deparment_id=1 - 200 - 15ms 2018-05-03 06:56:10,655 - [http-nio-8080-exec-6] - [INFO ] - [xxx.xxx.xxx.api.framework.aop.LogHttpTraceRepository.add(line:34)] - RequestHeader:{host=[localhost:8080], connection=[keep-alive], cache-control=[no-cache], user-agent=[Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36], postman-token=[e9a16988-64a6-1363-bdbd-6b63fe40da5c], accept=[*/*], dnt=[1], accept-encoding=[gzip, deflate, br], accept-language=[zh-CN,zh;q=0.9,en;q=0.8,ja;q=0.7,zh-TW;q=0.6]}, ResponseHeader:{Content-Type=[application/json;charset=UTF-8], Transfer-Encoding=[chunked], Content-Encoding=[gzip], Vary=[Accept-Encoding], Date=[Thu, 03 May 2018 06:56:10 GMT]}
LogHttpTraceRepository:
@Aspect @Component @Slf4j public class LogHttpTraceRepository implements HttpTraceRepository { @Override public List<HttpTrace> findAll() { return Collections.emptyList(); } @Override public void add(HttpTrace trace) { HttpTrace.Request request = trace.getRequest(); HttpTrace.Response response = trace.getResponse(); long timeToken = trace.getTimeTaken(); log.info("{} {} - {} - {}ms", request.getMethod(), request.getUri(), response.getStatus(), timeToken); log.info("RequestHeader:{}, ResponseHeader:{}", request.getHeaders(), response.getHeaders()); } @Around("execution(* com.xxx..controller.*.*(..))") Object around(ProceedingJoinPoint proceedingJoinPoint) throws Throwable { StringBuilder logBuilder = new StringBuilder(); Optional<String> requestOptional = JsonUtils.toJson(proceedingJoinPoint.getArgs()); requestOptional.ifPresent(request -> logBuilder.append("RequestParam:").append(request).append(", ")); Object response = proceedingJoinPoint.proceed(); Optional<String> responseOptional = JsonUtils.toJson(response); responseOptional.ifPresent(res -> logBuilder.append("ResponseEntity:").append(res)); log.info(logBuilder.toString()); return response; } } -
Wang
[Spring Boot2] Common exception handler
When we develop API, how to handle exception is very important for us to locate error, find out exact error code.
Recently I extracted exceptionHandler to a common framework, and deploy it into our internal maven repository. If anyone wanna use it, just add maven dependency, and it will works automatically.
1.Add internal repository and dependency in your pom.xml
<repositories> <repository> <id>nexus-central</id> <url>https://nexus.tool.xxx.internal/repository/maven-public/</url> <releases> <enabled>true</enabled> <updatePolicy>always</updatePolicy> </releases> <snapshots> <enabled>true</enabled> <updatePolicy>always</updatePolicy> </snapshots> </repository> </repositories> <dependency> <groupId>com.xxx</groupId> <artifactId>xxx-framework-web</artifactId> <version>1.0.0-SNAPSHOT</version> </dependency>2.Add package scan annotation, the package prefix must be the same as framework’s package
@ComponentScan(basePackages = "com.xxx.xxx.api")
Then it will intercept all the exception and print error logs and respond to the client.
Error Logs:
2018-04-19 07:02:24,785 - [http-nio-8080-exec-2] - [ERROR] - [xxx.xxx.xxx.api.framework.aop.ApiExceptionHandler.internalErrorHandler(line:26)] - org.springframework.jdbc.BadSqlGrammarException: ### SQL: SELECT id, experiment_id, start_at, model, created_at, created_by, updated_at, updated_by FROM XXX WHERE experiment_id = ? ### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'xxx_xxx.XXX' doesn't exist ; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'xxx_xxx.XXX' doesn't exist at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:235) at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:72) at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73) ... ... at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'xxx_xxx.XXX' doesn't exist at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ... ... at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433) ... 95 moreClient Response:
{ "timestamp": "2018-05-03T07:02:24Z", "status": 500, "error": "Internal Server Error", "message": "n### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'xxx_xxx.xxx' doesn't existn### The error may exist in file [/Users/xxx/java/xxx-api-xxx/target/classes/com/xxx/xxx/api/xxx/mapper/xxxMapper.xml]n### The error may involve defaultParameterMapn### The error occurred while setting parametersn### SQL: SELECT id, department_id, start_at, created_at, created_by, updated_at, updated_by FROM xxx WHERE department_id = ?n### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'xxx_xxx.xxx' doesn't existn; bad SQL grammar []; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'xxx_xxx.xxx' doesn't exist", "path": "/v1/employees", "method": "GET" }
ApiExceptionHandler:
@RestControllerAdvice @Slf4j public class ApiExceptionHandler extends ResponseEntityExceptionHandler { @ExceptionHandler(RuntimeException.class) @ResponseStatus(code = HttpStatus.INTERNAL_SERVER_ERROR) public ApiResponseEntity internalErrorHandler(Exception exception, ServletWebRequest request) { log.error("{}", ExceptionUtils.getStackTrace(exception)); return new ApiResponseEntity(HttpStatus.INTERNAL_SERVER_ERROR.value(), HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase(), exception.getMessage(), request); } @ExceptionHandler(ResourceNotFoundException.class) @ResponseStatus(code = HttpStatus.NOT_FOUND) public ApiResponseEntity notFoundHandler(Exception exception, ServletWebRequest request) { log.warn("{}", exception.getMessage()); return new ApiResponseEntity(HttpStatus.NOT_FOUND.value(), HttpStatus.NOT_FOUND.getReasonPhrase(), exception.getMessage(), request); } @ExceptionHandler(IllegalArgumentException.class) @ResponseStatus(code = HttpStatus.BAD_REQUEST) public ApiResponseEntity illegalArgumentException(Exception exception, ServletWebRequest request) { log.warn("{}", exception.getMessage()); return new ApiResponseEntity(HttpStatus.BAD_REQUEST.value(), HttpStatus.BAD_REQUEST.getReasonPhrase(), exception.getMessage(), request); } @Override protected ResponseEntity<Object> handleExceptionInternal( Exception exception, @Nullable Object body, HttpHeaders headers, HttpStatus status, WebRequest request) { log.warn("{}", exception.getMessage()); if (HttpStatus.INTERNAL_SERVER_ERROR.equals(status)) { request.setAttribute(WebUtils.ERROR_EXCEPTION_ATTRIBUTE, exception, WebRequest.SCOPE_REQUEST); } ServletWebRequest servletWebRequest = (ServletWebRequest) request; ApiResponseEntity apiResponseEntity = new ApiResponseEntity(status.value(), status.getReasonPhrase(), exception.getMessage(), servletWebRequest); return new ResponseEntity<>(apiResponseEntity, headers, status); } } -
Wang
[Spring Boot2] Demo
Recently Spring Boot has released version 2.0.0.RELEASE, so I did a small demo which included the basic CRUD, I have uploaded the code to github.
There are two branches, master is the normal branch, and docker branch will create docker image when you build.
Wang's Tech Blog 
Reply