Spring Restful API - Sometimes, response time is too long-CodePudding

There is a server that I operate. I built a Restful API server with Spring Boot, and when I test my API with Postman, it usually takes about 20ms to 50ms to respond. But sometimes it takes up to 5.2 seconds to respond.

I wanted to find out the cause, so I tried to check where the bottleneck occurred. When I calculate the actual execution time by implementing PreHandle and PostHandle in the InterceptorHandler class, it ends in 5 ms. In the java log, I can check the 200OK log with the Servelet log 5 seconds after the business logic is already over.

What's a way to check what's happening in the meantime? Both network and memory CPU utilization have no singularity. There are no users yet because it is a test server. However, there are about three spring boot apps running on this server.

I checked these things.

    1004  pidstat 1
 1005  uptime
 1006   dmesg | tail
 1008  vmstat 1
 1011  mpstat -P ALL 1
 1012  iostat -xz 1
 1013   free -m
 1014  sar -n DEV 1
1019  sar -n TCP,ETCP 1

CodePudding user response：

Concerning the difference of performance between Tomcat/Jetty. May I suggest you to try an integration test with a MockMvc See the get started

I know how much is hard to split test between OPS infrastructures and DEV framework, but with SpringBoot you can test and display the execution performance with a unit test.

Iterate a call to one on your API any time you want and add a StopWatch around the execution.

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class ApplicationTest {
      private final static Logger LOGGER = LoggerFactory.getLogger(ApplicationTest .class);
  @Autowired
  private MockMvc mockMvc;

  @Test
  public void shouldReturnDefaultMessage() throws Exception {
    StopWatch stopWatch = new StopWatch("Testing REST API performances");

    for(int i=1; i<=5; i<  ) {
      stopWatch.start("Test iteration "   i);
      this.mockMvc.perform(get("/")).andDo(print()).andExpect(status().isOk())
            .andExpect(content().string(containsString("Hello World")));
      stopWatch.stop();
    }
    // Print the result
    LOGGER.info(stopWatch.prettyPrint());
  }
}

This test should bring to light the performance issue should be the init of the rest controller.

Locally I have also a latency at the first call.

StopWatch 'Testing REST API performances': running time (millis) = 806

00510ms 063 % Test iteration 1 00072ms 009 % Test iteration 2 00080ms 010 % Test iteration 3 00071ms 009 % Test iteration 4 00073ms 009 % Test iteration 5 As you can see the first call take a long time.

Hope I my answer will help you to have reach you performance expected and help you in your choice.

CodePudding user response：

Transfert time is the time required to get the first byte of the response.

According to this definition, I would tend to say that it's the time your API doing its processing --> At the API level, some requests could explain a longer processing time? Complexity of algorithm, not the same number of data processed ... ?

By the way, at first call, don't forget that the servlet is created so the first response can take more time.