Hikari CP Connection Error with Concurrent requests

Question

We have a location service application, that provides location related info to our other applications from the MySQL Database. Due to some reason, the location service fails to connect to the MySQL database when receiving multiple requests.We observed that it fails when getting a continuous 15-20 request simultaneously. The following snippets are the MySQL Configuration code and the error stack.

 My@Bean(name = "locationDataSource")
public HikariDataSource getDataSource(@Value("${projectxx.mysql.location.url}") String url,
        @Value("${projectxx.mysql.location.username}") String username,
        @Value("${projectxx.mysql.location.password}") String password) {


    HikariConfig config = new HikariConfig();
    config.setJdbcUrl(url);
    config.setUsername(username);
    config.setPassword(password);
    config.setDriverClassName("com.mysql.jdbc.Driver");
    config.setMaximumPoolSize(45);
    config.setPoolName("locationDBpool");
    config.setMinimumIdle(15);

    config.addDataSourceProperty("cachePrepStmts", "true");
    config.addDataSourceProperty("prepStmtCacheSize", "250");
    config.addDataSourceProperty("prepStmtCacheSqlLimit", "2048");

    return new HikariDataSource(config);

}

@Bean(name = "locationSession")
@Qualifier("locationDataSource")
public SessionFactory getSessionFactoryBean(@Autowired(required = true) HikariDataSource dataSource) {

    LocalSessionFactoryBean sessionFacBean = new LocalSessionFactoryBean();
    sessionFacBean.setDataSource(dataSource);
    sessionFacBean.setPackagesToScan("com.projectxxx.dao");
    Properties hibernateProperties = new Properties();
    hibernateProperties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQLDialect");
    sessionFacBean.setHibernateProperties(hibernateProperties);
    try {
        sessionFacBean.afterPropertiesSet();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return sessionFacBean.getObject();

}

StackTrace:

java.sql.SQLTransientConnectionException: locationDBpool - Connection is not available, request timed out after 30000ms.
        at com.zaxxer.hikari.pool.HikariPool.createTimeoutException(HikariPool.java:666) ~[HikariCP-2.7.4.jar:na]
        at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:182) ~[HikariCP-2.7.4.jar:na]
        at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:147) ~[HikariCP-2.7.4.jar:na]
        at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:85) ~[HikariCP-2.7.4.jar:na]
        at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at org.hibernate.internal.AbstractSessionImpl$NonContextualJdbcConnectionAccess.obtainConnection(AbstractSessionImpl.java:386) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:87) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:112) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getConnectionForTransactionManagement(LogicalConnectionManagedImpl.java:230) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.begin(LogicalConnectionManagedImpl.java:237) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.begin(JdbcResourceLocalTransactionCoordinatorImpl.java:214) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at org.hibernate.engine.transaction.internal.TransactionImpl.begin(TransactionImpl.java:52) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1512) ~[hibernate-core-5.0.12.Final.jar:5.0.12.Final]
        at com.projectxxx.actionImpl.LocationManagementImpl.findAddressByPostalCode(LocationManagementImpl.java:40) ~[classes/:na]
        at com.projectxxx.controller.LocationReadController.service3(LocationReadController.java:40) ~[classes/:na]
        at sun.reflect.GeneratedMethodAccessor51.invoke(Unknown Source) ~[na:na]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131]
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:108) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.12.RELEASE.jar:4.3.12.RELEASE]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) ~[tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_131]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_131]
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.23.jar:8.5.23]
        at java.lang.Thread.run(Thread.java:748) [na:1.8.0_131]

hi @user7294900 , The pool size cannot be changed due to some other reasons. I really appreciate if you can give me any explanation to do that? — , Dec 19 '17 at 18:49

score 0 · Answer 1 · answered Dec 20 '17 at 07:55

You set maximum pool size as 45, meaning if 45 connections are taken, next request will wait until one is released, in your case request waited until timeout occurred after 30 seconds.

If you have 15-20 requests, probably each request takes at least 3 connections and don't release them in 30 seconds.

There could be a connection leak, meaning you open a connection and didn't close it which cause connection to be left open in pool.

If there's no leak maybe your SQL are taking long time and need to improve their performance.

You should monitor your environment and find the bottleneck/leak.

Hikari CP Connection Error with Concurrent requests

1 Answers1