Spring Boot Does Not Seem to Start

Question

I am trying to get a Spring Boot WAR to deploy to a private Tomcat 7.0.68 instance hosted by DailyRazor. I cannot figure out why the Spring Boot application will not work. I do not seem to get any errors. Locally, I have gotten this to work with STS 3.8.4, Tomcat 7.0.78, Tomcat 8.5.11, and a couple other versions of Tomcat.

I never see the Spring Boot banner display on the DailyRazor instance nor much of the other logging indicating that my Spring Boot application is starting and loading all of the beans. This is the only logging I see:

INFO main org.apache.catalina.core.StandardService - Stopping service Catalina
INFO main org.apache.catalina.core.AprLifecycleListener - The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: /usr/local/tomcat/users/user_id/jdk/jre/lib/amd64/server:/usr/local/tomcat/users/user_id/jdk/jre/lib/amd64:/usr/java/packages/lib/amd64:/usr/lib64:/lib64:/lib:/usr/lib
INFO main org.apache.catalina.startup.Catalina - Initialization processed in 2299 ms
INFO main org.apache.catalina.core.StandardService - Starting service Catalina
INFO main org.apache.catalina.core.StandardEngine - Starting Servlet Engine: Apache Tomcat/7.0.68
INFO foobar.com-startStop-1 org.apache.catalina.startup.TldConfig - At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
INFO foobar.com-startStop-1 org.apache.catalina.util.SessionIdGeneratorBase - Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [271] milliseconds.
INFO foobar.com-startStop-1 org.apache.catalina.startup.HostConfig - Deploying web application archive /home/user_id/tomcat/webapps/foobar.com/ROOT.war
INFO foobar.com-startStop-1 org.apache.catalina.startup.TldConfig - At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
INFO foobar.com-startStop-1 org.apache.catalina.startup.HostConfig - Deployment of web application archive /home/user_id/tomcat/webapps/foobar.com/ROOT.war has finished in 1,603 ms
INFO foobar.com-startStop-1 org.apache.catalina.startup.HostConfig - Deploying web application archive /home/user_id/tomcat/webapps/foobar.com/plant-service-0.0.1-SNAPSHOT.war
INFO foobar.com-startStop-1 org.apache.catalina.startup.TldConfig - At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
INFO foobar.com-startStop-1 org.apache.catalina.core.ContainerBase.[Catalina].[foobar.com].[/plant-service-0.0.1-SNAPSHOT] - 3 Spring WebApplicationInitializers detected on classpath
INFO foobar.com-startStop-1 org.apache.catalina.core.ContainerBase.[Catalina].[foobar.com].[/plant-service-0.0.1-SNAPSHOT] - Initializing Spring embedded WebApplicationContext
INFO foobar.com-startStop-1 org.apache.catalina.startup.HostConfig - Deployment of web application archive /home/user_id/tomcat/webapps/foobar.com/plant-service-0.0.1-SNAPSHOT.war has finished in 21,769 ms
INFO main org.apache.catalina.startup.Catalina - Server startup in 26534 ms
INFO ajp-bio-127.0.0.1-9592-exec-1 org.apache.catalina.core.ContainerBase.[Catalina].[foobar.com].[/plant-service-0.0.1-SNAPSHOT] - Initializing Spring FrameworkServlet 'dispatcherServlet'

I have following the instructions for packaging as a WAR, extending SpringBootServletInitializer, overriding configure(...), etc. Again, this all works locally on multiple versions of Tomcat. I have tried to adjust the logging, but I do not see anything useful.

Any hints? Suggestions?

EDIT

Not sure if it is related, but when shutting down Tomcat, I see the following:

INFO main org.apache.catalina.core.StandardService - Stopping service Catalina
ERROR foobar.com-startStop-2 org.apache.catalina.loader.WebappClassLoaderBase - The web application [] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak.
INFO foobar.com-startStop-2 org.apache.catalina.core.ContainerBase.[Catalina].[foobar.com].[/plant-service-0.0.1-SNAPSHOT] - Destroying Spring FrameworkServlet 'dispatcherServlet'
INFO foobar.com-startStop-2 org.apache.catalina.core.ContainerBase.[Catalina].[foobar.com].[/plant-service-0.0.1-SNAPSHOT] - Closing Spring root WebApplicationContext
ERROR foobar.com-startStop-2 org.apache.catalina.loader.WebappClassLoaderBase - The web application [/plant-service-0.0.1-SNAPSHOT] registered the JDBC driver [com.mysql.jdbc.Driver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered.
ERROR foobar.com-startStop-2 org.apache.catalina.loader.WebappClassLoaderBase - The web application [/plant-service-0.0.1-SNAPSHOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak.

Answer 1

Could you please ensure you did all of this correctly ?

From Create a deployable war file (Spring boot documentation) :

Create a deployable war file

The first step in producing a deployable war file is to provide a SpringBootServletInitializer subclass and override its configure method. This makes use of Spring Framework’s Servlet 3.0 support and allows you to configure your application when it’s launched by the servlet container. Typically, you update your application’s main class to extend SpringBootServletInitializer:

@SpringBootApplication
public class Application extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(Application.class);
    }

    public static void main(String[] args) throws Exception {
        SpringApplication.run(Application.class, args);
    }

}

The next step is to update your build configuration so that your project produces a war file rather than a jar file. If you’re using Maven and using spring-boot-starter-parent (which configures Maven’s war plugin for you) all you need to do is to modify pom.xml to change the packaging to war:

<packaging>war</packaging>

EDIT

Do you have spring-boot-starter-web and spring-boot-starter-tomcat dependencies ?

To build a war file that is both executable and deployable into an external container you need to mark the embedded container dependencies as “provided”, e.g:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <!-- ... -->
    <packaging>war</packaging>
    <!-- ... -->
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <!-- ... -->
    </dependencies>
</project>