Spring-Boot: Exception when using Redis as a Session Store

Question

I'm trying to create a minimal web application using spring-boot which makes use of redis as a session store. The goal is to share session state between multiple instances of the web application. The application works fine without Redis (using "normal" sessions) but throws an exception after I enabled the configuration for Redis. I followed this tutorial. The application is started via "java -jar path_to.jar".

To make the app work again, it is sufficient to comment out the configuration class (see below).

The first attempt included the deployment to Heroku, but it's the same problem on my machine using a local Redis server. The environment variable for the connection string is set up properly.

The whole application consists only of the snippets shown below. Am I missing something? Thank you.

Configuration:

@Profile("production")
@Configuration
@EnableRedisHttpSession
public class ProductionRedisConfiguration {

    @Bean
    public JedisConnectionFactory connectionFactory() throws URISyntaxException {
        JedisConnectionFactory redis = new JedisConnectionFactory();
        String redisUrl = System.getenv("REDISCLOUD_URL");

        URI redisUri = new URI(redisUrl);
        redis.setHostName(redisUri.getHost());
        redis.setPort(redisUri.getPort());
        redis.setPassword(redisUri.getUserInfo().split(":",2)[1]);
        return redis;
    }

    static class Initializer  extends AbstractHttpSessionApplicationInitializer {
        public Initializer() {
            super(ProductionRedisConfiguration.class);
        }
    }
}

"App":

@EnableAutoConfiguration
@ComponentScan
public class Application {
    private static final Logger LOGGER = getLogger(Application.class);
    public static void main(String[] args) throws Throwable {
        SpringApplication.run(Application.class, args);
    }
}

.

@Controller
public class GreetingController {

    @RequestMapping("/")
    public @ResponseBody String session(HttpServletRequest request) {
        String name = (String) request.getSession().getAttribute("name");
        if(name != null) {
            return "Hello, " + name;
        } else {
            String newName = "User " + new Random().nextInt(1000000);
            request.getSession().setAttribute("name", newName);
            return "No session found, you are now called " + newName;
        }
    }
}

Dependencies:

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.session</groupId>
        <artifactId>spring-session</artifactId>
        <version>1.0.1.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-redis</artifactId>
    </dependency>
</dependencies>

Trace:

java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:53)
        at java.lang.Thread.run(Unknown Source)
Caused by: org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.c
ontext.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:140)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:476)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:124)
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:609)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:321)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:806)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:795)
        at com.backbase.progfun.Application.main(Application.java:17)
        ... 6 more
Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:104)
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.<init>(TomcatEmbeddedServletContainer.java:67)
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServ
letContainerFactory.java:258)
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletCon
tainerFactory.java:138)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:1
60)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137)
        ... 13 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
        at org.apache.catalina.startup.Tomcat.start(Tomcat.java:341)
        at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:77)
        ... 18 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:732)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 20 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat]]
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 22 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:302)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        ... 24 more

Answer 1

It appears that as of late you also need to set the REDIS_PROVIDER config var for apps deployed at Heroku.

Try running the following and for your app and lmk if it resolves the problem: heroku config:set REDIS_PROVIDER=REDISCLOUD_URL