我想用嵌入式tomcat会话集群设置一个Spring Boot应用程序。

由于嵌入式tomcat没有server.xml文件，因此我创建了TomcatEmbeddedServletContainerFactory并以编程方式设置集群配置。代码如下：

@Configuration
public class TomcatConfig
{
    @Bean
    public EmbeddedServletContainerFactory servletContainerFactory()
    {
        return new TomcatEmbeddedServletContainerFactory()
        {
            @Override
            protected TomcatEmbeddedServletContainer getTomcatEmbeddedServletContainer(
                Tomcat tomcat)
            {
                configureCluster(tomcat);
                return super.getTomcatEmbeddedServletContainer(tomcat);
            }

            private void configureCluster(Tomcat tomcat)
            {
                // static membership cluster

                SimpleTcpCluster cluster = new SimpleTcpCluster();
                cluster.setChannelStartOptions(3);
                {
                    DeltaManager manager = new DeltaManager();
                    manager.setNotifyListenersOnReplication(true);
                    cluster.setManagerTemplate(manager);
                }
                {
                    GroupChannel channel = new GroupChannel();
                    {
                        NioReceiver receiver = new NioReceiver();
                        receiver.setPort(localClusterMemberPort);
                        channel.setChannelReceiver(receiver);
                    }
                    {
                        ReplicationTransmitter sender = new ReplicationTransmitter();
                        sender.setTransport(new PooledParallelSender());
                        channel.setChannelSender(sender);
                    }
                    channel.addInterceptor(new TcpPingInterceptor());
                    channel.addInterceptor(new TcpFailureDetector());
                    channel.addInterceptor(new MessageDispatch15Interceptor());
                    {
                        StaticMembershipInterceptor membership =
                            new StaticMembershipInterceptor();
                        String[] memberSpecs = clusterMembers.split(",", -1);
                        for (String spec : memberSpecs)
                        {
                            ClusterMemberDesc memberDesc = new ClusterMemberDesc(spec);
                            StaticMember member = new StaticMember();
                            member.setHost(memberDesc.address);
                            member.setPort(memberDesc.port);
                            member.setDomain("MyWebAppDomain");
                            member.setUniqueId(memberDesc.uniqueId);
                            membership.addStaticMember(member);
                        }
                        channel.addInterceptor(membership);
                    }
                    cluster.setChannel(channel);
                }
                cluster.addValve(new ReplicationValve());
                cluster.addValve(new JvmRouteBinderValve());
                cluster.addClusterListener(new ClusterSessionListener());

                tomcat.getEngine().setCluster(cluster);
            }
        };
    }

    private static class ClusterMemberDesc
    {
        public String address;
        public int port;
        public String uniqueId;

        public ClusterMemberDesc(String spec) throws IllegalArgumentException
        {
            String[] values = spec.split(":", -1);
            if (values.length != 3)
                throw new IllegalArgumentException("clusterMembers element " +
                    "format must be address:port:uniqueIndex");
            address = values[0];
            port = Integer.parseInt(values[1]);
            int index = Integer.parseInt(values[2]);
            if ((index < 0) || (index > 255))
                throw new IllegalArgumentException("invalid unique index: must be >= 0 and < 256");
            uniqueId = "{";
            for (int i = 0; i < 16; i++, index++)
            {
                if (i != 0)
                    uniqueId += ',';
                uniqueId += index % 256;
            }
            uniqueId += '}';
        }
    };

    // This is for example. In fact these are read from application.properties
    private int localClusterMemberPort = 9991;
    private String clusterMembers = "111.222.333.444:9992:1";
}

我在以下环境中测试了代码：

• 单Windows PC
• 2个具有不同localClusterMemberPort和clusterMembers的Spring Boot应用程序实例

由于cookie没有考虑端口，因此包含JSESSIONID的cookie在两个实例之间共享。

启动实例时，tomcat群集似乎可以正常工作，因为两个实例的请求的JSESSIONID值相同。但是，当我使用第一个实例登录后向第二个实例发出请求时，第二个实例找不到HttpSession。它记录以下消息：

w.c.HttpSessionSecurityContextRepository : No HttpSession currently exists
w.c.HttpSessionSecurityContextRepository : No SecurityContext was available from the HttpSession: null. A new one will be created.

显然，HttpSession没有被共享。但是，当第二个实例创建新会话时，第一个实例的登录信息将被清除，并且登录无效。

这是怎么回事 会话是共享的，但是HttpSession不是共享的？

顺便说一句，我读过<distributed />必须web.xml为应用程序使用tomcat会话集群指定标记。但是我不知道如何在Spring
Boot的no-xml环境中指定它。这是问题的原因吗？那么如何指定呢？

我搜索并找到了一些显示使用Redis进行聚类的文档。但是目前，我不想在配置中添加其他活动部件。在我的配置中，最大3〜4个节点。