Nacos  启动报错 Unable to start embedded Tomcat

问题一： Unable to start embedded Tomcat

     nacos版本为：1.4.0 

从github下载压缩包解压之后启动Nacos出现 Unable to start embedded Tomcat 的错误是因为   Nacos的启动是以“cluster" 集群模式启动，所以才会出现这个问题

如图

org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:156)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544)
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:744)
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:391)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:312)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1204)
        at com.alibaba.nacos.Nacos.main(Nacos.java:35)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49)
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:108)
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
        at org.springframework.boot.loader.PropertiesLauncher.main(PropertiesLauncher.java:467)
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
        at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:124)
        at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:86)
        at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:416)
        at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:180)
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:180)
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:153)
        ... 16 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'authFilterRegistration' defined in class path resource [com/alibaba/nacos/core/auth/AuthConfig.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.web.servlet.FilterRegistrationBean]: Factory method 'authFilterRegistration' threw exception; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'authFilter': Unsatisfied dependency expressed through field 'authManager'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'nacosAuthManager': Unsatisfied dependency expressed through field 'authenticationManager'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'nacosAuthConfig': Unsatisfied dependency expressed through field 'userDetailsService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'nacosUserDetailsServiceImpl': Unsatisfied dependency expressed through field 'userPersistService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'externalUserPersistServiceImpl': Unsatisfied dependency expressed through field 'persistService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'externalStoragePersistServiceImpl': Invocation of init method failed; nested exception is java.lang.RuntimeException: java.lang.RuntimeException: [db-load-error]load jdbc.properties error
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627)
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1318)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1158)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:554)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:514)
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:321)

 解决方案：

1.如果单机启动：我们只需要修改startup.cmd中的    set MODE="cluster" 修改为 standalone

2.如果我们集群启动： 

首先要把数据库脚本导入本地数据库，数据库名要与application.properties里的数据库配置一致，一般都叫nacos库，
然后修改conf下的配置文件application.properties，把db等配置改改。

如图：

分析：在nacos 有两种启动模式，一种单机，一种集群（默认）

而nacos本事有内置的小型数据库来支持单机模式，所以如果我们单机启动的时候，不需要外部的数据库，但是如果集群模式启动，就必要要配置对应的数据库连接和表

问题二：Failed to create database ‘/data/soft/nacos/data/derby-data’

Caused by: java.lang.RuntimeException: load schema.sql error.org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Failed to create database '/data/nacos/data/derby-data', see the next exception for details.)
    at com.alibaba.nacos.config.server.service.LocalDataSourceServiceImpl.reload(LocalDataSourceServiceImpl.java:110)
    at com.alibaba.nacos.config.server.service.LocalDataSourceServiceImpl.init(LocalDataSourceServiceImpl.java:94)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleElement.invoke(InitDestroyAnnotationBeanPostProcessor.java:363)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor$LifecycleMetadata.invokeInitMethods(InitDestroyAnnotationBeanPostProcessor.java:307)
    at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessBeforeInitialization(InitDestroyAnnotationBeanPostProcessor.java:136)
    ... 70 common frames omitted

 删除报错信息中的’/data/nacos/data/derby-data’目录，重新启动。

如有其他问题。希望大家积极留言共同进步