此前使用的nacos版本是1.4.5，现在nacos最新版本为2.2.2，且修复了旧版本的一些安全问题，下面把详细的升级步骤记录一下，大家一起学习，亲测有效。
该文档是nacos升级的上篇，主要介绍nacos软件升级，“nacos-下篇” 是介绍nacos升级到2.2.2之后，代码中相关版本的对应升级，传送门： Nacos升级2.2.2 相关版本升级及升级中问题【下篇】
主要参考nacos官方升级文档：https://nacos.io/zh-cn/docs/v2/upgrading/2.0.0-upgrading.html
和官方鉴权操作：https://nacos.io/zh-cn/docs/v2/guide/user/auth.html
但是在实际操作会有一些问题，这里作补充说明。我在升级过程中遇到了2个主要的问题：
1、nacos 报错 Unknown column ‘encrypted_data_key’ in ‘field list’ *
2、Unable to start embedded Tomcat
解决方法在后面的详细操作步骤中！！！

开始操作前先下载最新的nacos版本2.2.2：https://github.com/alibaba/nacos/releases
如已下载可跳过，直接到操作步骤！！！

也可以选择自己想要升级的版本，点击tags进行版本选择


选择版本后，接到最下面进行下载

好了，现在开始升级操作吧

一、停止旧节点

二、替换文件

三、修改配置

修改启动脚本：

#!/bin/bash
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#      http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
cygwin=false
darwin=false
os400=false
case "`uname`" in
CYGWIN*) cygwin=true;;
Darwin*) darwin=true;;
OS400*) os400=true;;
error_exit ()
    echo "ERROR: $1 !!"
    exit 1
[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=$HOME/jdk/java
[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=/usr/java
[ ! -e "$JAVA_HOME/bin/java" ] && JAVA_HOME=/opt/taobao/java
[ ! -e "$JAVA_HOME/bin/java" ] && unset JAVA_HOME
if [ -z "$JAVA_HOME" ]; then
  if $darwin; then
    if [ -x '/usr/libexec/java_home' ] ; then
      export JAVA_HOME=`/usr/libexec/java_home`
    elif [ -d "/System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home" ]; then
      export JAVA_HOME="/System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home"
    JAVA_PATH=`dirname $(readlink -f $(which javac))`
    if [ "x$JAVA_PATH" != "x" ]; then
      export JAVA_HOME=`dirname $JAVA_PATH 2>/dev/null`
  if [ -z "$JAVA_HOME" ]; then
        error_exit "Please set the JAVA_HOME variable in your environment, We need java(x64)! jdk8 or later is better!"
export SERVER="nacos-server"
export MODE="cluster"
export FUNCTION_MODE="all"
export MEMBER_LIST=""
export EMBEDDED_STORAGE=""
while getopts ":m:f:s:c:p:" opt
    case $opt in
            MODE=$OPTARG;;
            FUNCTION_MODE=$OPTARG;;
            SERVER=$OPTARG;;
            MEMBER_LIST=$OPTARG;;
            EMBEDDED_STORAGE=$OPTARG;;
        echo "Unknown parameter"
        exit 1;;
export JAVA_HOME
export JAVA="$JAVA_HOME/bin/java"
export BASE_DIR=`cd $(dirname $0)/..; pwd`
export CUSTOM_SEARCH_LOCATIONS=file:${BASE_DIR}/conf/
#===========================================================================================
# JVM Configuration
#===========================================================================================
if [[ "${MODE}" == "standalone" ]]; then
    JAVA_OPT="${JAVA_OPT} -Xms8192m -Xmx8192m -Xmn4096m"
    JAVA_OPT="${JAVA_OPT} -Dnacos.standalone=true"
    if [[ "${EMBEDDED_STORAGE}" == "embedded" ]]; then
        JAVA_OPT="${JAVA_OPT} -DembeddedStorage=true"
    JAVA_OPT="${JAVA_OPT} -server -Xms2g -Xmx2g -Xmn1g -XX:MetaspaceSize=128m -XX:MaxMetaspaceSize=320m"
    JAVA_OPT="${JAVA_OPT} -XX:-OmitStackTraceInFastThrow -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=${BASE_DIR}/logs/java_heapdump.hprof"
    JAVA_OPT="${JAVA_OPT} -XX:-UseLargePages"
if [[ "${FUNCTION_MODE}" == "config" ]]; then
    JAVA_OPT="${JAVA_OPT} -Dnacos.functionMode=config"
elif [[ "${FUNCTION_MODE}" == "naming" ]]; then
    JAVA_OPT="${JAVA_OPT} -Dnacos.functionMode=naming"
JAVA_OPT="${JAVA_OPT} -Dnacos.member.list=${MEMBER_LIST}"
JAVA_MAJOR_VERSION=$($JAVA -version 2>&1 | sed -E -n 's/.* version "([0-9]*).*$/\1/p')
if [[ "$JAVA_MAJOR_VERSION" -ge "9" ]] ; then
  JAVA_OPT="${JAVA_OPT} -Xlog:gc*:file=${BASE_DIR}/logs/nacos_gc.log:time,tags:filecount=10,filesize=100m"
  JAVA_OPT_EXT_FIX="-Djava.ext.dirs=${JAVA_HOME}/jre/lib/ext:${JAVA_HOME}/lib/ext"
  JAVA_OPT="${JAVA_OPT} -Xloggc:${BASE_DIR}/logs/nacos_gc.log -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M"
JAVA_OPT="${JAVA_OPT} -Dloader.path=${BASE_DIR}/plugins,${BASE_DIR}/plugins/health,${BASE_DIR}/plugins/cmdb,${BASE_DIR}/plugins/selector"
JAVA_OPT="${JAVA_OPT} -Dnacos.home=${BASE_DIR}"
JAVA_OPT="${JAVA_OPT} -jar ${BASE_DIR}/target/${SERVER}.jar"
JAVA_OPT="${JAVA_OPT} ${JAVA_OPT_EXT}"
JAVA_OPT="${JAVA_OPT} --spring.config.additional-location=${CUSTOM_SEARCH_LOCATIONS}"
JAVA_OPT="${JAVA_OPT} --logging.config=${BASE_DIR}/conf/nacos-logback.xml"
JAVA_OPT="${JAVA_OPT} --server.max-http-header-size=524288"
if [ ! -d "${BASE_DIR}/logs" ]; then
  mkdir ${BASE_DIR}/logs
echo "$JAVA $JAVA_OPT_EXT_FIX ${JAVA_OPT}"
if [[ "${MODE}" == "standalone" ]]; then
    echo "nacos is starting with standalone"
    echo "nacos is starting with cluster"
# check the start.out log output file
if [ ! -f "${BASE_DIR}/logs/start.out" ]; then
  touch "${BASE_DIR}/logs/start.out"
# start
echo "$JAVA $JAVA_OPT_EXT_FIX ${JAVA_OPT}" > ${BASE_DIR}/logs/start.out 2>&1 &
if [[ "$JAVA_OPT_EXT_FIX" == "" ]]; then
  nohup "$JAVA" ${JAVA_OPT} nacos.nacos >> ${BASE_DIR}/logs/start.out 2>&1 &
  nohup "$JAVA" "$JAVA_OPT_EXT_FIX" ${JAVA_OPT} nacos.nacos >> ${BASE_DIR}/logs/start.out 2>&1 &
echo "nacos is starting，you can check the ${BASE_DIR}/logs/start.out"
修改application.properties
 
主要是修改mysql数据库配置
 
 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#      http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#*************** Spring Boot Related Configurations ***************#
### Default web context path:
server.servlet.contextPath=/nacos
### Include message field
server.error.include-message=ALWAYS
### Default web server port:
server.port=8848
#*************** Network Related Configurations ***************#
### If prefer hostname over ip for Nacos server addresses in cluster.conf:
# nacos.inetutils.prefer-hostname-over-ip=false
### Specify local server's IP:
# nacos.inetutils.ip-address=
#*************** Config Module Related Configurations ***************#
### If use MySQL as datasource:
### Deprecated configuration property, it is recommended to use `spring.sql.init.platform` replaced.
spring.datasource.platform=mysql
# spring.sql.init.platform=mysql
### Count of DB:
db.num=1
### Connect URL of DB:
db.url.0=jdbc:mysql://127.0.0.1:3306/nacos?characterEncoding=utf8&connectTimeout=1000&socketTimeout=3000&autoReconnect=true&useUnicode=true&useSSL=false&serverTimezone=UTC
db.user.0=xxxxx
db.password.0=xxxxx
### Connection pool configuration: hikariCP
db.pool.config.connectionTimeout=30000
db.pool.config.validationTimeout=10000
db.pool.config.maximumPoolSize=20
db.pool.config.minimumIdle=2
#*************** Naming Module Related Configurations ***************#
### If enable data warmup. If set to false, the server would accept request without local data preparation:
# nacos.naming.data.warmup=true
### If enable the instance auto expiration, kind like of health check of instance:
# nacos.naming.expireInstance=true
nacos.naming.empty-service.auto-clean=true
nacos.naming.empty-service.clean.initial-delay-ms=50000
nacos.naming.empty-service.clean.period-time-ms=30000
### Add in 2.0.0
### The interval to clean empty service, unit: milliseconds.
# nacos.naming.clean.empty-service.interval=60000
### The expired time to clean empty service, unit: milliseconds.
# nacos.naming.clean.empty-service.expired-time=60000
### The interval to clean expired metadata, unit: milliseconds.
# nacos.naming.clean.expired-metadata.interval=5000
### The expired time to clean metadata, unit: milliseconds.
# nacos.naming.clean.expired-metadata.expired-time=60000
### The delay time before push task to execute from service changed, unit: milliseconds.
# nacos.naming.push.pushTaskDelay=500
### The timeout for push task execute, unit: milliseconds.
# nacos.naming.push.pushTaskTimeout=5000
### The delay time for retrying failed push task, unit: milliseconds.
# nacos.naming.push.pushTaskRetryDelay=1000
### Since 2.0.3
### The expired time for inactive client, unit: milliseconds.
# nacos.naming.client.expired.time=180000
#*************** CMDB Module Related Configurations ***************#
### The interval to dump external CMDB in seconds:
# nacos.cmdb.dumpTaskInterval=3600
### The interval of polling data change event in seconds:
# nacos.cmdb.eventTaskInterval=10
### The interval of loading labels in seconds:
# nacos.cmdb.labelTaskInterval=300
### If turn on data loading task:
# nacos.cmdb.loadDataAtStart=false
#*************** Metrics Related Configurations ***************#
### Metrics for prometheus
#management.endpoints.web.exposure.include=*
### Metrics for elastic search
management.metrics.export.elastic.enabled=false
#management.metrics.export.elastic.host=http://localhost:9200
### Metrics for influx
management.metrics.export.influx.enabled=false
#management.metrics.export.influx.db=springboot
#management.metrics.export.influx.uri=http://localhost:8086
#management.metrics.export.influx.auto-create-db=true
#management.metrics.export.influx.consistency=one
#management.metrics.export.influx.compressed=true
#*************** Access Log Related Configurations ***************#
### If turn on the access log:
server.tomcat.accesslog.enabled=true
### The access log pattern:
server.tomcat.accesslog.pattern=%h %l %u %t "%r" %s %b %D %{User-Agent}i %{Request-Source}i
### The directory of access log:
server.tomcat.basedir=file:.
#*************** Access Control Related Configurations ***************#
### If enable spring security, this option is deprecated in 1.2.0:
#spring.security.enabled=false
### The ignore urls of auth
nacos.security.ignore.urls=/,/error,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*.png,/**/*.ico,/console-ui/public/**,/v1/auth/**,/v1/console/health/**,/actuator/**,/v1/console/server/**
### The auth system to use, currently only 'nacos' and 'ldap' is supported:
nacos.core.auth.system.type=nacos
### If turn on auth system:
nacos.core.auth.enabled=false
### Turn on/off caching of auth information. By turning on this switch, the update of auth information would have a 15 seconds delay.
nacos.core.auth.caching.enabled=true
### Since 1.4.1, Turn on/off white auth for user-agent: nacos-server, only for upgrade from old version.
#nacos.core.auth.enable.userAgentAuthWhite=false
nacos.core.auth.enable.userAgentAuthWhite=true
### Since 1.4.1, worked when nacos.core.auth.enabled=true and nacos.core.auth.enable.userAgentAuthWhite=false.
### The two properties is the white list for auth and used by identity the request from other server.
nacos.core.auth.server.identity.key=
nacos.core.auth.server.identity.value=
### worked when nacos.core.auth.system.type=nacos
### The token expiration in seconds:
nacos.core.auth.plugin.nacos.token.cache.enable=false
nacos.core.auth.plugin.nacos.token.expire.seconds=18000
### The default token (Base64 String):
nacos.core.auth.plugin.nacos.token.secret.key=SecretKey012345678901234567890123456789012345678901234567890123456789
### worked when nacos.core.auth.system.type=ldap，{0} is Placeholder,replace login username
#nacos.core.auth.ldap.url=ldap://localhost:389
#nacos.core.auth.ldap.basedc=dc=example,dc=org
#nacos.core.auth.ldap.userDn=cn=admin,${nacos.core.auth.ldap.basedc}
#nacos.core.auth.ldap.password=admin
#nacos.core.auth.ldap.userdn=cn={0},dc=example,dc=org
#nacos.core.auth.ldap.filter.prefix=uid
#nacos.core.auth.ldap.case.sensitive=true
#*************** Istio Related Configurations ***************#
### If turn on the MCP server:
nacos.istio.mcp.server.enabled=false
#*************** Core Related Configurations ***************#
### set the WorkerID manually
# nacos.core.snowflake.worker-id=
### Member-MetaData
# nacos.core.member.meta.site=
# nacos.core.member.meta.adweight=
# nacos.core.member.meta.weight=
### MemberLookup
### Addressing pattern category, If set, the priority is highest
# nacos.core.member.lookup.type=[file,address-server]
## Set the cluster list with a configuration file or command-line argument
# nacos.member.list=192.168.16.101:8847?raft_port=8807,192.168.16.101?raft_port=8808,192.168.16.101:8849?raft_port=8809
## for AddressServerMemberLookup
# Maximum number of retries to query the address server upon initialization
# nacos.core.address-server.retry=5
## Server domain name address of [address-server] mode
#address.server.domain=jmenv.tbsite.net
## Server port of [address-server] mode
#address.server.port=8080
## Request address of [address-server] mode
#address.server.url=/nacos/serverlist
#*************** JRaft Related Configurations ***************#
### Sets the Raft cluster election timeout, default value is 5 second
# nacos.core.protocol.raft.data.election_timeout_ms=5000
### Sets the amount of time the Raft snapshot will execute periodically, default is 30 minute
# nacos.core.protocol.raft.data.snapshot_interval_secs=30
### raft internal worker threads
# nacos.core.protocol.raft.data.core_thread_num=8
### Number of threads required for raft business request processing
# nacos.core.protocol.raft.data.cli_service_thread_num=4
### raft linear read strategy. Safe linear reads are used by default, that is, the Leader tenure is confirmed by heartbeat
# nacos.core.protocol.raft.data.read_index_type=ReadOnlySafe
### rpc request timeout, default 5 seconds
# nacos.core.protocol.raft.data.rpc_request_timeout_ms=5000
#*************** Distro Related Configurations ***************#
### Distro data sync delay time, when sync task delayed, task will be merged for same data key. Default 1 second.
# nacos.core.protocol.distro.data.sync.delayMs=1000
### Distro data sync timeout for one sync data, default 3 seconds.
# nacos.core.protocol.distro.data.sync.timeoutMs=3000
### Distro data sync retry delay time when sync data failed or timeout, same behavior with delayMs, default 3 seconds.
# nacos.core.protocol.distro.data.sync.retryDelayMs=3000
### Distro data verify interval time, verify synced data whether expired for a interval. Default 5 seconds.
# nacos.core.protocol.distro.data.verify.intervalMs=5000
### Distro data verify timeout for one verify, default 3 seconds.
# nacos.core.protocol.distro.data.verify.timeoutMs=3000
### Distro data load retry delay when load snapshot data failed, default 30 seconds.
# nacos.core.protocol.distro.data.load.retryDelayMs=30000
### enable to support prometheus service discovery
#nacos.prometheus.metrics.enabled=true
### Since 2.3
#*************** Grpc Configurations ***************#
## sdk grpc(between nacos server and client) configuration
## Sets the maximum message size allowed to be received on the server.
#nacos.remote.server.grpc.sdk.max-inbound-message-size=10485760
## Sets the time(milliseconds) without read activity before sending a keepalive ping. The typical default is two hours.
#nacos.remote.server.grpc.sdk.keep-alive-time=7200000
## Sets a time(milliseconds) waiting for read activity after sending a keepalive ping. Defaults to 20 seconds.
#nacos.remote.server.grpc.sdk.keep-alive-timeout=20000
## Sets a time(milliseconds) that specify the most aggressive keep-alive time clients are permitted to configure. The typical default is 5 minutes
#nacos.remote.server.grpc.sdk.permit-keep-alive-time=300000
## cluster grpc(inside the nacos server) configuration
#nacos.remote.server.grpc.cluster.max-inbound-message-size=10485760
## Sets the time(milliseconds) without read activity before sending a keepalive ping. The typical default is two hours.
#nacos.remote.server.grpc.cluster.keep-alive-time=7200000
## Sets a time(milliseconds) waiting for read activity after sending a keepalive ping. Defaults to 20 seconds.
#nacos.remote.server.grpc.cluster.keep-alive-timeout=20000
## Sets a time(milliseconds) that specify the most aggressive keep-alive time clients are permitted to configure. The typical default is 5 minutes
#nacos.remote.server.grpc.cluster.permit-keep-alive-time=300000
四、数据库表字段添加
 
nacos 报错 Unknown column ‘encrypted_data_key’ in ‘field list’
 看提示是数据表缺少encrypted_data_key字段，那就手动为据表添加该字段
 为保证用户敏感配置数据的安全，Nacos 提供了配置加密的新特性。降低了用户使用的风险，也不需要再对配置进行单独的加密处理。
 数据库表 config_info、config_info_beta、his_config_info中需要新增字段 encrypted_data_key ，用来存储每一个配置项加密使用的秘钥。新版本的默认创建表的sql中已经添加该字段。
 
ALTER TABLE config_info ADD COLUMN `encrypted_data_key` text NOT NULL COMMENT '秘钥';
ALTER TABLE his_config_info ADD COLUMN `encrypted_data_key` text NOT NULL COMMENT '秘钥';
ALTER TABLE config_info_beta ADD COLUMN `encrypted_data_key` text NOT NULL COMMENT '秘钥';
五、启动Nacos2.x
 
进入Nacos目录下nacos/bin/startup.sh 进行启动
 命令：sh startup.sh 默认是集群模式下的启动
 如果是单机版使用命令：sh startup.sh -m standalone
 否则会有会有异常：
 
				
Nacos 2.X 版本迎来了首秀，在 1.X 的架构基础上 新增了对长连接模型的支持。通信层目前通过 grpc 实现了长连接 RPC 调用和推送能力，使用长链接的好处大幅度减少了 1.x 轮询心跳频繁导致 JVM Full GC。
nacos 1
1.X架构存在的问题:心跳多，无效查询多，心跳续约感知变化慢，连接消耗大，资源空耗严重。
心跳数量多，导致 TPS 居高不下
通过心跳续约，当服务规模上升时，特别是类似 Dubbo 的接口级服务较多时，心跳及配置元数据的轮询数量众多，导致集群 TPS 很高，系统
				
1. 升级生产环境时是从 rc 环境上把运行中的 Nacos server 直接复制到生产环境用于升级，而复制过去的目录包含了 rc 环境的缓存数据，会影响 Nacos server 的正常工作。
2. 生产环境各个业务服务使用的 Nacos 客户端版本没有统一管控，有的版本比服务端高。而高版本的客户端在 server 端升级上去后，被开启了一些高版本的功能。回滚回低版本的 server 端时，这些高版本的功能低版本的 server 端无法兼容，导致回滚后无法自动注册，需要重启业务服务才能注册。
				
Nacos 2.x 的源码是开源的，可以从 Nacos 的官方 GitHub 仓库中获取：https://github.com/alibaba/nacos。
Nacos 2.x 的代码结构比较清晰，主要分为以下几个模块：
1. `nacos-api`: Nacos 的 Java API 接口定义；
2. `nacos-common`: Nacos 的通用工具类和配置项定义；
3. `nacos-config`: Nacos 的配置管理模块，包括配置的读写、监听和推送等功能；
4. `nacos-core`: Nacos 的核心模块，包括服务注册和发现、健康检查、集群管理等功能；
5. `nacos-discovery`: Nacos 的服务发现模块，包括服务注册和发现的 API、服务实例的管理和心跳检测等功能；
6. `nacos-naming`: Nacos 的命名服务模块，包括服务的命名、分组和标签等功能；
7. `nacos-server`: Nacos 的服务端实现，包括 Nacos 的启动和配置、日志输出、插件管理等功能；
8. `nacos-standalone`: Nacos 的单机模式启动脚本和配置文件；
9. `nacos-upgrade`: Nacos 的升级脚本和工具。
如果您想深入了解 Nacos 2.x 的实现原理，可以从 `nacos-server` 模块的入口类 `com.alibaba.nacos.Nacos` 开始阅读源码，并结合其他模块的实现逐步深入理解。
在阅读源码的过程中，需要注意 Nacos 的模块之间的相互依赖关系和调用关系，以及各个模块的核心功能实现方式和细节问题。同时，还需要结合 Nacos 的文档和官方社区的讨论，以便更好地理解和使用 Nacos。