springcloud第4季分布式事务seata作用服务搭建1

一 seata作用

1.1 seata简介

1.seata是一款解决分布式事务的解决方案，致力于在微服务架构下提供高性能和简单易用的分布式事务服务。

1.2 seata的术语

一个中心：全局事务id，xid，在调用服务链路的上下文中进行传播。TC(Transaction Coordinator):事务协调者。其中seata服务器就是TC角色,负责维护全局和分支事务的状态，驱动全局事务的提交或回滚。TC只有1个；

TM(Transaction Manager):事务管理者。标注了@GlobalTransaction注解的微服务模块（如订单模块）；它是事物的发起者，负责定义事务的全局范围，根据TC维护全局事务和分支事务的状态，做出开启事务，提交事务，回滚事物的决议。TM只有1个

RM(Resource Manager): 资源管理器。Mysql数据库本身就是，负责管理分支事务的资源，向TC注册分支事务，汇报分支事务的状态，驱动分支事务的提交或者回滚。可以多个RM。

Tc以seata服务器形式独立部署。TM,RM是以seata client的形式集成在微服务中运行。

1.3 seata的工作流程

1.简述版

1.TM向TC申请开启一个全局事务，全局事务创建成功并生成一个全局唯一的xid。

2.xid在微服务调用链路的上下文张工传播

3.RM向TC注册分支事务，将其纳入到xid对应的全局事务的管辖范围

4.TM向TC发起针对xid的全局提交或回滚决议。

5.TC调度xid管辖的全部分支事务，完成提交或回滚请求。

2.详情版：

1.服务A中的TM向TC申请开启一个全局事务，TC就会创建一个全局事务并返回一个唯一的XID。

2.服务A中的RM向TC注册分支事务，然后将这个分支事务纳入XID对应的全局事务管辖中。

3.服务A开始执行分支事务。

4.服务A开始远程调用B服务，此时XID会根据调用链传播

5.服务B中的RM也向TC注册分支事务，然后将这个分支事务纳入XID对应的全局事务管辖中。

6.服务B开始执行分支事务。

7.全局事务调用处理结束后，TM会根据有无异常情况，向TC发起全局事务的提交或回滚。

8.TC协调其管辖之下的所有分支事务，决定是提交还是回滚。

二 seata服务端搭建

2.1 seata搭建

2.2.1 seata 服务端下载安装

下载地址： Seata-Server下载 | Apache Seata

截图如下：

2.2.2 使用mysql初始化seata所需表

1.下载脚本地址：

incubator-seata/script/server/db/mysql.sql at 2.x · apache/incubator-seata · GitHub

2.脚本内容

--
-- Licensed to the Apache Software Foundation (ASF) under one or more
-- contributor license agreements.  See the NOTICE file distributed with
-- this work for additional information regarding copyright ownership.
-- The ASF licenses this file to You 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.
--

-- -------------------------------- The script used when storeMode is 'db' --------------------------------
-- the table to store GlobalSession data
CREATE TABLE IF NOT EXISTS `global_table`
(
    `xid`                       VARCHAR(128) NOT NULL,
    `transaction_id`            BIGINT,
    `status`                    TINYINT      NOT NULL,
    `application_id`            VARCHAR(32),
    `transaction_service_group` VARCHAR(32),
    `transaction_name`          VARCHAR(128),
    `timeout`                   INT,
    `begin_time`                BIGINT,
    `application_data`          VARCHAR(2000),
    `gmt_create`                DATETIME,
    `gmt_modified`              DATETIME,
    PRIMARY KEY (`xid`),
    KEY `idx_status_gmt_modified` (`status` , `gmt_modified`),
    KEY `idx_transaction_id` (`transaction_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4;

-- the table to store BranchSession data
CREATE TABLE IF NOT EXISTS `branch_table`
(
    `branch_id`         BIGINT       NOT NULL,
    `xid`               VARCHAR(128) NOT NULL,
    `transaction_id`    BIGINT,
    `resource_group_id` VARCHAR(32),
    `resource_id`       VARCHAR(256),
    `branch_type`       VARCHAR(8),
    `status`            TINYINT,
    `client_id`         VARCHAR(64),
    `application_data`  VARCHAR(2000),
    `gmt_create`        DATETIME(6),
    `gmt_modified`      DATETIME(6),
    PRIMARY KEY (`branch_id`),
    KEY `idx_xid` (`xid`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4;

-- the table to store lock data
CREATE TABLE IF NOT EXISTS `lock_table`
(
    `row_key`        VARCHAR(128) NOT NULL,
    `xid`            VARCHAR(128),
    `transaction_id` BIGINT,
    `branch_id`      BIGINT       NOT NULL,
    `resource_id`    VARCHAR(256),
    `table_name`     VARCHAR(32),
    `pk`             VARCHAR(36),
    `status`         TINYINT      NOT NULL DEFAULT '0' COMMENT '0:locked ,1:rollbacking',
    `gmt_create`     DATETIME,
    `gmt_modified`   DATETIME,
    PRIMARY KEY (`row_key`),
    KEY `idx_status` (`status`),
    KEY `idx_branch_id` (`branch_id`),
    KEY `idx_xid` (`xid`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4;

CREATE TABLE IF NOT EXISTS `distributed_lock`
(
    `lock_key`       CHAR(20) NOT NULL,
    `lock_value`     VARCHAR(20) NOT NULL,
    `expire`         BIGINT,
    primary key (`lock_key`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4;

INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('AsyncCommitting', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('RetryCommitting', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('RetryRollbacking', ' ', 0);
INSERT INTO `distributed_lock` (lock_key, lock_value, expire) VALUES ('TxTimeoutCheck', ' ', 0);

3.附加mysql数据库

2.2.3 nacos的信息配置

1.创建namespace

2.创建dataid，groupid

3.具体seata-server.properties的内容

# socket通信方式, 公共部分
transport.type=TCP
transport.server=NIO
transport.heartbeat=true
transport.enableTmClientBatchSendRequest=false
transport.enableRmClientBatchSendRequest=true
transport.enableTcServerBatchSendResponse=false
transport.rpcRmRequestTimeout=30000
transport.rpcTmRequestTimeout=30000
transport.rpcTcRequestTimeout=30000
transport.threadFactory.bossThreadPrefix=NettyBoss
transport.threadFactory.workerThreadPrefix=NettyServerNIOWorker
transport.threadFactory.serverExecutorThreadPrefix=NettyServerBizHandler
transport.threadFactory.shareBossWorker=false
transport.threadFactory.clientSelectorThreadPrefix=NettyClientSelector
transport.threadFactory.clientSelectorThreadSize=1
transport.threadFactory.clientWorkerThreadPrefix=NettyClientWorkerThread
transport.threadFactory.bossThreadSize=1
transport.threadFactory.workerThreadSize=default
transport.shutdown.wait=3
transport.serialization=seata
transport.compressor=none
# 首先应用程序（客户端）中配置了事务分组，若应用程序是SpringBoot则通过配置seata.tx-service-group=[事务分组配置项]
# 事务群组，service.vgroupMapping.[事务分组配置项]=TC集群的名称
service.vgroupMapping.default_tx_group=default
#If you use a registry, you can ignore it
service.default.grouplist=127.0.0.1:8091
service.enableDegrade=false
service.disableGlobalTransaction=false

# undo配置
server.undo.logSaveDays=7
server.undo.logDeletePeriod=86400000
client.undo.logTable=undo_log
client.undo.compress.enable=true
client.undo.compress.type=zip
client.undo.compress.threshold=64k

#For TCC transaction mode
tcc.fence.logTableName=tcc_fence_log
tcc.fence.cleanPeriod=1h
# You can choose from the following options: fastjson, jackson, gson
tcc.contextJsonParserType=fastjson
#Log rule configuration, for client and server
log.exceptionRate=100
#事务会话信息存储方式
store.mode=db
#事务锁信息存储方式
store.lock.mode=db
#事务回话信息存储方式
store.session.mode=db
#db或redis存储密码解密公钥
#store.publicKey=
#存储方式为db
## druid数据源
store.db.datasource=druid
store.db.dbType=mysql
store.db.driverClassName=com.mysql.jdbc.Driver
store.db.url=jdbc:mysql://127.0.0.1:3306/seata?useUnicode=true&rewriteBatchedStatements=true
store.db.user=root
store.db.password=cloudiip
store.db.minConn=5
store.db.maxConn=30
store.db.globalTable=global_table
store.db.branchTable=branch_table
store.db.distributedLockTable=distributed_lock
store.db.queryLimit=100
store.db.lockTable=lock_table
store.db.maxWait=5000
# 事务规则配置
server.recovery.committingRetryPeriod=1000
server.recovery.asynCommittingRetryPeriod=1000
server.recovery.rollbackingRetryPeriod=1000
server.recovery.timeoutRetryPeriod=1000
server.maxCommitRetryTimeout=-1
server.maxRollbackRetryTimeout=-1
server.rollbackRetryTimeoutUnlockEnable=false
server.distributedLockExpireTime=10000
server.session.branchAsyncQueueSize=5000
server.session.enableBranchAsyncRemove=false
server.enableParallelRequestHandle=true
server.enableParallelHandleBranch=false
server.raft.cluster=127.0.0.1:7091,127.0.0.1:7092,127.0.0.1:7093
server.raft.snapshotInterval=600
server.raft.applyBatch=32
server.raft.maxAppendBufferSize=262144
server.raft.maxReplicatorInflightMsgs=256
server.raft.disruptorBufferSize=16384
server.raft.electionTimeoutMs=2000
server.raft.reporterEnabled=false
server.raft.reporterInitialDelay=60
server.raft.serialization=jackson
server.raft.compressor=none
server.raft.sync=true
#Metrics配置
metrics.enabled=false
metrics.registryType=compact
metrics.exporterList=prometheus
metrics.exporterPrometheusPort=9898

2.2.4 seata 服务端进行配置

1.application的配置，打开config/application.yml文件，我们主要关注以下几个模块的配置。

1)server端配置中心指定，seata.config.type

2)server端注册中心指定，seata.registry.type

3)server端存储模式指定，seata.store.mode

修改config/application.yml文件，指定nacos为配置中心、注册中心，并将seata.store.mode屏蔽，后续中配置中心中进行配置。

详情代码：

#  Copyright 1999-2019 Seata.io Group.
#
#  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.
 
server:
  port: 7091
 
spring:
  application:
    name: seata-server-zdy
 
logging:
  config: classpath:logback-spring.xml
  file:
    path: ${log.home:${user.home}/logs/seata}
  extend:
    logstash-appender:
      destination: 127.0.0.1:4560
    kafka-appender:
      bootstrap-servers: 127.0.0.1:9092
      topic: logback_to_logstash
 
console:
  user:
    username: seata
    password: seata
 
 
seata:
  config:
    type: nacos
    nacos:
      server-addr: 127.0.0.1:8848
      namespace: c364e76c-e133-4bc0-951e-205cf732a19f
      group: LJF_GROUP #后续自己在nacos里面新建,不想新建SEATA_GROUP，就写DEFAULT_GROUP
      username: nacos
      password: nacos
      data-id: seata-server.properties
  registry:
    type: nacos
    nacos:
      application: seata-server-zdy
      server-addr: 127.0.0.1:8848
      group: LJF_GROUP #后续自己在nacos里面新建,不想新建SEATA_GROUP，就写DEFAULT_GROUP
      namespace: c364e76c-e133-4bc0-951e-205cf732a19f
      cluster: default
      username: nacos
      password: nacos    
  store:
    mode: db
    db:
      datasource: druid
      db-type: mysql
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://localhost:3306/seata?characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2B8&rewriteBatchedStatements=true&allowPublicKeyRetrieval=true
      user: root
      password: cloudiip
      min-conn: 10
      max-conn: 100
      global-table: global_table
      branch-table: branch_table
      lock-table: lock_table
      distributed-lock-table: distributed_lock
      query-limit: 1000
      max-wait: 5000
 
 
 
  #  server:
  #    service-port: 8091 #If not configured, the default is '${server.port} + 1000'
  security:
    secretKey: SeataSecretKey0c382ef121d778043159209298fd40bf3850a017
    tokenValidityInMilliseconds: 1800000
    ignore:
      urls: /,/**/*.css,/**/*.js,/**/*.html,/**/*.map,/**/*.svg,/**/*.png,/**/*.jpeg,/**/*.ico,/api/v1/auth/login,/metadata/v1/**