SpringCloudAlibaba-分布式事务-Seata

一、概述

Seata(Simple Extensible Autonomous Transaction Architecture 简单的可扩展自治事务架构) 是 阿里巴巴开源的分布式事务中间件，致力于提供高性能，零入侵和简单易用的分布式事务服务。Seata 将为用户提供了 AT、TCC、SAGA 和 XA 事务模式，为用户打造一站式的分布式解决方案。

Seata 的设计思路是将一个分布式事务可以理解成一个全局事务，下面挂了若干个分支事务，而一个分支事务是一个满足 ACID 的本地事务，因此我们可以操作分布式事务像操作本地事务一样。

二、Seata相关术语

一.TC (Transaction Coordinator) - 事务协调者

维护全局和分支事务的状态，驱动全局事务提交或回滚。

二.TM (Transaction Manager) - 事务管理器

定义全局事务的范围：开始全局事务、提交或回滚全局事务。

三.RM (Resource Manager) - 资源管理器

管理分支事务处理的资源，与TC交谈以注册分支事务和报告分支事务的状态，并驱动分支事务提交或回滚。

四.Transcation ID（XID）

由事务协调者创建的全局唯一的事务ID

三、Seata 工作流程

一.AT 模式工作机制(默认模式，二阶段提交,DB中实现)

两阶段提交协议的演变：

• 一阶段：业务数据和回滚日志记录在同一个本地事务中提交，释放本地锁和连接资源。
• 二阶段：
  提交异步化，非常快速地完成。
  回滚通过一阶段的回滚日志进行反向补偿。

1、一阶段（拦截SQL，解析数据，保存原数据快照与更新后快照）

拦截业务SQL，根据业务SQL解析出需要修改或者提交的表的原数据，统一放入before image的快照当中。然后更新业务数据，将更新后的数据放入after image当中。此事会进行行锁，避免其他数据进行脏读。

2、二阶段

1.事务成功

因为业务SQL已经更新过了，只需要将第一阶段保存的快照数据删掉，解锁行锁即可。

2.事务回滚

事务回滚操作就比较复杂了，分为三步。

(1).校验脏读

比较after image中的数据和数据库数据，如果两份数据完全一致，则说明没有进行脏写。

(2).还原数据

将before image 中的数据你想SQL进行数据还原

(3).删除中间数据

删除before image和after image中的数据，并且解锁。

二.TCC 模式（二阶段提交，需要用户自己去实现）

TCC模式需要用户根据自己的业务实现Try，Confirm，Cancel三个操作。TCC模式侵入式比较强，AT模式无侵入，但是AT模式会有行锁，效率较差。
TCC 模型的隔离性思想就是通过业务的改造，在第一阶段结束之后，从底层数据库资源层面的加锁过渡为上层业务层面的加锁，从而释放底层数据库锁资源，放宽分布式事务锁协议，将锁的粒度降到最低，以最大限度提高业务并发性能。

1、try

预留资源

2、confirm

完成业务

3、concel

发生回滚，释放Try阶段预留的资源

三.Saga 模式

之后再补充

四、Seata配置文件

一.file.conf（持久化配置文件,db）

其他的我就删掉了

如果配置方式选择的是nacos,那么这个文件可以选择不修改。

## transaction log store, only used in seata-server 事务日志存储，仅用于 seata-server
store {
  ## store mode: file、db、redis
  mode = "db" #事务日志存储模式文件、数据库、redis
  ## rsa decryption public key
  publicKey = ""

  ## database store property
  db {
    ## the implement of javax.sql.DataSource, such as DruidDataSource(druid)/BasicDataSource(dbcp)/HikariDataSource(hikari) etc.
    datasource = "druid" #数据库连接池选择
    ## mysql/oracle/postgresql/h2/oceanbase etc.
    dbType = "mysql" #数据库选择
    ##driverClassName = "com.mysql.jdbc.Driver" #5.0版本SQL驱动
	driverClassName = "com.mysql.cj.jdbc.Driver" ##8.0版本SQL驱动
    ## if using mysql to store the data, recommend add rewriteBatchedStatements=true in jdbc connection param
    ## url = "jdbc:mysql://139.155.49.250:3306/seata?rewriteBatchedStatements=true" ##5.0版本url
	url = "jdbc:mysql://127.0.0.1:3306/seata?useSSL=false&&serverTimezone=GMT%2B8&useInformationSchema=true" ##8.0版本url
    user = "root"
    password = "xxxxxxx"
    minConn = 5
    maxConn = 100
    globalTable = "global_table" ##三张表名
    branchTable = "branch_table"
    lockTable = "lock_table"
    queryLimit = 100
    maxWait = 5000
  }
}

二.registry.conf（注册中心配置文件，nacos）

registry {
  # file 、nacos 、eureka、redis、zk、consul、etcd3、sofa
  type = "nacos" ##注册中心支持的模式
  nacos {
    application = "seata-server" ##服务名称
    serverAddr = "119.91.99.85:8849"  ##注册中心IP
    group = "SEATA_GROUP" ##分组
    namespace = "seata" ## 命名空间
    cluster = "default" ##是否集群
    username = "nacos" ##nacos账务密码
    password = "nacos"
  }
}
## 配置中心
config {
  # file、nacos 、apollo、zk、consul、etcd3
  type = "nacos"#默认是去读取file.conf中的信息

  nacos {
    serverAddr = "119.91.99.85:8849"
    namespace = "seata"
    group = "SEATA_GROUP"
    username = "nacos"
    password = "nacos"
    dataId = "seataServer.properties"
  }
 # file {
 #   name = "file.conf"
 # }
}

三.config.txt

注册中心的配置文件，需要用脚本把这些配置文件全部上传上去。

1、下载脚本

地址

https://github.com/seata/seata/blob/develop/script/config-center/nacos/nacos-config.sh

脚本

#!/bin/sh
# 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.

while getopts ":h:p:g:t:u:w:" opt
do
  case $opt in
  h)
    host=$OPTARG
    ;;
  p)
    port=$OPTARG
    ;;
  g)
    group=$OPTARG
    ;;
  t)
    tenant=$OPTARG
    ;;
  u)
    username=$OPTARG
    ;;
  w)
    password=$OPTARG
    ;;
  ?)
    echo " USAGE OPTION: $0 [-h host] [-p port] [-g group] [-t tenant] [-u username] [-w password] "
    exit 1
    ;;
  esac
done

if [ -z ${host} ]; then
    host=localhost
fi
if [ -z ${port} ]; then
    port=8848
fi
if [ -z ${group} ]; then
    group="SEATA_GROUP"
fi
if [ -z ${tenant} ]; then
    tenant=""
fi
if [ -z ${username} ]; then
    username=""
fi
if [ -z ${password} ]; then
    password=""
fi

nacosAddr=$host:$port
contentType="content-type:application/json;charset=UTF-8"

echo "set nacosAddr=$nacosAddr"
echo "set group=$group"

urlencode() {
  length="${#1}"
  i=0
  while [ $length -gt $i ]; do
    char="${1:$i:1}"
    case $char in
    [a-zA-Z0-9.~_-]) printf $char ;;
    *) printf '%%%02X' "'$char" ;;
    esac
    i=`expr $i + 1`
  done
}

failCount=0
tempLog=$(mktemp -u)
function addConfig() {
  dataId=`urlencode $1`
  content=`urlencode $2`
  curl -X POST -H "${contentType}" "http://$nacosAddr/nacos/v1/cs/configs?dataId=$dataId&group=$group&content=$content&tenant=$tenant&username=$username&password=$password" >"${tempLog}" 2>/dev/null
  if [ -z $(cat "${tempLog}") ]; then
    echo " Please check the cluster status. "
    exit 1
  fi
  if [ "$(cat "${tempLog}")" == "true" ]; then
    echo "Set $1=$2 successfully "
  else
    echo "Set $1=$2 failure "
    failCount=`expr $failCount + 1`
  fi
}

count=0
for line in $(cat $(dirname "$PWD")/config.txt | sed s/[[:space:]]//g); do
    count=`expr $count + 1`
	key=${line%%=*}
    value=${line#*=}
	addConfig "${key}" "${value}"
done

echo "========================================================================="
echo " Complete initialization parameters,  total-count:$count ,  failure-count:$failCount "
echo "========================================================================="

if [ ${failCount} -eq 0 ]; then
	echo " Init nacos config finished, please start seata-server. "
else
	echo " init nacos config fail. "
fi

2、执行脚本

sh nacos-config.sh -h ip -t namespace

执行脚本要注意，需要把下载的脚本放到配置文件的下级目录里再去执行。

官网给的配置文件里面有一些参数是空的，如果你不给那些参数填值，执行脚本会报错的，如果用不上那个参数，报错就报错吧。

3、配置文件

## Netty配置
transport.type=TCP
transport.server=NIO
transport.heartbeat=true
transport.enableClientBatchSendRequest=true
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
## service
service.vgroupMapping.my_test_tx_group=default
service.default.grouplist=127.0.0.1:8091
service.enableDegrade=false
service.disableGlobalTransaction=false
client.rm.asyncCommitBufferLimit=10000
client.rm.lock.retryInterval=10
client.rm.lock.retryTimes=30
client.rm.lock.retryPolicyBranchRollbackOnConflict=true
client.rm.reportRetryCount=5
client.rm.tableMetaCheckEnable=false
client.rm.tableMetaCheckerInterval=60000
client.rm.sqlParserType=druid
client.rm.reportSuccessEnable=false
client.rm.sagaBranchRegisterEnable=false
client.rm.sagaJsonParser=fastjson
client.rm.tccActionInterceptorOrder=-2147482648
client.tm.commitRetryCount=5
client.tm.rollbackRetryCount=5
client.tm.defaultGlobalTransactionTimeout=60000
client.tm.degradeCheck=false
client.tm.degradeCheckAllowTimes=10
client.tm.degradeCheckPeriod=2000
client.tm.interceptorOrder=-2147482648
## store
store.mode=db
store.lock.mode=file
store.session.mode=file
store.publicKey=
store.file.dir=file_store/data
store.file.maxBranchSessionSize=16384
store.file.maxGlobalSessionSize=512
store.file.fileWriteBufferCacheSize=16384
store.file.flushDiskMode=async
store.file.sessionReloadReadSize=100
store.db.datasource=druid
store.db.dbType=mysql
store.db.driverClassName=com.mysql.jdbc.Driver
store.db.url=jdbc:mysql://139.155.49.250:3306/seata?useSSL=false&&serverTimezone=GMT%2B8&useInformationSchema=true
store.db.user=username
store.db.password=password
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
store.redis.mode=single
store.redis.single.host=127.0.0.1
store.redis.single.port=6379
store.redis.sentinel.masterName=
store.redis.sentinel.sentinelHosts=
store.redis.maxConn=10
store.redis.minConn=1
store.redis.maxTotal=100
store.redis.database=0
store.redis.password=
store.redis.queryLimit=100
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
client.undo.dataValidation=true
client.undo.logSerialization=jackson
client.undo.onlyCareUpdateColumns=true
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
log.exceptionRate=100
transport.serialization=seata
transport.compressor=none
metrics.enabled=false
metrics.registryType=compact
metrics.exporterList=prometheus
metrics.exporterPrometheusPort=9898
tcc.fence.logTableName=tcc_fence_log
tcc.fence.cleanPeriod=1h

三.服务端SQL脚本（1.4.2版本）

源链接

https://github.com/seata/seata/tree/develop/script/server

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_gmt_modified_status` (`gmt_modified`, `status`),
    KEY `idx_transaction_id` (`transaction_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

-- 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 = utf8;

-- 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),
    `gmt_create`     DATETIME,
    `gmt_modified`   DATETIME,
    PRIMARY KEY (`row_key`),
    KEY `idx_branch_id` (`branch_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

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);

四.客户端SQL脚本（1.4.2版本）

客户端SQL脚本根据不同的模式有不同的SQL脚本

https://github.com/seata/seata/tree/develop/script/client

1、AT模式

-- for AT mode you must to init this sql for you business database. the seata server not need it.
CREATE TABLE IF NOT EXISTS `undo_log`
(
    `branch_id`     BIGINT       NOT NULL COMMENT 'branch transaction id',
    `xid`           VARCHAR(128) NOT NULL COMMENT 'global transaction id',
    `context`       VARCHAR(128) NOT NULL COMMENT 'undo_log context,such as serialization',
    `rollback_info` LONGBLOB     NOT NULL COMMENT 'rollback info',
    `log_status`    INT(11)      NOT NULL COMMENT '0:normal status,1:defense status',
    `log_created`   DATETIME(6)  NOT NULL COMMENT 'create datetime',
    `log_modified`  DATETIME(6)  NOT NULL COMMENT 'modify datetime',
    UNIQUE KEY `ux_undo_log` (`xid`, `branch_id`)
) ENGINE = InnoDB
  AUTO_INCREMENT = 1
  DEFAULT CHARSET = utf8 COMMENT ='AT transaction mode undo table';

2、TCC模式

-- -------------------------------- The script use tcc fence  --------------------------------
CREATE TABLE IF NOT EXISTS `tcc_fence_log`
(
    `xid`           VARCHAR(128)  NOT NULL COMMENT 'global id',
    `branch_id`     BIGINT        NOT NULL COMMENT 'branch id',
    `action_name`   VARCHAR(64)   NOT NULL COMMENT 'action name',
    `status`        TINYINT       NOT NULL COMMENT 'status(tried:1;committed:2;rollbacked:3;suspended:4)',
    `gmt_create`    DATETIME(3)   NOT NULL COMMENT 'create time',
    `gmt_modified`  DATETIME(3)   NOT NULL COMMENT 'update time',
    PRIMARY KEY (`xid`, `branch_id`),
    KEY `idx_gmt_modified` (`gmt_modified`),
    KEY `idx_status` (`status`)
) ENGINE = InnoDB
DEFAULT CHARSET = utf8;

3、SAGA模式

-- -------------------------------- The script used for sage  --------------------------------


CREATE TABLE IF NOT EXISTS `seata_state_machine_def`
(
    `id`               VARCHAR(32)  NOT NULL COMMENT 'id',
    `name`             VARCHAR(128) NOT NULL COMMENT 'name',
    `tenant_id`        VARCHAR(32)  NOT NULL COMMENT 'tenant id',
    `app_name`         VARCHAR(32)  NOT NULL COMMENT 'application name',
    `type`             VARCHAR(20)  COMMENT 'state language type',
    `comment_`         VARCHAR(255) COMMENT 'comment',
    `ver`              VARCHAR(16)  NOT NULL COMMENT 'version',
    `gmt_create`       DATETIME(3)  NOT NULL COMMENT 'create time',
    `status`           VARCHAR(2)   NOT NULL COMMENT 'status(AC:active|IN:inactive)',
    `content`          TEXT COMMENT 'content',
    `recover_strategy` VARCHAR(16) COMMENT 'transaction recover strategy(compensate|retry)',
    PRIMARY KEY (`id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

CREATE TABLE IF NOT EXISTS `seata_state_machine_inst`
(
    `id`                  VARCHAR(128)            NOT NULL COMMENT 'id',
    `machine_id`          VARCHAR(32)             NOT NULL COMMENT 'state machine definition id',
    `tenant_id`           VARCHAR(32)             NOT NULL COMMENT 'tenant id',
    `parent_id`           VARCHAR(128) COMMENT 'parent id',
    `gmt_started`         DATETIME(3)             NOT NULL COMMENT 'start time',
    `business_key`        VARCHAR(48) COMMENT 'business key',
    `start_params`        TEXT COMMENT 'start parameters',
    `gmt_end`             DATETIME(3) COMMENT 'end time',
    `excep`               BLOB COMMENT 'exception',
    `end_params`          TEXT COMMENT 'end parameters',
    `status`              VARCHAR(2) COMMENT 'status(SU succeed|FA failed|UN unknown|SK skipped|RU running)',
    `compensation_status` VARCHAR(2) COMMENT 'compensation status(SU succeed|FA failed|UN unknown|SK skipped|RU running)',
    `is_running`          TINYINT(1) COMMENT 'is running(0 no|1 yes)',
    `gmt_updated`         DATETIME(3) NOT NULL,
    PRIMARY KEY (`id`),
    UNIQUE KEY `unikey_buz_tenant` (`business_key`, `tenant_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

CREATE TABLE IF NOT EXISTS `seata_state_inst`
(
    `id`                       VARCHAR(48)  NOT NULL COMMENT 'id',
    `machine_inst_id`          VARCHAR(128) NOT NULL COMMENT 'state machine instance id',
    `name`                     VARCHAR(128) NOT NULL COMMENT 'state name',
    `type`                     VARCHAR(20)  COMMENT 'state type',
    `service_name`             VARCHAR(128) COMMENT 'service name',
    `service_method`           VARCHAR(128) COMMENT 'method name',
    `service_type`             VARCHAR(16) COMMENT 'service type',
    `business_key`             VARCHAR(48) COMMENT 'business key',
    `state_id_compensated_for` VARCHAR(50) COMMENT 'state compensated for',
    `state_id_retried_for`     VARCHAR(50) COMMENT 'state retried for',
    `gmt_started`              DATETIME(3)  NOT NULL COMMENT 'start time',
    `is_for_update`            TINYINT(1) COMMENT 'is service for update',
    `input_params`             TEXT COMMENT 'input parameters',
    `output_params`            TEXT COMMENT 'output parameters',
    `status`                   VARCHAR(2)   NOT NULL COMMENT 'status(SU succeed|FA failed|UN unknown|SK skipped|RU running)',
    `excep`                    BLOB COMMENT 'exception',
    `gmt_updated`              DATETIME(3) COMMENT 'update time',
    `gmt_end`                  DATETIME(3) COMMENT 'end time',
    PRIMARY KEY (`id`, `machine_inst_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8;

五、案例（AT模式，配置中心Nacos，注册中心Nacos）

六、案例（TCC模式，配置中心Nacos，注册中心Nacos）