分布式事务之dtm

github: https://github.com/dtm-labs/dtm

本人使用场景, 目前微服务中存在的用户服务, 商品服务,订单服务, 支付服务, 在进行下单操作的时候,需要创建订单并扣减库存, 这个时候就需要保证事务的一致性, 但是对于目前的微服务架构来说就需要一套分布式的事务来实现,于是引入DTM

介绍:

　　他是一种跨语言的分布式事务管理器,无论你是php,python,golang还是java,nodejs等,都可以使用它来解决

使用场景:

• 缓存管理：彻底保证缓存最终一致及强一致
• 秒杀扣库存：极端情况下，也能保证Redis中精准的库存，和最终创建的订单完全一致，无需手动调整
• 非单体的订单系统： 大幅简化架构
• 事件发布/订阅：更好的发件箱模式

使用:

1)本地运行dtm

git clone https://github.com/dtm-labs/dtm && cd dtm
go run main.go
注:他是无需配置也可以运行起来,但是如果有定制需求的话, 可以将根目录下的conf.sample.yml文件改为conf.yml 启动的时候指定配置文件即可

go run .\main.go -c ./conf.yml

注: 在启动服务之前, 需要先执行sqls目录下的对应的存储引擎的相关sql,否则启动的时候会一直报表不存在的错误, 例如使用的是mysql, 则需要执行

CREATE DATABASE if not exists dtm_busi
/*!40100 DEFAULT CHARACTER SET utf8mb4 */
;
drop table if exists dtm_busi.user_account;
create table if not exists dtm_busi.user_account(
  id int(11) PRIMARY KEY AUTO_INCREMENT,
  user_id int(11) UNIQUE,
  balance DECIMAL(10, 2) not null default '0',
  trading_balance DECIMAL(10, 2) not null default '0',
  create_time datetime DEFAULT now(),
  update_time datetime DEFAULT now(),
  key(create_time),
  key(update_time)
) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4;
insert into dtm_busi.user_account (user_id, balance)
values (1, 10000),
  (2, 10000) on DUPLICATE KEY
UPDATE balance =
values (balance);

---------------------------------

create database if not exists dtm_barrier
/*!40100 DEFAULT CHARACTER SET utf8mb4 */
;
drop table if exists dtm_barrier.barrier;
create table if not exists dtm_barrier.barrier(
  id bigint(22) PRIMARY KEY AUTO_INCREMENT,
  trans_type varchar(45) default '',
  gid varchar(128) default '',
  branch_id varchar(128) default '',
  op varchar(45) default '',
  barrier_id varchar(45) default '',
  reason varchar(45) default '' comment 'the branch type who insert this record',
  create_time datetime DEFAULT now(),
  update_time datetime DEFAULT now(),
  key(create_time),
  key(update_time),
  UNIQUE key(gid, branch_id, op, barrier_id)
) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4;


-------------------------------------


CREATE DATABASE IF NOT EXISTS dtm
/*!40100 DEFAULT CHARACTER SET utf8mb4 */
;
drop table IF EXISTS dtm.trans_global;
CREATE TABLE if not EXISTS dtm.trans_global (
  `id` bigint(22) NOT NULL AUTO_INCREMENT,
  `gid` varchar(128) NOT NULL COMMENT 'global transaction id',
  `trans_type` varchar(45) not null COMMENT 'transaction type: saga | xa | tcc | msg',
  `status` varchar(12) NOT NULL COMMENT 'transaction status: prepared | submitted | aborting | succeed | failed',
  `query_prepared` varchar(1024) NOT NULL COMMENT 'url to check for msg|workflow',
  `protocol` varchar(45) not null comment 'protocol: http | grpc | json-rpc',
  `create_time` datetime DEFAULT NULL,
  `update_time` datetime DEFAULT NULL,
  `finish_time` datetime DEFAULT NULL,
  `rollback_time` datetime DEFAULT NULL,
  `options` varchar(1024) DEFAULT '' COMMENT 'options for transaction like: TimeoutToFail, RequestTimeout',
  `custom_data` varchar(1024) DEFAULT '' COMMENT 'custom data for transaction',
  `next_cron_interval` int(11) default null comment 'next cron interval. for use of cron job',
  `next_cron_time` datetime default null comment 'next time to process this trans. for use of cron job',
  `owner` varchar(128) not null default '' comment 'who is locking this trans',
  `ext_data` TEXT comment 'extra data for this trans. currently used in workflow pattern',
  `result` varchar(1024) DEFAULT '' COMMENT 'result for transaction',
  `rollback_reason` varchar(1024) DEFAULT '' COMMENT 'rollback reason for transaction',
  PRIMARY KEY (`id`),
  UNIQUE KEY `gid` (`gid`),
  key `owner`(`owner`),
  key `status_next_cron_time` (`status`, `next_cron_time`) comment 'cron job will use this index to query trans'
) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4;
drop table IF EXISTS dtm.trans_branch_op;
CREATE TABLE IF NOT EXISTS dtm.trans_branch_op (
  `id` bigint(22) NOT NULL AUTO_INCREMENT,
  `gid` varchar(128) NOT NULL COMMENT 'global transaction id',
  `url` varchar(1024) NOT NULL COMMENT 'the url of this op',
  `data` TEXT COMMENT 'request body, depreceated',
  `bin_data` BLOB COMMENT 'request body',
  `branch_id` VARCHAR(128) NOT NULL COMMENT 'transaction branch ID',
  `op` varchar(45) NOT NULL COMMENT 'transaction operation type like: action | compensate | try | confirm | cancel',
  `status` varchar(45) NOT NULL COMMENT 'transaction op status: prepared | succeed | failed',
  `finish_time` datetime DEFAULT NULL,
  `rollback_time` datetime DEFAULT NULL,
  `create_time` datetime DEFAULT NULL,
  `update_time` datetime DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `gid_uniq` (`gid`, `branch_id`, `op`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4;
drop table IF EXISTS dtm.kv;
CREATE TABLE IF NOT EXISTS dtm.kv (
  `id` bigint(22) NOT NULL AUTO_INCREMENT,
  `cat` varchar(45) NOT NULL COMMENT 'the category of this data',
  `k` varchar(128) NOT NULL,
  `v` TEXT,
  `version` bigint(22) default 1 COMMENT 'version of the value',
  create_time datetime default NULL,
  update_time datetime DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE key `uniq_k`(`cat`, `k`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4;

使用的配置参考:

#####################################################################
### dtm can be run without any config.
### all config in this file is optional. the default value is as specified in each line
### all configs can be specified from env. for example:
### MicroService.EndPoint => MICRO_SERVICE_END_POINT
#####################################################################

Store: # specify which engine to store trans status
  Driver: 'mysql'
  Host: 'localhost'
  User: 'root'
  Password: '123456'
  Port: 3306
  Db: 'dtm'

#   Driver: 'boltdb' # default store engine

#   Driver: 'redis'
#   Host: 'localhost'
#   User: ''
#   Password: ''
#   Port: 6379

#   Driver: 'postgres'
#   Host: 'localhost'
#   User: 'postgres'
#   Password: 'mysecretpassword'
#   Port: '5432'
#   Db: 'postgres'
#   Schema: 'public' # default value is 'public'

### following config is for only Driver postgres/mysql
  MaxOpenConns: 500
  MaxIdleConns: 500
  ConnMaxLifeTime: 5 # default value is 5 (minutes)

### flollowing config is only for some Driver
#   DataExpire: 604800 # Trans data will expire in 7 days. only for redis/boltdb.
#   FinishedDataExpire: 86400 # finished Trans data will expire in 1 days. only for redis.
#   RedisPrefix: '{a}' # default value is '{a}'. Redis storage prefix. store data to only one slot in cluster

MicroService: # gRPC/HTTP based microservice config
  Driver: 'dtm-driver-gozero' # name of the driver to handle register/discover
  Target: 'etcd://localhost:2379/dtmservice' # register dtm server to this url
  EndPoint: 'localhost:36790'

### the unit of following configurations is second
TransCronInterval: 3 # the interval to poll unfinished global transaction for every dtm process
TimeoutToFail: 35 # timeout for XA, TCC to fail. saga's timeout default to infinite, which can be overwritten in saga options
RetryInterval: 10 # the subtrans branch will be retried after this interval
RequestTimeout: 3 # the timeout of HTTP/gRPC request in dtm

LogLevel: 'debug'              # default: info. can be debug|info|warn|error
Log:
   Outputs: 'stderr'           # default: stderr, split by ",", you can append files to Outputs if need. example:'stderr,/tmp/test.log'
   RotationEnable: 0           # default: 0
   RotationConfigJSON: '{}'    # example: '{"maxsize": 100, "maxage": 0, "maxbackups": 0, "localtime": false, "compress": false}'

HttpPort: 36789
GrpcPort: 36790
JsonRpcPort: 36791

### advanced options
UpdateBranchAsyncGoroutineNum: 1 # num of async goroutine to update branch status
TimeZoneOffset: '+8' #default '' using system default. '+8': Asia/Shanghai; '0': GMT
AdminBasePath: '' #default '' set admin access base path

# ConfigUpdateInterval: 10   # the interval to update configuration in memory such as topics map... (seconds)
# TimeZoneOffset: '' # default '' using system default. '+8': Asia/Shanghai; '0': GMT
# AlertRetryLimit: 3 # default 3; if a transaction branch has been retried 3 times, the AlertHook will be called
# AlertWebHook: '' # default ''; sample: 'http://localhost:8080/dtm-hook'. this hook will be called like this:
## curl -H "Content-Type: application/json" -d '{"gid":"xxxx","status":"submitted","retry_count":3}' http://localhost:8080/dtm-hook

　　1)指定使用了MySQL作为数据存储层

       2)开启微服务的支持MicroService,并选择了etcd

这样服务已经启动了之后就可以参考官方文档进行一些demo测试和与项目的结合使用了

官方文档: https://dtm.pub/

文档中讲解的很细致,并且都有中文翻译, 还有一些接入的例子,

结合go-zero使用的实例:

• 　　https://github.com/lanlangdeai/go-zero-mall