DTM distributed transaction manager PHP collaboration client V0.1 beta release!!!

https://github.com/dtm-php/dtm-client

Introduce

dtm/dtm-client It is a distributed transaction manager DTM Of PHP client , Already supported TCC Pattern 、Saga、 Distributed transaction mode of two-stage message mode , And realize and DTM Server With HTTP Agreement or gRPC Protocol communication , The client can run safely in PHP-FPM and Swoole In a collaborative environment , More right Hyperf Made more easy-to-use function support .

About DTM

DTM It's based on Go Language implementation of open source distributed transaction manager , Provide cross language , The power of combining transactions across storage engines .DTM Elegantly solved idempotent 、 Air compensation 、 Hanging equally distributed transaction problems , It also provides ease of use 、 High performance 、 A distributed transaction solution that is easy to scale horizontally .

Bright spot

• Easy to use
  • Zero configuration start service , Provide very simple HTTP Interface , Greatly reduce the difficulty of starting distributed transactions
• Cross language
  • It can be used by companies with multi language stack . convenient Go、Python、PHP、NodeJs、Ruby、C# And other languages .
• Easy to use
  • Developers no longer worry about hanging 、 Air compensation 、 Idempotent problems , The first sub transaction barrier technology is used for processing
• Easy to deploy 、 Easy to expand
  • Rely only on MySQL/Redis, Simple deployment , Easy clustering , Easy horizontal expansion
• Multiple distributed transaction protocols support
  • TCC、SAGA、XA、 Phase II message , One stop solution to multiple distributed transaction problems

contrast

In Africa Java Under the language , I haven't seen anything except DTM Mature distributed transaction managers beyond , So here's going to be DTM and Java The most mature open source project in Seata comparing ：

characteristic	DTM	SEATA	remarks
Support language	Go、C#、Java、Python、PHP...	Java	DTM Easy access to a new language
Storage engine	Support database 、Redis、Mongo etc.	database
exception handling	Sub transaction barrier automatic processing	Handle by hand	DTM Solved idempotent 、 Hang 、 Air compensation
SAGA Business	It's very easy to use	Complex state machine
Phase II message	*	*	The simplest message final consistency architecture
TCC Business	*	*
XA Business	*	*
AT Business	It is recommended to use XA	*	AT And XA similar , But there's dirt
Single service multiple data sources	*	*
Communication protocol	HTTP、gRPC	Dubbo Such agreement	DTM More friendly to the cloud
star Number			DTM from 2021-06-04 Release 0.1 edition , Rapid development

From the characteristics of the above comparison ,DTM It has great advantages in many aspects . If you consider multilingual support 、 Multi storage engine support , that DTM It is undoubtedly your first choice .

install

adopt Composer It's very easy to install dtm-client

composer require dtm/dtm-client

• Don't forget to start when using DTM Server Oh

To configure

The configuration file

If you are in Hyperf Use... In the framework , After installing the components , This can be done by vendor:publish Command a release configuration file on ./config/autoload/dtm.php

php bin/hyperf.php vendor:publish dtm/dtm-client

If you are in Africa Hyperf Use... In the framework , Replicable ./vendor/dtm/dtm-client/publish/dtm.php File to the corresponding configuration directory .

use DtmClient\\Constants\\Protocol;use DtmClient\\Constants\\DbType;return [    //  The client and  DTM Server  Communication protocol , Support  Protocol::HTTP  and  Protocol::GRPC  Two kinds of     'protocol' => Protocol::HTTP,    // DTM Server  The address of     'server' => '127.0.0.1',    // DTM Server  The port of     'port' => [        'http' => 36789,        'grpc' => 36790,    ],    //  Sub transaction barrier configuration     'barrier' => [        // DB  Sub transaction barrier configuration in mode         'db' => [            'type' => DbType::MySQL        ],        // Redis  Sub transaction barrier configuration in mode         'redis' => [            //  Timeout of sub transaction barrier record             'expire_seconds' => 7 * 86400,        ],        //  Not  Hyperf  Classes that apply sub transaction barriers under the framework         'apply' => [],    ],    // HTTP  Under the agreement  Guzzle  General configuration of the client     'guzzle' => [        'options' => [],    ],];

Configuration middleware

Before use , Need configuration DtmClient\\Middleware\\DtmMiddleware Middleware as Server Global middleware , The middleware supports PSR-15 standard , It can be applied to all frameworks supporting the specification .
stay Hyperf Refer to Hyperf file - middleware chapter .

Use

dtm-client Is very simple to use , We provide a sample project dtm-php/dtm-sample To help you better understand and debug .
Before using this component , It is also strongly recommended that you read DTM Official documents , For a more detailed understanding .

TCC Pattern

TCC Pattern is a very popular flexible transaction solution , from Try-Confirm-Cancel The acronyms of three words are composed of TCC The concept of , The first is the Pat Helland On 2007 A piece published in was called 《Life beyond Distributed Transactions:an Apostate’s Opinion》 In my paper, I put forward .

TCC Of 3 Stages

Try Stage ： Trying to perform , Complete all business checks （ Uniformity ）, Reserve necessary business resources （ Quasi isolation ）
Confirm Stage ： If all branches Try It's all done , Go to Confirm Stage .Confirm Really do business , No business checks , Use only Try Business resources reserved in the stage
Cancel Stage ： If all branches Try One failed , Go to Cancel Stage .Cancel Release Try Business resources reserved in the stage .

If we want to carry out a business similar to inter-bank transfer , Transfer out （TransOut） And transfer in （TransIn） In different microservices , A successful TCC A typical sequence diagram of a transaction is as follows ：

Code example

The following is shown in Hyperf How to use it in the framework , Other frameworks are similar

<?phpnamespace App\\Controller;use DtmClient\\TCC;use DtmClient\\TransContext;use Hyperf\\Di\\Annotation\\Inject;use Hyperf\\HttpServer\\Annotation\\Controller;use Hyperf\\HttpServer\\Annotation\\GetMapping;use Throwable;#[Controller(prefix: '/tcc')]class TccController{    protected string $serviceUri = 'http://127.0.0.1:9501';    #[Inject]    protected TCC $tcc;    #[GetMapping(path: 'successCase')]    public function successCase()    {        try {                        $this->tcc->globalTransaction(function (TCC $tcc) {                //  Create sub transactions  A  Call data for                 $tcc->callBranch(                    //  call  Try  Method parameters                     ['amount' => 30],                    // Try  Methodical  URL                    $this->serviceUri . '/tcc/transA/try',                    // Confirm  Methodical  URL                    $this->serviceUri . '/tcc/transA/confirm',                    // Cancel  Methodical  URL                    $this->serviceUri . '/tcc/transA/cancel'                );                //  Create sub transactions  B  Call data for , And so on                 $tcc->callBranch(                    ['amount' => 30],                    $this->serviceUri . '/tcc/transB/try',                    $this->serviceUri . '/tcc/transB/confirm',                    $this->serviceUri . '/tcc/transB/cancel'                );            });        } catch (Throwable $e) {            var_dump($e->getMessage(), $e->getTraceAsString());        }        //  adopt  TransContext::getGid()  get   Global transaction ID  And back to         return TransContext::getGid();    }}

Saga Pattern

Saga Pattern is one of the most famous solutions in the field of distributed transactions , It is also very popular in major systems , It first appeared in 1987 year from Hector Garcaa-Molrna & Kenneth Salem Published papers SAGAS in .

Saga It is a final consistency transaction , It's also a flexible transaction , It's also called Long running transactions （Long-running-transaction）,Saga It consists of a series of local transactions . After each local transaction updates the database , Will release a message or an event to trigger Saga Execution of the next local transaction in the global transaction . If a local transaction fails because some business rules cannot be met ,Saga It will perform the compensation operation of all transactions successfully committed before this failed transaction . therefore Saga Patterns are contrasting TCC Mode time , Due to the lack of resource reservation steps , It often becomes more troublesome when implementing rollback logic .

Saga Sub transaction splitting

For example, we need to carry out a business similar to bank inter-bank transfer , take A In the account 30 Yuan transferred to B Account , according to Saga How things work , We will deal with the overall situation , Split into the following services ：

• Transfer out （TransOut） service , Here will be the operation A Account deduction 30 element
• Transfer out compensation （TransOutCompensate） service , Rollback the above transfer out operation , namely A Account increase 30 element
• into （TransIn） service , There will be B Account increase 30 element
• Transfer out compensation （TransInCompensate） service , Rollback the above transfer in operation , namely B The accounts are down 30 element

The logic of the whole transaction is ：

Transfer out succeeded => Execution transfer succeeded => Global transaction completed

If an error occurs in the middle , For example, transfer in B An error occurred in the account , Then the compensation operation of the executed branch will be called , namely ：

Transfer out succeeded => Failed to execute transfer in => Successful implementation of transfer in compensation => Successfully execute transfer out compensation => Global transaction rollback completed

Here is a successful SAGA A typical sequence diagram of a transaction ：

Code example

The following is shown in Hyperf How to use it in the framework , Other frameworks are similar

namespace App\\Controller;use DtmClient\\Saga;use DtmClient\\TransContext;use Hyperf\\Di\\Annotation\\Inject;use Hyperf\\HttpServer\\Annotation\\Controller;use Hyperf\\HttpServer\\Annotation\\GetMapping;#[Controller(prefix: '/saga')]class SagaController{    protected string $serviceUri = 'http://127.0.0.1:9501';        #[Inject]    protected Saga $saga;    #[GetMapping(path: 'successCase')]    public function successCase(): string    {        $payload = ['amount' => 50];        //  initialization  Saga  Business         $this->saga->init();        //  Add transfer out sub transaction         $this->saga->add(            $this->serviceUri . '/saga/transOut',             $this->serviceUri . '/saga/transOutCompensate',             $payload        );        //  Add transfer in sub transaction         $this->saga->add(            $this->serviceUri . '/saga/transIn',             $this->serviceUri . '/saga/transInCompensate',             $payload        );        //  Submit  Saga  Business         $this->saga->submit();        //  adopt  TransContext::getGid()  get   Global transaction ID  And back to         return TransContext::getGid();    }}