XA Datasource в драйвере Microsoft JDBC и драйвер JTDS JDBC

Question

Я немного новичок в SQL Server и работаю в приложении Java, подключающемся к нему. Я нашел эти 2 хорошо известных драйвера JDBC, microsoft one и jTDS. Я пытаюсь использовать источник данных XA.

В соответствии с документацией Microsoft, here говорится, что я должен настроить сервер, прежде чем использовать источник данных XA. Согласно этому документу, он хочет включить XA в сервер.

Но я не вижу такой модификации на стороне сервера, необходимой для jTDS. (Я не мог найти ни одного документа, говорящего так, here)

Итак, мой вопрос в том, как сам jTDS позволяет включить XA на сервере, в то время как Microsoft мне нужна для выполнения этой задачи?

Или я что-то упустил?

Answer 1

Нашел ответ после копания в дистрибутиве jTDS. У него есть файл README.XA, в котором говорится все. Копирование содержимого ниже.

XA support in jTDS 
================== 

This version of jTDS includes a XADataSource class which allows the driver to 
be used with J2EE servers that only support XA JDBC connections. The class name 
is net.sourceforge.jtds.jdbcx.JtdsDataSource. 

By default the driver will emulate distributed transactions fooling the J2EE 
environment into believing that two phase commit is supported. This emulation 
has the serious drawback that when used in a true distributed environment, the 
driver may not be able to commit or rollback when requested by the transaction 
manager. In this situation data loss or corruption can occur. 

In general this emulation is safe to use when jTDS is the only transactional 
resource manager or where the database is read only and never updated. 
Emulation is much faster than support for true distributed transactions and 
this may be another reason to consider using the driver in this mode if the 
risks are understood. 

Many J2EE servers provide their own XA emulations that allow the normal 
net.sourceforge.jtds.jdbc.Driver to be used. The recommendation is to use the 
vendor's emulation, if available, rather than the XADataSource as this 
configuration is likely to be more stable. 

The driver will support true distributed transactions with MS SQL2000 provided 
that the extended stored procedure in JtdsXA.dll is installed in the target 
server. To disable the XA emulation and use the stored procedure, set the 
connection property "xaemulation" to "false". This implementation is very 
immature and cannot be recommended for production use at this stage. It may 
however be useful for development when true two phase commit support is 
required. 

Another connection property, "LogFile" has been added to JtdsDataSource which 
allows the jTDS logging to be enabled in a J2EE environment. The parameter 
value specifies the output file path for the logging information. 

Two example configurations for the popular JBoss server are included in the 
conf directory. One configuration uses the Driver interface and the server's XA 
emulation the other shows how to use the driver's XA support in either emulated 
or real mode. 


Installing JtdsXA.dll 
===================== 

For true distributed transaction support JtdsXA.dll has to be installed on the 
server. The installation procedure consists of two simple steps: 

1. Copy JtdsXA.dll from the XA directory to the <SQL_Server_Root>/binn 
    directory of the SQL Server installation. 

2. From the command prompt run the following command in the directory where 
    you extracted jTDS: 

    isql -Usa -P<sa_password> -S<server_name_or_ip> -iXA\instjtds.sql 

    Alternatively, use any DB tool (such as Query Analyzer or any JDBC tool) to 
    execute the script within the 'master' database. Don't forget to log in as 
    'sa'. 

This will install the xp_jtdsxa extended stored procedure, used by jTDS to 
provide true distributed transacition support. 

Answer 2

Вы бы использовали драйвер sqljdbc_4.0 (http://www.microsoft.com/en-us/download/details.aspx?id=11774). Здесь объясните XA Datasource и как это разрешено на сервере .. это работает для меня.

-- This script installs the extended stored procedures that implement 
-- distributed transaction and XA support for the Microsoft JDBC Driver 4.0 for SQL Server. 
-- Works only with SQL 2005 and above 

-- Notes for SQL Administrators: 

-- #1. Prior to running this script you must copy the extended stored procedure dll SQLJDBC_XA.dll 
--  to the target SQL Server's Binn folder. 

-- #2. Permissions to the distributed transaction support procedures for the Microsoft JDBC Driver 4.0 
--  for SQL Server are granted through the SQL Server role [SqlJDBCXAUser]. To maintain a secure default 
--  configuration, no user is granted access to this role by default. 

-- Drop and re-create the extended stored procedure definitions in master. 

use master 
go 

-- Drop any existing procedure definitions. 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_init') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_init' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_start') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_start' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_end') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_end' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_prepare') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_prepare' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_commit') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_commit' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_rollback') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_rollback' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_forget') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_forget' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_recover') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_recover' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_rollback_ex') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_rollback_ex' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_forget_ex') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_forget_ex' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_prepare_ex') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_prepare_ex' 
if exists (select * from sys.objects where object_id = object_id('xp_sqljdbc_xa_init_ex') and OBJECTPROPERTY(object_id, N'IsExtendedProc') = 1) exec sp_dropextendedproc 'xp_sqljdbc_xa_init_ex' 
go 

-- Install the procedures. 
exec sp_addextendedproc 'xp_sqljdbc_xa_init', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_start', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_end', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_prepare', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_commit', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_rollback', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_forget', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_recover', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_rollback_ex', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_forget_ex', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_prepare_ex', 'SQLJDBC_XA.dll' 
exec sp_addextendedproc 'xp_sqljdbc_xa_init_ex', 'SQLJDBC_XA.dll' 
go 

-- Create the [SqlJDBCXAUser] role in master database. 
-- The SQL administrator can later add users to this role to allow users to participate 
-- in Microsoft JDBC Driver 4.0 for SQL Server distributed transactions. 
if exists (select * from sys.schemas where name = 'SqlJDBCXAUser') 
drop schema [SqlJDBCXAUser]; 

if exists (select * from sys.database_principals where name = 'SqlJDBCXAUser' and type='R') 
drop role [SqlJDBCXAUser]; 

create role [SqlJDBCXAUser] 
go 


-- Grant privileges to [SqlJDBCXAUser] role to the extended stored procedures. 
grant execute on xp_sqljdbc_xa_init to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_start to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_end to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_prepare to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_commit to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_rollback to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_recover to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_forget to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_rollback_ex to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_forget_ex to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_prepare_ex to [SqlJDBCXAUser] 
grant execute on xp_sqljdbc_xa_init_ex to [SqlJDBCXAUser] 
go 

-- Add users to the [SqlJDBCXAUser] role as needed. 

-- Example for adding a SQL authentication user to the SqlJDBCXAUser role. 
-- exec sp_addrolemember [SqlJDBCXAUser], 'MySQLUser' 

-- Example for adding a windows domain user to the SqlJDBCXAUser role. 
-- exec sp_addrolemember [SqlJDBCXAUser], 'MyDomain\MyWindowsUser' 

print '' 
print 'SQLJDBC XA DLL installation script complete.' 
print 'Check for any error messages generated above.'