Chapter 6. Transaction Support

Table of Contents

Introduction
Configuration
JDBC Transaction Integration
LDAP Compensating Transactions Explained
Renaming Strategies

Introduction

Programmers used to working with relational databases coming to the LDAP world often express surprise to the fact that there is no notion of transactions. It is not specified in the protocol, and thus no servers support it. Recognizing that this may be a major problem, Spring LDAP provides support for client-side, compensating transactions on LDAP resources.

LDAP transaction support is provided by ContextSourceTransactionManager, a PlatformTransactionManager implementation that manages Spring transaction support for LDAP operations. Along with its collaborators it keeps track of the LDAP operations performed in a transaction, making record of the state before each operation and taking steps to restore the initial state should the transaction need to be rolled back.

In addition to the actual transaction management, Spring LDAP transaction support also makes sure that the same DirContext instance will be used throughout the same transaction, i.e. the DirContext will not actually be closed until the transaction is finished, allowing for more efficient resources usage.

Note

It is important to note that while the approach used by Spring LDAP to provide transaction support is sufficient for many cases it is by no means "real" transactions in the traditional sense. The server is completely unaware of the transactions, so e.g. if the connection is broken there will be no hope to rollback the transaction. While this should be carefully considered it should also be noted that the alternative will be to operate without any transaction support whatsoever; this is pretty much as good as it gets.

Note

The client side transaction support will add some overhead in addition to the work required by the original operations. While this overhead should not be something to worry about in most cases, if your application will not perform several LDAP operations within the same transaction (e.g. a modifyAttributes followed by a rebind), or if transaction synchronization with a JDBC data source is not required (see below) there will be nothing to gain by using the LDAP transaction support.