You are viewing a plain text version of this content. The canonical link for it is here.

Posted to dev@jena.apache.org by "Stephen Allen (JIRA)" <ji...@apache.org> on 2011/03/17 18:08:30 UTC

[jira] Updated: (JENA-41) Different policy for concurrency access in TDB supporting a single writer and multiple readers

     [ https://issues.apache.org/jira/browse/JENA-41?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Stephen Allen updated JENA-41:
------------------------------

    Attachment: TransactionManagerBase.java
                TransactionManager.java
                TransactionHandler.java
                TransactionHandle.java
                TransactionalDatasetGraph.java
                Transaction.java

Classes and interfaces to add Transaction support to DatasetGraphs.

> Different policy for concurrency access in TDB supporting a single writer and multiple readers
> ----------------------------------------------------------------------------------------------
>
>                 Key: JENA-41
>                 URL: https://issues.apache.org/jira/browse/JENA-41
>             Project: Jena
>          Issue Type: New Feature
>          Components: Fuseki, TDB
>            Reporter: Paolo Castagna
>         Attachments: Transaction.java, TransactionHandle.java, TransactionHandler.java, TransactionManager.java, TransactionManagerBase.java, TransactionalDatasetGraph.java
>
>
> As a follow up to a discussion about "Concurrent updates in TDB" [1] on the jena-users mailing list, I am creating this as a new feature request.
> Currently TDB requires developers to use a Multiple Reader or Single Writer (MRSW) locking policy for concurrency access [2]. Not doing this could cause data corruptions.
> The MRSW is indeed a MR xor SW (i.e. while a writer has a lock, no readers are allowed and, similarly, if a reader has a lock, no writes are possible).
> This works fine in most of the situation, but there might be problems in presence of long writes or long reads.
> It has been suggested that a "journaled file access" could be used to solve the issue regarding a long write blocking reads.
>  [1] http://markmail.org/message/jnqm6pn32df4wgte
>  [2] http://openjena.org/wiki/TDB/JavaAPI#Concurrency

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira