On 01/05/2020 21:08, Bart van Leeuwen wrote:
Hi,
I'm trying to migrate a web application which uses TDB to use TDB2
From everything I have ready it should be pretty straight forward, but
I immediately run into exceptions like:
java.nio.channels.OverlappingFileLockException
I don't know what this is - it may be an environment factor. Is this
Docker? Virtual machines?
Or are there classloaders around?
org.apache.jena.tdb2.TDBException: dataset closed
In TDB1 close() does not have any effect except that it flushes the
database if the dataset has never been used transactionally.
There is no need to close databases - transactions are
better/safer/robust. In fact, it is a bit meaningless with transactions
because there are different views of the data fro different threads.
org.apache.jena.dboe.transaction.txn.TransactionException: Currently in
an active transaction
This is API use of the dataset (not Fuseki)?
TDB1 works non-transactionally until the app first uses it in a transaction.
TDB2 requires transactions from the start.
Ideally, use Txn to wrap dataset access. Txn both supports nesting of
usage (it is not nested tranactions - it uses the existing trasnaction)
and the patten means the code can't forget to commit/abort.
https://jena.apache.org/documentation/txn/
https://jena.apache.org/documentation/txn/txn.html
Sometimes, apps have code usage that doesn't fit this pattern.
---
It looks like there is non-transactional use of the dataset at some point.
This does not obviously explain
java.nio.channels.OverlappingFileLockException
but it might be related.
Andy
I've looked at the samples and the minimal tutorials I could find and
couldn't find hints on what could cause this.
I did a initdebug:
Looks OK.
JenaSystem.init - start
Found:
InitTDB2 [42]
InitRIOT [20]
InitARQ [30]
InitJenaCore [10]
Initialization sequence:
JenaInitLevel0 [0]
InitJenaCore [10]
InitRIOT [20]
InitARQ [30]
InitTDB2 [42]
Init: JenaInitLevel0
Init: InitJenaCore
JenaCore.init - start
JenaCore.init - finish
Init: InitRIOT
RIOT.init - start
RIOT.init - finish
Init: InitARQ
ARQ.init - start
ARQ.init - finish
Init: InitTDB2
TDB2.init - start
TDB.init - finish
JenaSystem.init - finish
Any help appreciated.
Met Vriendelijke Groet / With Kind Regards
Bart van Leeuwen
twitter: @semanticfire
tel. +31(0)6-53182997
Netage B.V.
http://netage.nl <http://netage.nl/>
Esdoornstraat 3
3461ER Linschoten
The Netherlands
