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Posted to dev@jena.apache.org by Andy Seaborne <an...@apache.org> on 2020/01/15 18:44:35 UTC
Re: [] Apache Jena 3.14.0 RC 1
Hi Aaron,
Could you say some more about how the concurrent writes are happening
and what they are doing? Just from the stacktrace I haven't managed to
write a test case.
My guess is that another transaction is finishing a commit about the
same time. But if the other transaction is mid-processing then its
something else.
If you are able to putting in a JVM-suspend breakpoint at
ThreadBufferingCache:88 and capture a thread dump, that would be very
helpful - I realise it's not always easy to get up.
Andy
On 15/01/2020 16:55, Aaron Coburn wrote:
> This might be good to split off into a separate issue (and it doesn't
> necessarily need to block the release), but I'm finding that, when using
> TDB2 with this release candidate in a concurrent write context, I start
> encountering a lot of errors. And those errors are definitely not present
> with 3.13.1. Specifically, the issue seems to be related to contention over
> the TDB2 ThreadBufferingCache. That buffering cache is present in the
> 3.13.1 release, and I'm not entirely sure what changed with 3.14.0 that
> would trigger these errors, but this is the relevant part of the stack
> trace:
>
> Caused by: org.apache.jena.tdb2.TDBException: ThreadBufferingCache: already
> buffering
> at
> org.apache.jena.tdb2.store.nodetable.ThreadBufferingCache.enableBuffering(ThreadBufferingCache.java:88)
> at
> org.apache.jena.tdb2.store.nodetable.NodeTableCache.updateStart(NodeTableCache.java:352)
> at
> org.apache.jena.tdb2.store.nodetable.NodeTableCache.notifyTxnStart(NodeTableCache.java:319)
> at
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.lambda$notifyBegin$14(TransactionCoordinator.java:915)
> at
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.lambda$listeners$0(TransactionCoordinator.java:207)
> at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
> at
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.listeners(TransactionCoordinator.java:207)
> at
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.notifyBegin(TransactionCoordinator.java:915)
> at
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.begin(TransactionCoordinator.java:553)
> at
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.begin(TransactionCoordinator.java:509)
> at
> org.apache.jena.dboe.transaction.txn.TransactionalBase.begin(TransactionalBase.java:110)
> at
> org.apache.jena.dboe.storage.system.DatasetGraphStorage.begin(DatasetGraphStorage.java:59)
> at
> org.apache.jena.sparql.core.DatasetGraphWrapper.begin(DatasetGraphWrapper.java:233)
> at org.apache.jena.sparql.core.DatasetImpl.begin(DatasetImpl.java:116)
> at org.apache.jena.system.Txn.exec(Txn.java:76)
> at org.apache.jena.system.Txn.executeWrite(Txn.java:125)
> at
> org.apache.jena.rdfconnection.RDFConnectionLocal.update(RDFConnectionLocal.java:80)
>
> Effectively, I get that error at the first time a client attempts to
> concurrently write to the TDB2 store. Subsequent attempts just hang.
>
> Cheers,
> Aaron
>
>
>
>
>
> On Mon, 13 Jan 2020 at 11:23, Andy Seaborne <an...@apache.org> wrote:
>
>> Hi,
>>
>> Here is a vote on the release of Apache Jena 3.14.0
>> This is the first proposed release candidate.
>>
>> ==== Changes:
>>
>> https://s.apache.org/jena-3.14.0-jira
>>
>> ==== Release Vote
>>
>> Everyone, not just committers, is invited to test and vote.
>> Please download and test the proposed release.
>>
>> Staging repository:
>> https://repository.apache.org/content/repositories/orgapachejena-1035
>>
>> Proposed dist/ area:
>> https://dist.apache.org/repos/dist/dev/jena/
>>
>> Keys:
>> https://svn.apache.org/repos/asf/jena/dist/KEYS
>>
>> Git commit (browser URL):
>> https://github.com/apache/jena/commit/19d42a5
>>
>> Git Commit Hash:
>> 19d42a57a9debc675047b2d1ce9769979c43e7d8
>>
>> Git Commit Tag:
>> jena-3.14.0
>>
>> Please vote to approve this release:
>>
>> [ ] +1 Approve the release
>> [ ] 0 Don't care
>> [ ] -1 Don't release, because ...
>>
>> This vote will be open until at least
>>
>> Thursday, 16th January 2020 at 187:00 UTC
>>
>> If you expect to check the release but the time limit does not work
>> for you, please email within the schedule above with an expected time
>> and we can extend the vote period.
>>
>> Thanks,
>>
>> Andy
>>
>> Checking needed:
>>
>> + are the GPG signatures fine?
>> + are the checksums correct?
>> + is there a source archive?
>>
>> + can the source archive really be built?
>> (NB This requires a "mvn install" first time)
>> + is there a correct LICENSE and NOTICE file in each artifact
>> (both source and binary artifacts)?
>> + does the NOTICE file contain all necessary attributions?
>> + have any licenses of dependencies changed due to upgrades?
>> if so have LICENSE and NOTICE been upgraded appropriately?
>> + does the tag/commit in the SCM contain reproducible sources?
>>
>
Re: [] Apache Jena 3.14.0 RC 1
Posted by Andy Seaborne <an...@apache.org>.
Hi Aaron,
So it it the trailing edge of the transaction.
That synchronization should be happening anyway because flushing should
be inside the transaction commit before the overall transaction finished
commiting. The TransactionCoordinator controls this.
The bug is that the flush is being triggered from the "CompleteFinish"
step, not the "CommitFinish".
In TransactionCoordinator
do CommitFinish
releaseWriterLock
do Complete steps
so other writer are released before flush and clearup.
In NodeTableCache:
notifyCompleteFinish should be notifyCommitFinish
Around line 330:
@Override
//public void notifyCompleteFinish(Transaction transaction) {
public void notifyCommitFinish(Transaction transaction) {
if(transaction.isWriteTxn()) {
updateCommit();
}
}
I have got a test case now.
I'll cancel the RC1 VOTE and redo the release.
Andy
On 16/01/2020 03:39, Aaron Coburn wrote:
> Hi Andy,
>
> It appears that there is a subtle race condition in how the
> ThreadBufferingCache coordinates write access to the underlying storage. In
> debugging this, I made the following changes
> https://github.com/apache/jena/compare/feature/debug_concurrent_writes
> Effectively,
> I added a Semaphore object to the class. With that change, my test suite
> passes (this is the Trellis codebase, in case you are wondering). I also
> checked for any significant changes to the performance from 3.13.1 to
> 3.14.0 (with this change in place), and after running the tests repeatedly,
> I didn't see any appreciable performance change one way or the other. If
> this seems like a reasonable adjustment to that class, I can write up a
> JIRA issue and submit this as a PR.
>
> Best, Aaron
>
> On Wed, 15 Jan 2020 at 14:25, Aaron Coburn <aa...@gmail.com> wrote:
>
>> Hi Andy,
>> I'll dig a little deeper into what's going on and will put together a
>> reproducible test case for this. I first wanted to find out if it might be
>> something obvious.
>>
>> Thanks,
>> Aaron
>>
>> On Wed, 15 Jan 2020 at 13:44, Andy Seaborne <an...@apache.org> wrote:
>>
>>> Hi Aaron,
>>>
>>> Could you say some more about how the concurrent writes are happening
>>> and what they are doing? Just from the stacktrace I haven't managed to
>>> write a test case.
>>>
>>> My guess is that another transaction is finishing a commit about the
>>> same time. But if the other transaction is mid-processing then its
>>> something else.
>>>
>>> If you are able to putting in a JVM-suspend breakpoint at
>>> ThreadBufferingCache:88 and capture a thread dump, that would be very
>>> helpful - I realise it's not always easy to get up.
>>>
>>> Andy
>>>
>>>
>>>
>>> On 15/01/2020 16:55, Aaron Coburn wrote:
>>>> This might be good to split off into a separate issue (and it doesn't
>>>> necessarily need to block the release), but I'm finding that, when using
>>>> TDB2 with this release candidate in a concurrent write context, I start
>>>> encountering a lot of errors. And those errors are definitely not
>>> present
>>>> with 3.13.1. Specifically, the issue seems to be related to contention
>>> over
>>>> the TDB2 ThreadBufferingCache. That buffering cache is present in the
>>>> 3.13.1 release, and I'm not entirely sure what changed with 3.14.0 that
>>>> would trigger these errors, but this is the relevant part of the stack
>>>> trace:
>>>>
>>>> Caused by: org.apache.jena.tdb2.TDBException: ThreadBufferingCache:
>>> already
>>>> buffering
>>>> at
>>>>
>>> org.apache.jena.tdb2.store.nodetable.ThreadBufferingCache.enableBuffering(ThreadBufferingCache.java:88)
>>>> at
>>>>
>>> org.apache.jena.tdb2.store.nodetable.NodeTableCache.updateStart(NodeTableCache.java:352)
>>>> at
>>>>
>>> org.apache.jena.tdb2.store.nodetable.NodeTableCache.notifyTxnStart(NodeTableCache.java:319)
>>>> at
>>>>
>>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.lambda$notifyBegin$14(TransactionCoordinator.java:915)
>>>> at
>>>>
>>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.lambda$listeners$0(TransactionCoordinator.java:207)
>>>> at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
>>>> at
>>>>
>>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.listeners(TransactionCoordinator.java:207)
>>>> at
>>>>
>>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.notifyBegin(TransactionCoordinator.java:915)
>>>> at
>>>>
>>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.begin(TransactionCoordinator.java:553)
>>>> at
>>>>
>>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.begin(TransactionCoordinator.java:509)
>>>> at
>>>>
>>> org.apache.jena.dboe.transaction.txn.TransactionalBase.begin(TransactionalBase.java:110)
>>>> at
>>>>
>>> org.apache.jena.dboe.storage.system.DatasetGraphStorage.begin(DatasetGraphStorage.java:59)
>>>> at
>>>>
>>> org.apache.jena.sparql.core.DatasetGraphWrapper.begin(DatasetGraphWrapper.java:233)
>>>> at org.apache.jena.sparql.core.DatasetImpl.begin(DatasetImpl.java:116)
>>>> at org.apache.jena.system.Txn.exec(Txn.java:76)
>>>> at org.apache.jena.system.Txn.executeWrite(Txn.java:125)
>>>> at
>>>>
>>> org.apache.jena.rdfconnection.RDFConnectionLocal.update(RDFConnectionLocal.java:80)
>>>>
>>>> Effectively, I get that error at the first time a client attempts to
>>>> concurrently write to the TDB2 store. Subsequent attempts just hang.
>>>>
>>>> Cheers,
>>>> Aaron
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Mon, 13 Jan 2020 at 11:23, Andy Seaborne <an...@apache.org> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> Here is a vote on the release of Apache Jena 3.14.0
>>>>> This is the first proposed release candidate.
>>>>>
>>>>> ==== Changes:
>>>>>
>>>>> https://s.apache.org/jena-3.14.0-jira
>>>>>
>>>>> ==== Release Vote
>>>>>
>>>>> Everyone, not just committers, is invited to test and vote.
>>>>> Please download and test the proposed release.
>>>>>
>>>>> Staging repository:
>>>>>
>>> https://repository.apache.org/content/repositories/orgapachejena-1035
>>>>>
>>>>> Proposed dist/ area:
>>>>> https://dist.apache.org/repos/dist/dev/jena/
>>>>>
>>>>> Keys:
>>>>> https://svn.apache.org/repos/asf/jena/dist/KEYS
>>>>>
>>>>> Git commit (browser URL):
>>>>> https://github.com/apache/jena/commit/19d42a5
>>>>>
>>>>> Git Commit Hash:
>>>>> 19d42a57a9debc675047b2d1ce9769979c43e7d8
>>>>>
>>>>> Git Commit Tag:
>>>>> jena-3.14.0
>>>>>
>>>>> Please vote to approve this release:
>>>>>
>>>>> [ ] +1 Approve the release
>>>>> [ ] 0 Don't care
>>>>> [ ] -1 Don't release, because ...
>>>>>
>>>>> This vote will be open until at least
>>>>>
>>>>> Thursday, 16th January 2020 at 187:00 UTC
>>>>>
>>>>> If you expect to check the release but the time limit does not work
>>>>> for you, please email within the schedule above with an expected time
>>>>> and we can extend the vote period.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Andy
>>>>>
>>>>> Checking needed:
>>>>>
>>>>> + are the GPG signatures fine?
>>>>> + are the checksums correct?
>>>>> + is there a source archive?
>>>>>
>>>>> + can the source archive really be built?
>>>>> (NB This requires a "mvn install" first time)
>>>>> + is there a correct LICENSE and NOTICE file in each artifact
>>>>> (both source and binary artifacts)?
>>>>> + does the NOTICE file contain all necessary attributions?
>>>>> + have any licenses of dependencies changed due to upgrades?
>>>>> if so have LICENSE and NOTICE been upgraded appropriately?
>>>>> + does the tag/commit in the SCM contain reproducible sources?
>>>>>
>>>>
>>>
>>
>
Re: [] Apache Jena 3.14.0 RC 1
Posted by Aaron Coburn <aa...@gmail.com>.
Hi Andy,
It appears that there is a subtle race condition in how the
ThreadBufferingCache coordinates write access to the underlying storage. In
debugging this, I made the following changes
https://github.com/apache/jena/compare/feature/debug_concurrent_writes
Effectively,
I added a Semaphore object to the class. With that change, my test suite
passes (this is the Trellis codebase, in case you are wondering). I also
checked for any significant changes to the performance from 3.13.1 to
3.14.0 (with this change in place), and after running the tests repeatedly,
I didn't see any appreciable performance change one way or the other. If
this seems like a reasonable adjustment to that class, I can write up a
JIRA issue and submit this as a PR.
Best, Aaron
On Wed, 15 Jan 2020 at 14:25, Aaron Coburn <aa...@gmail.com> wrote:
> Hi Andy,
> I'll dig a little deeper into what's going on and will put together a
> reproducible test case for this. I first wanted to find out if it might be
> something obvious.
>
> Thanks,
> Aaron
>
> On Wed, 15 Jan 2020 at 13:44, Andy Seaborne <an...@apache.org> wrote:
>
>> Hi Aaron,
>>
>> Could you say some more about how the concurrent writes are happening
>> and what they are doing? Just from the stacktrace I haven't managed to
>> write a test case.
>>
>> My guess is that another transaction is finishing a commit about the
>> same time. But if the other transaction is mid-processing then its
>> something else.
>>
>> If you are able to putting in a JVM-suspend breakpoint at
>> ThreadBufferingCache:88 and capture a thread dump, that would be very
>> helpful - I realise it's not always easy to get up.
>>
>> Andy
>>
>>
>>
>> On 15/01/2020 16:55, Aaron Coburn wrote:
>> > This might be good to split off into a separate issue (and it doesn't
>> > necessarily need to block the release), but I'm finding that, when using
>> > TDB2 with this release candidate in a concurrent write context, I start
>> > encountering a lot of errors. And those errors are definitely not
>> present
>> > with 3.13.1. Specifically, the issue seems to be related to contention
>> over
>> > the TDB2 ThreadBufferingCache. That buffering cache is present in the
>> > 3.13.1 release, and I'm not entirely sure what changed with 3.14.0 that
>> > would trigger these errors, but this is the relevant part of the stack
>> > trace:
>> >
>> > Caused by: org.apache.jena.tdb2.TDBException: ThreadBufferingCache:
>> already
>> > buffering
>> > at
>> >
>> org.apache.jena.tdb2.store.nodetable.ThreadBufferingCache.enableBuffering(ThreadBufferingCache.java:88)
>> > at
>> >
>> org.apache.jena.tdb2.store.nodetable.NodeTableCache.updateStart(NodeTableCache.java:352)
>> > at
>> >
>> org.apache.jena.tdb2.store.nodetable.NodeTableCache.notifyTxnStart(NodeTableCache.java:319)
>> > at
>> >
>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.lambda$notifyBegin$14(TransactionCoordinator.java:915)
>> > at
>> >
>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.lambda$listeners$0(TransactionCoordinator.java:207)
>> > at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
>> > at
>> >
>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.listeners(TransactionCoordinator.java:207)
>> > at
>> >
>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.notifyBegin(TransactionCoordinator.java:915)
>> > at
>> >
>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.begin(TransactionCoordinator.java:553)
>> > at
>> >
>> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.begin(TransactionCoordinator.java:509)
>> > at
>> >
>> org.apache.jena.dboe.transaction.txn.TransactionalBase.begin(TransactionalBase.java:110)
>> > at
>> >
>> org.apache.jena.dboe.storage.system.DatasetGraphStorage.begin(DatasetGraphStorage.java:59)
>> > at
>> >
>> org.apache.jena.sparql.core.DatasetGraphWrapper.begin(DatasetGraphWrapper.java:233)
>> > at org.apache.jena.sparql.core.DatasetImpl.begin(DatasetImpl.java:116)
>> > at org.apache.jena.system.Txn.exec(Txn.java:76)
>> > at org.apache.jena.system.Txn.executeWrite(Txn.java:125)
>> > at
>> >
>> org.apache.jena.rdfconnection.RDFConnectionLocal.update(RDFConnectionLocal.java:80)
>> >
>> > Effectively, I get that error at the first time a client attempts to
>> > concurrently write to the TDB2 store. Subsequent attempts just hang.
>> >
>> > Cheers,
>> > Aaron
>> >
>> >
>> >
>> >
>> >
>> > On Mon, 13 Jan 2020 at 11:23, Andy Seaborne <an...@apache.org> wrote:
>> >
>> >> Hi,
>> >>
>> >> Here is a vote on the release of Apache Jena 3.14.0
>> >> This is the first proposed release candidate.
>> >>
>> >> ==== Changes:
>> >>
>> >> https://s.apache.org/jena-3.14.0-jira
>> >>
>> >> ==== Release Vote
>> >>
>> >> Everyone, not just committers, is invited to test and vote.
>> >> Please download and test the proposed release.
>> >>
>> >> Staging repository:
>> >>
>> https://repository.apache.org/content/repositories/orgapachejena-1035
>> >>
>> >> Proposed dist/ area:
>> >> https://dist.apache.org/repos/dist/dev/jena/
>> >>
>> >> Keys:
>> >> https://svn.apache.org/repos/asf/jena/dist/KEYS
>> >>
>> >> Git commit (browser URL):
>> >> https://github.com/apache/jena/commit/19d42a5
>> >>
>> >> Git Commit Hash:
>> >> 19d42a57a9debc675047b2d1ce9769979c43e7d8
>> >>
>> >> Git Commit Tag:
>> >> jena-3.14.0
>> >>
>> >> Please vote to approve this release:
>> >>
>> >> [ ] +1 Approve the release
>> >> [ ] 0 Don't care
>> >> [ ] -1 Don't release, because ...
>> >>
>> >> This vote will be open until at least
>> >>
>> >> Thursday, 16th January 2020 at 187:00 UTC
>> >>
>> >> If you expect to check the release but the time limit does not work
>> >> for you, please email within the schedule above with an expected time
>> >> and we can extend the vote period.
>> >>
>> >> Thanks,
>> >>
>> >> Andy
>> >>
>> >> Checking needed:
>> >>
>> >> + are the GPG signatures fine?
>> >> + are the checksums correct?
>> >> + is there a source archive?
>> >>
>> >> + can the source archive really be built?
>> >> (NB This requires a "mvn install" first time)
>> >> + is there a correct LICENSE and NOTICE file in each artifact
>> >> (both source and binary artifacts)?
>> >> + does the NOTICE file contain all necessary attributions?
>> >> + have any licenses of dependencies changed due to upgrades?
>> >> if so have LICENSE and NOTICE been upgraded appropriately?
>> >> + does the tag/commit in the SCM contain reproducible sources?
>> >>
>> >
>>
>
Re: [] Apache Jena 3.14.0 RC 1
Posted by Aaron Coburn <aa...@gmail.com>.
Hi Andy,
I'll dig a little deeper into what's going on and will put together a
reproducible test case for this. I first wanted to find out if it might be
something obvious.
Thanks,
Aaron
On Wed, 15 Jan 2020 at 13:44, Andy Seaborne <an...@apache.org> wrote:
> Hi Aaron,
>
> Could you say some more about how the concurrent writes are happening
> and what they are doing? Just from the stacktrace I haven't managed to
> write a test case.
>
> My guess is that another transaction is finishing a commit about the
> same time. But if the other transaction is mid-processing then its
> something else.
>
> If you are able to putting in a JVM-suspend breakpoint at
> ThreadBufferingCache:88 and capture a thread dump, that would be very
> helpful - I realise it's not always easy to get up.
>
> Andy
>
>
>
> On 15/01/2020 16:55, Aaron Coburn wrote:
> > This might be good to split off into a separate issue (and it doesn't
> > necessarily need to block the release), but I'm finding that, when using
> > TDB2 with this release candidate in a concurrent write context, I start
> > encountering a lot of errors. And those errors are definitely not present
> > with 3.13.1. Specifically, the issue seems to be related to contention
> over
> > the TDB2 ThreadBufferingCache. That buffering cache is present in the
> > 3.13.1 release, and I'm not entirely sure what changed with 3.14.0 that
> > would trigger these errors, but this is the relevant part of the stack
> > trace:
> >
> > Caused by: org.apache.jena.tdb2.TDBException: ThreadBufferingCache:
> already
> > buffering
> > at
> >
> org.apache.jena.tdb2.store.nodetable.ThreadBufferingCache.enableBuffering(ThreadBufferingCache.java:88)
> > at
> >
> org.apache.jena.tdb2.store.nodetable.NodeTableCache.updateStart(NodeTableCache.java:352)
> > at
> >
> org.apache.jena.tdb2.store.nodetable.NodeTableCache.notifyTxnStart(NodeTableCache.java:319)
> > at
> >
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.lambda$notifyBegin$14(TransactionCoordinator.java:915)
> > at
> >
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.lambda$listeners$0(TransactionCoordinator.java:207)
> > at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
> > at
> >
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.listeners(TransactionCoordinator.java:207)
> > at
> >
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.notifyBegin(TransactionCoordinator.java:915)
> > at
> >
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.begin(TransactionCoordinator.java:553)
> > at
> >
> org.apache.jena.dboe.transaction.txn.TransactionCoordinator.begin(TransactionCoordinator.java:509)
> > at
> >
> org.apache.jena.dboe.transaction.txn.TransactionalBase.begin(TransactionalBase.java:110)
> > at
> >
> org.apache.jena.dboe.storage.system.DatasetGraphStorage.begin(DatasetGraphStorage.java:59)
> > at
> >
> org.apache.jena.sparql.core.DatasetGraphWrapper.begin(DatasetGraphWrapper.java:233)
> > at org.apache.jena.sparql.core.DatasetImpl.begin(DatasetImpl.java:116)
> > at org.apache.jena.system.Txn.exec(Txn.java:76)
> > at org.apache.jena.system.Txn.executeWrite(Txn.java:125)
> > at
> >
> org.apache.jena.rdfconnection.RDFConnectionLocal.update(RDFConnectionLocal.java:80)
> >
> > Effectively, I get that error at the first time a client attempts to
> > concurrently write to the TDB2 store. Subsequent attempts just hang.
> >
> > Cheers,
> > Aaron
> >
> >
> >
> >
> >
> > On Mon, 13 Jan 2020 at 11:23, Andy Seaborne <an...@apache.org> wrote:
> >
> >> Hi,
> >>
> >> Here is a vote on the release of Apache Jena 3.14.0
> >> This is the first proposed release candidate.
> >>
> >> ==== Changes:
> >>
> >> https://s.apache.org/jena-3.14.0-jira
> >>
> >> ==== Release Vote
> >>
> >> Everyone, not just committers, is invited to test and vote.
> >> Please download and test the proposed release.
> >>
> >> Staging repository:
> >>
> https://repository.apache.org/content/repositories/orgapachejena-1035
> >>
> >> Proposed dist/ area:
> >> https://dist.apache.org/repos/dist/dev/jena/
> >>
> >> Keys:
> >> https://svn.apache.org/repos/asf/jena/dist/KEYS
> >>
> >> Git commit (browser URL):
> >> https://github.com/apache/jena/commit/19d42a5
> >>
> >> Git Commit Hash:
> >> 19d42a57a9debc675047b2d1ce9769979c43e7d8
> >>
> >> Git Commit Tag:
> >> jena-3.14.0
> >>
> >> Please vote to approve this release:
> >>
> >> [ ] +1 Approve the release
> >> [ ] 0 Don't care
> >> [ ] -1 Don't release, because ...
> >>
> >> This vote will be open until at least
> >>
> >> Thursday, 16th January 2020 at 187:00 UTC
> >>
> >> If you expect to check the release but the time limit does not work
> >> for you, please email within the schedule above with an expected time
> >> and we can extend the vote period.
> >>
> >> Thanks,
> >>
> >> Andy
> >>
> >> Checking needed:
> >>
> >> + are the GPG signatures fine?
> >> + are the checksums correct?
> >> + is there a source archive?
> >>
> >> + can the source archive really be built?
> >> (NB This requires a "mvn install" first time)
> >> + is there a correct LICENSE and NOTICE file in each artifact
> >> (both source and binary artifacts)?
> >> + does the NOTICE file contain all necessary attributions?
> >> + have any licenses of dependencies changed due to upgrades?
> >> if so have LICENSE and NOTICE been upgraded appropriately?
> >> + does the tag/commit in the SCM contain reproducible sources?
> >>
> >
>