not that i could see, however, if it appeared just once, most likely i missed it.

I think I found the issue.

After some research, what I did is the following:

Stop ubooquity

Delete both db file and the DB.old

Change the configuration file memory option from 512 to 4096

Start ubooquity

After a long scan I now have 30,000 books and comics available and without issues.

Thank you for trying to help me.

Adi

i tried this morning to click on clear books database and restart the scan, somewhere in the middle the errors have started again so, yes it does happen several times:

20180731 10:01:39 [Scanner thread] INFO
com.ubooquity.fileformat.pdf.b - Reading metadata of pdf file:
/volume1/Books/2.7K IT Books/Model-Based Development_ Applications.pdf
20180731 10:01:40 [Scanner thread] INFO
com.ubooquity.data.database.a - Inserting/updating book entry in
database : /volume1/Books/2.7K IT Books/Model-Based Development_
Applications.pdf
20180731 10:01:40 [Scanner thread] ERROR com.ubooquity.data.database.a - Error while creating/updating book in database
org.h2.jdbc.JdbcSQLException:
General error: "java.lang.IllegalStateException: Reading from
nio:/volume1/homes/Ubooquity/.Ubooquity2/ubooquity-5.mv.db failed; file
length -1 read length 768 at 4085534 [1.4.193/1]"; SQL statement:
merge
into book(parentid, rootid, isdirectory, title, norm_title, authors,
norm_authors, description, language, norm_language, rating, seriesname,
norm_seriesname, seriesindex, filedate, filepath, filename,
norm_filename, identifier, publisher,
lastupdatedate,filesize,publicationdate,pagecount)
key(filepath)values(?, ?, ? ,? , ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,
?, ?, ?, ?, ?, ?, ?) [50000-193]
at org.h2.message.DbException.getJdbcSQLException(DbException.java:345) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.message.DbException.get(DbException.java:168) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.message.DbException.convert(DbException.java:295) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.Command.executeUpdate(Command.java:266) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]

at
org.h2.jdbc.JdbcPreparedStatement.execute(JdbcPreparedStatement.java:201)
~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at com.ubooquity.data.database.a.a(SourceFile:987) [Ubooquity.jar:2.1.1]
at com.ubooquity.data.database.a.a(SourceFile:59) [Ubooquity.jar:2.1.1]
at com.ubooquity.data.feeder.a.a(SourceFile:221) [Ubooquity.jar:2.1.1]
at com.ubooquity.data.feeder.a.a(SourceFile:305) [Ubooquity.jar:2.1.1]
at com.ubooquity.data.feeder.a.b(SourceFile:105) [Ubooquity.jar:2.1.1]
at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_161]
Caused
by: java.lang.IllegalStateException: Reading from
nio:/volume1/homes/Ubooquity/.Ubooquity2/ubooquity-5.mv.db failed; file
length -1 read length 768 at 4085534 [1.4.193/1]
at org.h2.mvstore.DataUtils.newIllegalStateException(DataUtils.java:765) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.DataUtils.readFully(DataUtils.java:435) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.FileStore.readFully(FileStore.java:98) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.Page.read(Page.java:190) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.MVStore.readPage(MVStore.java:1954) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.MVMap.readPage(MVMap.java:736) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.Page.getChildPage(Page.java:217) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.Cursor.min(Cursor.java:129) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.Cursor.hasNext(Cursor.java:36) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]

at
org.h2.mvstore.db.TransactionStore$TransactionMap$1.fetchNext(TransactionStore.java:1388)
~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.db.TransactionStore$TransactionMap$1.(TransactionStore.java:1384) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]

at
org.h2.mvstore.db.TransactionStore$TransactionMap.keyIterator(TransactionStore.java:1379)
~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at
org.h2.mvstore.db.TransactionStore$TransactionMap.keyIterator(TransactionStore.java:1367)
~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.db.MVSecondaryIndex.find(MVSecondaryIndex.java:309) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.db.MVSecondaryIndex.find(MVSecondaryIndex.java:254) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.index.BaseIndex.find(BaseIndex.java:128) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.index.IndexCursor.find(IndexCursor.java:169) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.table.TableFilter.next(TableFilter.java:467) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.dml.Update.update(Update.java:102) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.dml.Merge.merge(Merge.java:154) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.dml.Merge.update(Merge.java:106) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.CommandContainer.update(CommandContainer.java:98) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.Command.executeUpdate(Command.java:258) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
... 7 common frames omitted
Caused by: java.nio.channels.ClosedChannelException: null
at sun.nio.ch.FileChannelImpl.ensureOpen(FileChannelImpl.java:110) ~[na:1.8.0_161]
at sun.nio.ch.FileChannelImpl.read(FileChannelImpl.java:721) ~[na:1.8.0_161]
at org.h2.store.fs.FileNio.read(FilePathNio.java:74) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.DataUtils.readFully(DataUtils.java:421) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
... 28 common frames omitted
20180731 10:01:40 [Scanner thread] INFO com.ubooquity.fileformat.pdf.b - Reading metadata of pdf file: /volume1/Books/2.7K IT Books/model-based_visual_tracking.pdf
20180731 10:01:40 [Scanner thread] INFO
com.ubooquity.data.database.a - Inserting/updating book entry in
database : /volume1/Books/2.7K IT Books/model-based_visual_tracking.pdf
20180731 10:01:40 [Scanner thread] ERROR com.ubooquity.data.database.a - Error while creating/updating book in database
org.h2.jdbc.JdbcSQLException:
General error: "java.lang.IllegalStateException: Reading from
nio:/volume1/homes/Ubooquity/.Ubooquity2/ubooquity-5.mv.db failed; file
length -1 read length 768 at 4085534 [1.4.193/1]"; SQL statement:
merge
into book(parentid, rootid, isdirectory, title, norm_title, authors,
norm_authors, description, language, norm_language, rating, seriesname,
norm_seriesname, seriesindex, filedate, filepath, filename,
norm_filename, identifier, publisher,
lastupdatedate,filesize,publicationdate,pagecount)
key(filepath)values(?, ?, ? ,? , ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?,
?, ?, ?, ?, ?, ?, ?) [50000-193]
at org.h2.message.DbException.getJdbcSQLException(DbException.java:345) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.message.DbException.get(DbException.java:168) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.message.DbException.convert(DbException.java:295) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.Command.executeUpdate(Command.java:266) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]

at
org.h2.jdbc.JdbcPreparedStatement.execute(JdbcPreparedStatement.java:201)
~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at com.ubooquity.data.database.a.a(SourceFile:987) [Ubooquity.jar:2.1.1]
at com.ubooquity.data.database.a.a(SourceFile:59) [Ubooquity.jar:2.1.1]
at com.ubooquity.data.feeder.a.a(SourceFile:221) [Ubooquity.jar:2.1.1]
at com.ubooquity.data.feeder.a.a(SourceFile:305) [Ubooquity.jar:2.1.1]
at com.ubooquity.data.feeder.a.b(SourceFile:105) [Ubooquity.jar:2.1.1]
at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_161]
Caused
by: java.lang.IllegalStateException: Reading from
nio:/volume1/homes/Ubooquity/.Ubooquity2/ubooquity-5.mv.db failed; file
length -1 read length 768 at 4085534 [1.4.193/1]
at org.h2.mvstore.DataUtils.newIllegalStateException(DataUtils.java:765) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.DataUtils.readFully(DataUtils.java:435) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.FileStore.readFully(FileStore.java:98) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.Page.read(Page.java:190) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.MVStore.readPage(MVStore.java:1954) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.MVMap.readPage(MVMap.java:736) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.Page.getChildPage(Page.java:217) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.Cursor.min(Cursor.java:129) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.Cursor.hasNext(Cursor.java:36) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]

at
org.h2.mvstore.db.TransactionStore$TransactionMap$1.fetchNext(TransactionStore.java:1388)
~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.db.TransactionStore$TransactionMap$1.(TransactionStore.java:1384) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]

at
org.h2.mvstore.db.TransactionStore$TransactionMap.keyIterator(TransactionStore.java:1379)
~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at
org.h2.mvstore.db.TransactionStore$TransactionMap.keyIterator(TransactionStore.java:1367)
~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.db.MVSecondaryIndex.find(MVSecondaryIndex.java:309) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.db.MVSecondaryIndex.find(MVSecondaryIndex.java:254) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.index.BaseIndex.find(BaseIndex.java:128) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.index.IndexCursor.find(IndexCursor.java:169) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.table.TableFilter.next(TableFilter.java:467) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.dml.Update.update(Update.java:102) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.dml.Merge.merge(Merge.java:154) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.dml.Merge.update(Merge.java:106) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.CommandContainer.update(CommandContainer.java:98) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.command.Command.executeUpdate(Command.java:258) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
... 7 common frames omitted
Caused by: java.nio.channels.ClosedChannelException: null
at sun.nio.ch.FileChannelImpl.ensureOpen(FileChannelImpl.java:110) ~[na:1.8.0_161]
at sun.nio.ch.FileChannelImpl.read(FileChannelImpl.java:721) ~[na:1.8.0_161]
at org.h2.store.fs.FileNio.read(FilePathNio.java:74) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
at org.h2.mvstore.DataUtils.readFully(DataUtils.java:421) ~[h2-1.4.193.jar.4067930195476961885.tmp:1.4.193]
... 28 common frames omitted
20180731 10:01:40 [Scanner thread]

so how do i get in touch with the developers to investigate the database corruption i am experiencing?

thanks.

adi

sorry, forgot to say, running on synology 918+ with os version 6.2