DB restart required between oelt runs for OpenBeerDB tutorial

[Sygyzmundovych]

I am going through http://orientdb.com/docs/3.0.x/gettingstarted/tutorials/Import-the-Database-of-Beers.html tutorial. To be able to load each file I needed to shutdown (Ctrl+C) and to start the database before every load (I do not know what is other way to restart the server, or to close and reopen a database).

On Win10 I was not getting any messages (see issue #335), but on Linux (using docker on Google Cloud Shell) I am getting mesages from oetl, and see the following:

...
2018-11-12 12:10:20:173 INFO  Started execution with 1 worker threads [OETLProcessor]Exception `5AEBE890` in storage `plocal:/orientdb/bin/../databases//openbeerdb`: 3.0.10 - Veloce (build eac0654847df662ca03b45a6a5efa5eadd229ca5, branch 3.0.x)
com.orientechnologies.orient.core.exception.OStorageException: Database is locked by another process, please shutdown process and try again
        at com.orientechnologies.orient.core.storage.impl.local.paginated.OPaginatedStorageDirtyFlag.lockFile(OPaginatedStorageDirtyFlag.java:102)
        at com.orientechnologies.orient.core.storage.impl.local.paginated.OPaginatedStorageDirtyFlag.open(OPaginatedStorageDirtyFlag.java:127)
        at com.orientechnologies.orient.core.storage.impl.local.paginated.OLocalPaginatedStorage.preOpenSteps(OLocalPaginatedStorage.java:430)
        at com.orientechnologies.orient.core.storage.impl.local.OAbstractPaginatedStorage.open(OAbstractPaginatedStorage.java:383)
        at com.orientechnologies.orient.core.db.OrientDBEmbedded.poolOpen(OrientDBEmbedded.java:280)
        at com.orientechnologies.orient.core.db.ODatabasePoolImpl$1.createNewResource(ODatabasePoolImpl.java:43)
        at com.orientechnologies.orient.core.db.ODatabasePoolImpl$1.createNewResource(ODatabasePoolImpl.java:40)
        at com.orientechnologies.common.concur.resource.OResourcePool.getResource(OResourcePool.java:95)
        at com.orientechnologies.orient.core.db.ODatabasePoolImpl.acquire(ODatabasePoolImpl.java:61)
        at com.orientechnologies.orient.core.db.ODatabasePool.acquire(ODatabasePool.java:132)
        at com.orientechnologies.orient.etl.loader.OETLOrientDBLoader.beginLoader(OETLOrientDBLoader.java:412)
        at com.orientechnologies.orient.etl.OETLPipeline.begin(OETLPipeline.java:64)
        at com.orientechnologies.orient.etl.OETLPipelineWorker.<init>(OETLPipelineWorker.java:34)
        at com.orientechnologies.orient.etl.OETLProcessor.lambda$runExtractorAndPipeline$0(OETLProcessor.java:193)
        at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
        at java.util.stream.IntPipeline$4$1.accept(IntPipeline.java:250)
        at java.util.stream.Streams$RangeIntSpliterator.forEachRemaining(Streams.java:110)
        at java.util.Spliterator$OfInt.forEachRemaining(Spliterator.java:693)
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
        at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
        at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
        at com.orientechnologies.orient.etl.OETLProcessor.runExtractorAndPipeline(OETLProcessor.java:195)
        at com.orientechnologies.orient.etl.OETLProcessor.execute(OETLProcessor.java:171)
        at com.orientechnologies.orient.etl.OETLProcessor.main(OETLProcessor.java:114)

2018-11-12 12:10:20:293 SEVER ETL process has problem:  [OETLProcessor]
...

I see this is happening if I am checking loaded data after each load by logging via the CLI console or web studio. Now that I did not check data, but ran four loads right after each other then all are executed and all data is loaded into the database.

C:\Tools\orientdb-3.0.10\bin>oetl.bat ".....\Datasets\open-beer-database-dumps-brewdega\categories.json"
OrientDB etl v.3.0.10 - Veloce (build eac0654847df662ca03b45a6a5efa5eadd229ca5, branch 3.0.x) https://www.orientdb.com
C:\Tools\orientdb-3.0.10\bin>oetl.bat ".....\Datasets\open-beer-database-dumps-brewdega\styles.json"
OrientDB etl v.3.0.10 - Veloce (build eac0654847df662ca03b45a6a5efa5eadd229ca5, branch 3.0.x) https://www.orientdb.com
C:\Tools\orientdb-3.0.10\bin>oetl.bat ".....\Datasets\open-beer-database-dumps-brewdega\breweries.json"
OrientDB etl v.3.0.10 - Veloce (build eac0654847df662ca03b45a6a5efa5eadd229ca5, branch 3.0.x) https://www.orientdb.com
C:\Tools\orientdb-3.0.10\bin>oetl.bat ".....\Datasets\open-beer-database-dumps-brewdega\beers.json"
OrientDB etl v.3.0.10 - Veloce (build eac0654847df662ca03b45a6a5efa5eadd229ca5, branch 3.0.x) https://www.orientdb.com
C:\Tools\orientdb-3.0.10\bin>

[luigidellaquila]

Hi @Sygyzmundovych

Thank you for pointing it out, I'm adding a note to the tutorial.
This is an expected behavior: to avoid conflicts, two JVM processes (eg. an ETL and an OrientDB server) cannot access the same DB folders

Thanks

Luigi