Metastore error while launching multiple Jupyter Spark notebooks from same directory - apache-spark

Question

I am running a Jupyter Notebook (Jupyter 1.0.0) with Spark (Spark 2.1.0) and am successfully able to run Pyspark code. But when I launch two notebooks that are located under same directory as shown below:
notebooks
|__ Notebook1
|__ Notebook2
and launch Notebook1 and then launch Notebook2, Notebook1 launches and works successfully but the Notebook2 does not launch successfully due to Spark Context initiation errors. It looks like it is something to do with the spark metastore.
Below is the stack trace from Spark:
Caused by: ERROR XSDB6: Another instance of Derby may have already booted the database XXXXXXXX/notebooks/metastore_db.
at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
at org.apache.derby.iapi.error.StandardException.newException(Unknown Source)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.privGetJBMSLockOnDB(Unknown Source)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.getJBMSLockOnDB(Unknown Source)
at org.apache.derby.impl.store.raw.data.BaseDataFileFactory.boot(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.startModule(Unknown Source)
at org.apache.derby.impl.services.monitor.FileMonitor.startModule(Unknown Source)
at org.apache.derby.iapi.services.monitor.Monitor.bootServiceModule(Unknown Source)
at org.apache.derby.impl.store.raw.RawStore$6.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.derby.impl.store.raw.RawStore.bootServiceModule(Unknown Source)
at org.apache.derby.impl.store.raw.RawStore.boot(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.startModule(Unknown Source)
at org.apache.derby.impl.services.monitor.FileMonitor.startModule(Unknown Source)
at org.apache.derby.iapi.services.monitor.Monitor.bootServiceModule(Unknown Source)
at org.apache.derby.impl.store.access.RAMAccessManager$5.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.derby.impl.store.access.RAMAccessManager.bootServiceModule(Unknown Source)
at org.apache.derby.impl.store.access.RAMAccessManager.boot(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.startModule(Unknown Source)
at org.apache.derby.impl.services.monitor.FileMonitor.startModule(Unknown Source)
at org.apache.derby.iapi.services.monitor.Monitor.bootServiceModule(Unknown Source)
at org.apache.derby.impl.db.BasicDatabase$5.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.derby.impl.db.BasicDatabase.bootServiceModule(Unknown Source)
at org.apache.derby.impl.db.BasicDatabase.bootStore(Unknown Source)
at org.apache.derby.impl.db.BasicDatabase.boot(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.boot(Unknown Source)
at org.apache.derby.impl.services.monitor.TopService.bootModule(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.bootService(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.startProviderService(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.findProviderAndStartService(Unknown Source)
at org.apache.derby.impl.services.monitor.BaseMonitor.startPersistentService(Unknown Source)
at org.apache.derby.iapi.services.monitor.Monitor.startPersistentService(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection$4.run(Unknown Source)
at org.apache.derby.impl.jdbc.EmbedConnection$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.derby.impl.jdbc.EmbedConnection.startPersistentService(Unknown Source)

Answer 1

It looks like your issue may be with Derby, Sparks default database for storing its instructions to itself. Derby can only be used by one entity at a time, So starting a second Notebook confuses it. I ran into this problem myself, and solved it by connecting Spark to Postgres instead.
Check out this answer and see if it works for you:
How to run multiple instances of spark 2.0