Caused by: ERROR XSDB6: Another instance of Derby may have already booted the database

问题

I am trying to run SparkSQL :

val sqlContext = new org.apache.spark.sql.hive.HiveContext(sc)

But the error i m getting is below:

        ... 125 more
Caused by: java.sql.SQLException: Another instance of Derby may have already booted the database /root/spark/bin/metastore_db.
        at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
        at org.apache.derby.impl.jdbc.SQLExceptionFactory40.wrapArgsForTransportAcrossDRDA(Unknown Source)
        at org.apache.derby.impl.jdbc.SQLExceptionFactory40.getSQLException(Unknown Source)
        at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
        ... 122 more
Caused by: ERROR XSDB6: Another instance of Derby may have already booted the database /root/spark/bin/metastore_db.
        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)

I see there is a metastore_db folder exists..
My hive metastore includes mysql as metastore.But not sure why the error shows as derby execption

回答1:

I was getting the same error while creating Data frames on Spark Shell :

Caused by: ERROR XSDB6: Another instance of Derby may have already booted the database /metastore_db.

Cause:

I found that this is happening as there were multiple other instances of Spark-Shell already running and holding derby DB already, so when i was starting yet another Spark Shell and creating Data Frame on it using RDD.toDF() it was throwing error:

Solution:

I ran the ps command to find other instances of Spark-Shell:

ps -ef | grep spark-shell

and i killed them all using kill command:

kill -9 Spark-Shell-processID ( example: kill -9 4848)

after all the SPark-Shell instances were gone, i started a new SPark SHell and reran my Data frame function and it ran just fine :)

回答2:

If you're running in spark shell, you shouldn't instantiate a HiveContext, there's one created automatically called sqlContext (the name is misleading - if you compiled Spark with Hive, it will be a HiveContext). See similar discussion here.

If you're not running in shell - this exception means you've created more than one HiveContext in the same JVM, which seems to be impossible - you can only create one.

回答3:

Another case where you can see the same error is a Spark REPL of an AWS Glue dev endpoint, when you are trying to convert a dynamic frame into a dataframe.

There are actually several different exceptions like:

pyspark.sql.utils.IllegalArgumentException: u"Error while instantiating 'org.apache.spark.sql.hive.HiveSessionState':"
ERROR XSDB6: Another instance of Derby may have already booted the database /home/glue/metastore_db.
java.sql.SQLException: Failed to start database 'metastore_db' with class loader org.apache.spark.sql.hive.client.IsolatedClientLoader

The solution is hard to find with google but eventually it is described here.

The loaded REPL contains an instantiated SparkSession in a variable spark and you just need to stop it before creating a new SparkContext:

>>> spark.stop()
>>> from pyspark.context import SparkContext
>>> from awsglue.context import GlueContext
>>>
>>> glue_context = GlueContext(SparkContext.getOrCreate())
>>> glue_frame = glue_context.create_dynamic_frame.from_catalog(database=DB_NAME, table_name=T_NAME)
>>> df = glue_frame.toDF()

回答4:

If you are facing issue during bringing up WAS application on windows machine:

kill java processes using task manager
delete db.lck file present in WebSphere\AppServer\profiles\AppSrv04\databases\EJBTimers\server1\EJBTimerDB (My DB is EJBTimerDB which was causing issue)
restart application.

回答5:

I was facing the same issue while creating table.

sqlContext.sql("CREATE TABLE....

I could see many entries for ps -ef | grep spark-shell so I killed all of them and restarted spark-shell. It worked for me.

回答6:

This happened when I was using pyspark ml Word2Vec. I was trying to load previously built model. Trick is, just create empty data frame of pyspark or scala using sqlContext. Following is the python syntax -

from pyspark.sql.types import StructType

schema = StructType([])`
empty = sqlContext.createDataFrame(sc.emptyRDD(), schema)

This is a workaround. My problem fixed after using this block. Note - It only occurs when you instantiate sqlContext from HiveContext, not SQLContext.

回答7:

I got this error by running sqlContext._get_hive_ctx() This was caused by initially trying to load a pipelined RDD into a dataframe I got the error Exception: ("You must build Spark with Hive. Export 'SPARK_HIVE=true' and run build/sbt assembly", Py4JJavaError(u'An error occurred while calling None.org.apache.spark.sql.hive.HiveContext.\n', JavaObject id=o29)) So you could running this before rebuilding it, but FYI I have seen others reporting this did not help them.

回答8:

The error came because of the multiple spark shell you are trying to run in same node or due to system failure its shut down without proper exit the spark shell, In any of the reason you just find out the process id and kill them, for that us

[hadoop@localhost ~]$ ps -ef | grep spark-shell
hadoop    11121   9197  0 17:54 pts/0    00:00:00 grep --color=auto spark-shell
[hadoop@localhost ~]$ kill 9197

回答9:

an lck(lock) file is an access control file which locks the database so that only a single user can access or update the database. The error suggests that there is another instance which is using the same database. Thus you need to delete the .lck files. In your home directory, go to metastore_db and delete any .lck files.

回答10:

its very difficult to find where your derby metastore_db is access by another thread, if you are able to find the process then you can kill it using kill command.

Best solutions to restart the system.

来源：https://stackoverflow.com/questions/34465516/caused-by-error-xsdb6-another-instance-of-derby-may-have-already-booted-the-da

标签

Hadoop

apache-spark

derby