[DERBY-2749] Client connection closed during heavy load connections to network server

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 10.2.2.0
• Component/s: Network Server
• Environment: Sun JDK 1.5.0
• Assignee: Unassigned
• Reporter: Kurt Huwig
• Created: 03/Jun/07 07:23
• Updated: 06/Jul/09 18:09
• Resolved: 06/Jul/09 18:09

Description

I am using HA-JDBC to cluster two machines with ~3,5 GB of data. It is a mailserver which gets about 100 mails per minute with each mail causing several SQL reads and writes. After synchronizing the 3,5 GB which takes around 15 minutes, soon after that I get this exception:

Caused by: java.sql.SQLException: Unzureichende Daten beim Lesen aus dem Netz. Erwartet wurden mindestens 6 Bytes, empfangen wurden jedoch nur -1 Bytes. Die Verbindung wurde beendet.
at org.apache.derby.client.am.SQLExceptionFactory.getSQLException(Unknown Source)
at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.executeUpdate(Unknown Source)
at net.sf.hajdbc.sql.PreparedStatement$5.execute(PreparedStatement.java:144)
at net.sf.hajdbc.sql.PreparedStatement$5.execute(PreparedStatement.java:142)
at net.sf.hajdbc.sql.SQLObject$1.call(SQLObject.java:390)
at net.sf.hajdbc.util.concurrent.SynchronousExecutor$SynchronousFuture.<init>(SynchronousExecutor.java:178)
at net.sf.hajdbc.util.concurrent.SynchronousExecutor.submit(SynchronousExecutor.java:89)
at net.sf.hajdbc.sql.SQLObject.executeWriteToDatabase(SQLObject.java:394)
... 11 more
Caused by: org.apache.derby.client.am.DisconnectException: Unzureichende Daten beim Lesen aus dem Netz. Erwartet wurden mindestens 6 Bytes, empfangen wurden jedoch nur -1 Bytes. Die Verbindung wurde beendet.
at org.apache.derby.client.net.Reply.fill(Unknown Source)
at org.apache.derby.client.net.Reply.ensureALayerDataInBuffer(Unknown Source)
at org.apache.derby.client.net.Reply.readDssHeader(Unknown Source)
at org.apache.derby.client.net.Reply.startSameIdChainParse(Unknown Source)
at org.apache.derby.client.net.NetStatementReply.readExecute(Unknown Source)
at org.apache.derby.client.net.StatementReply.readExecute(Unknown Source)
at org.apache.derby.client.net.NetPreparedStatement.readExecute_(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.readExecute(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.flowExecute(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.executeUpdateX(Unknown Source)
... 18 more

The number of bytes read is in fact 0; I filed DERBY-2747 for this. I think the reason for this is the server issuing a Socket.close(). This seems to be called only by DRDAConnThread.closeSession() which is called by

• DRDAConnThread.handleException(Exception)
• DRDAConnThread.run()
• DRDAConnThread.sessionInitialState()

I did not set any timeslice, so the bugs mentioned in DERBY-2026 and DERBY-2748 should not apply. A timeout cannot happen on the client, as this would yield a SocketTimeoutException and not a read() of -1, so for some reason I believe, the server seems to close the connection.