Errors from sql-server

[ericmock]

This may just be the particular Java connection layer I'm using, but when I do:

select homepage_url, count(*) as cnt from hospitals h where chargemaster_indirect_url is null group by homepage_url;

everything is fine. However, when I do

select homepage_url, count(*) as cnt from hospitals h where chargemaster_indirect_url is null group by homepage_url order by cnt;

I get "Socket error"

[fulghum]

Thanks for reporting this one @ericmock. Can you share any more details about the Java connection layer you're using? Is it just over the standard MySQL ConnectorJ JDBC library, or is there another library/tool in there somewhere?

@jennifersp – could you try to repro this one today? Adding it to the client integration tests could be an easy way to run it over a JDBC connection.

[ericmock]

I'm just using DBeaver (on Manjaro). The error log is below if it's useful. Since updating to the latest version, I'm seeing this quite often (but seemingly randomly). This was one case where I could reliably reproduce.

org.jkiss.dbeaver.model.sql.DBSQLException: SQL Error [08000]: (conn=114) Socket error
	at org.jkiss.dbeaver.model.impl.jdbc.exec.JDBCStatementImpl.executeStatement(JDBCStatementImpl.java:133)
	at org.jkiss.dbeaver.ui.editors.sql.execute.SQLQueryJob.executeStatement(SQLQueryJob.java:578)
	at org.jkiss.dbeaver.ui.editors.sql.execute.SQLQueryJob.lambda$1(SQLQueryJob.java:487)
	at org.jkiss.dbeaver.model.exec.DBExecUtils.tryExecuteRecover(DBExecUtils.java:173)
	at org.jkiss.dbeaver.ui.editors.sql.execute.SQLQueryJob.executeSingleQuery(SQLQueryJob.java:494)
	at org.jkiss.dbeaver.ui.editors.sql.execute.SQLQueryJob.extractData(SQLQueryJob.java:913)
	at org.jkiss.dbeaver.ui.editors.sql.SQLEditor$QueryResultsContainer.readData(SQLEditor.java:3726)
	at org.jkiss.dbeaver.ui.controls.resultset.ResultSetJobDataRead.lambda$0(ResultSetJobDataRead.java:123)
	at org.jkiss.dbeaver.model.exec.DBExecUtils.tryExecuteRecover(DBExecUtils.java:173)
	at org.jkiss.dbeaver.ui.controls.resultset.ResultSetJobDataRead.run(ResultSetJobDataRead.java:121)
	at org.jkiss.dbeaver.ui.controls.resultset.ResultSetViewer$ResultSetDataPumpJob.run(ResultSetViewer.java:4982)
	at org.jkiss.dbeaver.model.runtime.AbstractJob.run(AbstractJob.java:105)
	at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)
Caused by: java.sql.SQLNonTransientConnectionException: (conn=114) Socket error
	at org.mariadb.jdbc.export.ExceptionFactory.createException(ExceptionFactory.java:291)
	at org.mariadb.jdbc.export.ExceptionFactory.create(ExceptionFactory.java:357)
	at org.mariadb.jdbc.client.impl.StandardClient.readPacket(StandardClient.java:856)
	at org.mariadb.jdbc.client.impl.StandardClient.readResults(StandardClient.java:772)
	at org.mariadb.jdbc.client.impl.StandardClient.readResponse(StandardClient.java:691)
	at org.mariadb.jdbc.client.impl.StandardClient.execute(StandardClient.java:634)
	at org.mariadb.jdbc.Statement.executeInternal(Statement.java:935)
	at org.mariadb.jdbc.Statement.execute(Statement.java:1061)
	at org.mariadb.jdbc.Statement.execute(Statement.java:452)
	at org.jkiss.dbeaver.model.impl.jdbc.exec.JDBCStatementImpl.execute(JDBCStatementImpl.java:329)
	at org.jkiss.dbeaver.model.impl.jdbc.exec.JDBCStatementImpl.lambda$0(JDBCStatementImpl.java:131)
	at org.jkiss.dbeaver.utils.SecurityManagerUtils.wrapDriverActions(SecurityManagerUtils.java:96)
	at org.jkiss.dbeaver.model.impl.jdbc.exec.JDBCStatementImpl.executeStatement(JDBCStatementImpl.java:131)
	... 12 more
Caused by: java.io.EOFException: unexpected end of stream, read 0 bytes from 4 (socket was closed by server)
	at org.mariadb.jdbc.client.socket.impl.PacketReader.readPacket(PacketReader.java:78)
	at org.mariadb.jdbc.message.ClientMessage.readPacket(ClientMessage.java:118)
	at org.mariadb.jdbc.client.impl.StandardClient.readPacket(StandardClient.java:833)
	... 22 more

[fulghum]

Perfect! This is super helpful; thank you! We'll try to repro with DBeaver. I also notice that DBeaver is using the MariaDB JDBC driver. We have Java tests with the MySQL ConnectorJ driver, but I'm not sure that we have tests for the MariaDB driver. We'll look into adding that as well.

[ericmock]

FYI...

org.jkiss.dbeaver.model.sql.DBSQLException: SQL Error [08S01]: Communications link failure

The last packet successfully received from the server was 6 milliseconds ago. The last packet sent successfully to the server was 7 milliseconds ago.
at org.jkiss.dbeaver.model.impl.jdbc.exec.JDBCStatementImpl.executeStatement(JDBCStatementImpl.java:133)
at org.jkiss.dbeaver.ui.editors.sql.execute.SQLQueryJob.executeStatement(SQLQueryJob.java:578)
at org.jkiss.dbeaver.ui.editors.sql.execute.SQLQueryJob.lambda$1(SQLQueryJob.java:487)
at org.jkiss.dbeaver.model.exec.DBExecUtils.tryExecuteRecover(DBExecUtils.java:173)
at org.jkiss.dbeaver.ui.editors.sql.execute.SQLQueryJob.executeSingleQuery(SQLQueryJob.java:494)
at org.jkiss.dbeaver.ui.editors.sql.execute.SQLQueryJob.extractData(SQLQueryJob.java:913)
at org.jkiss.dbeaver.ui.editors.sql.SQLEditor$QueryResultsContainer.readData(SQLEditor.java:3726)
at org.jkiss.dbeaver.ui.controls.resultset.ResultSetJobDataRead.lambda$0(ResultSetJobDataRead.java:123)
at org.jkiss.dbeaver.model.exec.DBExecUtils.tryExecuteRecover(DBExecUtils.java:173)
at org.jkiss.dbeaver.ui.controls.resultset.ResultSetJobDataRead.run(ResultSetJobDataRead.java:121)
at org.jkiss.dbeaver.ui.controls.resultset.ResultSetViewer$ResultSetDataPumpJob.run(ResultSetViewer.java:4982)
at org.jkiss.dbeaver.model.runtime.AbstractJob.run(AbstractJob.java:105)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)
Caused by: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet successfully received from the server was 6 milliseconds ago. The last packet sent successfully to the server was 7 milliseconds ago.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.StatementImpl.executeInternal(StatementImpl.java:763)
at com.mysql.cj.jdbc.StatementImpl.execute(StatementImpl.java:648)
at org.jkiss.dbeaver.model.impl.jdbc.exec.JDBCStatementImpl.execute(JDBCStatementImpl.java:329)
at org.jkiss.dbeaver.model.impl.jdbc.exec.JDBCStatementImpl.lambda$0(JDBCStatementImpl.java:131)
at org.jkiss.dbeaver.utils.SecurityManagerUtils.wrapDriverActions(SecurityManagerUtils.java:96)
at org.jkiss.dbeaver.model.impl.jdbc.exec.JDBCStatementImpl.executeStatement(JDBCStatementImpl.java:131)
... 12 more
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure

The last packet successfully received from the server was 6 milliseconds ago. The last packet sent successfully to the server was 7 milliseconds ago.
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.base/java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:581)
at com.mysql.cj.protocol.a.NativeProtocol.checkErrorMessage(NativeProtocol.java:761)
at com.mysql.cj.protocol.a.NativeProtocol.sendCommand(NativeProtocol.java:700)
at com.mysql.cj.protocol.a.NativeProtocol.sendQueryPacket(NativeProtocol.java:1051)
at com.mysql.cj.protocol.a.NativeProtocol.sendQueryString(NativeProtocol.java:997)
at com.mysql.cj.NativeSession.execSQL(NativeSession.java:663)
at com.mysql.cj.jdbc.StatementImpl.executeInternal(StatementImpl.java:723)
... 17 more
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
at com.mysql.cj.protocol.FullReadInputStream.readFully(FullReadInputStream.java:67)
at com.mysql.cj.protocol.a.SimplePacketReader.readHeaderLocal(SimplePacketReader.java:81)
at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:63)
at com.mysql.cj.protocol.a.SimplePacketReader.readHeader(SimplePacketReader.java:45)
at com.mysql.cj.protocol.a.TimeTrackingPacketReader.readHeader(TimeTrackingPacketReader.java:52)
at com.mysql.cj.protocol.a.TimeTrackingPacketReader.readHeader(TimeTrackingPacketReader.java:41)
at com.mysql.cj.protocol.a.MultiPacketReader.readHeader(MultiPacketReader.java:54)
at com.mysql.cj.protocol.a.MultiPacketReader.readHeader(MultiPacketReader.java:44)
at com.mysql.cj.protocol.a.NativeProtocol.readMessage(NativeProtocol.java:575)
... 23 more

[ericmock]

Same issue. Works without the order by but not with it.

[jennifersp]

Hi @ericmock, thank you for issuing this bug! I found where the issue is coming from and will get the fix in as soon as I can.

[jennifersp]

The fix will be merged into dolt very soon, and it will be out in the next Dolt release. A workaround for this bug is that you can set arbitrary limit (that is bigger than the number of query result) without offset for the query; for example,

select homepage_url, count(*) as cnt from hospitals h where chargemaster_indirect_url is null group by homepage_url order by cnt limit 5000;

[ericmock]

Great work!

[jennifersp]

Fixed by dolthub/go-mysql-server#1414