[LOG4J2-438] JDBCDatabaseManager does not send commit command

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0-beta9
• Fix Version/s: 2.0-rc1
• Component/s: Appenders

Environment

Java 7u45, Windows, H2

• Assignee: Nick Williams
• Reporter: Ralph Schaer
• Created: 27/Oct/13 14:47
• Updated: 08/Feb/14 03:01
• Resolved: 08/Feb/14 02:57

Description

I'm fiddling with the log4j jdbc appender and found an issue with datasources that have the flag defaultAutoCommit set to false. With such datasources the application has to call the method connection.commit() after an update statement, if omitted nothing will be updated or inserted in the database.

That is the problem with the class JDBCDatabaseManager. It executes the statement (with this.statement.executeUpdate()) but does not call commit. Nothing is inserted if the defaultAutoCommit flag of the datasource is set to false.

One possible solution is to check the autoCommit flag of the datasource and call commit when it's set to false.

if (this.statement.executeUpdate() == 0) {
throw new AppenderLoggingException(
"No records inserted in database table for log event in JDBC manager.");
}

if (!this.connection.getAutoCommit()) {
this.connection.commit();
}

Maybe this has to be done differently when a buffer is used. The method AbstractDatabaseManager.flush should only call commit after the loop.

if (this.isConnected() && this.buffer.size() > 0) {
for (final LogEvent event : this.buffer)

{ this.writeInternal(event); }

if (!connection.getAutoCommit())

{ connection.commit(); }

this.buffer.clear();
}

Or maybe using the batch methods of jdbc would improve the performance even more

if (this.isConnected() && this.buffer.size() > 0) {
for (final LogEvent event : this.buffer)

{ //create statement ....... statement.addBatch() }

statement.executeBatch();
if (!connection.getAutoCommit())

{ connection.commit(); }

this.buffer.clear();
}

Issue Links

• is related to: LOG4J2-442 Log4j2 Database insert problem in Websphere
• is related to: LOG4J2-407 JDBCAppender cannot recover from loss of database connectivity
• is related to: LOG4J2-457 JDBCAppender does not release JDBC connections to the connection pool when WAR/EAR is stopped
• is related to: LOG4J2-489 Should JPADatabaseManager being using so many transactions?
• relates to: LOG4J2-442 Log4j2 Database insert problem in Websphere
• relates to: LOG4J2-407 JDBCAppender cannot recover from loss of database connectivity
• relates to: LOG4J2-457 JDBCAppender does not release JDBC connections to the connection pool when WAR/EAR is stopped
• relates to: LOG4J2-489 Should JPADatabaseManager being using so many transactions?