[logback-user] Migrating from log4j: replacing JDBCAppender

[Paul Gifford]

I wrote a custom database appender and I just extended
AppenderBase<ILoggingEvent>.  In the start() method I get the DataSource
from a JNDI lookup.  Since I'm using Spring JDBC under the hood I use the
DataSource to instantiate a JDBCTemplate which is used in the append()
method.

Paul



On Sun, Oct 16, 2011 at 7:51 PM, Stevo Slavić <sslavic at gmail.com> wrote:

> Hello Logback users,
>
> As subject states, I'm trying to migrate a project from log4j to
> logback, and need to replace log4j JDBCAppender.
>
> I've found following related stackoverflow questions:
>
> -
> http://stackoverflow.com/questions/1364322/log-to-a-database-using-log4j/1366684#1366684
> - http://stackoverflow.com/questions/7659837/logback-dbappender-custom-sql
>
> DBAppender is nice, but it's not 1-to-1 replacement for log4j's
> JDBCAppender, since it mandates what gets logged, db layout (number of
> tables and columns) and thus SQL statements number and layout (number
> of and indexes of parameters).
>
> Trying now to implement custom extension of DBAppenderBase to achieve the
> goal.
>
> It would be great if in the logback DB appender hierarchy was
> additional level, before DBAppenderBase which would abstract away just
> ConnectionSource related logic, so without subAppend,
> secondarySubAppend, or selectEventId.
>
> Also, to support using to-be-append logging event when generating
> insert SQL (e.g. using PatternLayout) it would be good if getInsertSQL
> would receive ILoggingEvent.
>
> Now when implementing JDBCAppender which extends DBAppenderBase I have
> lots of abstract methods "do-nothing" implementations, pattern layout
> configured with insert statement SQL and following relevant code:
>
>
>        protected Layout<ILoggingEvent> layout;
>
>        protected void setLayout(Layout<ILoggingEvent> layout) {
>                this.layout = layout;
>        }
>
>        protected String getInsertSQL(ILoggingEvent event) {
>                return layout.doLayout(event);
>        }
>
>        @Override
>        public void append(ILoggingEvent eventObject) {
>                Connection connection = null;
>                try {
>                        connection = connectionSource.getConnection();
>                        connection.setAutoCommit(false);
>                        PreparedStatement insertStatement;
>
>                        insertStatement = connection
>
>  .prepareStatement(getInsertSQL(eventObject));
>
>                        int updateCount = insertStatement.executeUpdate();
>                        if (updateCount != 1) {
>                              addWarn("Failed to insert loggingEvent");
>                        }
>
>                        // we no longer need the insertStatement
>                        close(insertStatement);
>                        insertStatement = null;
>
>                        connection.commit();
>                } catch (Throwable sqle) {
>                        addError("problem appending event", sqle);
>                } finally {
>                        DBHelper.closeConnection(connection);
>                }
>        }
>
>
>
> What do you think about improvement requests? Should I log them in JIRA?
>
> Any thoughts on this JDBCAppender replacement? What will be the
> penalty for generating insert statement SQL for every logging event
> using Layout?
>
> Regards,
> Stevo.
> _______________________________________________
> Logback-user mailing list
> Logback-user at qos.ch
> http://mailman.qos.ch/mailman/listinfo/logback-user
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qos.ch/pipermail/logback-user/attachments/20111017/5e796338/attachment.html>