[jira] [Created] (LOG4J2-2060) AbstactDatabase appender issue with AsyncLogger

["Tolga Kavukcu (JIRA)" <ji...@apache.org>]

Tolga Kavukcu created LOG4J2-2060:
-------------------------------------

             Summary: AbstactDatabase appender issue with AsyncLogger
                 Key: LOG4J2-2060
                 URL: https://issues.apache.org/jira/browse/LOG4J2-2060
             Project: Log4j 2
          Issue Type: Bug
          Components: Appenders
    Affects Versions: 2.8.2, 2.8.1
            Reporter: Tolga Kavukcu


Log4j2 AsycLogger Implementation with a database appender has an issue.

As i investigated the async logger mechanism works like that.

Messages are put into DistruptorRingBuffer

Than

*RingBufferLogEventHandler*'s *onEvent* mehtod is called and message is passed to appender asyncronously.

In *AbstractDatabaseAppender* case

The messages also put into an *ArrayList* to make batches for bulk insert to table.


{code:java}
@Override
public final void append(final LogEvent event) {
    this.readLock.lock();
    try {
        this.getManager().write(event);
    } catch (final LoggingException e) {
        LOGGER.error("Unable to write to database [{}] for appender [{}].", this.getManager().getName(),
                this.getName(), e);
        throw e;
    } catch (final Exception e) {
        LOGGER.error("Unable to write to database [{}] for appender [{}].", this.getManager().getName(),
                this.getName(), e);
        throw new AppenderLoggingException("Unable to write to database in appender: " + e.getMessage(), e);
    } finally {
        this.readLock.unlock();
    }
}
{code}


Than *Abstract Database Manager* puts *LogEvent* into *ArrayList*


{code:java}
public final synchronized void write(final LogEvent event) {
    if (this.bufferSize > 0) {

        this.buffer.add(event);
        if (this.buffer.size() >= this.bufferSize || event.isEndOfBatch()) {
            this.flush();
        }
    } else {
        this.connectAndStart();
        try {
            this.writeInternal(event);
        } finally {
            this.commitAndClose();
        }
    }
}
{code}


After that correspoding *LogEvent* object can be re-used in the *DistruptorRingBuffer* mechanism.

So if a delay could happen in the database the *LogEvent* objects are overriden with same referance which causes inconsitency while preparing batches.

I believe this points to a bug or design problem. 

I would like to contribute solution if anyone can guide where to start what might be the possible design.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)