I am experimenting with an Avro layout:
https://github.com/apache/logging-log4j-plugins/tree/avro-layout
It happens to be the case that the generated Avro value class implements
Serializable, but is it appropriate to return that? Or should it return
null? What if you want to make another binary layout, and no such
Serializable class exist?
Maybe the Layout.toSerializable method should be documented to allow
null return, and all call sites adapted to handle that it returns null
(unless they assume a specific layout)?
On 2018-01-16 17:35, Ralph Goers wrote:
Well, in looking at the various uses of that method I am a bit confused.
1. The JMSAppender will use Java serialization if it isn’t a MapMessage or a
String.
2. CassandraManager uses some sort of TypeConverter to convert the Serializable
- but it only seems to handle a limited set of types. For example, using a
LogEventProxy will result in a null value being inserted.
3. NoSQLDatabaseManager only uses the serializable form if it is a MapMessage.
4. What JdbcDatabaseManager does seems to depend on what the column type is.
Those are pretty much the only usages I have seen. So what should be done
depends on how it would apply to any one of those cases. I suspect you are
correct Remko, and that it should just return the byte array.
Ralph
On Jan 16, 2018, at 8:38 AM, Remko Popma <[email protected]> wrote:
I think what Mikael meant is that Serializable is just a marker interface
that does not provide any guidance on what methods to call on it to turn
the result into bytes.
Unless we want to use java serialization, and I presume one of the main
reasons for creating a custom binary layout (other than performance) is to
avoid java serialization and the associated security risks.
How should a custom binary layout turn the result of `toSerializable` into
bytes without using java serialization? - may be the question that Mikael
is trying to answer. Correct me if I'm wrong, Mikael.
I think a custom binary layout should just return the bytes it produced
itself. Either as a byte array or as a ByteBuffer.
On Wed, Jan 17, 2018 at 12:23 AM, Ralph Goers <[email protected]>
wrote:
I think MessageLayout is a special case as it only returns the message
portion of the LogEvent. Most Layouts return all of the LogEvent
attributes. Even so, you could have AbstractLayout<LogEventProxy> if you
wanted the serialized version of the LogEvent. It can also be anything else
that implements Serializable.
Ralph
On Jan 16, 2018, at 8:06 AM, Remko Popma <[email protected]> wrote:
Doesn't that depend on the generic type T of the Layout<T>?
For example, MessageLayout extends AbstractLayout<Message> returns a
Message instance.
You could return a ByteBuffer, but generally for an efficient binary
layout
I would look at the encode method instead.
On Tue, Jan 16, 2018 at 11:45 PM, Mikael Ståldal <[email protected]>
wrote:
How is a binary layout (extending AbstractLayout) supposed to implement
the toSerializable method in the Layout interface?
Why is that method there?
