We already use a bit of NIO (ByteBuffer for layouts and appenders/managers, MappedByteBuffer for mmap'd files, FileLock for locking files, etc.), and I've been playing around with the NIO API lately. I have some sample code here <https://github.com/jvz/nio-logger> to show some trivial use case of AsynchronousFileChannel. In Java 7, there is also AsynchronousSocketChannel which could theoretically be used instead of adding Netty for a faster socket appender. In that regard, I'm curious as to how useful it would be to have similar appenders as the OutputStream ones, but instead using WritableByteChannel, GatheringByteChannel (possible parallelization of file writing?), and the async channels (there's an AsynchronousByteChannel class, but I think they screwed this one up as only one of the three async channel classes implements it).
Another related issue I've seen is that in a message-oriented appender (e.g., the Kafka one), being able to stream directly to a ByteBuffer is not the right way to go about encoding log messages into the appender. Instead, I was thinking that a pool of reusable ByteBuffers could be used here where a ByteBuffer is borrowed on write and returned on completion (via a CompletionHandler callback). The Kafka client uses a similar strategy for producing messages by dynamically allocating a pool of ByteBuffers based on available memory. Also, I don't have much experience with this, but if we had a pool of reusable ByteBuffers, could we use direct allocation to get off-heap buffers? That seems like an interesting use case. -- Matt Sicker <boa...@gmail.com>
