IOUtils.copy throws IOException for files larger than ~1 mb - google-app-engine

Question

I'm using Apache Commons IO's IOUtils.copy to make copies of existing files, on Google Cloud Storage.
Here is the problem: if the files goes beyond around 1 mb, IOUtils.copy will throw an exception. Files below 1 mb works perfectly fine.
Code snippet
AppEngineFile newFile = null;
GSFileOptionsBuilder optionsBuilder = new GSFileOptionsBuilder().setBucket("bucket-name")
.setKey(newFilename).setMimeType("image/jpeg");
try {
//currentFile is an instance of a AppEngineFile
FileReadChannel readChannel = fileService.openReadChannel(currentFile, true);
newFile = fileService.createNewGSFile(optionsBuilder.build());
FileWriteChannel writeChannel = fileService.openWriteChannel(newFile, true);
InputStream inputStream = Channels.newInputStream(readChannel);
OutputStream outputStream = Channels.newOutputStream(writeChannel);
IOUtils.copy(inputStream, outputStream);
outputStream.flush();
outputStream.close();
inputStream.close();
writeChannel.closeFinally();
} catch (IOException e) {
log.warning(e.toString());
}
I also attempted a more primitive method: but it doesn't work too
byte[] buffer = new byte[1024];
int len = inputStream.read(buffer);
while (len != -1) {
outputStream.write(buffer, 0, len);
len = inputStream.read(buffer);
}
My assumption now: there is some kind of restriction on the App Engine platform.
Note: I've also tried IOUtiles.copyLarge (which is meant for files larger than 2 GB), but it doesn't work too.

Answer 1

Try using a smaller than 1mb buffer. Latest appengine version reduced buffer size.