CloudWatchLogWriter.java 文件源码

private List<LogMessage> attemptToSend(List<LogMessage> batch)
{
    if (batch.isEmpty())
        return batch;

    PutLogEventsRequest request = new PutLogEventsRequest()
                                  .withLogGroupName(groupName)
                                  .withLogStreamName(streamName)
                                  .withLogEvents(constructLogEvents(batch));

    // sending is all-or-nothing with CloudWatch; we'll return the entire batch
    // if there's an exception

    try
    {
        LogStream stream = findLogStream();
        request.setSequenceToken(stream.getUploadSequenceToken());
        client.putLogEvents(request);
        return Collections.emptyList();
    }
    catch (Exception ex)
    {
        LogLog.error("failed to send batch", ex);
        return batch;
    }
}