This log line
Code:
230608 15:13:09.477(T684396)(156) DEBUG/phex.download.DownloadDataWriter [SWDownloadWorker-55a0eb24-PhexPool-thread-15]:: Triggering write cycle.
indicates that thread-15 is telling the DownloadDataWriter thread that his buffer is full. You could see multiple threads calling this or the same thread calling this very often. Its only a wake up call to the DownloadDataWriter thread to start flushing the buffers.