hplog
A High-Performance Logger

The hplog contains a high-performance logger interface.


Features:
  + Separate logger process so no log lines get lost on application crash
  + Buffered read and writes to increase performance
  + Automatically rotating logs with configurable number of backlogs
  + Configurable log size
  + up-to-date logfile (in spite of buffering)


Other interesting things:
  Uses 6 systems calls in underload situations per log line
    1 send() in the application
    1 nonblocking recv() in the log process
    1 select() in the log process
    1 recv() in the log process
    1 time() in the log process
    1 write() (called from fflush()) in the log process
  Uses LESS systems calls in overload situations per log line
    1 send in the application
    the kernel buffers several log lines into one chunk recevied by recv()
    for each chunk:
      1 recv()
      (select() and second recv() is optimized away)
      1 time()
     <1 write()  (is buffered into 32K chunks)


Compilation / use
  Compile hplogd.cc as a separate application
  Put it somewhere in your path

  Include hplog.cc in your normal application. If it is multithreaded make sure that you compile hplog.cc with -D_REENTRANT


Fan letters / suggestions:
  isj@dont_forget_to_remove_this.image.dk.invalid