Hi gzip maintainers! In the course of trying to use gzip as a stream-compressor with Apache's "piped logs" feature I hit what I think is a bug in gzip. Additionally, using gzip as a stream log compressor triggered two related "feature requests".
For the time being, I have rolled my own mini-reimplementation of gzip.c (in python, I was in a rush...) and the tool I will describe below. However, I think these improvements belong in gzip proper. Bug: gzip.c discards its buffers when it gets SIGTERM, with no effort made to flush them to disk. Logging via gzip adds buffering, when apache is stopped (or restarted, usually daily to rotate logs), apache sends SIGTERM before it closes the fh; gzip discards everything it has buffered. [ Apache logs are highly compressible, so the loss is quite significant! ] Feature requests: - for debugging / diagnostics of live services, gzip (when in "stream" mode) should flush its buffers to disk when it receives a SIGUSR1 - zcat needs to support a "followtail" option, where it reads to the end of an open gzipped file and then "follows" it (as in tail -f). This tool would be one user of the "flush on SIGUSR1" feature. Working implementations of "compresslog" (a gzip-stream-compressor) and "ztail", implemented in Python, are available here: http://repo.or.cz/w/compresslog.git Is there any interest in this? I am not familiar with gzip.c sources; and hesitant to throw a lot of effort without hearing from the maintainers. cheers, m -- martin.langh...@gmail.com - ask interesting questions - don't get distracted with shiny stuff - working code first ~ http://docs.moodle.org/en/User:Martin_Langhoff
