22.01.2010 14:50, Brian J. France написав(ла):
Funny you should bring this up, at work we have been look at out patches to apr
and httpd that we can give back to the up stream public source and one of those
patches is to apr to allow hupless log rotation in httpd 2.x.
The patch adds APR_FOPEN_ROTATING to the flags when opening a file (which we
patch httpd to add it), then open will save extra data after opening (flags,
perm, apr_finfo_t, last check and timeout). If APR_FOPEN_ROTATING is set then
before every write call it will check to see if it needs to re-stat the file to
see if anything has change (device/inode) and if it has it will re-open the
file automatically.
This allows us to move log files to a new name, wait X seconds (our default
timeout is 60, so we wait 90 to be safe) and then we can do what ever we want
to the log file because all children will have either re-opened it or will
re-opened it before the next write call.
Is that what you are looking for?
I was going to bring up the patch during the Monday/Tuesday hack days along
with a few others.
It is very close, thank you very much. If you publish it, I will be able
to improve it to my taste -- instead of stat-ing every time (a
potentially expensive thing to do), it would only perform the reopening
upon receiving a signal (such as SIGUSR2).
With that you'll have to rename the current files, send all
httpd-processes the signal and wait for the new files to appear before
compressing the renamed ones, etc.
BTW, if you are on Irix, Linux, Solaris-10, or a BSD system, you can
improve your work yourself to avoid that 90 second wait too. The OSes I
listed all have mechanisms, whereby a program can ask the kernel to
notify it of certain events (such as new files appearing in a given
directory). Unfortunately, the mechanisms are quite different on all
OSes (dnotify on Linux, kqueue on BSD, etc.), but you only need to
implemented it for /yours/ :-)
And finally, should not a module be able to perform all the reopening on
its own -- without patching the server code? Or the modules don't have
access to all the necessary functions/values?
Thanks! Yours,
-mi
