This is just plain weird, from my error logs for a site that about five people ought to be accessing:
[Wed Jan 16 14:48:39 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:39 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:40 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:40 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:41 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:41 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:42 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:42 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:43 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
[Wed Jan 16 14:48:43 2008] [info] (32)Broken pipe: core_output_filter: writing data to the network
Apache has a helpfile on this particular error, but I wouldn't call it the most illuminating manuscript out there:
Invalid argument: core_output_filter: writing data to the network
Apache uses the sendfile syscall on platforms where it is available in order to speed sending of responses. Unfortunately, on some systems, Apache will detect the presence of sendfile at compile-time, even when it does not work properly. This happens most frequently when using network or other non-standard file-system.
Symptoms of this problem include the above message in the error log and zero-length responses to non-zero-sized files. The problem generally occurs only for static files, since dynamic content usually does not make use of sendfile.
To fix this problem, simply use the EnableSendfile directive to disable sendfile for all or part of your server. Also see the EnableMMAP, which can help with similar problems.
I'm using ext3, which I don't think qualifies as a "network or other non-standard file-system."
So what gives? I don't know where to start.
View Mumbling about the Frankenserver