Ran across these posts today on virtual memory overcommit in linux. Interesting reading and I learned quite a few things.
Thanks to Chris Siebenmann for helping me to understand things a bit better.
Originally published 2012-06-16
Configuration file: nginx.conf
Block: main
Value type: number
Default: none - system determined (see notes section below)
What it does: sets the value for the maximum file descriptors
that can be opened by a single worker process
Example: worker_rlimit_nofile 1024;
NOTES:
When any program opens a file, the operating system (OS) returns a file descriptor (FD) that corresponds to that file. The program will refer to that FD in order to process the file. The limit for the maximum FDs on the server is usually set by the OS. To determine what the FD limits are on your server use the commands ‘ulimit -Hn’ and ‘ulimit -Sn’ which will give you the per user hard and soft file limits. To determine the maximum number of FDs available, use the command ‘sysctl fs.file-max’ or ‘cat /proc/sys/fs/file-max’.
I’ve just gone through a boatload of “pseudo”-spam. Pseudo-spam is what I call legitimate e-mail that, when using a vanilla installation of Spamassassin, is marked as spam solely through the e-mail creator’s carelessness, thoughtlessness, whatever adjective you want to use (I refrained from using stupidity although I desperately wanted to). This morning, 25% of the number of e-mails that were classified as spam were actually legitimate. After analyzing the Spamassassin rules that were triggered, many rules were needlessly fired. Had the creator taken the time to format the html properly, many of the rules wouldn’t have been triggered.
I loathe HTML email for many reasons. Privacy and security are two. A Google search for “html email security” returned about 328,000,000 results and “html email privacy” returned about 2,010,000,000 results. That’s billions, folks.
For me, it’s one of those “just because you can doesn’t mean you should” things. I just analyzed a corpus of 4267 messages, a mixture of personal and marketing, looking for image references. One message contained 343 references to images. Seriously? I have less images of my wedding, one of the most important events of my life. The size of the message, without the images downloaded - 188K. I don’t have the time to download all the images and come up with a true size.