Cache

SSL caching and redirects in chrome

While setting up SSL reverse proxy using lets encrypt and nginx i  had a few troubles with testing via googles Chrome browser.

  • Chrome caches some SSL responses which can be cleared by deleting your browsing data via settings or Ctrl+Shift+Del.
  • Chrome also caches http -> https redirects, you can see these by going to chrome://net-internals and select “HSTS” from the drop down. Enter the domain name under “Delete domain” and press the Delete button

The easiest thing to do during testing is use incognito mode. You will not need to clear the cache every time you change config or re-issue certificates.

bye bye http - hello letsencrypt

I’ve been a fan of HTTP and caching since my dial-up modem.

Skip to today where google returns HTTPS sites higher in its search results. Its could also be possible that you cannot trust a man in the middle HTTP cache any longer either right? :)

SSL certs have traditionally been expensive, but say welcome to lets encrypt which provides a free way of securing all of your websites. If you haven’t heard of it check it out here - https://letsencrypt.org/

zfs : accidentally adding cache drive to raidz zpool

http://forums.freebsd.org/showthread.php?t=23127

Unfortunately if you have accidentally added a single drive into your raidz pool at the top-level there is no way to just remove the non redundant disk. Your pool is now dependant on this disk.

If you want your pool to be just raidz vdevs, then you will need to backup your data, destroy your pool, create a new pool, and restore your data.

There is no current way to remove a top-level vdev from a pool.

Squid - optimizing cache hits

The first place to look for increasing your hit ratio is the refresh_pattern parameter within the squid.conf file.

Note: the following applies to squid 3.0 and higher only….

I have found a really good page here http://linux.com/archive/feature/153221 that explains some good setups if you with to increase your cache hits…

refresh_pattern ^ftp: 1440 20% 10080 refresh_pattern ^gopher: 1440 0% 1440 refresh_pattern -i \.(gif|png|jpg|jpeg|ico)$ 10080 90% 43200 override-expire ignore-no-cache ignore-no-store ignore-private refresh_pattern -i \.(iso|avi|wav|mp3|mp4|mpeg|swf|flv|x-flv)$ 43200 90% 432000 override-expire ignore-no-cache ignore-no-store ignore-private refresh_pattern -i \.(deb|rpm|exe|zip|tar|tgz|ram|rar|bin|ppt|doc|tiff)$ 10080 90% 43200 override-expire ignore-no-cache ignore-no-store ignore-private refresh_pattern -i \.index.(html|htm)$ 0 40% 10080 refresh_pattern -i \.(html|htm|css|js)$ 1440 40% 40320 refresh_pattern . 0 40% 40320