One consistent pain has always been resizing a filesystem without rebooting on Linux. Thank fully in recent years, this has changed with filesystems like BTRFS – where you can do something like the following….
xdebug – profiling a really long running PHP application (and handling really large cachegrind output files)
Normally, profiling a PHP application is pretty straight forward thanks to the great xDebug . Normally, we’re looking at profiling a slow page (taking 5-15 seconds to load) and improving it’s performance down to a sub-second response. Such profiling can produce relatively large output files – e.g. in the order of a few hundred megabytes. Unfortunately […]
Somehow we’d not come across this little “hack” before, so perhaps others haven’t…. Anyway, rather than recreating a new TCP connection to a host, SSH can multiplex the traffic down an existing connection to that host. This results in subsequent ssh connections opening quicker. The magic stuff is – * Edit ~/.ssh/config * Add in […]
A new wordpress site we’ve architect-ed has just gone live – Flashbak.com
One customer parse a substantial amount of (somewhat poorly formed) XML on a daily basis. (I say poorly formed as the prolog does not specify a character set — i.e. the file starts with <?xml version=”1.0″> and not <?xml version=”1.0″ charset=”UTF-8″> and different files will contain either UTF-8 or ISO-8859-1 text depending on the data […]
If you’re running low of memory on a server, there may be scope to free up memory through use of ‘ksm‘. (Note, that the kernel will start looking for memory to de-duplicate if KSM is turned on AND there are some processes running which have notified the kernel that they’re candidates; ‘kvm’ does the latter.) […]
We have a set of PHPUnit tests running against a Propel/PDO application. Recently, with a recent increase in the number of tests, we’ve found that we’ve been hitting MySQL’s max_connections or max_user_connections limit (see /etc/mysql/my.cnf on the MySQL server).
Historically we had a ‘normal’ pxe boot server in the office (DHCP server points to a TFTP server and specified a pxelinux file to load) from which we could choose to install various distributions. The only problem with this is that it was initially limited to the a specific release/version of Debian/Ubuntu (as we’d just […]
Today we received an email along the lines of : “Help! A customer’s website is slow and they’re complaining it’s taking over 2 seconds to load!”