There are lots of tricks out and about that provide advice on performance improvements, most are common sense… don’t use network drives for files, have enough RAM, blah, blah, blah.  I knew none of these were my issue.   Finally, however, I saw something that caught my eye, something about the JVM having performance issues with Intel’s graphic card EXA acceleration method which my laptop uses.  The fix was the simple addition of the following to the pycharm.vmoptions file.

-Dsun.java2d.pmoffscreen=false

I’ll be the first to admit that this trick didn’t make PyCharm a screamer however it is certainly usable again and hopefully I can squeeze a few more months out of my old Dell

First adding modules to nginx requires recompiling nginx so you’ve got to get your hands a little dirty to get it going.  I’m currently running Debian 6 in a hosted environment so I’ll give you the blow by blow based on my config.

Build Process

The first thing we’ll do is cd to /usr/src and grab the source for nginx by issuing the command…

cd /usr/src/
apt-get source nginx

Also make sure you have the following packages installed…

• fakeroot
• debhelper
• dpkg-dev
• autotools-dev
• libssl-dev
• libpq5
• libpq-dev

You’ll also need git installed so that you can grab the sources for the nginx modules you’ll need.  Along with ngx_postgres, you’ll also need rds-json-nginx-module to help with the json production.

cd nginx-x.x.xx/modules
git clone https://github.com/agentzh/rds-json-nginx-module.git
git clone https://github.com/FRiCKLE/ngx_postgres.git

Next you’ll need to see if there are any other dependencies you’ll need for the build which is quite easy on Debian using…

apt-get build-dep nginx

After you know you’ve got everything you’ll need for the build you can modify the ./configure parameters of the build to include the two new modules.  Use your editor of choice to modify the rules file.  Something like vim ../debian/rules

You’ll need to add the –add-module lines to ./configure for the new modules.

--add-module=$(CURDIR)/modules/ngx_postgres \
--add-module=$(CURDIR)/modules/rds-json-nginx-module

That’s it. Now run

dpkg-buildpackage

After a couple of minutes you should have a few .deb files in /usr/src for your enjoyment.  Install the appropriate .deb using dpkg and you’re ready to get ndx_postgres working.

nginx/ndx_postgres Setup

So the build part was pretty straightforward and didn’t take very long but getting it setup and working without any instructions was a bit more challenging.  There are a few configuration examples that come with ngx_postgres that you’ll need to read through to get a feel how a configuration is created and mapped to your tables.

Once you’ve established a basic configuration file for your database tables save the file in the /etc/nginx/sites-enabled/ directory.  The important thing to note is that by default you already have a file in this directory called default. This file does the obvious and creates the default site for a basic nginx installation.  What I didn’t realize was that ngx_postgres wouldn’t work with the default site enabled.  I spent at least an hour going through everything until I finally tried disabling the default file from sites-enabled.  After disabling the default site for nginx.  Everything should start working fine… assuming you’ve formatted your ndx_postgres configuration correctly .

Good Luck.

Celery has some built in methods to allow you to check the completeness of a remote job by calling the successful() method on a returned AsyncResult object.  For example you can do something like this…

From Python interpreter…  (BTW, the add task as a sleep in it for testing purposes)

>>> from celery.execute import send_task
>>> result=send_task('tasks.add', [4,5])
>>> result.successful()
False
>>> result.successful()
False
>> result.successful()
True
>>> result.get()
9

So the question was how to wrap this Celery mechanism in something I could use from Twisted and Cyclone. Here is what I came up…

from twisted.internet import task
def monitor_task(self, celery_jobResult, reactor):
  if celery_jobResult.successful():
     self.result = celery_jobResult.get()
     print self.result
       return self.result
   else:
       self.result = None
  return task.deferLater(reactor, 0.5, self.monitor_task, celery_jobResult, reactor)

This allowed me to call Celery jobs and poll periodically to see if the task had finished before returning the result.

def printResult(result):
   print result

from twisted.internet.threads import deferToThread
from celery.execute import send_task as send_celery_task
deferred = deferToThread(send_celery_task, 'tasks.add', [4,5]).\
addCallback(monitor_task, reactor).\
addCallback(printResult)

This is a bit simplified and doesn’t take into account any error handling but this is the jist of it. If you’ve found a better more elegant way please leave a comment.

Before we begin you’ll need two things installed on your Linux machine…

1. The first thing you’ll need is the dellBiosUpdate program. Depending on your distro you’ll need to Google around and find the appropriate package for your distro that contains this program and it’s associated libraries.
2. Second you’ll need either Wine installed or an old Windows PC lying around.  My wife has an old Dell Windows machine so I chose to use it rather than bloat my Linux distro with Wine.

That’s it for prerequisites, the rest is easy.

1. Download the appropriate BIOS update program from the Dell website.  It will be a Windows program but that’s not a problem for us now.  In my case the file was called D830_A15.exe.
2. Use Wine or the second Windows machine to create a .hdr file which you’ll use later to update the BIOS.  You do this by running the BIOS update .exe from the command line and using the -writehdrfile switch like so…  D830_A15.exe -writehdrfile.
3. This should have created a second file for you in the same directory that you ran the program from.  This will be the file you use to update the BIOS with so copy it (the .hdr file)  to the Linux machine if you ran this from a Windows machine.
4. Run the dellBiosUpdate program with -u  and -f switches and ensure that the laptop is running on AC before you begin or the update will fail.  dellBiosUpdate -u -f D830_A15.hdr
5. Reboot and you should see your Dell getting updated.

Word of caution: Updating the BIOS can be a dangerous undertaking.  I do not under any circumstances guarantee the procedure above to work.  It worked for me but may not work for you.  You’ve been warned.  I take no responsibility for what may happen during your attempt.

In file included from psycopg/psycopgmodule.c:32:
./psycopg/psycopg.h:31:22: error: libpq-fe.h: No such file or directory

include_dirs=/opt/local/include/postgresql91

library_dirs=/opt/local/lib/postgresql91