Breaking the Monolith by Stefan Tilkov at QConLondon 2012

Stefan Tilkov (@stilkov) from innoQ gave an excellent talk on the importance of a “system-of-systems approach” to software architecture (Breaking the Monolith, slides [PDF, 1MB]). [Update: the video is now online here:]

In essence, he argued for a distinction between micro-architecture (the design of the individual [sub]system) and macro architecture (the design of interacting systems).

QConLondon 2012 blog posts
See all QConLondon 2012 blog posts…

Continue reading Breaking the Monolith by Stefan Tilkov at QConLondon 2012

Node.js is faster on Windows than on Linux – what can we learn?

In an interesting interview on DevBeat (, Rackspace systems architect and Node.js contributor Paul Querna talks about the Node.js implementation on Windows. (Original video here:

Paul’s points in the interview about making use of I/O completion ports on Windows highlights a key issue in cross-platform software development: Windows has some incredibly powerful and advanced APIs, which – if used directly – can provide huge performance benefits for software that uses them.

Continue reading Node.js is faster on Windows than on Linux – what can we learn?

Speed up Web Applications with SSL Offloading

Web sites and web applications are increasingly using secure connections (HTTPS) for all traffic not just obviously sensitive data, as a way to guard against security threats. However, HTTPS requires encryption/decryption of data, which is computationally intensive. Web applications can therefore benefit from “offloading” the encryption/decryption processing required for HTTPS to specialised hardware devices.

Continue reading Speed up Web Applications with SSL Offloading

You are invited to ScaleCamp 2010

Very pleased to receive this email today:

From: Michael Brunton-Spall
Sent: 19 November 2010 16:07
To: Matthew Skelton
Subject: You are invited to ScaleCamp 2010 – 10th December at the Guardian offices, London


We are so pleased to be able to invite you to Scale Camp 2010 on the 10th December at the Guardian Offices here in London.

I’m looking forward to some great conversations and debate, particularly around DevOps and how that can contribute to scaling a software platform.

Improving broadband speed with BT

If you are not one of the lucky ones to have received a recent cost-free upgrade from BT to 20MBit/s ADSL, and your broadband speed is less than good, here are some steps to diagnose the problems.

First we’ll check the actual line speed.

Go to http://bthomehub/ or maybe http://bthomehub.home/ – note: no “www” or “com” in there. If you get a status page then you are looking at the modem/router (BT Home Hub). It should give some stats like these:

My broadband connection
Your broadband line is connected.
Broadband connection details:
Downstream 15,323 Kbps
Upstream 888 Kbps
Connection time 3 days, 22:58:21
Data transmitted 166.57 MB
Data received 3.21 GB

It’s the Upstream an Downstream values which you need to record somewhere. The values should be at least 2,000 Kbps Downstream (“2 Meg”) and at least 200Kbps Downstream for a basic broadband service (these speeds will soon be mandatory).

If your speeds are less than or close to these values, you can try some of these steps:

1. Get a BT Broadband Accelerator – basically a better microfilter. consumerProducts/ topicId=25075&s_cid=btb_FURL_accelerator

Go here, and select “Yes” in response to “Do you have more than one working phone socket in your home?” Then choose the socket which matches your “master socket” – hopefully it’s like #4. Sockets #1-#3 do not work with the Accelerator. Then you pay the P&P and BT deliver it – no other charges.

Installation should be simple. Do this first (or else establish that your socket is incompatible), and then (if the speed does not increase) try option 2 below.

2. Run the BT speed test wizard: p_sid=&cat_lvl1=346&cat_lvl2=401&cat_lvl3=407&cat_lvl4=753 &p_cv=4.753&p_cats=346,401,407,753&p_faqid=12666 or here: php/enduser/doc_serve.php?&5=7. This asks you some questions about your connection.

This page also contains some good advice, which you can check, particularly around faulty wiring: php/enduser/cci/bt_adp.php? p_sid=bgLqHKKj&p_faqid=9611&cat_lvl1=346 &cat_lvl2=401&cat_lvl3=407& p_cv=3.407&p_cats=346,401,407


Check for faulty home internal phone wiring

Poorly-installed home phone wiring or poor quality phone extension leads (often with a flat rather then round cable profile) are the most common causes of slow broadband speeds. This is because they are more prone to electrical interference, which causes BT Broadband to reduce data speeds to compensate. You can test for this as follows:

  1. If you have a phone master socket like the one in the photo here (that is, square with a horizontal groove halfway down it, and removable upper and lower cover), we recommend you remove the lower cover as shown, taking care not to dislodge any wiring. Do not remove the upper cover. This will reveal a test socket on the right-hand side. This connects directly to the exchange, bypassing your home phone wiring and extensions.Phone master socket
  2. Plug your router or modem directly into this test socket via a microfilter.
  3. Recheck your connection speed as per Step 2 above, ensuring you refresh your browser page first. If your connection speed has increased significantly, this indicates a likely fault or interference source within your home wiring. If it remains unchanged, this indicates either no fault, or the fault or interference is more likely to be in BT’s wiring or in your local exchange.

Re-run the line speed checks (at http://bthomehub/) and check the new Upstream and Downstream speeds. Are they significantly different?

3. Finally, if the above do not fix the issue, BT have a “Broadband Accellerator” service where an engineer comes to the house: php/enduser/cci/bt_catpage.php? cat_lvl1=346&cat_lvl2=1282& cat_lvl3%20=1859&p_cv=3.1859&p_cats=346,1282,1859

The work we do on your home wiring should increase your connection speed by at least 1Mbps” – if your current connection is only 2Mbps, this would represent a 50% speed increase.

If your Internet connection speed (independent of the broadband network speed) has not increased by at least 0.5Mbps, you are entitled to claim your money back.

It’s not clear how much this service costs, but I think it’s about £80.

Your final option is… move to the city!