We are hitting a few walls with a CouchDB deployment and both Damien and I are a bit puzzled. This posting tries to attract someone with a clue to help us out. Our problems might result from not understanding the documentation correctly, but with evidently inaccurate material, we stand little chance. Here it goes.

Spidermonkey hogs memory

Or its garbage collection is a little ineffective. CouchDB uses Spidermonkey, Mozilla’s Javascript engine to create views on its databases. The user provides a Javascript function and CouchDB uses Spidermonkey to determine which documents to include in a View. The Javascript script that evaluates and executes the user’s function runs as a daemon.

We have a global variable there, map_results (declaration in line 19) that gets reset to {} for each document and map …

To illustrate how easy and straightforward writing applications for CouchDB is, we are going to build a simple todo-list application in Javascript. You should be familiar with HTML and Javascript and the DOM. You do not need any Ajax experience. Although we are going to use it, all will be abstracted away.

The interface is quite plain, as is the functionality. This is only to demonstrate how to work with CouchDB and not meant as a real application. We could turn this into something nice with some spit & polish.

How it works

We take a top level view here, working our way from the user’s perspective down to the actual code. This ensures we do not screw up the …

Damien Katz and the CouchDB development team are proud to announce:

CouchDB version 0.7.0 is now available.

This release is a major milestone in the project’s history.

Key features include:

• a REST API using JSON instead of XML for data transport,
• a JavaScript view engine based on Mozilla Spidermonkey,
• a GNU Autotools build system supporting most POSIX systems (Noah Slater),
• a built-in …

Thank you Frankfurt, what an evening! Thanks a lot for the invitation and my trip-sponsors. In fact the people and venue were so nice, I am seriously looking for an excuse to go again.

For housekeeping, here are the promised slides (PDF, 0.662 MB, sans images). In Some Context I wrote:

I rarely see the point of posting the slides of a presentation for people who didn’t see the original presentation. Yet, this is often requested. I don’t have a problem with posting my […] slides […], but they are of little value without context and I do have a problem with posting things of little value, so here’s the context.

And it goes on to comment the slides I used for my CouchDB presentation in Zurich. The new slides are …

Installing software on the Mac is usually a no-brainer: You get a ZIP archive or disk image that gets uncompressed or mounted for you. What is left for you is to move whatever application to your Applications folder. Done.

In case of a disk image, developers often go so far to include a reference to your Applications folder on the disk image itself. So all you have to do is to drag an icon onto another one less than 200 pixels away. This works so nicely on the Mac (the advantages of a controlled environment) because in the majority of cases, it is at /Applications on your filesystem.

To make that even easier, developers usually put nice background images onto those disk images to illustrate (with an arrow for example), what the user has to do. Skype, among others, nail this experience. (I’m not talking about the ZIP-only approach here). They have, on their download page, a step-by-step guide accompanied …

The kind folks at the PHP Usergroup Frankfurt invited me to talk about CouchDB. We meet on November 8th between 19:30 and 20:00 at the Brotfabrik in Frankfurt. If you are in the area and like to hear about CouchDB, feel free to join us.

I will be presenting CouchDB’s core concepts, its recent improvements and the programming interface to give you an overview. Building on that, I will explain how to architect CouchDB applications and show best practices for writing them not forgetting how to do all that from PHP.

In case you forgot:

CouchDB is designed for highly concurrent, distributed and fault tolerant systems. The core principles for scaling database applications are the foundation of CouchDB’s feature set. It supports on- and offline replication, data …

Note: This one comes in a bit late and it might not be as relevant as it could have been three weeks ago. But it also gives me the chance to take a more distanced look at the meeting. It might turn out that this post is more about working for MySQL than about the actual day.

It is about communication

I mentioned it a number of times, MySQL AB is a company with a very special structure. Its employees mostly work from home and home in this case is all over the world. By this time, most continents are covered as well as an impressive number of countries. It is obvious that solving communication issues is key to MySQL AB’s success. Different communication channels have all their merits and drawbacks and they are good at picking the right channel for the communication at hand.

MySQL is, of course, Open Source Software and MySQL AB has been an Open Company from the very beginning in terms of …

Imagine you and your friends have a project and a website each. You are likely to look for ways to increase the number of visitors on your site that are actually interested in your project. And you don't want to spend a lot of money on it. Additionally, you probably don't mind helping your friend's projects along the way (since you have been blogging about it anyway).

Suits you? Thought so. Read on, this is for you. Ad Mates revives the old idea of web-rings (remember 1997?) and gives it a modern polish as well as fundamental change in thought. It works like this:

• You all join a group (signup is free),
• create advertisements for you projects,
• add a bit of code to your websites and
• Boom, you show each other's ads on your sites.

So far so easy, but why is this noteworthy? Because Ad Mates is based on the idea of …

They did it

The order had been delayed. Shipping should now happen somewhere in September. Two more months?! Amazon had to be kidding. I want that book and I want it now. Or tomorrow. Or before the weekend — BUT NOT IN SEPTEMBER.

This was last Wednesday and my shouting must have been heard. I got a mail later that day telling me my order had been shipped. Nice. It arrived on Thursday afternoon, good job Amazon.

The book is a full 209 pages including index and glossary and I love the index: It has soaking and NIH and freakouts and Spiderman. Rands has quite a vocabulary, a vocabulary that is perfectly suited for a …

I hereby declare what from now on shall be known as “Jan's Law”:

Whenever a discussion about storage systems arises, the proximity of discussing the amounts of adult content that fits onto such systems reaches one.