Memcached Internals

Ilya Grigorik has posted a very good summary of a talk that Brian Aker and Alan Kasindorf gave about memcached at MySQL User Conference last week. The article is straight to the point in regards to several key attributes about memcached, and serves up almost 30 direct tips and tidbits about how to use memcached in a more optimal way. Awesome reading, and well worth to check out together with the slides from the memcached talk.

PHP Vikinger Registration Up and Running

This year’s version of the unconference PHP Vikinger is taking place 21st of June in Skien, Norway. Derick has just opened up the registration which involves using high tech methods such as an E-mail-client and writing your name and other relevant information. One thing’s for sure, I, Eirik and Christer are heading out, and hopefully we’ll get a few more friends to join in.. and that includes YOU!

Canon EOS 5D Mark II Coming?

Wired’s Gadget Lab has noted a neat scoop in regards to the long awaited upgraded version of the Canon EOS 5D! According to the information that supposedly were put online by the german division of Canon, the upgraded full frame camera gets a Digic III processor, a total of 16 megapixels and 6.5 fps shooting speed. I’m already drooling enough to make a small puddle.

Earlier rumors has indicated a price somewhere around $3299 ($3000 – $3500). An announcement from Canon is to be released at friday, but it’s not known wether that will have anything to do with a Canon EOS 5D Mark II.

New Week, New Book: Software Estimation: Demystifying the Black Art

It’s a new week and as I finished my previous “to read while taking the train” book last week, I’ve now started on another well received book, this time about software estimates. The book is published by Microsoft Press and is named Software Estimation: Demystifying the Black Art. The author, Steve McConnel also have a webpage online, in addition to keeping track of the blog 10x Software Development. It’s been a good read so far, and considering the current exchange rate between norwegian kroners and the us dollar, it’s a steal at $26.39 at Amazon.

Stuart Herbert Takes a Look at apache2-mpm-itk

Stuart Herbert has taken a closer look at apache2-mpm-itk , a patch for the apache2 prefork handler to enable Apache to switch which user it runs under based on which VirtualHost that serves the request. The author of the module, Steinar H. Gunderson is a good friend of mine, and it’s always good to see familiar names getting attention for things they’re writing.

The post from Stuart is pretty straight forward, but he fails to mention that apache2-mpm-itk is available as a regular package in all current debian versions . Simply apt-get away, and you’re all set.

Solr: Deleting Multiple Documents with One Request

One of the finals steps in my current Solr adventure was to make it possible to remove a large number of documents form the index at the same time. As we’re currently using Solr to store phone information, we may have to remove several thousand records in one large update. The examples on the Solr Wiki shows how to remove one single document by posting a simple XML-document, or remove something by query. I would rather avoid beating our solr server with 300k of single delete requests, so I tried the obvious tactics with submitting several id’s in one document, making several <delete>-elements in one document etc, but nothing worked as I wanted it to.

After a bit of searching and stumbling around with Google, I finally found this very useful tip from Erik Hatcher. The clue is to simply rewrite the delete request as a delete by query, and then submit all the id’s to be removed as a simple OR query. On our development machine, Solr removed 1000 documents in somewhere around 900ms. Needless to say, that’s more than fast enough and solved our problem.

To sum it up; write a delete-by-query-statement as:

id:(123123 OR 13371337 OR 42424242 .. ) 

Thanks intarwebs!

Solrj and JSTL EL: java.lang.NumberFormatException

While working with a view of a collection of documents returned from Solr using Solrj earlier today, I was attempting to write out the number of documents found in the search. In pure Java code you’d just request this by just calling .getNumFound() on the SolrDocumentList containing your documents, which whould also mean that they should be available through EL in JSTL by calling ${solrDocumentList.numFound} (which in turn calls getNumFound() in the SolrDocumentList object). The code in question was as simple as:


Which resulted in this error message, which kind of came as a surprise:

java.lang.NumberFormatException: For input string: "numFound"
        at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
        at java.lang.Integer.parseInt(Integer.java:447)
        at java.lang.Integer.parseInt(Integer.java:497)

After digging around a bit and reading the error message yet again, it suddenly hit me: $solrDocumentList was being interpreted and casted to a List, and as such, EL expected an index into the List instead of my call to a function. I’ve not been working with JSTL for too long, so I thought a bit about how to solve this. One solution would be to do the calls in the Action and then just map them to separate variables in the template, but this wasn’t really as pretty as it could be. Instead I wrote a simple wrapper around the SolrDocumentList, which is not a list in itself, but exposes all the elements through it’s getDocumentList-method. That way we can access it in the template by calling ${solrDocumentList.documentList…}.

I’ve included the simple, simple wrapper here. It should be expanded with access to Facet fields etc, but this should be a simple indicator of my suggested solution.

public class SolrSearchResult
{
    SolrDocumentList resultDocuments = null;

    public SolrSearchResult(SolrDocumentList results)
    {
        this.resultDocuments = results;
    }

    public long getNumFound()
    {
        return this.resultDocuments.getNumFound();
    }

    public long getStart()
    {
        return this.resultDocuments.getStart();
    }

    public float getMaxScore()
    {
        return this.resultDocuments.getMaxScore();
    }

    public SolrDocumentList getDocumentList()
    {
        return this.resultDocuments;
    }

    public void setDocumentList(SolrDocumentList results)
    {
        this.resultDocuments = results;
    }
}

Any comments and updates are of course as always welcome.

Writing a Custom Validator for Zend_Form_Element

My good friend Christer has written a simple tutorial on how to write a custom validator for a Zend_Form_Element. If you’ve ever laid your hands on Zend_Form, you’ll want to have a look at this for a short and concise introduction to the topic. He’ll show you how to create a “repeat the password”-field by creating a custom validator and hooking it onto the original password field. Neat stuff.

Yay for PDO_MYSQLND!

Just found a post detailing the release of the preview version of the MYSQLND support for PDO! For those of us who have grown fond of PDO during the last years and still uses MySQL, this is great news! The MYSQLND library is a reimplementation of the MySQL library, intended for native PHP usage instead of bridging it with the regular interface to libmysql. This brings a neat speed increase and overall goodness.

All hail MYSQLND! I’ll try to give the preview version a try over the weekend. You can read even more over at The PDO/MYSQLND Annoucement at lists.mysql.com or you can have a look at the installation procedure.