Chrome OS to Open Source

Google Chrome OS Brings New Era in Cloud Computing
— More good news for cloud computing! Google last week released its once mysterious Chrome Operating System to open source. Chrome OS, available in 2010 – is a web-based operating system that promises to boot up super-fast on a netbook – way faster than the time it takes to start your basic PC. And Chrome has web applications (competing with Microsoft Windows Azure) that will run on application tabs. Users can access with one click and manage in a series of windows.

MySQL Conf memcached Tutorial Quick Review

Here are the notes I take from the Tutorial.

* For cache maintenance, simply invalidate all keys on memcached when you did an update on the related records on the database.
* Memcached is mainly used for reading but there can be solutions like you update keys on memcached and a separate process work on these changes and updated the related records on DB.
* You should be using Consistent Hash to distribute data over memcached servers which is a client library feature. With using that you will be able to maintain enough cached object even if there is a down issue on one of your memcached servers. Note: On a simple `mod` distribution there will be missed cache hits like %67 if one of the servers goes down.
* There is only one reason to run multiple memcached daemons on one server. It's when you do have a 32bit server and want to allocate more then 2GB of RAM.
* Do create a memcached server pool and use it for different applications using a namespace/pre_key. It's much easy.
* The basic use of memcached is, ask the object to memcached, If it doesn't have the object ask to the database, put it on memcached.
* In most of the cases you don't need a return value from the request. Just make the request and forget. If it doesn't happen cause of a problem of the network or etc. It will happen when the next request comes in. You should be monitoring your servers with other tools.
* It's better to put all the related data in one memcached server other then putting it on several memcached servers which forces you to make lots of request. Also do minimize your request and try to get all the data at once if possible. use mget..
* Get use of UDF API in MySQL and libmemcached to simplify actions on database level and integrate memcached with MySQL.
* Use blackhole tables to replicate the actions on DR/other DC site.
* on v1.3 you can send multi commands on single request.
* You might have problems if you have firewalls between the client and memcached server because the firewall state table might fill up.
* It's ok to keep the connections open because they are lightweigth.
* If you don't need CAS disable it.
* For big objects you can split them and set them partically on different memcached servers.


Thanks Brain Aker for this fantastic talk.

San Francisco Web 2.0 Expo

San Francisco da düzenlenecek olan Web 2.0 Expo için 30 Mart günü uçuyorum. Eminim Istanbul'dan katılan birçok arkadaş vardır. Orada görüşmek dileğiyle.

Dikkatimi çeken birkaç Session da aşağıda.

* The Lean Startup (Eric Ries)
* Sparking a Crush: Attracking and Retaining New Users (Alexa Andrzejewski)
* Content Strategy (Kristina Halvorson)


http://www.web2expo.com/webexsf2009


email: cemal -at- dalar -dot- net

svn url değiştirme

Daha önce checkout etmiş olduğunuz dizinin url'ini değiştirmek oldukça kolaymış. SVN'in switch metodunu kullanarak aşağıdaki gibi yapabilirsiniz.

svn switch --relocate eski_url yeni_url

Örn: svn switch --relocate svn://192.168.1.1/rep/eski svn://192.168.1.5/rep/yeni

SPF kayıtlarınızı kontrol edin.

E-postalarınızın SPAM klasörlerinden dolaşmasını istemiyorsanız kendi alan adınız için SPF kayıtlarına bakmanızda fayda var. Aşağıdaki link bunu online ve basit bir şekilde yapıyor.

http://www.kitterman.com/spf/validate.html

SPF hakkında ayrıntılı bilgi için buraya bakınız

Exit Strategy

"Trading without a predefined exit strategy is a recipe for disaster" Bill Dunn.

Craigslist Sphinx kullanmaya başladı.

Jeremy Zawodny'un yardımları sayesinde Craigslist metin aramalarını MySQL FULLTEXT üzerinden Sphinx index yapısına taşıdı. Tabiki daha verimli bir yöntem olduğu tartışmasız. Ben de bu aralar sphinx üzerine yolunlaşıp, pratik kullanımları üzerine çalışıyorum. Gerçekten de indexleme ve cevap hızları çok tatmin edici.

Sphinx Search at Craigslist