This kinda funny error, but surely did not make me laugh.
‘clocksource/0: Time went backwards’
If a domU crashes or freezes while uttering the famous lasts words ‘clocksource/0: Time went backwards’, your domU is likely using the xen clocksource instead of it’s own clock ticks. In practice, this seems to be the cause of infrequent lockups under load (and/or problems with suspending). A workaround is to decouple the clock in the domU from the dom0.
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I did a presentation on distributed Distributed Key-Value stores, featuring Riak, to my team. The presentation was mostly vocal, and the slides were just an aiding medium. And here they are.
When you speak of the Cloud, the hot topic that tags along is security. And delivering secure content is the need of the hour for many websites. I am sure there are many such contents floating around for making your site content secure. Here! Add this to many such tutorials or howto’s.
As the first step you need to move the SSL certificate(public.crt) and Intermediate Certificate(intermediate.crt) to the server machine where you need the SSL enabled.
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Riak is a decentralized key-value of promise. Simply because it is simple, and RESTful. The features, listed here make it more appealing. But the lack of documentation is a pain, many a times, in such great projects, hence making things like these look geeky. But having said that, the developers are more than welcome to sort your problems out. I have just managed to get this riak working in clustered mode. This post will only talk about Installation and Cluster setup.
The motivation for going in for a decentralized key-value store arised out the need to maintain sticky session behind a load balancer that did not allow sticky sessions. So the solution was to have a decentralized datastore which stored the sessions, across a cluster that was running a web application. For example, Elastic Loadbalancer of EC2 does not allow you sticky session, and node failures need a decentralized data store with effective replication mechanisms. Enter riak.
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Ok, 10 minutes! We had to setup a proxy server to test our CloudBuddy Personal application, as there were some issues running it behind a proxy. The requirement was pretty simple, so we need something simple as well. So, Squid was out of the question.
So I typed “light proxy server” on google, and there it was the Tinypoxy. The target environment was Debian Lenny so the installation was as easy doing the following
When I started of I thought this going to be a breeze!. But things don’t come easy in this Cloud world. The information is rather scattered; and scratching one itch seems to lead to many scratches of many a itch.
But when you have got to the solution, I hope many have already, its just a matter of taking time post a blog like this and it feels like scratching just one itch. The steps to creating an Eucalyputs AMI or rather EMI would seem as simple creating an AMI.
Yeah, I thought so, but ended up doing this. Here is my story.
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This has been completely need based learning. It might not be of real help to anyone but like of the things on my blog, they are self referencing. And I am glad in the process I have managed to scratch many people’s itches. And this is no different.
Enough of the gyan(a sankrit word for preaching) and lets get to the crux of thing. Its was not until I managed to get eucalyptus launch windows instances that I had a chance to use EC2 like windows instances. Once I was up with a Windows instance, there was need to add EBS volumes to the windows, and I managed to do it. Then, when I had to unmount(Linux umount) the volume, was a bit suprised that there was no such command line utility. But to just do it the brute force way; detaching the volume from instance, was a solution for many a macho men.
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Its been quite a wonderful year for me. My first strides into the cloud arena have been quite eventful and definitely fun. The next decade is going to be a decade of web services ruling the computing world, with the cloud at the forefront. I hope all is well with our planet, Cloud Computing will go a long way in helping the cause.
Calvin and Hobbes
This a post on the Euclyptus forum, where user was asking few basic questions. For many power users these might be not of real interest but they are essential queries nevertheless.
1. what is actually an img file used for. What actually it contains ?
2. what is the VmLinuz file and init.d file which come along with any operating system image available in Eucalyptus site.
3. How actually theses get related when they are uploaded in the Walrus.
4. Whats actually the manifest file which is available in https://mayhem9.cs.ucsb.edu:8443/#login
5. How actually these files work in the User work space.
6. How these manifest files help to create the environment for the user.
7. does each time the user run instance will have a same environment as before. I mean the files he saved in first instance can be seen in other instance.
Cape: An Eye Opener
This is long overdue. Few of my colleagues and me last weekend, travelled south to Nagercoil(8° 11′ N 77° 29′ E) from Chennai(13° 04′ N 80° 17′ E), where we live to college called Cape Institute of Technology, to do a day long Conference on Cloud Computing.
Windmills
Cape has sprawling campus with wonderful backdrop of a rocky hill, and all around the campus are these huge power generating windmills. The windmill bed there is supposed the be the 4th largest in the world. That was the first eye opener. I have heard about the North Sea windmill bed, but I had no clue that there was something in comparison just about 5° south of us.
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