Author Archives: zation99

my photo in Flickr

Posted on 12/10/2012

I just remembered that I have an account in Flickr and updated some photos:) The url is http://www.flickr.com/photos/zation/

Posted in Uncategorized | 1 Comment

Running sudo command via ssh

Posted on 26/07/2012

Ususally “sudo” requires a login session by default, and if we just use ssh, it returns “Sorry, you must have a tty to run sudo”. If it is easy for us to log in to the remote machine, we can … Continue reading →

Posted in Uncategorized | 1 Comment

sync ubuntu’s system time

Posted on 20/06/2012

This is usually ignored, but when using Amazon APIs, if the time on your system somehow doesn’t agree with that in Amazon, you often get the “client.InvalidSecurity: request expired” error. The way to sync the time is “ntpdate ntp.ubuntu.com”.

Posted in linux | Leave a comment

Extract all the metadata nodes in llvm

Posted on 06/05/2012

Sometimes it is very useful to get all the metadata nodes in llvm, for the purpose of, say, find the type name of some fields of a data structure. LLVM does not provide the this complete information via any well-formed … Continue reading →

Posted in compiler, Work | 1 Comment

Real Mega Seafood Noodle Soup

Posted on 01/05/2012

I find out that if I really want to enjoy something, I cannot depend on the cafe on the campus. So here is the mega seafood noodle soup I cook for myself. This is what it means by “MEGA”!!

Posted in cook | 2 Comments

Mounting a disk image in Linux

Posted on 26/04/2012

Previously I posted how to download amazon ec2 ami to local drive. And to use it, I posted there that we can copy it (actually “dd”) to a virtual disk in vmware in order to make use of it. That … Continue reading →

Posted in linux, virtual machine, Work | Leave a comment

Creating a language front end for llvm, and better error handling in flex and bison

Posted on 15/04/2012

Just two links. They are fantastic! Creating a language front end for llvm: http://gnuu.org/2009/09/18/writing-your-own-toy-compiler Better error handling in flex and bison: http://www.ibm.com/developerworks/opensource/library/l-flexbison/index.html

Posted in compiler, Work | Leave a comment

Downloading an Amazon EC2 ami to local drive

Posted on 08/04/2012

Sometimes it can be convenient if we can download Amazon EC2 virtual machine image to local, for whatever the reason. After this post, well, you may find that it might be a better idea to do all your stuff on … Continue reading →

Posted in cloud, virtual machine, Work | 3 Comments

How to start vmware 7.X on ubuntu 11.10 with Linux kernel > 2.6.39 (including 3.0)

Posted on 06/04/2012

I don’t understand why vmware7.1.X do not support the new Linux kernel. It stucks at starting phase when trying to build kernel modules. But when we really want to run it, there is a way. Download the patches post here http://weltall.heliohost.org/wordpress/2011/05/14/running-vmware-workstation-player-on-linux-2-6-39-updated/ … Continue reading →

Posted in virtual machine, Work | Leave a comment

How HBase creates a redo log (HLog)

Posted on 17/01/2012

Region Servers use HLog in order to record the modifications. It is a Write-Ahead-Log (WAL), and resides in the directory determined by HConstants.HREGION_LOGDIR_NAME. It uses HRegionServer.setupWALAndReplication() in handleReportForDutyResponse(), which is invoked in run()’s while loop. setupWALAndReplication() first builds the Path … Continue reading →

Posted in hadoop, Work | Leave a comment