Apache Kafka big picture and quick start
What is Apache Kafka? ( big picture) I found the article http://www.confluent.io/blog/stream-data-platform-1/ ( from Jay Kreps) presented a very good big picture on what Kafka suppose to do: you can…
Hadoop : A Single Node Cluster on debian 8
The core part of hadoop inlcudes HDFS and map/reduce. There are many projects around hadoop. Data lake is often associated with hadoop-oriented object storage. Now trying the hadoop ( on debian…
MPLS VPN/VRF
Why MPLS? Networks with more stringent QoS requirements might use IPSec-over-Internet for non-real-time traffic and MPLS for real-time and mission-critical traffic Basic MPLS, how it works: A good explanation is…
Ansible quick howto
Ansible is mainly using ssh to manage nodes, it is an agentless architecture different from chef, puppet. here is quick howto to get started: git clone git://github.com/ansible/ansible.git –recursive $ cd…
lxc /dev increased from 100k to 500k and some other minor issues
While using lxc container, one annoying thing is the disk size of /dev was limited to 100k by default, with some hardware ( with lxc.autodev=1), the /dev could go beyond…
what is application container, OS container , VM
Application container: docker OS containers: LXC, OpenVZ, Linux VServer, BSD Jails, Solaris Zones VM: KVM, VMware, VirtualBox Good images from https://blog.risingstack.com/operating-system-containers-vs-application-containers/ References https://blog.risingstack.com/operating-system-containers-vs-application-containers/ http://www.itworld.com/article/2915530/virtualization/containers-vs-virtual-machines-how-to-tell-which-is-the-right-choice-for-your-enterprise.html https://www.flockport.com/supercharge-lxc-with-btrfs/
mutex , semaphore, monitor, condition variable
mutex, semaphore, monitor, condition variable are basic computer science concepts, but can easily get confused. some notes here. mutex: thread has ownership, released by the one who acquired it. no execution order…
Linux device driver: A fix for insmod invalid module format
How to fix “insmod invalid module format” for a out-of-tree linux device driver or kernel module? If your kernel source tree matched your run time kernel, it turns out that…
C++ virtual base class , template specialization, friends
For some C++ features, it is much easier to understand using sample code virtual base class ( for multiple inheritance ) class A { public: A(int i); } class B: virtual…
C++ function overloading, name mangling, name hiding
C++ function overloading, name mangling, name hiding are somehow related to the same issue: overload resolution at compile time ( note override is run-time resolution). What is C++ Function overloading: two or…
