Evernote Completes Migration To Google, Data Center Shutdown

More companies to come...
http://www.informationweek.com/cloud/cloud-storage/evernote-completes-migration-to-google-data-center-shutdown-/d/d-id/1328240

Moving to Cloud computing (Legacy application migration to cloud)

Huge momentum has built to migrate applications to cloud computing nowadays. There are several motivation factors to adapt to cloud:  cost savings IT infrastructure and maintenance, time to market, rapid deployment & provisioning, auto-scale, flexible capacity, and business continuity.

Moving existing applications is not simply a matter of lifting and shifting to a cloud platform. Migration of existing applications to cloud computing must be done in a strategic and systematic manner. Identify individual business problems with existing applications that cloud computing can potentially address and provide specific business justification that the cloud is the right strategic alternative.

Enterprise applications must be thoroughly assessed to determine which application can benefit most from early migration to the cloud. Key considerations including costs of migration, application redesign, application performance and availability, security and privacy requirements, and regulatory requirements must be taken into account.  Create a pilot for one or two of these types of applications, test thoroughly, and gather customer feedback so that trust and confident can be built before going live.

The important point is that decisions about moving to the cloud need to start from an application standpoint, with a thorough consideration of followings:

Stateless: The thump of rule is keep your application from being affected by dynamic scaling: Build your application to be as generic and stateless as possible.  Avoid singleton.

Hardware dependency: Services that application calls should not be pointing particular host names or IP addresses. Abstracting environment-specific dependencies into a set of property files is still an inadequate. A better approach is to use an external service registry to resolve service endpoints like load balancer with virtual name.

Avoid local file system:  Avoid local file system as a store for temporary information, put temporary information in a remote store such as an S3, Amazon EFS, RDS or NoSQL database.

State-fullness: HTTPSession state is often stored in-memory, which presents a problem if your entire application server can be added or removed or moved at any time in the cloud. The best practice is to push it out to a highly available store that is external to your application server; that is, put it in a distributed caching store, such as  Memcached, or Redis.

Application Log Fie:  Application services are in auto scaling added/moved/removed often and storing log file in the local file system will crash your debugging option or the file you are looking for may not be available for debug. Use an open source aggregator, such as Scribe or Apache Flume, ELK or a commercial product, such as Splunk.

Asynchronous Calls: Consider that asynchronous protocols (Queue & RESTAPI) are still alive and well and can be extremely effective for cloud application programming.

Portability: Avoid OS dependency and application should be portable to any time of middleware.  Use Cygwin and Mono to port between Linux/.Net.

Closing statement:

Management should realize that every significant transition in technology has resulted in a significant rewrite or re-implementation of the technologies that businesses depend on but deep analysis and systematic approach converting to service-oriented architecture (SOA) can make your transition smooth and success.

                                 
Basic Linux Commands for freshers.

• check first the history than the last log-ins, system uptime, last reboot,

# history; last ; uptime ; last reboot;

• Checking Linux General system info:

# uname -a;id;uptime;date;free -mtol;who;cat /proc/cpuinfo;echo $PATH;df -m; sysctl vm;

• Checking Linux General network configuration info

# ip addr show ; ip route show ; ip neigh show; ip rule list; head /etc/resolv.conf

This will show the ip address of the interfaces, the routes, the arp cache , list the routing table rules and our DNS’s.

• Monitor the RAM usage of all processes :

ps -eo pid,ppid,rss,vsize,pcpu,pmem,cmd -ww --sort=pid

• Other Specific health checks

df -i; cat /proc/mdstats;

df -i checking Inodes state, and /proc/mdstats if we have RAID on the box.

• Check for big files and where are the most files on the system:

find . -type f -size +30000k -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'
--  (check for files more then 30000kb)

• Check  the logs if there are any warnings or fatal errors, and other important logs.

zcat messages-* | grep -i warning | less
zcat messages-* | grep -i fatal | less
dmesg | less

• Check full system configuration

sysctl -a

Open Source cloud: Openstack

The goal of OpenStack is to allow any organization to create and offer cloud computing capabilities using open source software running on standard hardware. OpenStack Compute is software for automatically creating and managing large groups of virtual private servers. OpenStack Storage is software for creating redundant, scalable object storage using clusters of commodity servers to store terabytes or even petabytes of data.

All of the code for OpenStack is freely available under the Apache 2.0 license.

Institutions and service providers with physical hardware that they'd like to use for large-scale cloud deployments

Clould computing

Cloud computing is a sold word in IT today.  It's matured and widely used by several companies.  If you are not evaluating or using cloud computing by now than you are slower in adopting new  technology and not ready for next big change in IT world.


Cloud computing is there from internet age 1990's in bit and pieces but one of the first milestones for cloud computing was the arrival of Salesforce.com in 1999, which pioneered the concept of delivering enterprise applications via a simple website. The services firm paved the way for both specialist and mainstream software firms to deliver applications over the internet.

The next development was Amazon Web Services in 2002, which provided a suite of cloud-based services including storage, computation and even human intelligence through the Amazon Mechanical Turk.

Then in 2006, Amazon launched its Elastic Compute cloud (EC2) as a commercial web service that allows small companies and individuals to rent computers on which to run their own computer applications. Amazon EC2/S3 was the first widely accessible cloud computing infrastructure service.

Another big milestone came in 2009, as Web 2.0 hit its stride, and Google and others started to offer browser-based enterprise applications, services such as Google Apps. Today's applications will naturally move towards a cloud model as they become more pervasively available through the web, require more data processing, and span the boundaries of multiple devices.

more to follow on cloud computing...