Rain Technology is a disk subsystem that provides distributed data storage and protection in network architecture by integrating inexpensive hardware and management software. This research is focused on - high performance, - fault tolerance , - portable clustering technology. It consist of heterogeneous cluster of computing nodes connected via multiple interfaces to networks configured in fault tolerant topologies.

1. RAIN Technology

2.  RAIN stands for Reliable Array Of Independent
Nodes.
 It may also be called as Reliable Array Of Inexpensive
Nodes.
 Definition: It is a disk subsystem that provides
distributed data storage & protection in network
architecture by integrating inexpensive hardware &
management software.
Introduction

3.  Concept of RAIN is derived from redundant array of
independent disks(RAID) which is a similar system that is
implemented at the disk level.
 It is implemented to increase fault tolerance in a cluster.
 The storage cluster can be managed through a centralized
management interface.
 The RAIN management software automatically detects any
new RAIN nodes & allows them to communicate with each
other.
 In case of a node failure, the lost data is replicated among
other RAIN nodes in a cluster to avoid immediate
replacement of the failed node.
Introduction

4.  RAIN technology originated in a research project at
california institute of technology (CALTECH) in
collaboration with NASA’s Jet propulsion laboratory &
the defense advanced research projects
agency(DARPA)
History

5. The main focus of research was on
 High performance
 Fault tolerance
 Portable clustering technology

6.  The RAIN platform consist of heterogeneous
cluster of computing nodes connected via multiple
interfaces to networks configured in fault tolerant
topologies.
 Rain technology making the existing node more
robust & independent of each other.
 Rain technology provides the feature of replacing a
faulty node by a healthy one.
Goals

7. RAIN Platform
Switch SwitchBus network
Nodes
Nodes

8. Architecture
Third Party Application Rain infinity Application
Rain Platform
Global & logical Monitor
Always – On – IP
Consistent Global State Sharing
Reliable Transport
Standard Operating System
RAIN
Management
Application

9. It is the most scalable software cluster technology for the
internet marketplace today.
There is no limit on the size or the performance of a cluster.
There is no master-slave relationship.
All nodes are active & can participate in load balancing
It can tolerate multiple node –failures, as long as at least
one node is healthy.
It employs highly efficient consistent state sharing and
decision making protocols, so that the entire cluster can
function as one system.
Benefits

10.  The problem
how to connect n computing nodes in a ring of n
switches?
Fault Tolerant

11. Ring network
S- Switch
n- nodes
S
S
S S
S
S S
S
n
n
n
n
n
n
n
n

12.  Take the nodes and connect it with the nearest
switch.
 In Ring network is 1 fault tolerant so, we can loose 1
switch without upset.
 2nd switch failure can lead to partitioning in the
network
Approach

13. <- Ring network
After connecting them with the nearest switches.

14. degree of nodes=2
degree of switches=4
This can tolerate 3 faults without partitioning the
network.
Diameter construction

15. Main function of group member:
 1) to tolerate the fault
 2) to ensure that all processes maintain a consistent
view of global membership
Group membership

16.  Token carries: sequence number & group
membership list.
Token ring based group membership
protocol
A B
D C
1

17. 2
5
4
3

18.  If a node is inaccessible. It is excluded and bypassed.
If node or link fails
5

19. 5
6 7 6
5
Node failure

20.  If token is lost then it is regenerated, highest
sequence number prevails.
If node with token fails
5
6
7
6

21.  High Availability Video Server
 High Availability Web Server
 Distributed Check pointing Mechanism
Applications

22.  Development of API’s for using the various building
blocks.
 The implementation of a real distributed file system
using the partitioning scheme developed here.
 The group communication protocols are being
extended to address more challenging scenarios.
Future scope

23.  The goal of the RAIN project has been to build a test-bed
for various building blocks that address fault management
 Communication and storage in a distributed environment.
 The creation of such building blocks is important for the
development of a fully functional distributed computing
system.
Conclusion