Rain technology, standing for Reliable Array of Independent Nodes, is a distributed data storage and protection system designed to enhance fault tolerance and robustness in network architecture. Originating from a Caltech research project, it utilizes inexpensive hardware and management software to operate a scalable cluster of nodes that can autonomously handle failures while maintaining consistent system performance. The document outlines its features, applications, and future scope, emphasizing the importance of creating resilient building blocks for efficient distributed computing.

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