project no. 9
DESCRIPTION
Project No. 9. Salone Gupta Amartya Dasgupta Syed Eqbal Alam Sneha Maria Joseph Arijit Mitra. High Availability???. A system design that ensures certain degree of operational continuity. Provides fault tolerance Provides data reliability. Virtual machine migration. Virtualization???. - PowerPoint PPT PresentationTRANSCRIPT
Project No. 9
Salone Gupta Amartya DasguptaSyed Eqbal AlamSneha Maria JosephArijit Mitra
High Availability???A system design that ensures certain degree
of operational continuity.Provides fault toleranceProvides data reliability
Virtual machine migration
Virtualization???
Goals
1. Implementation of active and passive servers on a virtual platform
2. Implementation of a heartbeat mechanism3. Implementation of process image transfer
for keeping track of data4. Implementation of switching mechanism
between active and passive servers
Low Level Architecture
Active Server
Physical Machine
HeartbeatModule
Image TransferModule
Virtual Machine
Physical Machine
Passive Server
Virtual Machine
Image TransferModule
Terminal ServerHeartbeatModule
Client
1
2
HeartbeatModule
Client Reconnector
4
6
5
7
3
Workflow WHEN THE ACTIVE SERVER IS WORKING1. The client requests the terminal server.2. The terminal server checks the heartbeat signals from the active server.3. If the heartbeat signal is ok, the client request is redirected to the active
server.4. After the request acknowledgement, the active server sends its image and
process checkpoint to the passive server at a certain frequency.
WHEN THE ACTIVE SERVER FAILS5. The terminal server pings the passive server to check its health status and the
passive server restarts from the previously received image and process checkpoint.
6. The terminal server redirects the client to the passive server.a. Now the passive server starts behaving as the active server and when the
previously failed active server is restored it behaves as a passive server i.e. the roles interchange.
b. The passive server now sends heartbeat signals to the terminal server to notify its health status.
7. The passive server sends its image and process checkpoint to the restored active server.
On the advent of another failure the steps are repeated and the roles again interchange.
Module DescriptionImage Transfer module – Salone Gupta and Amartya
DasguptaCreation of image of the server and the process checkpoint
associated with a client requestHeartbeat module – Arijit Mitra
Sends or receives a heartbeat signal or ping to notify or to check the health of a server.
Also used to check available passive servers in a passive server cluster.
Client Reconnector – Syed Eqbal and Sneha Joseph Client connection and redirection to the active and passive
servers.Server Setup – Salone Gupta, Arijit Mitra and Amartya
DasguptaSetup an active server and a passive server.Setup a terminal server for client reconnection.
Integration – Team
Implementation Plans1. Setup of the active, passive and the terminal
servers as virtual machines using Xen/Vmware.2. Using the heartbeat mechanism, the terminal
server checks the status of the other active servers.
3. Process transfer will be implemented by creating process checkpoints using an open source tool.
4. On the advent of failure, switching between active and passive servers will controlled by the terminal server.
Progress Till DateCheckpoint creation and restart on single
system using an open source tool “BLCR” - Berkeley Lab Checkpoint/Restart
Partial heartbeat implementation
Plans Ahead
Deliverables on March 9th,2009 Virtual server setup Client connection to the servers
Referenceshttp://www.ftg.lbl.gov/checkpoint (Berkeley
Lab Checkpoint/Restart) http:// www.ultramonkey.org http:// www.keepalived.org Remus virtualization projecthttp://www.eukhost.com/server-mirroring.ph
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