Checkpointing Facility on a Metasystem

1
Checkpointing Facility on a Metasystem

• Yudith Cardinale and Emilio Hernández
• Universidad Simón Bolívar
• Caracas, Venezuela

2
Metasystems

• Heterogeneous computational resources tied by
  middleware and accessible transparently through
  a network
• Checkpointing is a key service for recovery from
  component failures

3
Java Checkpointing

• Checkpoints can be taken in a machine independent
  format
• Strategies proposed for adding persistence to the
  Java execution environment
• Language-level mechanisms
• Extensions to the JVM
• Checkpointing layer underneath the JVM

4
Java Checkpointing on Metasystems

• The selection of an appropriate checkpointing
  approach for a metasystem should take into
  account
• Portability
• Transparency
• Low intrusiveness
• We chose the extended JVM approach

5
SUMA overview
6
Checkpointing facility in SUMA
7
Experiments

• Application which calculates first n prime
  numbers
• 143 MHz SUN Ultra 1 workstations with Solaris 7
  and JDK 1.2.2
• SUMACkpThreadMonitor takes a checkpoint every
  four minutes.
• Checkpoints are saved in a shared file system
  (NFS)

8
Results

• Execution time without ckpt 819 min 7 sec
• Execution time with ckpt 868 min 41 sec
• 201 checkpoints were taken

9
Conclusions and future work

• Transparent checkpointing and recovery services
  in a Java-based metasystem
• Architecture-independent Java checkpoints
• Ongoing research extend to parallel applications
  and heuristics to activate checkpointing
  automatically