Mid 1 Review

CH 1, 2, 4
HW
Labs

Distributed systems? 
    - a system component only interact to by passings messages 
    - Sharing of resources for a common goal
  -Characterstics
        - Scales of dist. systems
        - concurrency 
            - independetly functioning currently
            - no global clocks
            - independent failures
Existing dist system
    -search engines
    -online games
    -financial trading
Trends
-Pervasive Networks
    -Networks are everywhere
    - How are they protected?
    - How are they integrated?
- Mobile computing
    -What complexities are intorduced?
-Utiquitions computing 
-distr. computing as a utility

Challenges
-Heterogeneity
    - How might a system deal with heterogeneity?
        -Middleware
- Openess
    - Can the system be exponded and .....?
    -Why might a system be difficult to expand?
-security 
    -How can you protect your system??
    - 3 components of security 
        - condifentiality : protection against disclosure
        - Integrity : protection against alteration / corruption
        - Availability : protection of access
- Scalability
    - can they system remain effective if there was a large increase in users 
- Failure handlings 
    -what techniques can be implemented into the system to form component failures
-concurrency
    -how can you handle multiple uses on same process
-Transparency
    -What parts of your system is transparent?
    -Discuss the types of transparency that are in the system
-Quality of service 
-what can you do to ensure a client has good service?


CH2 Models
-Physical model
    -Describe systrm by its hardware components 
-architctural models
    -describe system components by their interactions 
- fundamental models
    -Describe system by a fundamental property
in phone firs pic Feb/24


Ch4 interprocess communication 

-shared memory
-message passing
-buffer capacity 
-IPC operations
-Event synchroization
    - blocking (synchronous) operations
-Socket (draw diagram for socket)
-Marshalling
    -process of assemblies a collection of data items in a form suitable 
        for transmission.
-corba's common data representation (CDR)
- Java's object senialization

Lab1: 
what is needed to use openmp ?
    - #include <omp.h>
How to create a parallel block?
how to use each thread? 
How to compile?

Lab2: 
-Fork-Join parallelism
-Race condition 
    - one thread unintentionaly affects the result of another thread

Lab3: 
-False sharing
    -Multiple threads are accessing the same cache line.
-synchronization 
    -Barrier
    -Mutual exclusion
        -critical area

Lab4: 
Single program multiple data (SPMD)
    from this lab you should learn: 
        work-sharing
            - Parallel for construct 
            - schedules


-given this code, what work-sharing construct would you use?
-SPMD vs. work-sharing?
-which synchronziation for program?