Abstract:
The objective of this paper is to introduce a model for causal delivery protocols in real-time systems. We start by showing that temporal order properties of realtime protocols are independent of whether they are timer-driven or clock-driven, being instead related to their degree of synchronism, that we call steadiness. Then, we derive a set of correctness conditions for such protocols to secure causal delivery order. To achieve this objective, we use an extension of Lamport's model of time-stamp based order. We show that both timer- and clock-driven protocols have order correctness limits dictated by the environment and the target applications, and define those limits, through a set of working formulas. We show that in extremely adverse cases, timerdriven protocols will perform as well as clock-driven ones, due to the restrictions imposed on the operation of the latter, which is perhaps surprising. These results open the door to exploring new forms of communication in time-critical systems, for example, supporting clock- and time-driven communication, and event- and timetriggered operation. We expect that the results of this paper will give insight to that problem, and will be useful in real-life systems, such as distributed computer control. 1
Citations
|
1752
|
Time, clocks and the ordering of events in a distributed system
– Lamport
- 1978
|
|
449
|
Reliable Communication in the Presence of Failures
– Birman, Joseph
- 1987
|
|
344
|
Transis: a communication sub-system for high availability
– Amir, Dolev, et al.
- 1992
|
|
220
|
Preserving and Using Context Information in Interprocess Communication
– Peterson, Bucholz, et al.
- 1989
|
|
78
|
A new algorithm to implement causal ordering
– Schiper, Eggli, et al.
- 1989
|
|
75
|
Understanding Protocols for Byzantine Clock Synchronization
– Schneider
- 1987
|
|
60
|
xAMp: a Multi-primitive Group Communications Service
– Rodrigues, Ver��ssimo
- 1992
|
|
41
|
TTP - A Time-Triggered Protocol for Fault-Tolerant Real-Time Systems
– Kopetz, Grünsteidl
- 1992
|
|
34
|
The Delta-4 extra performance architecture (XPA
– Barrett, Hilborne, et al.
- 1990
|
|
31
|
Temporal uncertainties in interactions among real-time objects
– Kopetz, Kim
- 1990
|
|
31
|
A posteriori agreement for fault-tolerant clock synchronization on broadcast networks
– Ver'issimo, Rodrigues
- 1992
|
|
16
|
Real-time and Dependability Concepts
– Kopetz, Veríssimo
- 1993
|
|
15
|
At.omic Broadcast: From simple message diffusion to Byzantine Agreement
– H, Dolev
- 1985
|
|
11
|
Clock Syncronization in Distributed Real-Time Systems
– Kopetz, Ochsenreiter
- 1987
|
|
6
|
Real-time Communication
– Verssimo
- 1993
|
|
5
|
The Atomic Multicast protocol (AMp
– Verssimo, Rodrigues, et al.
- 1991
|
|
3
|
Ordering and Timeliness Requirements of Dependable Real-Time Programs
– Verssimo
- 1994
|
|
2
|
LightweightCausalandAtomicGroup Multicast
– KennethBirman, Stephenson
- 1991
|
|
2
|
Real-time Data Management with Clock-less Reliable Broadcast Protocols
– Verssimo
- 1990
|
|
1
|
versus DenseTime in Distributed Systems
– SparseTime
- 1992
|
|
1
|
Fault-Tolerant Distributed SystemsBased on Broadcast Communication
– Melliar-Smith, Moser
- 1989
|
|
1
|
The performance of the xAMp protocol on token-bus and fddi nac's
– Verssimo, Rufino, et al.
- 1991
|
|
