M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....a formal system requirements document is discussed in [27] This work does not address the challenges associated with gathering accurate and sufficiently precise information about the run time behavior of a target system without changing its behavior. These issues are addressed in [10] 20] [21], 39] 35] among others. In [5] Brockmeyer et al. discuss a tool for monitoring and assertion checking as part of the Modechart toolset. The monitor in that work is an additional modechart state machine that is simulated concurrently with the target system specification to determine if the ....

M. Mansouri-Samani and M. Sloman, "GEM: A Generalised Event Monitoring Language for Distributed Systems," Tech. Rep. DOC95/8, Imperial College, Dept. of Computing, 180 Queen's Gate, London SW7 2BZ, UK, July 1995.

....large telecommunications networks suffering from a small number of different types of failures. In general, their syntax is not modular or clearly readable. Many of the research systems available are described in more detail in Henderson [23] The Generalized Event Monitor (GEM) was developed [41] for network management event correlation. It has a powerful expression language with syntax similar to C and introduces effective algorithms for enacting this language on events. RAPIDE [39] uses partially ordered sets to represent detected event patterns and then generates higher level events. ....

M. Mansouri-Samani and M. Sloman. GEM: A Generalised Event Monitoring Language for Distributed Systems. IEEE/IOP/BCS Distributed Systems Engineering Journal, 4(2), June 1997.

....a broken window was signaled, but only the first one. 3 Methods for Composite Event Filtering Several proposals have been made for the filtering of composite events. We distinguish approaches using automata (e.g. Ode [7] petri nets (e.g. Samos [6] Eve [9] or trees (e.g. Ready [11] GEM [16]) Here, we do not consider the specific conditions of distributed event filtering. Example 1. Let us consider a composite event profile for the sequence of two events within a time span T : E T = E 1 ; E 2 ) T . The steps for the detection of the composite event depend on the method used. Figure ....

M. Mansouri-Samani and M. Sloman. GEM: A generalised event monitoring language for distributed systems. IEE/IOP/BSC Distributed Engineering Journal, 4(2), Feb 1997.

....similar to the ones found in active databases, is introduced and an implementation using tree based detectors is provided. However, no automated method for distributing the detectors in the network is given, limiting the usefulness of this approach in a large scale context. The GEM architecture [7] has a complex, but expressive, rule based monitoring language for a distributed system. No notion of a composite event type exists which makes it difficult to integrate this system with a modern object oriented programming language. It introduces techniques to deal with network delays, but does ....

M. Mansouri-Samani and M. Sloman. GEM --- A Generalised Event Monitoring Language for Distributed Systems. In Proc. of ICODP/ICDP '97, 1997.

....to incorrect detection, whereas synchronous evaluation forces a detector to delay evaluation until all earlier events have arrived, and assumes a heartbeat infrastructure. Although detection is distributed, no decision on the e#cient placement of detectors in the network is made. The GEM system [10] has a rule based event monitoring language. It follows a tree based detection approach and assumes a total time order. Communication latency is handled by annotating rules with tolerable delays. Such an approach is not feasible in an environment with unpredictable delays. Research e#orts in ....

Mansouri-Samani, M., Sloman, M.: GEM: A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal 4 (1997) 96--108

....to incorrect detection, whereas synchronous evaluation forces a detector to delay evaluation until all earlier events have arrived, and assumes a heartbeat infrastructure. Although detection is distributed, no decision on the ecient placement of detectors in the network is made. The GEM system [10] has a rule based event monitoring language. It follows a tree based detection approach and assumes a total time order. Communication latency is handled by annotating rules with tolerable delays. Such an approach is not feasible in an environment with unpredictable delays. Research e orts in ....

Mansouri-Samani, M., Sloman, M.: GEM: A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal 4 (1997) 96-108

....physical time synchronization in wireless sensor networks are described in [5, 23] Temporal message ordering has also been an issue in traditional computer networks, for example in the context of system monitoring and distributed event systems in local area networks. Delaying techniques such as [17, 19, 26] assume that their is a small upper bound D on the message delay in the network, i.e. it takes at most time D to send a message from any node in the network to any other node. The receiver which wants to receive messages in temporal order, maintains a list of messages m sorted by their time ....

M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.

....a new entity model does not require the modification of any existing entity models. On every conceptual level scenarios correlate events that pertain to failure conditions on that level and generalize them into events with a higher degree of conceptuality using the concept of composite events [18, 19]. This layered correlation model is in compliance with recent work on modeling networks for supporting fault isolation and recovery [8, 23] We believe that the layered approach to scenario development has many advantages over other approaches, these include: Support for the development of ....

M. Mansouri-Samani and M. Sloman. GEM -- a generalised event monitoring language for distributed systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(2), Jun. 1997.

....played cards might already be detected slightly above the table) Although there are many event distribution services such as [2] and [9] none of them provides appropriate support for ad hoc networks, and intermittent disconnects. Likewise, there are systems for composite event detection [6], but the detection languages they provide are too simple to accomplish the tasks pointed out in this section. We are therefore working on an infrastructure for ubiquitous computing applications that supports, among other things, all the requirements pointed out above [7] 5 Related Work Many of ....

M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.

....to events or policies. Recently some work towards translating controlled English specifications into policy been undertaken at Cambridge [4] However, this has been confined to the functionality provided by OASIS access control policy. Traditional event frameworks like CEA [3] and GEM [11] also omit detailed mappings to English. We believe that translating an e commerce application specification into events will eliminate the separation between (English) specification and (programming language) code: the specification, once mapped to descriptive and normative events, can be stored ....

Mansouri-Samani M and Sloman M. GEM: A Generalised Event Monitoring Language for Distributed Systems. 1EE/lOP/BCS Distributed Systems Engineering dournal, Vol. 4 No. 2, June 1997.

....similar to the ones found in active databases, is introduced and an implementation using tree based detectors is provided. However, no automated method for distributing the detectors in the network is given, limiting the usefulness of this approach in a large scale context. The GEM architecture [7] has a complex, but expressive, role based monitoring language for a distributed system. No notion of a composite event type exists which makes it difficult to integrate this system with a modem object oriented programming language. It introduces techniques to deal with network delays, but does ....

M. Mansouri-Samani and M. Sloman. GEM A Generalised Event Monitoring Language for Distributed Systems. In Proc. of lCODP/ICDP '97, 1997.

....events. Although it supports a much more fine grained notion of location, it lacks support for counterparts. The event service and context event support in our infrastructure are related to various other content based messaging systems such as Elvin [15] and SIENA [2] Some systems such as GEM [9] also support event aggregation, but the mechanisms provided are insufficient to express complex event contexts. 8 Conclusion and Outlook We have presented the rationale, design, and implementation of an infrastructure for RFID based ubiquitous computing applications. In order to reach a high ....

M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.

....event received at until . All events sent before this event will arrive at the consumer no later . The consumer reorders arriving events according to their time stamps. There are also variants of this approach, where the application can specify different values for each type of event [16, 19]. While this approach looks attractive at first glance because it does not require any extra message exchanges for achieving temporal order delivery, it suffers from several problems. First of all it is not applicable to WSN due to arbitrary delays in such networks (see section 3) Even when ....

M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.

....might already be detected above the table) Although there are many event distribution services such as [4] and [11] none of them provides appropriate support for ad hoc networks, intermittent disconnects, and temporal delivery order. Likewise, there are systems for composite event detection [8], but the detection languages they provide are too simple to accomplish the tasks pointed out in this section. We are therefore working on an infrastructure for ubiquitous computing applications that supports all the requirements pointed out above. We are especially focusing on developing a ....

M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.

....in x4 above, where the video request event passes parameters bw and source to the agent. These events are detected by a monitoring service. The policy notation only specifies simple events as a generalised monitoring service can be used to combine complex event sequences to generate simple events [16]. The subject of a policy, defined in terms of a domain scope expression, specifies the human or automated managers to which the policies apply. The target of a policy, also defined in terms of a domain scope expression, specifies the objects on which actions are to be performed. Security agents ....

Mansouri-Samani M., Sloman, M.: GEM: A Generalised Event Monitoring Language for Distributed Systems. IEE/BCS/IOP Distributed Systems Engineering, 4(2):96-108, 1997.

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M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.

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M. Mansouri-Samani and M. Sloman, "GEM: A Generalised Event Monitoring Language for Distributed Systems," presented at IFIP/IEEE International Conference on Distributed Platforms (ICODP/ICDP'97), Toronto, Canada, 1997.

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M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.

No context found.

M. Mansouri-Samani and M. Sloman, "GEM: A Generalised Event Monitoring Language for Distributed Systems," presented at IFIP/IEEE International Conference on Distributed Platforms (ICODP/ICDP'97), Toronto, Canada, 1997.

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M. Mansouri-Samani and M. Sloman. GEM -- A Generalised Event Monitoring Language for Distributed Systems. IEE/IOP/BCS Distributed Systems Engineering Journal, 4(25), February 1997.

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