A SOFTWARE FRAMEWORK FOR OPEN STANDARD SELF-

MANAGING SENSOR OVERLAY FOR WEB SERVICES

Wail M. Omar

1,2

, Bassam A. Ahmad

, A. Taleb-Bendiab

, Yasir Karm

School of Computing and Mathematical Sciences

Liverpool John Moores University

Byrom Street

Liverpool, L3 3AF, UK

Faculty of Applied Sciences

Sohar University

Sohar, P.C. 311

Sultanate of Oman

Keywords: QoS, Sensors Framework, Senso

rs for web services.

Abstract: To improve the usability and reliability of grid-based applications, instrumentation middleware services are

now proposed and widely accepted as a means to monitor, control and manage grid users’ applications. A

plethora of research works now exist focusing on the design and implementation of a range of software

instrumentation techniques (Lee et al. 2003, Reilly and Taleb 2002) to enhance general systems’

management including; QoS, fault-tolerance, systems recovery and load-balancing. However, management,

assurance and fidelity concerns related to sensors and actuators (effectors) support for grid and web services

environment received little to no attention. This paper presents a lightweight framework for the generation,

deployment and discovery of different types of sensors and actuators together with two associated

description languages namely; monitor session description language and sensor and actuation description

langue. These are used respectively to describe the set of deployed sensors and actuators in a given self-

managing grid infrastructure, and to define monitoring properties and policies of a given target

service/application. Moreover, negotiation process is considered between different units of the grid

environment. In addition, the paper presents a developed sensor-based systems awareness fabric layer for

self-managing decentralised web services. The paper concludes with a case study illustrating the use of the

sensor framework for job monitoring.

1 INTRODUCTION

Recent advancements in networking, hardware, and

middleware technologies have been a major catalyst

for the recent popularity of grid-based applications

(Foster et al. 2001), which are characterized by their

very high computing and resource requirements.

Thus, it needs powerful and active instrumentation

strategy. Originally, instrumentation was used to

debug and test applications that run on single

processor machines and for analyzing the

performance of real-time systems. The parallel

computing community later adopted instrumentation

to debug, evaluate and visualize parallel

applications. More recently distributed application

developers have recognized the requirements of

instrumentation, used in a dynamic regime, to

monitor and manage distributed applications (Reilly

and Taleb 2002).

It is now generally accepted that systems’

introspection and general runtime monitoring for

instance; for inconsistency and faults detection

requires software instrumentation (introspection and

sensing) services. However, the quality of service of

sensor/actuation service received little or no

attention. There is a lack of focus on management

Software Instrumentation is the process of putting

probes into software to record systems’ operation

state data (Foster and Kesselman 2003).

M. Omar W., A. Ahmad B., Taleb-Bendiab A. and Karm Y. (2005).

A SOFTWARE FRAMEWORK FOR OPEN STANDARD SELF-MANAGING SENSOR OVERLAY FOR WEB SERVICES.

In Proceedings of the Seventh International Conference on Enterprise Information Systems, pages 72-81

DOI: 10.5220/0002514100720081

 SciTePress

and control issues related to sensors and actuation

(effectors) for grid and web services environment.

This paper presents a lightweight framework for

the generation, deployment and discovery of

different types of sensors and actuators together with

two associated description languages namely; the

Sensors and Actuator Description Language (SADL)

and the Monitor Session Description Languages

(MSDL). These are used respectively to describe the

set of deployed sensors and actuators in a given self-

managing grid infrastructure, and to define

monitoring properties and policies of a given target

including application services and environment.

This framework leverages the quality of services

(QoS) for sensors to achieve an enhanced fidelity

(accuracy), performance and offer standard method

for exchange information based on mark-up

language (XML). Each sensor cluster works with

the others to form a sensor farm referred to here as

cloud. Each of which has a zoning construct and

cloud manager agent responsible for general

management, access of deployed sensors and

actuators and exchange of sensing information with

other agents (clouds).

The remainder of this paper is structured as

follow: Section two outlines related works followed

by a software sensor and actuator overlay. Section 4

presents the main structure of the SADL followed by

an illustrative example of using it. Model for

Monitoring Sessions Description Language (MSDL)

is demonstrated in Section 5. Case study for using

on-fly instrumentation with the SADL framework is

presented in Section 6. Finally, the paper concludes

with general summary and statement of future work.

2 BACKGROUND

Over the coming years, many are anticipating grid

computing infrastructure, utilities and services to

grow dramatically in size and functions, over

heterogeneous system to become an integral part of

future socio-economical fabric (Omar et al. 2004).

This vision is predicated on that such grid-based

services, infrastructures and applications have to

provide a high-degree of assurance, dependability,

and agility to changes and cost effectiveness. This

warrant for new models and supports for web

services sensing and actuation infrastructures and

middleware resources.

Much work related to systems monitoring for

Grid computing is now widely published (Lee et al.

2003), describing numerous monitoring models

including; visPerf and NetSolve (Satoshi et al.

1999), Heart Beat Monitor (HBM) and Enterprise

Instrumentation Framework (EIF). Other approaches

for instance presented by Reilly and Taleb-Bendiab

(Reilly and Taleb-Bendiab 2002), describes a

dynamic instrumentation framework, which provides

support to monitor and manage Jini applications.

The framework adopts a service-oriented

programming model and the software factory pattern

to dynamically generate specific instrument types,

which are deployed and interfaced to client services

via Java’s dynamic proxy API and Jini’s remote

event. This enables on-demand insertion and

removal of instrumentation services.

Other models such as the Globus Heart Beat

Monitor (HBM) is provided at container level to

provide health-check monitoring service for instance

for faults detection of grid resource, that is, checking

the status of a target machine and reports it to a

higher-level collector machine (Globus 2003).

Others such as the GridMonitor provides access to

Grid information and server status for all sites

including Globus Meta-computing Directory Service

(MDS). This in combination with JAMM an agent-

based monitoring system for Grid environments it

automate the execution of monitoring sensors and

the collection of event data (Globus 2003).

Operating systems specific instrumentation

frameworks include Windows Management

Instrumentation (WMI) consists of three parts

described below (Travis B. 2003):

• Management Infrastructure: providing object

manager called Common Information Model

(CIM). Users use CIM Object Manager

(CIMOM) to handle communications between

management applications and providers.

• Managed Objects: provide management

services that access managed objects using the

CIM Object Manager.

• WMI Providers: provider components that

supply dynamic management data about

managed objects, handle object-specific requests,

or generate WMI events.

Enterprise Instrumentation Framework (EIF) is

another technology for monitoring and

troubleshooting high-volume, distributed

environments. EIF is a technology for Visual

Studio.NET applications. It works hand-in-hand

with Application Centre (AC) and Microsoft

Operations Manager (MOM), providing a uniform

data for event management, tracing and logs.

Other works focused on sensors discovery

mechanisms to support fault-tolerance of

heterogeneous distributed systems. For instance,

Karuppiah et al. (Karuppiah2001) discussed the

design of a distributed vision system that enables

several heterogeneous sensors with different

processing rates to exchange information in a timely

manner to support the tracking of multiple human

A SOFTWARE FRAMEWORK FOR OPEN STANDARD SELF-MANAGING SENSOR OVERLAY FOR WEB

SERVICES

subjects and mobile robots in an indoor smart

environment.

Moreover, many more concerns related to

enterprise systems self-awareness and monitoring

remain to be addressed including; the control and

management of sensors, the accuracy of selecting

sensors, robustness, assurance and scalability of the

sensor system. In this paper, we will discuss some of

these problems.

3 SOFTWARE SENSOR AND

ACTUATOR OVERLAY

In this work, a sensor framework is developed to

support sensor and actuator generation

(Reilly and

Taleb 2002), deployment, discovery and general

management providing high-availability, control and

management for the deploying sensors. As

illustrated in Figure 1, each deployed sensor cloud

(cluster) in the sensor overlay has at least an

associated sensor manager agent, which provide on-

demand sensor generation, deployment, lookup

and/or publish subscribe services for instance to

provide intelligent matching between the available

sensors and consumer requirements

. The consumers

can select different types of deploying sensors with a

framework and inject them to the targets (monitored

services). The consumers can select to access (or

subscribe) to more than one target instrumentation

data in accordance with a given the Service Level

Agreement (SLA) and/or a given contract between

the sensor consumers and providers. A third party

agent referred to here as “SLA administrator”, is

responsible for establish the SLA between the

consumer and services provider, which involves the

negotiation process.

In view of the scalability concerns of massively

decentralised systems of sensor networks and grid

computing a zoning/clouds abstraction is here

introduced, where each zone/cloud has a sensor

manager agent (Figure 1). Such an agent is also

responsible for the interaction with other agents in

other zones where it can act as a gateway sensor

node to its sensor node, as in sensor networks the

zone agent can be hosted by an edge sensor node.

For example as shown in Figure 1, an agent in zone

A is responsible for offering services for the sensor

provider and consumers register with zone A. In

addition, sensor manager agents implement various

zone-based policies for instance for; information

exchange, access control and self-healing

monitoring and actuation

. To this end, a Sensor and

Actuator Description Language (SADL) was

designed and developed to provide an open standard

description markup language for lightweight access

to deployed sensor and actuators (effectors)

metamodel in any given zone (Sec. 4). Thus, SADL

provides a ubiquitous interaction mechanism with a

given sensors overlay (Figure 1).

3.1 Fidelity of Sensors

Sensor fidelity, robustness and assurance are some

of the major concerns considered by the proposed

and developed sensor framework, which borrows

concepts developed by the intelligent systems

engineering community including; self-convergence,

self-optimization, self healing and self-adaptive.

Many critical concerns in the sensor and

actuations overlay are the on-demand selection and

access to the correct sensor type for a given

monitoring task. Thus, the sensor framework is

designed to assistant to the consumer in selecting the

most appropriate type of senor according to

consumer’s requirements.

This is based on the software factory pattern.

In addition the framework offers the monitoring,

management, control and advertisement for the

deployed sensors

The full description of the zoning and clouds

abstraction and sensor manager agent is out of the

scope of this paper and will be described in future

paper

ICEIS 2005 - SOFTWARE AGENTS AND INTERNET COMPUTING

Figure 1: Sensor Framework Scenario including Sensor zoning Framework

For this reason, Sensor and Actuator Description

Language is proposed to provide a ubiquitous access

to sensor meta-model, which assist in the discovery

and selection of required types of sensors. SADL

will feed the intelligent system (sensor manger

agent) with the data that is required to do the

intelligent matching between consumer request and

available sensors.

4 SENSING AND ACTUATION

DESCRIPTION LANGUAGE

Awareness and governance model exposes the

infrastructure states and associate conditional

triggers (actuations) to detected events and systems

events of interest. In particular, deployed sensors

(software instruments) publish monitoring data to

the infrastructure self-governance middleware

service (Kephart and Chess 2003), which provides

the actuation model triggering and enactment. For

example in the case of services/infrastructures

overload problem, different methods are used to

solve this problem; one of them is the replication.

The sensor is used here to get information from the

original node and from replication services after

creation. Many of researchers and developers

intended to generate different types of on-the-fly

sensors; the management system should have well

known information regarding each one of these

sensors. A prototype of the Sensing and Actuation

Description Language (SADL) is designed for the

purpose of deploying, discovering and managing the

sensors in an open-standard format.

SADL is used to deploy and discover different

types of sensors (processor, memory, web services,

etc.) in open standard format. This information

assists the consumer and the analysis system to

select the required sensor from the discover list.

The current prototype of a SADL has been

developed using a.Net-based sensor software factory

and environment to support remote monitoring,

logging and analysis of a range of web service

properties including; structural, functional and

operational aspects.

Table 1 describes the most important parameters

of SADL.

A SOFTWARE FRAMEWORK FOR OPEN STANDARD SELF-MANAGING SENSOR OVERLAY FOR WEB

SERVICES

Table 1: SADL parameters.

Elements Name Comments

SensorID This ID should be unique for each Infrastructure. The ID is generated

automatically by the system.

SensorName This should be give by the deplorer.

SensorDescription The deplorer can describe anything for the infrastructure

SensotType This element is used to describe the parameter that this sensor is used to

read it. Like performance, security, etc….

SensotDataType This can be string, integer, object, etc….

SensotDataStorageType This element is used to describe the location of storage data, if it is stored

locally, centre, or in a host computer.

SensorHost The host that hold the sensor software.

SensorContainer This can hold different type of sensors.

SensorExecution This may be control flow, on demand or event driven

SensorStatus If the sensor is online or offline.

SensorMethod Method that used by the sensor

SensorCategory The category of the sensor. This may be research, free, commercial,

military, etc…

SensorContract This element describes the sensor to whom it belongs and what is lease time

for the sensor.

SensorInterface Sensor interface is used to connect to the sensor

InterfaceName Interface name

InterfaceLocation The path to the sensor interface

SensorEnvironment Sensor environment is used to describe all the information about the

required environment for sensor to work

EnvirPlatform The required platform

EnvirMiddleware The required middleware

EnvirMxmNoUsers This describes the maximum number of users those can use the sensor at the

same time

EnvirCurrentUsers This describes the current users those use the sensor at the request time.

This may be changed dynamically by the system according to the current users.

SensorsResources Describes the minimum required resources for the sensor to work.

ResourcesProcessor The minimum speed for the processor

ResourcesMemory The minimum size for the memory

ResourcesFramework The required framework.

ure 2: A Sim

lified exam

le of SADL

ICEIS 2005 - SOFTWARE AGENTS AND INTERNET COMPUTING

4.1 Illustrative Example

Interfaces information of the sensor is exposed

via the SADL.

The software for the generation, deployment

and discovery of sensor services is implemented

using VS.Net. Figure 3 shows an example that

demonstrating the processes of sensor and actuator

generation, deployment and discovery. In this

example a sensor and actuator of type memory

usage monitor and analyser are selected. In

addition, the current prototype provides operational

information of discovered sensors and actuators

including; sensor properties, contract, interface,

environment, and resources.

Figure 2, provides an example of sensor and

actuators service deployment using the SADL

framework. This is for instance, to deploy and

activate a memory sensor in a given container

(node). Where the sensor in accordance with an

associated monitoring contract it reads at a

specified frequency memory measurement data,

which is made available to the monitoring layer

through either logging or streaming.

Figure 3.a: Sensor registration screen (sensor information). Figure 3.b: Discover results screen.

Figure 3: SADL Interface.

Figure 4: Monitor Sessions Description Language (MSDL)

A SOFTWARE FRAMEWORK FOR OPEN STANDARD SELF-MANAGING SENSOR OVERLAY FOR WEB

SERVICES

5 MONITOR SESSIONS

DESCRIPTION LANGUAGE

Monitor Sessions Description Language (MSDL)

is used to create a standard way for sending

monitor tasks by the consumers based on using

XML. The consumer sends a request to establish

sensor task to the SADL framework. The SADL

uses the passing information to find the suitable

sensor from its available sensor services. MSDL

categorized into three parts:

• the monitor session information,

• Service Level Agreement (SLA)

(contract),

• sensors information description.

The monitor session information is divided into

client information and job schedule information.

The client information includes host name, SLA

for the client and authentication information. The

job schedule tags describe the duration and

intervals of the task jobs, interval tags is used to

indicate the time between reading and next one,

this help to reduce the information that transfer

from the target to the control and analysis system.

The administrator (which uses the sensors to look

after his clients) can select more than one type of

sensors to get different types of reading such as;

memory, process, processor. Also he can use the

same sensors for more than one of its clients

according to his SLA. Figure 4 presents an

example of using MSDL.

6 CASE STUDY

A case study is used to show how the sensor

framework can be used to read in sensor

requirements from users and discover and select

suitable sensor from a sensor array. The

experiment is conducted using a set of PIV 2.7

GHz with RAM 256 nodes running .Net

framework 1.1 and a number of Web Services. The

case study is divided into three phases:

• the creation of the MSDL for a given

consumer and sending it to the SADL.

• the discovery of deployed sensors for a

given monitoring requirement,

• the interface with the sensor and exchange

measurement data.

As illustrated in Figure 5a, the scenario starts

by sending the monitor session request by the

consumer to the sensors framework as MSDL

(Figure 5.a). The consumer sends request for a

number of sensors to be injected in the target. In

this case study, the consumer demands processor,

memory, process, and web services sensors. In the

other hand, the sensor providers use the SADL to

pass information regarding their sensors to the

framework, which will be as an advertisement

location for the sensors. The SADL framework

reads this MSDL and tries to find the available

sensors those are deployed with it, as shown in the

Figures (5.b. and 5.c.). In many cases there is more

than one sensor for each type of sensors, the SADL

framework is responsible for selecting the most

appropriate sensor for each target. SADL

framework may depend on using one of the

intelligent services, such as prediction or

classification, to anticipate the most likely hood

sensors with the consumer’s requirements. The

SADL runs these sensors on the target and get the

information and send it to the consumer (Figure

5.d).

ICEIS 2005 - SOFTWARE AGENTS AND INTERNET COMPUTING

Figure 5.a: Monitor request information

Figure 5.b: Sensors required

Figure 5.c: Finding sensors with in SADL framework

A SOFTWARE FRAMEWORK FOR OPEN STANDARD SELF-MANAGING SENSOR OVERLAY FOR WEB

SERVICES

Figure 5.d: Running sensors

7 CONCLUSIONS AND FUTURE

WORK

The paper presented a proposed and developed

sensor framework that supports the deployment,

discovery and management of sensors to support

better quality of sensors. Sensor Manger Agent is

argued to do the intelligent stuff of matching

between user needs and available sensors inside the

framework. Sensors framework zones are

recommended to be used for overcoming the

problem of scalability. Sensor manger agent is in

charge to exchange information regarding available

sensors between different zones. A prototype of the

Sensing and Actuation Description Language

(SADL) is designed for the purpose of deploying,

discovering, and exchange information concerning

sensors (Sec. 4). The SADL will be used to discover

and invoke different types of sensors, which can be

used with different types of platform (heterogeneous

system). A prototype for Monitor Session

Description Language (MSDL) (Sec. 5) has been

developed to present standard method for sending

monitor job schedule from the consumer to the

sensor framework, which controls the huge numbers

of requested sensors sessions that read the required

information periodically through the Grid. A case

study is developed to show the importance and

usage of the sensor framework in finding the best

sensor for the consumer.

So far the results are promising; it has been tested

under LAN-Grid environment with different types of

deployed sensors. The framework provides the

consumer with most appropriate sensors for their

request and injects them in the target.

Further work is under way to investigate the

framework under WAN-Grid environment with

larger number of deployed heterogeneous sensors. A

storage system is suggested to be added to the

system for providing complete framework for

gathering information and provide it to the

consumers. Moreover, sensor framework will be

adopted to be used with different types of sensors for

different applications, such as; e-health system, and

intelligent connected home networks and self-

management middleware.

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A SOFTWARE FRAMEWORK FOR OPEN STANDARD SELF-MANAGING SENSOR OVERLAY FOR WEB

SERVICES