Remedy AR System architecture

Remedy AR System is based on a client/server architecture. The following figure depicts the relationship among the components that reside within each of the functional environments of the Remedy AR System architecture. Notice that no definitive starting and ending point separates the environments because their functions sometimes overlap.

Remedy AR System functional components

Remedy AR System includes the following functional environments:

Presentation — The presentation layer is responsible for presenting services and displaying data to clients through various interfaces, which include the following:
- Browsers
- Cell phones
- PCs
- Personal Digital Assistants (PDAs)
- BMC Remedy Developer Studio
- API programs
Business processing — The following business processing components manage the data entered through clients, perform services based on your business processes, and enforce your business rules. This portion of the architecture includes:
- Remedy Mid Tier
- AR System server
- Server functions such as the Distributed Server Option (DSO), and Remedy Approval Server
- Atrium Integrator (AI)
- Web services
Data storage — Remedy AR System supports Oracle and Microsoft SQL Server databases for storing data. For each of the relational databases, tables owned by other systems can be referenced as if they were owned by Remedy AR System.

Within these functional environments, several system components work together to provide power, flexibility, and scalability.

Remedy AR System server groups for scalability and high availability

To provide scalability and increase reliability, you can connect a group of Remedy AR System servers to the same database and manage them as a unit by configuring a server group. Server groups act as a single server to support the applications that they run. Servers in the server group can be configured to spread the load of shared services, and they can provide backup to each other to ensure that those services are always available.

The following figure depicts the high-level architecture of the Remedy AR System.

High-level architecture of Remedy AR System

Distributed environments provide scalability

Use Remedy Distributed Server Option (DSO) to build large-scale, distributed environments that behave like a single virtual system. DSO enables you to share common information among servers and to keep that information consistent.

For example, as illustrated in the following figure, you can transfer copies of a request to other servers and ensure that any changes made to the copies are also made to the original request. The way that you define the processes for transferring information is similar to the way that you define business processes for an application. First, managers at each site must agree on what information to transfer from one application to another, what conditions drive transfers, and which sites control the ability to update a record. An administrator at each site then uses DSO to implement these decisions.

Remedy AR System in a distributed environment

Heterogeneous environment provides flexibility

Because the multiple layers of Remedy AR System are independent of one another, you can combine operating system platforms to fulfill different functions. The heterogeneous environment enables you to mix and match client and server platforms. For example:

Remedy Developer Studio on a computer running Windows can manage forms on a UNIX or Linux server.
Browsers can use a Windows-based mid tier to access forms on a UNIX server.

A Remedy AR System server on Windows can interact with a database on UNIX.

Remedy AR System client/server architecture

Remedy AR System is based on a multitiered client/server architecture that includes the client tier, the mid tier, the server tier, and the data tier. The following figure shows the various tiers of the Remedy AR System.

Remedy AR System architecture

Client tier — Contains Remedy AR System clients. Most clients present information to application users and receive input from them, but the tools for migration and application development are also clients.
Mid tier — Contains components and add-in services that run on a web server, enabling users to view applications on the web.
Server tier — Contains the Remedy AR System server, which controls workflow processes and access to databases and other data sources in the data tier. This tier also contains server-side applications (such as Approval Server, Email Engine, and the Remedy Flashboards server) and the C and Oracle Java plug-in servers with plug-ins.
Data tier — Contains database servers and other data sources that can be accessed by the Remedy AR System server. The database server acts as the data storage and retrieval engine.

Remedy AR System clients provide the user interface. The Remedy Mid Tier makes the user interface available in browsers. The Remedy AR System server implements the workflow functions, access control, and flow of data into and out of the database. The database server acts as a data storage and retrieval engine.

Remedy AR System multitier architecture

Remedy AR System client/server communication

The following section explains how Remedy AR System components communicate with each other.

Communications between clients and the Remedy AR System server

All clients of the Remedy AR System server communicate with the server by using remote procedure calls (RPCs) on top of a TCP/IP transport stack. The type of RPC is the Oracle ONC RPC. TCP/IP networks are the de facto standard for corporate and Internet communications. The RPC mechanism is used because it is a "lightweight" transport that uses minimal network bandwidth, yet provides robust communications services. It can function over slower dial-up network links and high-speed internet and intranets, and is supported over most of the wireless networking technologies. The Remedy AR System web server communicates with the browsers using Hypertext Transfer Protocol (HTTP) or Secure HTTP (HTTPS).

Communications between Remedy AR System servers and database servers

From the perspective of the database server, the Remedy AR System server is a database client. Remedy AR System server uses the JDBC to connect to the database. When a Remedy AR System server is installed, the installer specifies the type and location of the database server that informs the Remedy AR server which JDBC driver to be used. The Remedy AR System servers support SQL Server and Oracle databases and communicate with the database servers using type 4 JDBC drivers. The Remedy AR server uses the JDBC connection pooling to allow multiple database connections in parallel. The Remedy AR server process comprises many threads to support user requests and share the connection pool. This provides tremendous data throughput and system scalability.

Many-to-many connections

In an Remedy AR System environment, one Remedy AR System server can theoretically support any number of Remedy AR System client connections (limited by network bandwidth and server host and database performance). The clients can be on any mix of platforms. Similarly, a Remedy AR System client can be connected to any number of servers at the same time. These servers can be any mix of server hosts and underlying database engines.

Remedy AR System clients

Remedy AR System clients provide user interface facilities available from various platforms, including the Web. Remedy AR System clients are available for a number of operating system environments, as listed in Remedy AR System client/server architecture. For each operating system, the client is composed of a set of native applications (tools) that use the standard user interface conventions for that environment. Individual users can run these tools as necessary.

Remedy AR System clients can be broadly divided into user client and developer clients.

User clients

Through the Remedy Mid Tier, users can access Remedy AR System in a browser. Using the web-based interface, users can submit and modify new requests, search for information about requests, and generate reports.

The following table summarizes the main clients used to perform administrative, user, and development tasks.

Client	Tasks
A browser	Administrator tasks: Create groups and roles Create users and assign licenses Manage Remedy AR System server settings and licenses User tasks: Access Remedy AR System forms and applications to create, submit, search, and modify requests Receive and respond to Remedy AR System notifications Chart data Generate reports Display alerts in the Alert List form, which can be refreshed automatically at specified intervals or manually at any time Search records, run or generate reports, and view flashboards

Client

Tasks

A browser

Administrator tasks:

Create groups and roles
Create users and assign licenses
Manage Remedy AR System server settings and licenses

User tasks:

Access Remedy AR System forms and applications to create, submit, search, and modify requests
Receive and respond to Remedy AR System notifications
Chart data
Generate reports
Display alerts in the Alert List form, which can be refreshed automatically at specified intervals or manually at any time
Search records, run or generate reports, and view flashboards

Developer clients

The developer clients are used to create, modify, and extend Remedy AR System applications.

Client	Tasks
Remedy Developer Studio	Developer tasks: Create and update application, forms, and workflow
Remedy Mid Tier Configuration Tool	Administrator tasks: Modify the Remedy Mid Tier settings for Remedy AR System servers, passwords, logging, caching, and authenticating web services Specify home page and preference and catalog servers
Remedy Data Import	Administrator tasks: Import Remedy AR System data from one Remedy AR System server to another Load external data into the Remedy AR System database Map between the columns in the external data set and the fields in the Remedy AR System form Remedy Data Import is available for Windows.
Import/export command line interface (CLI)	Administrator tasks: Connect to the Remedy AR System server to import and export object definitions without the graphical user interface of Remedy Developer Studio Automate tasks
Remedy Data Import Command Line Interface (CLI)	Connect to the Remedy AR System server to import data without the graphical user interface of Remedy Data Import Automate tasks
Remedy Migrator	Migrate applications, objects, and data between servers, servers and files, or files Reduce the difficulty and time required to synchronize Remedy AR System servers in development and production environments Note: For limitations on using Remedy Migrator with other BMC applications, see Known-and-corrected-issues.

Integration clients

BMC and its partners also offer the following tools for expanding the capabilities of core Remedy AR System. These tools act as clients of Remedy AR System.

Knowledge Management
Network management platform integration accessories
Systems management integration utilities

See Remedy AR System and web services introduction and Remedy AR System REST API overview.

Remedy AR System database server

Remedy AR System uses standard relational database engines for the actual storage and retrieval of data. Architecturally, the database server is an independent set of processes that are completely separate from the Remedy AR System server processes. Physically, the database server processes can be running on the same server host as the Remedy AR System server or on a different host. The database server can be any platform that the database engine supports. For information about supported platforms, see Compatibility matrix in the Remedy ITSM Deployment online documentation.

Support for an external database

Remedy AR System can also work with data stored in external databases and other data sources that are not managed by Remedy AR System. Remedy AR System accesses these data sources through view forms. In addition, Remedy AR System can use Remedy AR System database connectivity (ARDBC) to work with data not stored in databases as if the data was locally owned. In other words, ARDBC plug-ins can be created and configured to enable access to data stored outside the database as if it were in tables owned by Remedy AR System.

Support for multiple database types

Because the Remedy AR System server manages all workflow, applications are independent of the database. Therefore, applications created on a Remedy AR System server running one type of database can easily be moved to a server running a different type of database. BMC provides a simple export/import utility for this purpose.

Remedy AR System is not a database application in the typical sense. All of the workflow is managed by the Remedy AR System server, so proprietary database features such as triggers and stored procedures are not used. An application created on a Remedy AR System server running one type of database engine can easily be moved to a server running a different database engine through a simple export/import process.

Support for database searches

Remedy AR System workflow components can search for records (requests) in the Remedy AR System database and act on the results of the search. Clients can use the following types of searches:

Query-by-example (QBE)
Advanced search
Predefined
Recent

An administrator can create and store searches that are commonly performed by users. A user can define personal searches for forms to which the user has access.

Support for high availability and failover

Remedy AR System leverages common database architecture for high availability, including failover. For tested configurations, see the Compatibility matrix.