US-12619505-B2 - System of aggregating servers

US12619505B2US 12619505 B2US12619505 B2US 12619505B2US-12619505-B2

Abstract

A system of aggregating servers includes a first aggregating server that establishes a session for linking with a first system; a second aggregating server that establishes a session linking with a second system; wherein the first and second aggregating servers replicate mutually structured data provided by the first and/or second system, to provide access to the structured data of the respective systems for the first and second aggregating servers; and coordinate the respective sessions of the system of aggregating servers with the first and/or second system to prevent improper access to the at least first system to be aggregated and/or the at least second system to be aggregated.

Inventors

Sten Gruener
Roland Braun

Assignees

ABB SCHWEIZ AG

Dates

Publication Date: 20260505
Application Date: 20240411
Priority Date: 20211015

Claims (14)

1 . A system of aggregating servers, comprising: a first aggregating server configured to establish a session for communicatively linking with at least one first system to be aggregated; at least a second aggregating server configured to establish a session communicatively linking with at least one second system to be aggregated, wherein each of the first aggregating server and the second aggregating server comprises: an information model server configured to provide an aggregated information model, which aggregates the information models of each system to be aggregated, which are coupled for communication to the system of aggregating servers: a database configured to store the structured data of the systems to be aggregated according to an aggregated information model, which is related to the respective systems to be aggregated; a device connection manager configured for controlling a policy for establishing a session of the related systems to be aggregated with the related aggregating server; and a device client configured to enable and run a session with the systems to be aggregated, and wherein the first aggregating server and the second aggregating server are configured to: replicate mutually structured data provided by the first system to be aggregated and/or the second system to be aggregated to provide access to the structured data of the respective systems to be aggregated for the first aggregating server and the second aggregating server; and coordinate the respective sessions of the system of aggregating servers with the at least first system to be aggregated and/or the at least second system to be aggregated to prevent improper access to the at least first system to be aggregated and/or the at least second system to be aggregated.
2 . The system of aggregating servers according to claim 1 , wherein the first aggregating server is configured to establish respective communication links with a part of a plurality of systems to be aggregated; and the at least second aggregating server is configured to establish a communication link with another part of the plurality of systems to be aggregated; and wherein the aggregating servers are configured to coordinate respective sessions for establishing the communication link with the plurality of systems to be aggregated in such a way as to prevent improper access to the plurality of systems to be aggregated and/or for load balancing of the sessions.
3 . The system of aggregating servers according to claim 1 , wherein the improper access is caused by exceeding a permitted number of multiple sessions with the systems to be aggregated.
4 . The system of aggregating servers according to claim 1 , wherein each aggregating server is configured to be coupled for communication to a plurality of external client systems.
5 . The system of aggregating servers according claim 4 , wherein the system of aggregating servers comprise a reverse proxy server, which is coupled for communication with at least the first aggregating server and the at least second aggregating server for load balancing access for communication of a plurality of external client systems with the reverse proxy server.
6 . The system of aggregating servers according to claim 5 , wherein the reverse proxy server is configured to provide a dedicated IP address to decouple each external client system from the first aggregating server and the at least second aggregating server.
7 . The system of aggregating servers according to claim 1 , wherein the system of aggregating servers comprises OPC UA aggregating servers.
8 . The system of aggregating servers according to claim 7 , wherein the external client system is an OPC UA client system and/or the system to be aggregated is an OPC UA system to be aggregated and/or the information model is an OPC UA information model and/or the device client is an OPC UA device client.
9 . The system of aggregating servers according to claim 1 , wherein the first aggregating server and the at least second aggregating server are coupled for communication and the aggregating servers are configured to mutually replicate the structured data provided by the first system to be aggregated and/or the at least second system to be aggregated and respective session configuration data of the systems to be aggregated, to provide access of the structured data and the session configuration data of the respective systems to be aggregated for the first aggregating server and the at least second aggregating server.
10 . The system of aggregating servers according to claim 9 , wherein the coupling for communication between the first aggregating server and the at least second aggregating server is provided by using encrypted communication.
11 . The system of aggregating servers according to claim 9 , wherein the first aggregating server and the at least second aggregating server are coupled for communication to coordinated the mutual distribution of respective distributed sessions to the at least first system to be aggregated and/or the at least second system to be aggregated.
12 . The system of aggregating servers according to claim 11 , wherein each aggregating server is configured to respectively store the coordinated mutual distribution of respective distributed sessions with the at least first system to be aggregated and/or the at least second system to be aggregated, to enable the respective aggregating servers to take over at least the sessions of the respective other aggregating server in case of a failure within the system of aggregating servers.
13 . The system of aggregating servers according to claim 1 , wherein the first aggregating server and the second aggregating server are installed on different hardware computing systems for providing high availability aggregating servers.
14 . The system of aggregating servers according to claim 13 , wherein the at least second aggregating server on a second hardware computing system is running in a standby mode until a failure within the system of aggregating servers is detected.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The instant application claims priority to International Patent Application No. PCT/EP2022/075867, filed Sep. 16, 2022; European Patent Application No. 21202942.5, filed Oct. 15, 2021; and European Patent Application No. 21208778.7, filed Nov. 17, 2021, each of which is incorporated herein in its entirety by reference. FIELD OF THE DISCLOSURE The present disclosure generally relates to a system and method for aggregating servers and, more particularly, to aggregating Open Platform Communication Unified Architecture (OPC UA) Servers. BACKGROUND OF THE INVENTION An aggregating Open Platform Communication Unified Architecture (OPC UA, also standardized as IEC 62541) Server replicates the address space of individual OPC UA Servers providing a consolidated, coherent representation of distributed address spaces on individual OPC UA Servers. An aggregating OPC UA Server can be seen as a proxy for remote individual OPC UA Servers. In the context of integrating small servers, configured for OPC UA connected instrument devices, the Aggregating OPC UA Server can be considered as a kind of an extension cord, since an Aggregating OPC UA Server can handle more concurrent sessions than a small device server can do. Typically, such embedded OPC UA Servers run a maximum of two concurrent sessions. In the context of a distributed control system (DCS) there can be more than two OPC UA Clients to be connected to an instrument device server, wherein the instrument device server can be an individual small embedded OPC UA server. BRIEF SUMMARY OF THE INVENTION A single Aggregation OPC UA Server may be a single point of failure causing system-wide impact for e.g. a manufacturing site or other applications. The present disclosure describes systems and methods for aggregating servers. In the present disclosure, the sequence of procedural steps is presented in such a way that the process is easily comprehensible. However, the skilled person will recognize that many of the process steps can also be executed in a different order and lead to the same or a corresponding result. In this sense, the sequence of the process steps can be changed accordingly. Some features are provided with counting words to improve readability or to make the assignment more clear, but this does not imply the presence of certain features. To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a system of aggregating servers, including a first aggregating server, which is configured to establish a session for communicatively linking with at least one first system to be aggregated and at least a second aggregating server, wherein the second aggregating server is configured to establish a session communicatively linking with at least one second system to be aggregated. Thereby the first aggregating server and the second aggregating server are configured to: replicate mutually structured data provided by the first system to be aggregated and/or the second system to be aggregated, to provide access to the structured data of the respective systems to be aggregated for the first aggregating server and the second aggregating server. Additionally, the first aggregating server and the second aggregating server are configured to coordinate respective sessions of the system of aggregating servers with the at least first system to be aggregated and/or the at least second system to be aggregated, to prevent improper access to the at least first system to be aggregated and/or the at least second system to be aggregated. The mutually structured data provided by the first system to be aggregated and/or the second system to be aggregated can also be called “address space” or “information model.” A system to be aggregated, can, as an example, be an embedded system and/or an embedded server, which can be defined as a computer system, a combination of a computer processor, computer memory, and input/output peripheral devices, which has a dedicated function within a larger mechanical or electronic system. Such an embedded server can be embedded as part of a complete device including electrical or electronic hardware and mechanical parts. Because an embedded server typically controls physical operations of the machine that it is embedded within, it can have real-time computing constraints. Embedded servers can control a plurality of devices. A system to be aggregated can be an embedded system, particularly an OPC UA server for connection of OPC UA instrument devices. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, and illustrate embodiments of the disclosure. FIG. 1 is a schematic representation of a system of aggregating servers with shared sessions with the systems to be aggre