AggreGate is one of the only IoT platforms in the world that supports generic distributed architecture. It is designed to assure unlimited scalability by separating operations between multiple AggreGate servers subdivided into several layers. Servers maintain secure connections to each other, exchanging their data and living as a single coordinated organism.
Unlike nodes of the AggreGate failover cluster, servers participating in the distributed architecture are entirely independent. Each server has its database, local user accounts, associated permissions, etc.
AggreGate distributed architecture is extremely flexible. It is technically based on establishing peering relationship between servers and attaching parts of the unified data model from specific servers ("providers") to other servers ("consumers").
Objectives of Distributed Operations
The primary purposes of distributed architecture are:
Scalability. Lower-level servers may be heavily loaded with near-real-time control and extensive polling of devices. But in practice, the number of devices that can be managed by a single server is limited to several thousand. To scale the system for larger number of devices, it's reasonable to install multiple servers and join them into a distributed installation.
Role Distribution. Each server in a distributed installation may solve its task. Network management servers check availability and operability of the IP network infrastructure, while physical access control servers are serving requests from door/turnstile controllers. In addition, the supervising operations (such as generating and emailing reports) can be performed by a central server.
Firewall Penetration. Secondary "probe" servers may be installed in remote locations and connect to the central server themselves. System operators connect to the central server only, so there is no need to set up VPNs and port forwarding to the secondary servers.
Centralization. Lower-tier servers may work in a fully automated mode, while their overall operation may be supervised by a single operator via higher-tier server installed in the situation center.
Server Role Distribution
In this straightforward scenario, there are two servers joined into a distributed installation. System operators are connected to the monitoring server 24x7, performing their everyday duties. Company executives connect to the reporting and analytics server once a specific data slicing is required. Regardless of how expensive this data slicing is, it doesn’t affect operator interface performance.
Large-Scale IoT Cloud Platform
Telecom operators and managed service providers offer IoT services according to IaaS/PaaS/SaaS model. In this case, there are millions of devices that belong to thousands of tenants. Servicing such a considerable infrastructure requires hundreds of AggreGate servers most of which are grouped in two tiers:
Servers that keep the registry of users and their devices, route device and operator connections to proper lower-tier servers, and aggregate data during advanced data mining operations that involve multiple lower-tier servers
Servers that perform actual device management and monitoring, as well as data acquisition, storage, and processing
User and device directory servers are also responsible for interfacing the cloud control system that takes care about deploying new data storage and analytics servers, as well as supervising their operation.
Data storage and processing servers are using resources (alerts, models, workflows, dashboards, etc.) shared by templating servers that keep master copies of those resources.
Multi-tier IoT Infrastructure
Thanks to AggreGate's distributed architecture, a single solution may join multiple servers installed at several tiers. Some of them are running inside IoT gateways, some are storing and processing data, and others are responsible for high-level aggregation and distributed computing.
Field equipment, such as sensors and actuators, may be connected to processing servers directly, via agents, via gateways or through a combination of an agent and a gateway.
Smart City Management
Here is an example of multi-tier AggreGate-based architecture employed in a large metro area automation project:
Layer 2: direct management servers (network monitoring server, access control server, building automation server, etc.)
Layer 3: building control center servers (one server per building, consolidates information from all "specialized" Layer 2 servers in this building)
Layer 4: urban district servers (the final destination for escalated lower-level alerts, real-time monitoring by human operators, integration with Service Desk systems)
Layer 5: HQ server (overall supervision, incident and situation management, global reporting and alerting)
Any particular AggreGate server in the above schema may be a multi-node failover cluster.
Multi-segment Network Management
AggreGate Network Manager product built atop of AggreGate Platform is one of the most typical use cases for the distributed architecture. Large segmented networks of corporations and telecom operators cannot be monitored from a single location due to routing restrictions, security concerns and limited bandwidth between geographically separated segments.
Thus, a unified monitoring system is usually composed of several components:
A primary or central server consolidating aggregated information from all network segments
Secondary or probe servers that perform polling of devices in isolated segments
Specialized servers, such as the traffic decomposition server which handles billions of NetFlow events per day
Secondary and specialized servers act as data providers for the primary server, exposing a part of their data model for the control center. This can be:
The whole content of the probe server's context tree, allowing full monitoring and configuration through the central server. In this case, the probe server is just used as a proxy for overcoming network segmentation issues.
Alerts generated by probe servers. In this case, 99% of jobs are performed remotely, but central server operators are immediately notified about issues raised in secondary segments.
A custom set of probe server's data, such as specific mission-critical devices and important overview reports. The actual polling and report generation will be performed by the secondary server, allowing to balance system load properly.
High-Performance Event Management
Some AggreGate Platform usage scenarios, such as centralized incident management, assume that a vast number of events should be received, processed and persistently stored in the structured format. Some event streams may reach millions of events per second coming from several sources.
In such cases, a single AggreGate server won't be able to handle the whole event stream. Distributed architecture helps organize event processing:
Multiple local event processing servers are installed at event source locations. Several sources (probes) can be connected to a single processing server.
A dedicated storage server or a multi-server Big Data storage cluster is associated with each local processing server. The number of cluster nodes may vary according to event rate.
All local storage servers perform event pre-filtering, deduplication, correlation (using rules applicable to locally connected probes), enrichment and storage.
Local storage servers are connected to a central aggregation server. The aggregation server is responsible for system-wide correlation of significant events.
Central server operators may screen the whole event database while actual data search tasks are distributed among the storage servers. Thus, centralized reporting and alerting based on the entire event database is possible.
AggreGate may act as the central middleware platform of a digital enterprise. In this case, its servers play various roles from high-level BI and incident/situation management down to local monitoring and control servers in remote branches.
All servers of a digital enterprise are connected via the distributed architecture. Lower-level servers share parts of their unified model to higher-level servers, allowing to build a unified situation center for the whole enterprise.