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YellowHammer is an industry leading data aggregator.  YellowHammer does comprehensive data aggregation and is a federation platform for streaming data, that can publish data over low bandwidth to multiple consumption points.  YellowHammer facilitates the translation of data in flight, between multiple well-known protocols.  Additionally, sources publishing data at various rates or frequencies (number of data points per second) can be regularized into a desired frequency while being output.  YellowHammer is foundational to SigmaStream's interoperability value proposition.  The product's ability to handle data streaming at different rates, sets it apart. 


YellowHammer supports widely used data protocols including ETP, Modbus, OPC U/A, OPC-DA, WITS, WITSML, and MQTT. In addition to the protocols listed, YellowHammer can consume and produce many data formats such as JSON, CSV, and Wireshark PCAP. The software connects to RDBMSs and the popular NoSQL databases such as MongoDB, Cassandra, HBase, and Kudu and to a host of custom endpoints.


A repository of well documented RESTful and JSON APIs is in place to interact with the YellowHammer server, providing a mechanism to consume the services offered. Applications that follow the request-response paradigm use the RESTful APIs whereas applications that need to take advantage of the streaming capabilities of YellowHammer use the JSON APIs. This feature also facilitates development of custom adaptors using SDK.

Custom Subscription

The ability to choose channels from multiple devices producing data at different frequencies is a convenient and powerful mechanism to ensure just the right data at the right frequency. YellowHammer can regularize the data in terms of frequency for its consumers using waterwheel subscription mode. While configuring business asset hierarchy, levels are associated with assets for consolidation of data. YellowHammer allows consumers to subscribe to specific business assets based on the level of the asset in the hierarchy. It allows consolidation of data as well as event notification.

Device-centric Operations

Device is the lowest level in business asset hierarchy and basic entity for encapsulating interface to data providers. To start streaming data into YellowHammer, devices need to be configured. YellowHammer’s device-centric mode ensures speedy configuration of devices for faster commencement of streaming and linking it to appropriate business assets, without any changes in device configuration. Thus, continuous streaming of data is guaranteed irrespective of changes in upper levels of business asset hierarchy. Resultant is the accurate data consolidation and aggregation.

Time Synchronization

Sensors and data producers have on board clocks that rarely stay in-step with one another. YellowHammer assigns a uniform global timestamp to every data point and presents them as one steady stream to the consumers downstream.

Export and Replay

All the data that lands in the YellowHammer aggregator is persisted. Via the JSON and RESTful APIs and the CLI, the software offers an extensive range of export and replay options. For instance, one can replay data for a specific set of channels collected from a specific device between a start and end time. Or, one can replay data from the persisted store and a CSV file and merge the output, on-the-fly to feed a consuming application.

Data Backfilling

Publishing real-time data to consumer applications is a basic tenet for YellowHammer. However, network outages during data transportation may result in gaps in the time-series data at the destination. To address the problem, Backfilling process is designed to identify gaps and fill them up. The process optimized to ensure maximum coverage of data gaps using minimal bandwidth and time lapse.

Optimized Architecture

Segregation of functional units into separate components to facilitate distributed deployment for enhanced performance and scalability, without using high-end servers. For instance, WebClient which is a UI component for YellowHammer server is packaged and deployed separately. It allows the use of a single WebClient for the administration of multiple YellowHammer servers.

Contextual Data

A business rules engine built into YellowHammer ensure a “single version of the truth” regarding contextual data required to understand the time-series data being managed.

Units of Measurement

Using the YellowHammer AdminConsole an administrator can either create a device that consumes data or a publisher that emits data in the desired Units of Measurement irrespective of the source UoM. The same functionality is available via the secure JSON and RESTful APIs.


YellowHammer interfaces with LDAP for authentication. Administrators can exercise fine-grained control over access to various business assets and to configuration aspects such as adaptor settings, UoM, etc. Security of data during transit is assured.

Data Management

YellowHammer provides an abstraction layer above the persistence mechanism by offering a full featured set of data management tools for querying, extraction, streaming selectively and at different frequencies. The YellowHammer administrator is shielded from the complexities of the underlying technology.