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A Distributed Immutable Data Objects (DIDO), by definition, is a Distributed System comprised of a network and a collection of nodes particpating in a Peer to Peer (P2P) network. Each node within the DIDO operates asynchronously and independently from all the others nodes. The nodes communicate changes in the state of the distributed objects managed by each nde by publishing Transactions across the node network. See Figure 1. Notice that the DIDO is comprosed of different kinds of Nodes (See 3_node_tax).

Figure 1: Overview of a DIDO

Any one distributed Immutable DIstributed Data Objects can exists on any or all of the kinds of nodes. For example, in Figure 1, the Green nodes may represent Wallets without any distributed objects, while the pink nodes might represent Archival Nodes that not only have the distributed objects, but a complete journal (i.e., ledger) of all the transactions every applied to the distributed object.

One of the most important aspects about a DIDO is that each participating Node in the Node Network using the Distributed Object arrives at the same state for the object given any transaction. In essence, the result of the transaction needs to be deterministic in nature (i.e., the same input (Transaction) achieves the same output (Journal Entry in the Journal).

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The proposed DIDO Solution Stack is modeled after the Database Solution Stack. The core features of both stacks is persistent storage of data and the modification of data using Transaction. The major difference is that the DIDO data objects Transactions are journaled with each Transaction being distributed to all the nodes in the node network. The details about how the Transactions are bundled, validated and verified vary amongst DIDO platforms. For example, some platforms bundle the Transactions into a block and the block is distributed once it has been verified by a mining operation. Others use “neighboring” nodes to valid and verify the Transactions.

Figure 2: Proposed DIDO Management “stack”

The following is a brief description of each component in the DIDO Stack. Note, these components are normative in nature and each DIDO may be slightly different. On the left side of the diagram there the components that are good candidates for inclusion into the DIDO platform are identified.

• Application - The Application is similar to the Application in the Database Solution Stack, is the application, program, utility, service or microservice that needs to interact with the DIDO. This is done using standardized DIDO Data Definition Language (DDDL) or Data Manipulation Language (DDML) using textual commands that adhere to the DIDO-CLI specifications See: dblang-sql-part1 and related specifications.
• Users - And end user can enter DIDO compliant DDDL or DDML text commands into a terminal or even produce scripts that contain a series of commands that sent to the Open DIDO Connectivity API (ODAPI)for processing. Just as with the Application, these commands need to be compliant with the proposed Standard See: 04_dll, 06_dddl, and 09_dml.
• Open DIDO Connectivity API (Open DIDO Data Binary Connectivity Layer (ODDBCL) - This a utility (i.e., usually a library) that the application calls to process the DIDO-CLI commands and check for validity and verification that the commands are correct.
• DIDO Data Definition Language (DDDL) - The DIDO Data Definition Language (DDDL) is used to create and modify the structure of DIDO objects in a DIDO. These DIDO objects include Types, objects, oracles, exchanges, aggregates, and smart contracts, etc. Often, the DDDL commands require a different set of privileges than the DIDO Data Manipulation Language (DDML).
• DIDO Data Manipulation Language (DDML) - The DIDO Data Manipulation Language (DDML) includes commands permitting users to manipulate (i.e., read) data in a DIDO. Note, the Data in the DIDO is immutable. This manipulation involves inserting data into DIDO Objects, making for deletion objects, creating a Transaction to update the objects and associated data from different objects together.
• DIDO Drivers - The DIDO Drivers are computer programs that implements a protocol (i.e., ODDBCL) for a DIDO connection.
• DIDO Data Management System (DDMS) - The DIDO Data Management System is a software package designed to define, manipulate, retrieve and manage DIDO Objects in a DIDO. A DIDO generally manipulates the objects itself, the object format, field names, object structure. It also defines rules to validate and manipulate this data.

  • DIDO Data Command Line Interpreter (DDCLI) - The Command Line Interpreter translates the tokenized DIDO commands into DIDO Platform Specific instructions.
  • DIDO Platform CLI - Sme DIDO platforms offer their own proprietary CLI. There have been efforts to “re-use” a particular DIDO Platform CLI on different Platforms.
  • DIDO API - Many DIDO Platforms provide APIs allowing a programmer to directly access a DIDO. For example, Ethereum provides a Javascript API Libraures, https://ethereum.org/en/developers/docs/apis/javascript/ or Ethereum JSON RPC, https://ethereumbuilders.gitbooks.io/guide/content/en/ethereum_json_rpc.html.
  • DIDO Configuration - There are always two aspects to configuring a DIDO. The first is setting up the environment externally to the DIDO Platform (i.e., downloading the software, running a wizard to install and configure the DIDO, etc), the second is the startup, upgrade, shutdown, etc of the DIDO Platform.
  • DIDO Data Definition - A DIDO provides a way to define Types, objects, oracles, exchanges, aggregates, and smart contracts, etc. to the DIDO.
  • DIDO Data Manipulation - A DIDO provides a way to manipulate the inserting data into DIDO Objects, making for deletion objects, creating a Transaction to update the objects and associated data from different objects together.
  • DIDO Datastore - A data store is the actually distributed data held within the DIDO (i.e., the data itself). To store the data in the Datastore, a transaction is created that can make the desired change. Depending on the DIDO Platform, the methodology for verifying and validating the transaction varies. Once it has been valdated and verified, the transaction is propagated to all the Node in the Node Network.

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Figure 3: Three different User Scenario Paths through the DIDO Solution Stack.

This is currently the path used by most DIDOs.The DIDO Platform provides an Application Programming Interface (API) that an Applications can be use to access the DIDO Data Store. These APIs are proprietary in nature and although there are attempts to “re-use” one proprietary API specification on another proprietary platform (interchangeable implementations) it has met with limited success. Also, there are disagreements as to what languages the API should be written in (or support). For example, if the API is written in C, many languages have a way of accessing these function. For examplem Java can ue wither the Java Native Interface (JNI) or the Java Native Access (JNA)¹⁾.

Another issues is whether t use the Static Library and Shared Library approach. There advantages and disadvantages provided in Table 1²⁾.

Note: One of the goals for DIDOs is to minimize the side effects that can arise in distributed objects. Remember, each transactions when applied to any node should result in the same output. There is no guarantee that distributed object will be deterministic if there is “no need to recompile the executable” when new libraries are downloaded on different Nodes. This is particularly a problem on Nodes that host other software which may download different versions of the shared library. Furthermore, each component must be deterministic in its behavior, meaning that given the same set of inputs, the outputs will always be the same. In other words, not only will all the same implementations (i.e., configurations) of a node produce the same output, but multiple implementations of a component within a node will provide the same results given the same inputs.

Naturally, many of these APIs are focused on Representational State Transfer (REST) over Hypertext Transfer Protocol (HTTP) types of interfaces that define the standardized set of actions or verbs (i.e., GET, POST, PUT, DELETE, PATCH) as part of the Hypertext transfer protocol (HTTP) Request of what needs to be done, not the actual “what” needs to be acted upon. The what is usually sent along as a standardized document (payload) as Extensible Markup Language (XML) or JSON. also, sometimes the HTTP Request Header is used to send information to the service. The Header is a set of key-value pairs with no standardization as the what keys are to be returned nor what the values are.

There is a similar problem with the Hypertext transfer protocol (HTTP) Response. Although the document (payload) that is returned is in a standardized XML or JSON format, the contents of the document are not standardized. Some HTTP Responses send the results back as part of the HTTP Header which is comprised of non-standardized key-value pairs.

Figure 4: REST over HTTP