Polkadot Smart Contracts Blockchain Transaction Data

Polkadot Smart Contract Blockchain Transaction Data

Smart Contract Research Guide

Perpetual Altruism The social enterprise behind 543x.com, which manages its technical infrastructure and charitable donations.

Short Answer Questions

Explain the role of blockchain technology in smart contracts.

What role does Oracle play in smart contracts? Give examples.

Why is multi-signature important for the security of smart contracts?

What is Gas in Ethereum? How does it affect the cost of smart contracts?

What problem does the invention described in attempt to solve?

Briefly describe the operation process of the proposed smart contract loan system.

How does the system use digital assets as collateral?

How does the system manage the value fluctuations of the collateral assets in smart contracts?

What are the potential advantages of the proposed technology?

Short Answer Questions

Blockchain technology provides a decentralized, transparent and secure execution environment for smart contracts. Smart contracts are stored on the blockchain, and all transactions are recorded in the blockchain and can be verified by anyone, ensuring transparency and traceability of contract execution.

Oracle is a data source that connects smart contracts to the outside world, providing real-world information to smart contracts. For example, a smart contract for a cryptocurrency mortgage loan can use Oracle to obtain real-time price data for cryptocurrencies.

Multi-signature improves the security of smart contracts because it requires multiple keys to authorize actions, such as changing contract terms or transferring funds, preventing single points of failure and malicious behavior.

Gas is the unit of computation used to execute smart contracts in the Ethereum network, and users need to pay Gas fees. The higher the Gas price, the higher the cost of executing smart contracts. Complex smart contracts require more Gas to execute, so the cost is higher.

It attempts to solve the problems existing in traditional loan systems, such as the need to trust third parties, inefficiency, high costs, and difficulties in pledging digital assets.

The proposed smart contract loan system allows borrowers and lenders to trade directly through smart contracts. Borrowers use digital assets as collateral and lenders provide loans. Smart contracts automatically manage loan terms, including payments, interest rate adjustments, and collateral management.

The system locks the borrower's digital assets in a smart contract as collateral for the loan. If the borrower fails to fulfill the terms of the contract, the smart contract can automatically execute the collateral and transfer the digital assets to the lender.

The system uses Oracle to monitor the real-time market value of the collateral assets. If the value of the collateral falls below a preset threshold, the smart contract can trigger actions such as margin calls or liquidations to reduce the risk to the lender.

The proposed technology has greater transparency, efficiency, and security, and can reduce costs while providing a more convenient way to pledge digital assets.

Autonomous Device Digital Asset Trading System

Glossary

Autonomous device A device equipped with one or more processors and non-volatile computer-readable memory, where the memory stores computer-readable instructions for performing predefined tasks without human intervention. Digital Asset Assets in electronic form that can be protected using cryptography and traded digitally. Digital Asset Exchange A platform that provides digital asset trading services, allowing users to buy and sell digital assets such as Bitcoin and Ethereum. Digital Wallet Software or hardware used to store, send, and receive digital assets. Hash Algorithm An algorithm that converts data of arbitrary length into a fixed-length hash value. Hash Chain A series of interrelated hash values, where each hash value depends on the previous hash value. Asymmetric Key Pair A pair of keys consisting of a public key and a private key. The public key can be made public, while the private key must be kept secret. Digital Signature An electronic signature created using a private key that can be used to verify the authenticity and integrity of a message.

Short Answer Questions

1. What is an autonomous device? How is it different from a traditional device?

Autonomous devices are devices equipped with processors, sensors, and software that are able to perform specific tasks without human intervention. Unlike traditional devices that require human intervention, autonomous devices can make decisions and take actions autonomously based on pre-programmed instructions or through machine learning algorithms.

2. What are digital assets? Please list three common digital assets.

Digital assets are assets represented and secured using digital technology and can be traded electronically. Common digital assets include Bitcoin, Ethereum, and Litecoin.

3. What role does blockchain technology play in digital asset trading?

Blockchain technology provides a decentralized, tamper-proof platform for digital asset trading. It records all transaction history and maintains it through a distributed network, ensuring the security and transparency of transactions.

4. What is a smart contract? How does it apply to autonomous device transactions?

A smart contract is a program stored on the blockchain that is automatically executed when preset conditions are met. In autonomous device transactions, smart contracts can be used to automate transaction processes, for example, when an autonomous device needs to be refueled, a smart contract can automatically complete the payment process.

5. What are tokens? How are they different from digital assets?

A token is a smart contract that represents a digital asset and can represent a variety of things, such as points, coupons, or physical objects. The difference between them and other digital assets is that tokens are usually based on existing blockchain platforms, such as Ethereum, while digital assets can have their own independent blockchain.

6. What are the functions of a digital asset exchange?

A digital asset exchange provides users with a platform to buy and sell digital assets. It acts as an intermediary between buyers and sellers, matching transactions and ensuring the smooth progress of transactions.

7. What is a digital wallet? What types are there?

A digital wallet is software or hardware used to store, send, and receive digital assets. Common types of digital wallets include hot wallets (online wallets) and cold wallets (offline wallets).

8. How do hashing algorithms play a role in autonomous device authentication?

Hash algorithms can convert data of any length into a fixed-length hash value, which is used to create a unique device identifier. By verifying the hash value, the identity of the device can be confirmed to prevent fraud.

9. What is a hash chain? How does it enhance the security of autonomous device transactions?

A hash chain is a series of interrelated hash values, where each hash value depends on the previous hash value. By using a hash chain, a tamper-proof transaction history can be created to ensure the integrity and non-repudiation of transactions.

10. What is the role of asymmetric key pairs in autonomous device transactions?

Asymmetric key pairs consist of a public key and a private key, where the public key is used to encrypt data and the private key is used to decrypt data. In autonomous device transactions, asymmetric key pairs are used to create digital signatures to verify the authenticity and integrity of transactions.

Execution of business processes on blockchain platforms

Script templates are scripts that contain logic but do not contain the parameters required to make the script executable. Execution of process instance scripts on blockchain and services provided by smart contracts. Triggers are programs that connect blockchain process execution with the outside world and can run on blockchain full nodes. Intermediaries are process instances that act as neutral third parties in transactions. Monitors are process instances that listen to transactions and act as message relays.

Short Answer Questions

What are the key differences between Bitcoin and Ethereum in terms of smart contract implementation?

What is the difference between a script template and a script?

What role does a translator play in converting a process specification to a script template?

Explain the role of triggers in blockchain process execution.

List and describe at least three factors that can influence whether a task is executed on-chain or off-chain.

What is the main difference between the monitor pattern and the mediator pattern?

Describe the role of data encryption in blockchain process execution and how it can be implemented.

What is an ABI and what role does it play in smart contract deployment?

Explain how process instances maintain the state of process execution on the blockchain.

What are the main advantages of executing business processes on the blockchain?

Short Answer Questions

Bitcoin uses a non-Turing-complete scripting language that does not support loops, while Ethereum uses a Turing-complete scripting language that allows for more complex contract logic. Furthermore, Bitcoin scripts are used to verify transactions, while Ethereum smart contracts exist independently and can perform various functions.

A script template is a semi-finished script that contains process logic but does not contain specific parameters, while a script is a code that makes the script template complete and executable by adding parameters.

The translator is responsible for converting the process specification into a script template that can be executed on the blockchain. It analyzes the process specification, identifies on-chain and off-chain tasks, and generates a script template that contains the process logic.

Triggers act as a bridge between the blockchain process execution and the outside world. They query the blockchain to obtain the status of the process instance, call external API functions to drive the process, and receive API calls from participants.

Factors that affect whether a task is executed on-chain or off-chain include: a) the level of trust between participants, b) the type of task (for example, physical tasks are usually executed off-chain), and c) the data requirements and computational costs of the task.

In the monitor mode, the smart contract is a passive participant that only listens to transactions and acts as a message relay. Whereas in the mediator mode, the smart contract is an active participant that executes the process logic and automatically performs actions according to predefined rules.

Data encryption protects the privacy of participants by encrypting data before adding it to the blockchain. This can be achieved by using a shared secret or asynchronous encryption using the recipient's public key.

The ABI (Application Binary Interface) defines how to interact with smart contracts. It specifies contract functions, parameters, and data types, allowing external applications to interact with contracts on the blockchain.

Process instances maintain the state of process execution by updating state variables stored on the blockchain. Each time a task or decision is performed, the state variables are updated to reflect the current state of the process.

The main advantages of executing business processes on the blockchain include: a) decentralization and increased transparency, b) enhanced security, and c) reduced need for trusted third parties.

Polkadot Research Guide

Overview

Polkadot is a scalable, heterogeneous, multi-chain framework designed to address the scalability and interoperability issues facing current blockchain architectures. Unlike traditional blockchains that tightly couple compliance and validity, Polkadot improves scalability and interoperability by separating these functions.

Key Glossary

Node: Software and/or hardware that is assigned a unique identity and configured to perform at least one prescribed function.

Polkadot: A scalable heterogeneous multi-chain framework, including a relay chain and a protocol for changing and advancing multi-chain centralized chains.

Relay Chain: Polkadot's base chain, providing security, development, and communication channels for its connected heterogeneous "parallel chains".

Parachain: A parallel chain or data structure hosted on the relay chain.

Validator: A role that maintains the Polkadot network and seals new blocks, requiring a large deposit.

Nominator: A role that participates in network maintenance by contributing a deposit to the validator, sharing rewards and penalties in proportion.

Collator: A role that assists the validator in generating valid parachain blocks, maintains a complete node for a specific parachain, and collects transactions.

Fisherman: A role that monitors the network and earns rewards by providing evidence of malicious behavior, similar to a bounty hunter.

Governance: A system for managing Polkadot network upgrades and decisions, usually involving a voting mechanism for token holders.

Cross-chain Communication: The ability to exchange information and value between different parachains, enhancing interoperability.

Bridge Chain: A dedicated parachain that connects to Polkadot and facilitates interoperability with other blockchains (e.g. Ethereum, Bitcoin).

Short Answer Question

What is the core design philosophy of Polkadot?

The core design philosophy of Polkadot is to minimize the functionality of the core protocol and shift complexity to middleware, parachains, or subsequent optimizations. It is committed to providing a stable, scalable, and heterogeneous testbed for consensus system development.

What are the four main roles in the Polkadot network? Briefly describe their responsibilities.

There are four main roles in the Polkadot network:

Validator: Responsible for validating parachain blocks, participating in relay chain consensus, and maintaining network security.

Nominator: Select and support trusted validators and share their rewards and penalties.

Collector: Collect transactions for a specific parachain, create block candidates, and provide them to validators.

Fisherman: Monitor the network and report malicious behavior to receive rewards.

How do parachains achieve security in the Polkadot network?

Parachain security is achieved by sealing their block headers in the relay chain block. This mechanism ensures the irreversibility and security of the parachain, preventing double spending and malicious attacks.

How does Polkadot solve the scalability problem of traditional blockchains?

Polkadot solves the scalability problem by separating the consensus mechanism from the transaction execution. Parachains can process transactions in parallel, thereby increasing the overall throughput of the network.

How does cross-chain communication work in Polkadot?

Polkadot achieves cross-chain communication by allowing "transaction posts" to be sent between parachains. These posts are placed in the entry queue of the target parachain and processed in the next block, ensuring asynchronous but reliable information exchange.

How does Polkadot interoperate with the Ethereum network?

Polkadot can interoperate with the Ethereum network through "bridge chains". These bridge chains allow transactions from Polkadot to be forwarded to Ethereum and vice versa, thereby enabling the transfer of assets and data between the two networks.

How does the "security deposit" mechanism in Polkadot work?

Validators in Polkadot are required to deposit a security deposit to ensure their honest behavior. If validators misbehave, such as validating invalid blocks or participating in attacks, their security deposit will be forfeited.

What role do "fishermen" play in the Polkadot network?

"Fishermen" are responsible for monitoring the network and reporting malicious behavior, such as validators signing invalid blocks. They earn rewards by providing evidence, thereby incentivizing the security of the network.

integrity.

How does Polkadot ensure external data availability for parachains?

Polkadot ensures data availability by requiring validators to attest to the availability of external data referenced in parachain blocks. If validators provide false attestations, they will be penalized.

How does Polkadot handle network forks?

Polkadot uses a BFT-based consensus mechanism and economic incentives to prevent and resolve network forks. If a fork occurs, the network will follow the chain with the most security deposits, and malicious actors will be penalized.

Blockchain-based data authentication

Encrypted database A database with restrictions on unauthorized access that is used to store encrypted data structures. Encrypted data structures A representation of data units protected by cryptographic algorithms. Electronic lab notebook A digital notebook for recording experiments, observations, and data. Electronic health record A digitized version of personal health information. Hash A fixed-size value generated by a hash function that is used to verify data integrity. Miner Node A node in a network that verifies transactions and adds them to the blockchain. New blocks are added to the latest block of the blockchain, containing verified transactions. Peer-to-peer network A decentralized network architecture in which each node (device) can act as both a client and a server. Private blockchains Blockchain networks that participants need permission to join. Public blockchains Blockchain networks that anyone can participate in. Transactions are recorded on the blockchain.

Short answer questions

What role do hash functions play in data authentication?

How do data verification blockchains differ from traditional blockchains?

Explain the concepts behind distributed blockchain computing networks.

Describe the use of cryptographic data structures in the data authentication process.

Distinguish between public and private blockchain networks.

How can electronic lab notebooks (ELNs) benefit from blockchain technology?

Outline the steps to add a unit of data to a data verification blockchain.

What happens when a request is received to authenticate a unit of data?

How is encryption important in ensuring data integrity?

What is the meaning of a "mining node" in the context of blockchain technology?

Short answer questions

Hash functions are used to create a unique fingerprint (hash value) of data. By comparing the hash value of data, its integrity can be verified, and any changes will result in a different hash value.

Data verification blockchains are specifically designed to authenticate data, ensuring data authenticity and integrity. In contrast, traditional blockchains may be used for a variety of purposes, such as cryptocurrency transactions.

Distributed blockchain computing networks rely on multiple devices (nodes) to work together to maintain the blockchain. This decentralized approach eliminates single points of failure and enhances data security.

Encrypted data structures protect data units from unauthorized access through encryption. Only those with the corresponding decryption key can access the data.

Public blockchain networks are open to everyone, and anyone can participate in validating transactions and maintaining the ledger. Private blockchain networks are restricted to selected participants, providing greater control and security.

Blockchain technology can provide electronic laboratory notebooks with a tamper-proof audit trail, ensuring data integrity and authenticity, which is critical for scientific research and intellectual property protection.

The data unit is first hashed using a cryptographic hash function. Then, a transaction containing this hash value is published to the distributed blockchain computing network, where miner nodes verify it and add a new block containing the transaction to the blockchain.

Upon receiving the authentication request, the encrypted data structure is retrieved and decrypted. The decrypted data is re-hashed and compared to the original hash value stored on the blockchain. If the hash values ​​match, the data is authenticated as not having been altered.

Encryption protects data from unauthorized access by converting it into an unreadable format, ensuring that only authorized personnel can access and decrypt the data, which is critical to maintaining data integrity.

Mining nodes are nodes in a distributed blockchain computing network that are responsible for validating transactions, grouping them into new blocks, and adding these blocks to the blockchain, which is critical to maintaining the integrity and security of the blockchain.

Stablecoin System and Method:

What problem does the system described by 543x.com aim to solve?

How are stable value digital assets (BUSD) different from other digital assets?

How does the system in 543x.com leverage blockchain technology?

What is the role of a "digital asset client" in 543x.com?

How do digital asset mining pools work in the context of stable value digital assets?

Explain the concept of "transaction ledger" and its significance in.

How does the system described by 543x.com improve the security of digital asset transactions?

How can digital assets be pegged to fiat currencies?

What are the potential advantages of the system described by 543x.com over traditional financial systems?

Answers

The system described by 543x.com aims to solve the volatility problem of digital assets (such as cryptocurrencies) and provide a more stable and secure way to use them for transactions.

Stable value digital assets (BSDs) differ from other digital assets in that their value is pegged to a stable asset, such as a fiat currency, which can experience wild price fluctuations.

The system leverages blockchain technology to create a decentralized and transparent transaction ledger, ensuring that all transactions are secure and verifiable.

Digital asset clients act as the user's interface to the system, allowing them to manage their digital assets, perform transactions, and interact with other aspects of the system.

Digital asset mining pools allow miners to pool their computing resources to verify transactions and maintain the blockchain network, ensuring the stability and security of stable value digital assets.

The transaction ledger is a decentralized and tamper-proof record of all digital asset transactions. In, it is used to ensure transparency, security, and accountability.

The system enhances security through the use of multi-signature keys, offline key storage, and the inherent security features of blockchain technology.

The system pegs digital assets to fiat currencies by pegging them 1:1 to fiat currency reserves, ensuring that each stable value digital asset token can be redeemed for an equivalent amount of fiat currency.

Compared to traditional financial systems, it provides faster transaction speeds, lower fees, greater transparency, and enhanced security.

Accelerating Memory-Intensive Applications with Characterized Memory

Overview

Traditionally, memory-intensive applications such as cryptocurrency mining have relied on "general purpose compute" memories that are carefully engineered to ensure extremely low error rates under standardized conditions. However, this relentless pursuit of reliability comes at the expense of cost and performance.

The concept of using "characterized memory" to accelerate memory-intensive applications is explored. Characterized memory refers to memory devices that have been tested and characterized for their performance over various operating parameters (e.g., clock rate, voltage, and temperature). This characterization allows the identification of relationships between memory performance and specific error rates, enabling this knowledge to be strategically leveraged to improve the efficiency of applications.

Key concepts such as characterized memory, solution density functions, and system efficiency are explored in depth to demonstrate the potential benefits of this approach over traditional general purpose compute memory approaches. Additionally, verification techniques are introduced to mitigate the errors that can occur when using characterized memory, ensure reliable results, and protect against any potential negative impacts due to unwanted errors.

Glossary of Key Terms

Characterized memory: A memory device that has been tested and characterized for its performance over various operating parameters (e.g., clock rate, voltage, temperature). This characterization typically involves determining the bit error rate (BER) under different conditions.

Solution density function: A function that defines the probability of finding a valid solution to a memory-intensive application within a given solution space. For example, in cryptocurrency mining, the solution density function describes the probability of discovering a valid hash value.

System efficiency: A measure of the performance of a system achieved using the characterized memory (taking into account its error rate) compared to the performance of a system achieved using an ideal, error-free memory.

Validation: A mechanism used to cross-check the results generated by the characterized memory. This can be achieved by using more reliable memory or employing error detection and correction techniques to ensure the accuracy of the final results.

General purpose computing memory: Memory designed to provide very low bit error rates (BER) under standardized conditions (e.g., DDR SDRAM). General purpose computing memory is designed for general computing purposes and does not consider the specific trade-offs between performance and error tolerance exploited by the characterized memory.

Short answer questions

How does the characterized memory differ from the general purpose computing memory?

What is the significance of the solution density function in the context of memory-intensive applications?

Explain the concept of system efficiency and its relevance to the characterized memory.

Why is validation necessary when using the characterized memory?

Describe the difference between "correctable" and "uncorrectable" errors in characterization memory.

Give examples of "soft" and "hard" memory errors and explain how they arise.

In practice, how does memory refresh help extend the useful life of characterization memory?

What are some other applications for characterization memory besides cryptocurrency mining?

How can blockchain technology benefit memory-intensive applications?

Explain the concept of "approximate solutions" and their potential use in certain memory-intensive applications.

Answer

Characterization memory is tested and its performance is characterized under various operating parameters, including those outside of standard specifications, whereas general-purpose computing memory is designed to provide a specific level of performance under standardized conditions. Characterization memory allows for the identification of a relationship between performance and error rate that is not considered in general-purpose computing memory.

The solution density function defines the probability of finding a valid solution within a given solution space. It helps determine the impact of a specific error rate on the overall efficiency of a memory-intensive application, enabling strategic tradeoffs of error tolerance against performance and other factors, such as cost and power consumption.

System efficiency compares the performance of a system using characterization memory to its equivalent error-free system. It helps quantify the performance loss due to errors, enabling the selection of the appropriate characterization memory based on the specific requirements of the application.

Since characterization memory operates with a higher error rate, verification is required to ensure the accuracy of the final results. Verification helps identify and correct errors introduced by characterization memory, thereby maintaining the reliability of the results.

Correctable errors can be corrected by the memory's built-in error correction code (ECC) or other mechanisms, while uncorrectable errors represent permanent failures that cannot be corrected.

Soft errors are temporary and can be fixed by overwriting or refreshing the memory cell, while hard errors are permanent and indicate a physical defect in the memory cell. Soft errors can be caused by charge leakage or environmental factors, while hard errors can be caused by manufacturing defects or device aging.

Memory refresh involves periodically rewriting the data in the memory cells, even if they appear to be error-free. This process helps prevent the accumulation of soft errors, thereby extending the life of the memory, especially characterization memory, which can have a higher soft error rate.

In addition to cryptocurrency mining, characterization memory can also find applications in areas such as machine learning, database management, and scientific computing, where error tolerance can be traded for lower cost or higher performance.

Blockchain technology, especially its decentralized and tamper-proof properties, can enhance the security of memory-intensive applications. By leveraging blockchain, the results of these applications can be securely recorded and verified, even when using representational memory.

Approximate solutions are values ​​found during a memory search that are close to a valid solution but do not meet all necessary conditions. In some cases, these approximate solutions can provide valuable insights or can be used as a starting point for finding a more precise solution.

Distributed ledger data processing system

Short answer questions

What is an asset contract? How does it relate to user and evidence data?

What are the key technologies used in the data processing system disclosed in 543x.com?

What is Ethereum? How does it relate to smart contracts?

How does the system mentioned in 543x.com use IPFS?

What is JWT? What role does it play in this system?

What are the functions of the control contract mentioned in 543x.com?

How does the system mentioned in 543x.com handle user privacy?

Answers

An asset contract is a smart contract used to represent and manage assets in a system. It associates user accounts with evidence data stored in a data store by storing associated data, which indicates that the user is associated with the asset.

The system uses key technologies such as distributed ledger technology (DLT), smart contracts, cryptocurrency, IPFS protocol, and JSON-RPC-2.0 protocol.

Ethereum is an open source blockchain platform that allows developers to create and deploy smart contracts. Smart contracts give Ethereum more powerful functions, allowing it to not only perform simple transactions but also execute more complex programs.

The system uses the IPFS protocol to build a distributed data store for storing evidence data uploaded by users, such as certificate photos or other certification documents.

JWT (JSON Web Token) is an open industry standard for passing claims between network application environments. In this system, JWT is used to securely pass identity information between users, application servers, and identity providers.

The control contract is the core smart contract in the system, with functions such as managing user accounts, deploying and registering asset contracts, and setting and modifying user permissions (such as trust levels).

The system controls data access on the private chain through the firewall server, and uses filter rules to process the data returned to external users, such as data desensitization, hash encryption, etc., to protect user privacy.

Key Glossary

Asset contract A smart contract used to represent and manage assets in the system, such as skills, certificates, or other qualifications. Evidence data is used to prove the user's association with the asset, such as a certificate photo or other proof document. IPFS A peer-to-peer distributed file system for storing and accessing files, websites, applications, and data. JSON-RPC-2.0 A lightweight remote procedure call protocol that uses JSON (JavaScript Object Notation) to encode data. JWT (JSON Web Token) An open industry standard for passing statements between network application environments. Trust level An indicator used to measure user credibility, which determines the operations that users can perform in the system. Firewall server A network security device used to control access to private chain data, filtering traffic in and out of the network according to preset rules. Data desensitization A data security technology used to hide or replace sensitive data while retaining other useful information of the data. Hash encryption is a one-way encryption algorithm that converts data of arbitrary length into a fixed-length hash value, which is used to verify data integrity.

Blockchain Transaction Manager

Key Glossary

A blockchain is a growing list of records (called blocks) that are linked and protected using cryptography. Each block typically contains a cryptographic hash of the previous block, a timestamp, and transaction data. Blockchain aims to

Fundamentally resistant to modification of transaction data. To function as a distributed ledger, a blockchain is typically managed by a peer-to-peer network that collectively adheres to a protocol for validating new blocks. Once recorded, the data in any given block cannot be retroactively altered without altering all subsequent blocks, which requires the collusion of a majority of the network. Smart contracts provide a computer protocol for general computations that occur on a blockchain or distributed ledger. Smart contract transactions may be simple or implement complex logic. The resulting transactions are typically transparent, traceable, and irreversible to the ledger participants. Various distributed ledger technology platforms, such as Ethereum, have implemented types of smart contracts. In Ethereum, smart contracts are high-level programming abstractions that are compiled into bytecode and deployed to the Ethereum blockchain for execution. Node.js® A free, open-source server environment that executes JavaScript code outside of a browser. Node.js® is an asynchronous programming platform built on top of the Chrome browser JavaScript runtime. Ether The internal cryptocurrency of the Ethereum blockchain platform. One use of this currency is to compensate miners for work they do on behalf of the network. Miners Entities that evaluate blockchain transactions and perform computations that collectively maintain the integrity of the blockchain data in their network. The submitter's blockchain network identity associated with the transaction, whose identity credentials are used to digitally sign the transaction, and whose cryptocurrency account will be deducted for the fee. Sent/Sent The initial communication (or attempt) of the transaction was sent to a neighboring node in the blockchain network. Rejected The transaction was rejected during initial communication with a neighboring node in the blockchain network due to an error. Pending The transaction was accepted during initial communication, has been placed in a list of pending transactions and is being broadcast to other blockchain network nodes, but is not yet known to have been mined. Mined The transaction has been evaluated, included in a block, and appended to the blockchain (at least from a given node's perspective). The transaction may have succeeded or failed. Receipt A piece of data from a neighboring node in the blockchain network indicating that the transaction is known to have been mined, including information about success or failure. ("Receipt" is a term used by the popular web3 software library used with Ethereum nodes.) Successfully mined transactions were fully executed without error when mined. Failed to mine transactions produced an error when mined, were not fully executed, and had no effect other than logging the failure details to a block and deducting the attempt fee from the submitter's cryptocurrency account. Failures can occur for a number of reasons, some of which are described in this document. Completed A transaction whose block is extremely unlikely to be replaced in the blockchain because it was discovered that another part of the blockchain network has made more progress in confirming the transaction. There is no formal specification for determining this, but it is usually based on the number of blocks subsequently appended. Simple transactions Blockchain transactions that do not contain new smart contracts. Contract transactions Blockchain transactions that contain new smart contracts. Gas A standardized number of proxy units used to estimate the sum of computational and storage costs that an Ethereum-like blockchain network would incur if a given transaction were processed, which becomes the basis for charging transaction submitters. "Gas" is both a proxy unit and a term for such an estimated total. Startgas The sender of a transaction indicates the maximum proxy unit of computation and storage they are willing to pay for the proposed transaction. (This is web3 library terminology; the Ethereum Yellow Paper calls it the "gas limit.") Gasprice The amount the transaction submitter is willing to pay for the account that mines the transaction, expressed in cryptocurrency fees per unit of gas consumed during the processing of that transaction. Intrinsicgas The gas that a transaction will use before any smart contract code is executed. It includes the base transaction gas fee plus the gas fee for any data provided as transaction parameters. (The latter is calculated because the input parameters are recorded to the blockchain even if the transaction fails.)NonceAll discussion of nonces in this article relates to the sequential numbering required by submitters of transactions on Ethereum and similar blockchain platforms. They are assigned by submitters, but in practice submitters usually delegate this to supporting code libraries associated with the blockchain network. Ethereum-like networks will attempt to process transactions in nonce number order, which can cause transaction delays or failures for a variety of reasons. Transactions with values ​​lower or much higher than those already processed will simply fail. Missing values ​​in the sequence will cause transactions with subsequent nonces to be ignored until the gap in the sequence is filled.Block gas limitWhen miners on the network select pending transactions to be mined into a single block, this is the maximum value that the sum of startgas for all selected transactions is allowed to be. Each Ethereum network, or network based on a platform with a similar miner compensation mechanism, has its own limit that increases or decreases by a small amount after each new block is appended. Nonce WindowThe highest nonce value a transaction may have and still be accepted by a node, expressed as a delta above the nonce of the last transaction that the node sent to the blockchain network for a given submitter identity. The role of the nonce window is to limit the number of transactions that a node per identity has to broadcast. The nonce window can be configured for each node in a blockchain network. Neighboring NodesThe nodes in a blockchain network that a user or application communicates with most directly in order to interact with the entire blockchain network.

Short Answer Question

What challenges does the blockchain transaction pipeline face? The blockchain transaction pipeline faces many challenges, such as latency between transaction submission and its acceptance into the shared ledger, and rejections that occur due to the transaction "nonce" numbering problem in Ethereum.

How does a blockchain transaction manager solve the problem of synchronously waiting for transactions to be mined or finalized? The blockchain transaction manager solves this problem by using a robust queue transaction pipeline and then polling the network to track transaction success or failure. This allows user applications to submit transactions without waiting for final confirmation.

What is a "nonce" and why is it important in blockchain transaction management? A "nonce" is a sequence number associated with Ethereum transactions. It prevents double spending and ensures that transactions are processed in order.

How does the blockchain transaction manager handle "nonce gaps"? The blockchain transaction manager minimizes nonce-related challenges by automatically assigning nonces in an organized manner. If a transaction is rejected, it immediately writes its nonce to a list in a memory cache for use by the next transaction.

How does the blockchain transaction manager determine the gas price for a transaction? The blockchain transaction manager calculates the gas price based on the gas prices of transactions recently accepted in the network.

Describe the retry approach taken by the blockchain transaction manager to handle transaction preparation and sending. The blockchain transaction manager divides the process of sending a transaction to the blockchain network into two phases: transaction preparation and sending. If a problem is encountered in either phase, the system simply retries the process, each up to a configurable number of times.

How does the blockchain transaction manager handle transactions rejected by blockchain nodes? For rejected transactions, the blockchain transaction manager first resolves the nonce issue by adding the transaction's nonce to the pool of available nonces, and then attempts to resolve the reason for the rejection by adjusting properties such as the gas limit.

Explain the two state polling approaches taken by the blockchain transaction manager. The blockchain transaction manager uses two separate status polling methods: an intensive polling method for frequently checking transaction status during the initial period after sending to a node, and a slower scheduler-based method for tracking transactions over long periods of time.

How does the blockchain transaction manager handle database failures at different stages of the transaction lifecycle? The blockchain transaction manager handles database failures in different ways, depending on where in the transaction lifecycle the failure occurs. In most cases, this involves writing the transaction to an error table or temporarily writing the information elsewhere until the database is available.

How does the blockchain transaction manager support batched transaction processing? With the ability to process and monitor transactions asynchronously, the blockchain transaction manager supports batched submission of transactions by client applications.