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The mechanism by which Solana's scheduler reserves access to accounts for the duration of a transaction's execution, granting either shared read locks (multiple transactions can hold simultaneously) or exclusive write locks (only one transaction at a time). Before execution, the runtime inspects every transaction's declared account list and grants or denies locks accordingly, preventing data races without requiring a global mutex. Transactions that cannot acquire all required locks are queued or dropped, making correct account declaration in transaction instructions critical for both correctness and landing probability.

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Account Locking (Read/Write) (account-locking)
Category: Network
Definition: The mechanism by which Solana's scheduler reserves access to accounts for the duration of a transaction's execution, granting either shared read locks (multiple transactions can hold simultaneously) or exclusive write locks (only one transaction at a time). Before execution, the runtime inspects every transaction's declared account list and grants or denies locks accordingly, preventing data races without requiring a global mutex. Transactions that cannot acquire all required locks are queued or dropped, making correct account declaration in transaction instructions critical for both correctness and landing probability.
Related: Parallel Transaction Execution, Writable Account

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Parallel Transaction Execution

Solana's ability to process multiple transactions simultaneously by analyzing their account access lists and executing non-conflicting transactions in parallel across CPU cores via the Sealevel runtime. Two transactions can run in parallel only if they do not share any writable accounts; transactions sharing a writable account are serialized. This design allows Solana to fully exploit modern multi-core hardware and is a primary contributor to its high throughput.

Sealevel TPS (Transactions Per Second)

Open term

Branch

Writable Account

An account marked as writable in an instruction's account metas, allowing the program to modify its data or lamport balance. Non-writable accounts are read-only. The runtime enforces that programs can only modify writable accounts. Writable accounts also affect scheduling—transactions sharing writable accounts cannot run in parallel.

Account Transaction

Open term

Next concepts to explore

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Network

Parallel Transaction Execution

Solana's ability to process multiple transactions simultaneously by analyzing their account access lists and executing non-conflicting transactions in parallel across CPU cores via the Sealevel runtime. Two transactions can run in parallel only if they do not share any writable accounts; transactions sharing a writable account are serialized. This design allows Solana to fully exploit modern multi-core hardware and is a primary contributor to its high throughput.

Open term

Programming Model

Writable Account

An account marked as writable in an instruction's account metas, allowing the program to modify its data or lamport balance. Non-writable accounts are read-only. The runtime enforces that programs can only modify writable accounts. Writable accounts also affect scheduling—transactions sharing writable accounts cannot run in parallel.

Open term

Network

Airdrop (Devnet/Testnet)

The process of receiving free, valueless SOL on Devnet or Testnet via the Solana CLI (`solana airdrop`) or public faucet endpoints, used to fund accounts for testing without spending real SOL. Airdrops are rate-limited per IP and per address (typically 1–2 SOL per request, a few requests per hour) to prevent abuse. The term is also used colloquially for token distribution events on Mainnet Beta, but in a network/infrastructure context it specifically refers to the test-cluster faucet mechanism.

Open term

Network

Mainnet Beta

Solana's primary production cluster where real SOL and real economic activity occur; the "beta" designation reflects the network's ongoing protocol development despite being fully live since March 2020. It uses the same architecture as other clusters but with real validator stakes, live staking rewards, and permanent on-chain state. All production dApps, tokens, and NFTs exist on Mainnet Beta.

Open term

Related terms

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Networkparallel-execution

Parallel Transaction Execution

Solana's ability to process multiple transactions simultaneously by analyzing their account access lists and executing non-conflicting transactions in parallel across CPU cores via the Sealevel runtime. Two transactions can run in parallel only if they do not share any writable accounts; transactions sharing a writable account are serialized. This design allows Solana to fully exploit modern multi-core hardware and is a primary contributor to its high throughput.

Open term

Programming Modelwritable

Writable Account

An account marked as writable in an instruction's account metas, allowing the program to modify its data or lamport balance. Non-writable accounts are read-only. The runtime enforces that programs can only modify writable accounts. Writable accounts also affect scheduling—transactions sharing writable accounts cannot run in parallel.

Open term

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Network

Mainnet Beta

Solana's primary production cluster where real SOL and real economic activity occur; the "beta" designation reflects the network's ongoing protocol development despite being fully live since March 2020. It uses the same architecture as other clusters but with real validator stakes, live staking rewards, and permanent on-chain state. All production dApps, tokens, and NFTs exist on Mainnet Beta.

Open term

Network

Devnet

A persistent public Solana cluster intended for application development and testing, running the same software version as Mainnet Beta but with no real economic value. Devnet SOL can be freely airdropped via the CLI or faucet APIs, and the ledger may be reset periodically by Solana Labs. Developers use Devnet to test programs and integrations before deploying to Mainnet Beta.

Open term

Network

Testnet

A public Solana cluster used primarily by the Solana core team and validators to test new software releases, performance benchmarks, and network upgrades under real network conditions before they reach Mainnet Beta. Testnet SOL has no monetary value, and the ledger is reset more frequently than Devnet; it is less suitable for application development and more suited for validator operators validating their infrastructure.

Open term

Network

TPS (Transactions Per Second)

The rate at which a Solana cluster processes and commits transactions; Solana's theoretical maximum exceeds 65,000 TPS due to its parallel execution model, though real-world sustained throughput on Mainnet Beta typically ranges from 2,000–5,000 non-vote TPS under normal load. Vote transactions (used for consensus) make up a significant portion of all on-chain activity and are counted separately. High TPS is enabled by Proof of History timestamps, Sealevel parallel execution, and Gulf Stream mempool-less forwarding.

Open term