github.com/pokt-network/tendermint@v0.32.11-0.20230426215212-59310158d3e9/docs/architecture/adr-037-deliver-block.md (about)

     1  # ADR 037: Deliver Block
     2  
     3  Author: Daniil Lashin (@danil-lashin)
     4  
     5  ## Changelog
     6  
     7  13-03-2019: Initial draft
     8  
     9  ## Context
    10  
    11  Initial conversation: https://github.com/tendermint/tendermint/issues/2901
    12  
    13  Some applications can handle transactions in parallel, or at least some
    14  part of tx processing can be parallelized. Now it is not possible for developer
    15  to execute txs in parallel because Tendermint delivers them consequentially.
    16  
    17  ## Decision
    18  
    19  Now Tendermint have `BeginBlock`, `EndBlock`, `Commit`, `DeliverTx` steps
    20  while executing block. This doc proposes merging this steps into one `DeliverBlock`
    21  step. It will allow developers of applications to decide how they want to
    22  execute transactions (in parallel or consequentially). Also it will simplify and
    23  speed up communications between application and Tendermint.
    24  
    25  As @jaekwon [mentioned](https://github.com/tendermint/tendermint/issues/2901#issuecomment-477746128)
    26  in discussion not all application will benefit from this solution. In some cases,
    27  when application handles transaction consequentially, it way slow down the blockchain,
    28  because it need to wait until full block is transmitted to application to start
    29  processing it. Also, in the case of complete change of ABCI, we need to force all the apps
    30  to change their implementation completely. That's why I propose to introduce one more ABCI
    31  type.
    32  
    33  # Implementation Changes
    34  
    35  In addition to default application interface which now have this structure
    36  
    37  ```go
    38  type Application interface {
    39      // Info and Mempool methods...
    40  
    41      // Consensus Connection
    42      InitChain(RequestInitChain) ResponseInitChain    // Initialize blockchain with validators and other info from TendermintCore
    43      BeginBlock(RequestBeginBlock) ResponseBeginBlock // Signals the beginning of a block
    44      DeliverTx(tx []byte) ResponseDeliverTx           // Deliver a tx for full processing
    45      EndBlock(RequestEndBlock) ResponseEndBlock       // Signals the end of a block, returns changes to the validator set
    46      Commit() ResponseCommit                          // Commit the state and return the application Merkle root hash
    47  }
    48  ```
    49  
    50  this doc proposes to add one more:
    51  
    52  ```go
    53  type Application interface {
    54      // Info and Mempool methods...
    55  
    56      // Consensus Connection
    57      InitChain(RequestInitChain) ResponseInitChain           // Initialize blockchain with validators and other info from TendermintCore
    58      DeliverBlock(RequestDeliverBlock) ResponseDeliverBlock  // Deliver full block
    59      Commit() ResponseCommit                                 // Commit the state and return the application Merkle root hash
    60  }
    61  
    62  type RequestDeliverBlock struct {
    63      Hash                 []byte
    64      Header               Header
    65      Txs                  Txs
    66      LastCommitInfo       LastCommitInfo
    67      ByzantineValidators  []Evidence
    68  }
    69  
    70  type ResponseDeliverBlock struct {
    71      ValidatorUpdates      []ValidatorUpdate
    72      ConsensusParamUpdates *ConsensusParams
    73      Tags                  []kv.Pair
    74      TxResults             []ResponseDeliverTx
    75  }
    76  
    77  ```
    78  
    79  Also, we will need to add new config param, which will specify what kind of ABCI application uses.
    80  For example, it can be `abci_type`. Then we will have 2 types:
    81  - `advanced` - current ABCI
    82  - `simple` - proposed implementation
    83  
    84  ## Status
    85  
    86  In review
    87  
    88  ## Consequences
    89  
    90  ### Positive
    91  
    92  - much simpler introduction and tutorials for new developers (instead of implementing 5 methods whey
    93  will need to implement only 3)
    94  - txs can be handled in parallel
    95  - simpler interface
    96  - faster communications between Tendermint and application
    97  
    98  ### Negative
    99  
   100  - Tendermint should now support 2 kinds of ABCI