if you want to learn more about State Sync, or if you'd like your application to use it.
(If you don't want to support State Sync in your application, you can just implement these new
ABCI methods as no-ops, leaving them empty.)
* `KV.Pair` has been replaced with `abci.EventAttribute`. The `EventAttribute.Index` field
allows ABCI applications to dictate which events should be indexed.
* The blockchain can now start from an arbitrary initial height,
* The blockchain can now start from an arbitrary initial height,
provided to the application via `RequestInitChain.InitialHeight`.
* ABCI evidence type is now an enum with two recognized types of evidence:
`DUPLICATE_VOTE` and `LIGHT_CLIENT_ATTACK`.
Applications should be able to handle these evidence types
* ABCI evidence type is now an enum with two recognized types of evidence:
`DUPLICATE_VOTE` and `LIGHT_CLIENT_ATTACK`.
Applications should be able to handle these evidence types
(i.e., through slashing or other accountability measures).
* The [`PublicKey` type](https://github.com/tendermint/tendermint/blob/master/proto/tendermint/crypto/keys.proto#L13-L15)
(used in ABCI as part of `ValidatorUpdate`) now uses a `oneof` protobuf type.
Note that since Tendermint only supports ed25519 validator keys, there's only one
* The [`PublicKey` type](https://github.com/tendermint/tendermint/blob/master/proto/tendermint/crypto/keys.proto#L13-L15)
(used in ABCI as part of `ValidatorUpdate`) now uses a `oneof` protobuf type.
Note that since Tendermint only supports ed25519 validator keys, there's only one
option in the `oneof`. For more, see "Protocol Buffers," below.
* The field `Proof`, on the ABCI type `ResponseQuery`, is now named `ProofOps`.
For more, see "Crypto," below.
* The field `Proof`, on the ABCI type `ResponseQuery`, is now named `ProofOps`.
For more, see "Crypto," below.
### P2P Protocol
The default codec is now proto3, not amino. The schema files can be found in the `/proto`
directory. For more, see "Protobuf," below.
directory. For more, see "Protobuf," below.
### Blockchain Protocol
* `Header#LastResultsHash` previously was the root hash of a Merkle tree built from `ResponseDeliverTx(Code, Data)` responses.
As of 0.34,`Header#LastResultsHash` is now the root hash of a Merkle tree built from:
* `BeginBlock#Events`
* Root hash of a Merkle tree built from `ResponseDeliverTx(Code, Data,
GasWanted, GasUsed, Events)` responses
* `BeginBlock#Events`
* `Header#LastResultsHash`, which is the root hash of a Merkle tree built from
`ResponseDeliverTx(Code, Data)` as of v0.34 also includes `GasWanted` and `GasUsed`
fields.
* Merkle hashes of empty trees previously returned nothing, but now return the hash of an empty input,
to conform with [RFC-6962](https://tools.ietf.org/html/rfc6962).
to conform with [RFC-6962](https://tools.ietf.org/html/rfc6962).
This mainly affects `Header#DataHash`, `Header#LastResultsHash`, and
`Header#EvidenceHash`, which are often empty. Non-empty hashes can also be affected, e.g. if their
inputs depend on other (empty) Merkle hashes, giving different results.
### Transaction Indexing
Tendermint now relies on the application to tell it which transactions to index. This means that
in the `config.toml`, generated by Tendermint, there is no longer a way to specify which
Tendermint now relies on the application to tell it which transactions to index. This means that
in the `config.toml`, generated by Tendermint, there is no longer a way to specify which
transactions to index. `tx.height`&`tx.hash` will always be indexed when using the `kv` indexer.
Applications must now choose to either a) enable indexing for all transactions, or
Applications must now choose to either a) enable indexing for all transactions, or
b) allow node operators to decide which transactions to index.
Applications can notify Tendermint to index a specific transaction by setting
Applications can notify Tendermint to index a specific transaction by setting
`Index: bool` to `true` in the Event Attribute:
```go
@ -82,19 +79,19 @@ Applications can notify Tendermint to index a specific transaction by setting
### Protocol Buffers
Tendermint 0.34 replaces Amino with Protocol Buffers for encoding.
This migration is extensive and results in a number of changes, however,
Tendermint 0.34 replaces Amino with Protocol Buffers for encoding.
This migration is extensive and results in a number of changes, however,
Tendermint only uses the types generated from Protocol Buffers for disk and
wire serialization.
wire serialization.
**This means that these changes should not affect you as a Tendermint user.**
However, Tendermint users and contributors may note the following changes:
* Directory layout changes: All proto files have been moved under one directory, `/proto`.
This is in line with the recommended file layout by [Buf](https://buf.build).
* Directory layout changes: All proto files have been moved under one directory, `/proto`.
This is in line with the recommended file layout by [Buf](https://buf.build).
For more, see the [Buf documentation](https://buf.build/docs/lint-checkers#file_layout).
* ABCI Changes: As noted in the "ABCI Changes" section above, the `PublicKey` type now uses
a `oneof` type.
* ABCI Changes: As noted in the "ABCI Changes" section above, the `PublicKey` type now uses
a `oneof` type.
For more on the Protobuf changes, please see our [blog post on this migration](https://medium.com/tendermint/tendermint-0-34-protocol-buffers-and-you-8c40558939ae).
@ -114,30 +111,30 @@ Tendermint 0.34 includes new and updated consensus parameters.
#### Keys
* Keys no longer include a type prefix. For example, ed25519 pubkeys have been renamed from
`PubKeyEd25519` to `PubKey`. This reduces stutter (e.g., `ed25519.PubKey`).
* Keys no longer include a type prefix. For example, ed25519 pubkeys have been renamed from
`PubKeyEd25519` to `PubKey`. This reduces stutter (e.g., `ed25519.PubKey`).
* Keys are now byte slices (`[]byte`) instead of byte arrays (`[<size>]byte`).
* The multisig functionality that was previously in Tendermint now has
a new home within the Cosmos SDK:
* The multisig functionality that was previously in Tendermint now has
* Similarly, secp256k1 has been removed from the Tendermint repo.
There is still [a secp256k1 implementation in the Cosmos SDK](https://github.com/cosmos/cosmos-sdk/tree/443e0c1f89bd3730a731aea30453bd732f7efa35/crypto/keys/secp256k1),
* Similarly, secp256k1 has been removed from the Tendermint repo.
There is still [a secp256k1 implementation in the Cosmos SDK](https://github.com/cosmos/cosmos-sdk/tree/443e0c1f89bd3730a731aea30453bd732f7efa35/crypto/keys/secp256k1),
and we recommend you use that package for all your secp256k1 needs.
#### `merkle` Package
* `SimpleHashFromMap()` and `SimpleProofsFromMap()` were removed.
* The prefix `Simple` has been removed. (For example, `SimpleProof` is now called `Proof`.)
* All protobuf messages have been moved to the `/proto` directory.
* The protobuf message `Proof` that contained multiple ProofOp's has been renamed to `ProofOps`.
As noted above, this affects the ABCI type `ResponseQuery`:
* The prefix `Simple` has been removed. (For example, `SimpleProof` is now called `Proof`.)
* All protobuf messages have been moved to the `/proto` directory.
* The protobuf message `Proof` that contained multiple ProofOp's has been renamed to `ProofOps`.
As noted above, this affects the ABCI type `ResponseQuery`:
The field that was named Proof is now named `ProofOps`.
* `HashFromByteSlices` and `ProofsFromByteSlices` now return a hash for empty inputs, to conform with