Since both are same can we remove GenesisValidator if there is no specific need

Our fee model on Heimdall needs to send the transaction fees to the block proposer. We need to find the block proposer while executing the tx.

We could probably use txhash to validate message data while validating transactions in heimdall.

We could also fetch the block details and make sure we have enough confirmations before accepting transactions, for example we could include a TxHash field in ValidatorJoin and then we could pick data like signer , amountStaked etc from TxReceipt.

Pros :

1. We can make sure we accept transactions only when difference between currentBlock and block in which tx was present on main chain is atleast 6(or more)
2. We can change signer without having the previous signer or validator to sign the transaction on heimdall making it easy to change signer incase you lost your private keys or via a validator contract.
3. We can make sure that validation of transactions is always deterministic so while syncing of new nodes we dont have to worry about current state of contract.

Possible cons could be slow syncing of new nodes as every transaction would need to query main chain for TxReceipt.

Add this in MsgValidateBasic probably

We need to add pagination with api's that return large arrays. For example /overview

We need to implement slashing of validators, where we would need to slash validators on multiple parameters.
Some of the parameters can be:

1. no-ack received for a proposer.
2. vote not submitted by validator.
3. validator inactive

More parameters to be discussed in this issue.

Ideal behaviour is to not write config files like config.toml and heimdall-config.toml on init if they already exist

Some params are valuable for consensus, those should not be present or configurable via heimdall-config file, instead they should be in the genesis file.

• bor-chainID
• numberOfConfirmations

Add version files so that versions of heimdall and peppermint can be tracked.

Adding a pre-commit go-fmt will help us keep the code base clean and standardly formatted.
Using : https://pre-commit.com

We need to add signature in genesis.json to make sure people don't add validators who aren't validators.
OR
Maybe we can validate genesis while initChain by querying stakeManager contract.

We should move all the time bounds to config so that we can control the pace of checkpoints and other processes without rebuilding the image.

Currently we have 2 export commands, one in heimdalld and one in heimdallcli. To avoid confusion we need to make sure there is only one.

We need to wait for some confirmations on heimdall to make sure we pick up data from the longest ethereum chain always. Need to think more on how to do this.

Cosmos/Tendermint prevents user to submit same tx bytes twice. We have to add nonce or something in each tx to prevent that.

Instead of taking timestamp from user we should do time.Now().Unix() i think .

We need to remove using latest block number to order stake-update and signer-update related transactions.

We need to have an API to various types of lists.

For example:

• All spans
• All records synced by clerk
• All headers

We need to fix test cases in all modules

We need to remove current start block checks from handleMsg and while validating message and only have that when we need to send checkpoint .

It would be really useful to have a state-dump from where heimdall could start from , it will allow us to restart testnet from a specific state instead of deploying new contracts . State dump would generate a genesis file with the current state and heimdall can add the state to keeper and restart successfully.

This will also allow validators to move back a few blocks and sync in case of sync failures or consensus failure or panics.

I[2020-01-10|09:29:08.955] starting ABCI with Tendermint module=main
panic: Unknown db_backend leveldb, expected either fsdb or goleveldb or memdb
goroutine 1 [running]:
github.com/tendermint/tm-db.NewDB(0x13fa77d, 0xa, 0xc000a16c80, 0x7, 0xc00094fe20, 0x1c, 0x203000, 0xc00113f158)
/home/ubuntu/go/pkg/mod/github.com/tendermint/[email protected]/db.go:67 +0x39c
github.com/tendermint/tendermint/node.DefaultDBProvider(0xc0008b5180, 0xc0008b5180, 0xc000aa24c8, 0x183, 0xc00113f280)
/home/ubuntu/go/pkg/mod/github.com/maticnetwork/[email protected]/node/node.go:66 +0xcb
github.com/tendermint/tendermint/node.initDBs(0xc0009457c0, 0x169cad8, 0xc00113f298, 0x408bba, 0x18db8a0, 0x12b4bc0, 0x12b4bc0)
/home/ubuntu/go/pkg/mod/github.com/maticnetwork/[email protected]/node/node.go:207 +0x6c
github.com/tendermint/tendermint/node.NewNode(0xc0009457c0, 0x18b3640, 0xc0008bb040, 0xc000ac1b30, 0x1893de0, 0xc0008b5120, 0xc000ac1c40, 0x169cad8, 0xc000ac1c50, 0x18ba840, ...)
/home/ubuntu/go/pkg/mod/github.com/maticnetwork/[email protected]/node/node.go:548 +0x50
github.com/cosmos/cosmos-sdk/server.startInProcess(0xc0008b46a0, 0x169d360, 0x1d, 0x0, 0x0)
/home/ubuntu/go/pkg/mod/github.com/cosmos/[email protected]/server/start.go:152 +0x4c1
github.com/cosmos/cosmos-sdk/server.StartCmd.func1(0xc000a45400, 0xc0009562e0, 0x0, 0x1, 0x0, 0x0)
/home/ubuntu/go/pkg/mod/github.com/cosmos/[email protected]/server/start.go:65 +0xb4
github.com/spf13/cobra.(*Command).execute(0xc000a45400, 0xc0009562c0, 0x1, 0x1, 0xc000a45400, 0xc0009562c0)
/home/ubuntu/go/pkg/mod/github.com/spf13/[email protected]/command.go:826 +0x460
github.com/spf13/cobra.(*Command).ExecuteC(0xc000a44500, 0x2, 0xc0008b48a0, 0x1422715)
/home/ubuntu/go/pkg/mod/github.com/spf13/[email protected]/command.go:914 +0x2fb
github.com/spf13/cobra.(*Command).Execute(...)
/home/ubuntu/go/pkg/mod/github.com/spf13/[email protected]/command.go:864
github.com/tendermint/tendermint/libs/cli.Executor.Execute(0xc000a44500, 0x169d7a8, 0x2, 0xc000ba0b80)
/home/ubuntu/go/pkg/mod/github.com/maticnetwork/[email protected]/libs/cli/setup.go:89 +0x3c
main.main()
/home/ubuntu/go/src/github.com/maticnetwork/heimdall/cmd/heimdalld/main.go:95 +0x43a

Tendermint has gone through some breaking changes, which need to be merged with heimdall and peppermint as some bugs have been resolved regarding consensus mechanism.

The current readme file is outdated and needs to be updated, current docs are being maintained at docs.matic.network

Currently, we send checkpoints as soon as the average checkpoint length is achieved, we should ideally wait for one sprint before we accept a new checkpoint.

Right now the validators are indexed with ValidatorAddress as key . Signers are the true validators wrt to Peppermint and hence can be identified uniquely with SignerAddress only . Incase of signer update the ValidatorAddress would remain same but the signer address and signer pubkey would be changed . These changes cannot be tracked via current indexing .

All rest apis will use signer address to reference Validator not Validator Address , Validator Address is only the address who stakes on rootchain contract.

Currently, if blocks are not found we validate the transaction with the blocks found, instead of throwing Roothash doesnt match error we should throw blocks not found error.

Currently, if there has been a consensus issue or some other fault at Heimdall the bridge still keeps sending transactions this creates a lot of load for all the nodes and would drain fees for any validator. Instead, we should check the health of the node before broadcasting.

Implement log levels via log_level flag on the bridge module so that we can show debug logs only when necessary.

Currently, if checkpoint buffer is not found the /overview API returns with a failure response

All the modules currently contain a lot of comments left over from the latest refactor, we need to remove those.

Currently heimdall fetches checkpoint data from bor and bor fetches span data from heimdall. While this solves a lot of problems it creates an issue when we are trying to sync nodes, because to evaluate the checkpoint data while syncing heimdall node needs a fully synched bor node.

We want to evaluate different ways to solve this using this issue.

We should not expose the private key on show-account command, instead, we should do that only when explicitly asked to.

go install on current master is not working whereas go build is.

Need to remove usage of time.Now() in transaction handlers and instead use the UTC time to ensure deterministic transaction evaluation

There are traces of vetic on heimdall which need to be cleaned up to avoid confusion, since fee tokens on heimdall are 1:1 pegged with matic let's call it matic

Using these block confirmation checks might lead to nondeterministic results for nodes while might lead to consensus faults.
Move these checks to ante-handler or msg.ValidateBasic()

If heimdall fetches header information as soon as we send checkpoint on main chain we are unable to get proper information probably because it takes time for checkpoint transaction to propagate to all ethereum nodes and sometimes checkpoint is lost in a re-org. Ideally we should wait for some confirmation blocks and only then accept the ACK message.

Currently if an API returns non 200 status code we throw an error, instead we should throw error on 404 and 5XX only.

We need to send votes and the SignedHeader to on-chain contract to correctly determine on the contract that a transaction was included on heimdall