Dump execution

⚠️ This step will be executed by Horizen admins and does not require action from ZEN holders, unless they want to perform a migration check

In the previous step, the network has reached the migration heights, and the final block hashes/heights of both chains are now revealed.
This section will describe how to generate the data with all the balances to be migrated.

We will need to interact with a node of each chain:

Fully synced ZEND Mainchain node
Fully synced EON Chain node with dump support enabled:
- To enable dump support, the following fragment must be present in the config file (important: to generate a valid state dump, the fragment must be added BEFORE starting to sync the chain):
```
evmStateDump {
    enabled = true
}
```
- If using Docker and the Docker image zencash/evmapp:1.5.0 , you can configure the following env property:
```
 SCNODE_EVM_STATE_DUMP_ENABLED=true
```
This will set automatically the previous property in the container.

How to obtain the dump data

Execute a dump of ZEND balances at that specified height. ZEND is shipped with a dumper command line utility to do this:
```
zen-cli stop
dumper -H MC_MIGRATION_HEIGHT > utxos.csv
```
Please note the following:
- The stop command is needed because ZEND must not be running while performing the dump
- If executing a dump of the testnet you must add the flag: -t
- MC_MIGRATION_HEIGHT must be not too old in the past compared to the latest tip: maximum supported height is tip-100

Execute a dump of EON State:

Execute the following call on the EON node:

 curl --request POST 'http://127.0.0.1:9085/ethv1' -H 'Content-Type: application/json' -H 'accept: application/json' -d '{ "jsonrpc":"2.0", "method":"zen_dump", "params":["0xbda76ab769c4e158f8e8add81bdf17c9d919fb54cd5e32f1c83cebdfc3dc363c","/zendata/eon.dump"], "id":1 }'

First parameter of the method must be replaced by EON_MIGRATION_HASH
Second parameter is the local-path of the output dump.

How to create the restore artifacts

Download and follow the README instructions of this folder to execute the create_restore_artifacts.sh bash script.

The script will process the following data:
- two previous full dumps
- the list of the staked ZEN at the specific dump height, obtained by querying a running EON node
- a list of "auto mapped" addresses: they are hardcoded mappings that comes from offchain agreements between selected partners (centralized exchanges) and HorizenLabs.
The script will perform the following:
- For ZEND:
  - transform the addresses in Base58 decoded format (is easier to handle in the solidity code), without chain prefix
  - transform the balances in "wei" format (1 ZEN = 1 with 18 zeros)
  - exclude the automapped addresses
  - order the addresses alphabetically
- For EON:
  - filters out the smart contracts addresses and the stakes belonging to smart contracts
  - merge the EON staked ZEN to EOA balances
  - filters out addresses with 0 balance and no stakes
  - filters out the 0x0000000000000000000000000000000000000000 account
  - transforms the balances in "wei" format (1 ZEN = 1 with 18 zeros)
  - include the automapped addresses
  - orders the addresses alphabetically

The result of the script will be two restore artifacts:

a zend.json file, containing a key-value json data structure like this:
```
{
    "0xabf1FF91cECD9990B3f29363B62B87FD76f55F4A": 10001500000000000000000,
    "0x448ae34180D03AD7da48975d6Fd7B297bb871E26": 2082100000000000000,
    "0x144e0FE5e69893577107a15a7c76bABd59f0A279": 100000000000000000
}
```
The keys represent the ZEND address in a Base58check decoded format, without the first 2 bytes chain prefix (so 20 bytes in total), prepended with 0x.
The values represent the ZEND balance, in "wei format" (1 ZEN = 1 with 18 zeros).

an eon.json file, containing a key-value json data structure like this:

{
    "0xBa2290AEaAE3e1ea336431911C97a67Ebff46528": 1500000000000000000,
    "0xFEB3DE3D4A6F49bbF643c44E64dfd3e46D3E0F04": 821003000000000000,
    "0x2a085Ca4E931938Aa383C88026b0566cFce1A34b": 45500000000000000
}

The keys represent the EON address in the hex form with “0x” prefix.
The values represent the EON balance, in "wei format" (1 ZEN = 1 with 18 zeros).

These artifacts will be the ones used for the data loading and migration check steps.