Zachary Bowen e6893632dc Create migration election class (#2535).
* Problem: We need a way to synchronize a halt to block production to allow for upgrades across breaking changes.

* Solution: Created `MigrationElection`.

* Problem: Need documentation for `migration` elections.

* Solution: Updated the docs.

* Problem: `MigrationElection` needs 'new' CLI method.

* Solution: Updated the definition of `election` to include the new `migration` type.

* Problem: The way `end_block` checks for concluded elections assumes there is only one type of election (so we can't conclude an `upsert-validator` and a `chain-migration` at the same height).

* Solution: Re-engineered the code in `Elections` to conclude multiple elections in the same block. If more than one election change the validator set, only one of them is applied.

* Problem: Tendermint change to store validator changes at height h+2 will break `Election.get_status`.

* Solution: Reworked `get_validator_change` to look at only the latest block height or less.
2018-09-17 13:59:57 +02:00

8.7 KiB

Command Line Interface (CLI)

The command-line command to interact with BigchainDB Server is bigchaindb.

bigchaindb --help

Show help for the bigchaindb command. bigchaindb -h does the same thing.

bigchaindb --version

Show the version number. bigchaindb -v does the same thing.

bigchaindb configure

Generate a local configuration file (which can be used to set some or all BigchainDB node configuration settings). It will ask you for the values of some configuration settings. If you press Enter for a value, it will use the default value.

At this point, only one database backend is supported: localmongodb.

If you use the -c command-line option, it will generate the file at the specified path:

bigchaindb -c path/to/new_config.json configure localmongodb

If you don't use the -c command-line option, the file will be written to $HOME/.bigchaindb (the default location where BigchainDB looks for a config file, if one isn't specified).

If you use the -y command-line option, then there won't be any interactive prompts: it will use the default values for all the configuration settings.

bigchaindb -y configure localmongodb

bigchaindb show-config

Show the values of the BigchainDB node configuration settings.

bigchaindb init

Create a backend database (local MongoDB), all database tables/collections, various backend database indexes, and the genesis block.

bigchaindb drop

Drop (erase) the backend database (the local MongoDB database used by this node). You will be prompted to make sure. If you want to force-drop the database (i.e. skipping the yes/no prompt), then use bigchaindb -y drop

bigchaindb start

Start BigchainDB. It always begins by trying a bigchaindb init first. See the documentation for bigchaindb init. The database initialization step is optional and can be skipped by passing the --no-init flag, i.e. bigchaindb start --no-init.

Options

The log level for the console can be set via the option --log-level or its abbreviation -l. Example:

$ bigchaindb --log-level INFO start

The allowed levels are DEBUG, INFO, WARNING, ERROR, and CRITICAL. For an explanation regarding these levels please consult the Logging Levels section of Python's documentation.

For a more fine-grained control over the logging configuration you can use the configuration file as documented under Configuration Settings.

bigchaindb election

Manage elections to manage the BigChainDB network. The specifics of the election process are defined in BEP-18, please refer it for more details.

Election management is broken into several subcommands. Below is the command line syntax for each,

election new

Create a new election which proposes a change to your BigChainDB network.

If the command succeeds, it will create an election and return an election_id.

NOTE: The election proposal consists of vote tokens allocated to each current validator as per their voting power. Validators then cast their votes to approve the election by spending their vote tokens, (see the documentation on election approve).

There are multiple types of election, which each take different parameters. Below is a short description of each type of election, as well as their command line syntax and the return value.

election new upsert-validator

Create an election to add/update/remove a validator from the validator set.

$ bigchaindb election new upsert-validator E_PUBKEY E_POWER E_NODE_ID --private-key PATH_TO_YOUR_PRIVATE_KEY
[SUCCESS] Submitted proposal with id: <election_id>
  • E_PUBKEY: Public key of the node to be added/updated/removed.
  • E_POWER: The new power for the E_PUBKEY. NOTE, if power is set to 0 then E_PUBKEY will be removed from the validator set when the election concludes.
  • E_NODE_ID: Node id of E_PUBKEY. The node operator of E_PUBKEY can generate the node id via tendermint show_node_id.
  • --private-key: The path to Tendermint's private key which can be generally found at /home/user/.tendermint/config/priv_validator.json.

For example, to add a new validator, provide the public key and node id for some node not already in the validator set, along with whatever voting power you'd like them to have. To remove an existing validator, provide their public key and node id, and set E_POWER to 0. Please note that the private key provided here is of the node which is generating this election i.e.

NOTE: A change to the validator set can only be proposed by one of the exisitng validators.

Example usage,

$ bigchaindb election new upsert-validator HHG0IQRybpT6nJMIWWFWhMczCLHt6xcm7eP52GnGuPY= 1 fb7140f03a4ffad899fabbbf655b97e0321add66 --private-key /home/user/.tendermint/config/priv_validator.json
[SUCCESS] Submitted proposal with id: 04a067582cf03eba2b53b82e4adb5ece424474cbd4f7183780855a93ac5e3caa

A successful execution of the above command doesn't imply that the validator set will be immediately updated but rather it means the proposal has been succcessfully accepted by the network. Once the election_id has been generated the node operator should share this election_id with other validators in the network and urge them to approve the proposal. Note that the node operator should themsleves also approve the proposal.

election new migration

Create an election to halt block production, to allow for a version change across breaking changes.

$ bigchaindb election new migration --private-key PATH_TO_YOUR_PRIVATE_KEY
[SUCCESS] Submitted proposal with id: <election_id>
  • --private-key: The path to Tendermint's private key which can be generally found at /home/user/.tendermint/config/priv_validator.json.

Example usage,

$ bigchaindb election new migration --private-key /home/user/.tendermint/config/priv_validator.json
[SUCCESS] Submitted proposal with id: 04a067582cf03eba2b53b82e4adb5ece424474cbd4f7183780855a93ac5e3caa

NOTE migration elections will halt block production at whichever blockheight they are approved. Once the election is concluded, the validators will need to restart their systems with a new chain_id to resume normal operations.

election approve

Approve an election by voting for it. The proposal generated by executing bigchaindb election new ... can be approved by the validators using this command. The validator who is approving the proposal will spend all their votes i.e. if the validator has a network power of 10 then they will cast 10 votes for the proposal.

Below is the command line syntax and the return value,

$ bigchaindb election approve <election_id> --private-key PATH_TO_YOUR_PRIVATE_KEY
[SUCCESS] Your vote has been submitted
  • election_id is the transaction id of the election the approval should be given for.
  • --private-key should be the path to Tendermint's private key which can be generally found at /home/user/.tendermint/config/priv_validator.json.

Example usage,

$ bigchaindb election approve 04a067582cf03eba2b53b82e4adb5ece424474cbd4f7183780855a93ac5e3caa --private-key /home/user/.tendermint/config/priv_validator.json
[SUCCESS] Your vote has been submitted

If the command succeeds a message will be returned stating that the vote was submitted successfully. Once a proposal has been approved by sufficent validators (more than 2/3 of the total voting power) then the proposed change is applied to the network. For example, consider a network wherein the total power is 90 then the proposed changed is applied only after 60 (2/3 * 90) have been received.

election show

Retrieves information about an election initiated by election new.

Below is the command line syntax and the return value,

$ bigchaindb election show ELECTION_ID
<election_data>
status=<status>

The election data is the same set of arguments used in the election new command that originally triggered the election. status takes three possible values, ongoing, if the election has not yet reached a 2/3 majority, concluded, if the election reached the 2/3 majority needed to pass, or inconclusive, if the validator set changed while the election was in process, rendering it undecidable.

bigchaindb tendermint-version

Show the Tendermint versions supported by BigchainDB server.

$ bigchaindb tendermint-version
{
    "description": "BigchainDB supports the following Tendermint version(s)",
    "tendermint": [
        "0.22.8"
    ]
}