BFT SMaRt Configuration

The parameters to configure BFT-SMaRt replicas are stored in two files: hosts.config and system.config. To comment out a configuration parameter in those files, the line must start with the character #.

hosts.config

The address and port of all replicas must be specified in this file. The number or replicas must be the same as defined in the property system.servers.num of system.config.

system.config

In this file there are several options to configure the replication protocol, number or replicas, timeouts and others. These parameters are described below:

Parameter and Description	Values	Default value
system.servers.num Number of servers in the system	integer	4
system.servers.f Maximum number of faulty replicas supported	integer	1
system.communication.useSenderThread Specify if the communication system should use a thread to send data	boolean	true
system.communication.inQueueSize Number of messages that can be stored in the receive queue of the communication system	integer	100000
system.communication.outQueueSize Number of messages taht can be stored in the send queue of each replica	integer	100000
system.communication.useSignatures Used to define if clients should use signatures for MAC vectors	0 or 1	0
system.communication.useMACs Used for communication between the replicas. It defines if replicas should use authentication channels among them	0 or 1	0
system.communication.defaultkeys Forces all processes to use the same public/private keys pair and secret key. This is useful when deploying experiments and benchmarks, because it enables the programmer to avoid generating keys for all principals involved in the system. However, it must not be used in a real system.	boolean	true
system.communication.bindaddress IP address this replica should bind to. If this parameter does not have a valid ip address, the replica will fetch the host address on its own. If config/hosts.config specifies the loopback address for the host machine, this parameter is overridden by that.	string	auto
system.communication.hashAlgorithm Algorithm used to compute hashes.	string	SHA-512
system.communication.hmacAlgorithm HMAC algorithm used to authenticate messages between processes.	string	HmacSHA512
system.communication.secretKeyAlgorithm Algorithm to generate secret keys used to generate MACs.	string	PBKDF2WithHmacSHA1
system.communication.signatureAlgorithm Signature algorithm used to verify clients requests and to perform the authenticated Diffie-Hellman exchange during replica start-up. This parameter is overriden in the event that a custom key loader is supplied	string	SHA512withRSA
system.communication.hmacAlgorithmProvider HMAC algorithm provider.	string	SunJCE
system.communication.secretKeyAlgorithmProvider Secret keys algorithm provider.	string	SunJCE
system.communication.signatureAlgorithmProvider Signature algorithm provider.	string	SunRsaSign
system.communication.hashAlgorithmProvider Hash algorithm provider.	string	SUN
system.totalordermulticast.timeout Time that a replica waits for the propose of a request. If the request is not proposed by the leader within the interval defined, the replica invokes the leader change protocol	integer (milliseconds)	10000
system.totalordermulticast.highMark Maximum ahead-of-time message not discarded. When a replica is delayed it stores the consensus in an out-of-context queue.\n If the number of consensus to be processed is above the value defined in this parameter, the replicas discard the messages and invoke the state transfer protocol	integer	10000
system.totalordermulticast.maxtachsize Maximun number of messages to be included in a single propose message	integer	400
system.totalordermulticast.nonces Number of nonces (for non-determinism actions) generated	integer	0
system.totalordermulticast.state_transfer Activate the state transfer protocol	boolean	true
system.totalordermulticast.checkpoint_period Period at which the replica asks the state from the application and clear the log. Used to record a checkpoint and bound the size of the log. This number is the count of consensuns messages processed	integer	50
system.totalordermulticast.revival_highMark Maximum ahead-of-time message not discarded when the replica is still on EID 0 (after which the state transfer is triggered). In practice this is used for a replica to verify if it crashed and was revived	integer	10
system.initial.view Replicas IDs for the initial view, separated by comma. The number of replicas in this parameter should be equal to the one specified in system.servers.num	integer	0,1,2,3
system.ttp.id The ID of the trusted third party (TTP). The TTP is used to add and remove replicas to the system	integer	7002
system.numnettyworkers This sets the number of netty worker threads created at each replica. If set to "0", the threads created are twice the number of available cores.	integer	0
system.bft This sets if the system will function in Byzantine or crash-only mode. Set to "true" to support Byzantine faults.	boolean	true
system.samebatchsize Force all replicas to deliver to the application the same number of requests per batch. This is not the same batch used during the ordering protocol.	boolean	false
system.bft This sets if the system will function in Byzantine or crash-only mode. Set to "true" to support Byzantine faults.	boolean	true

Public keys

If you need to generate public/private keys for replicas or clients, you can use the following command to generate files for public and private keys:

./smartrun.sh bftsmart.tom.util.RSAKeyPairGenerator <id of the replica/client>

Keys are stored in the config/keys folder. The command above creates key pairs both for clients and replicas. Currently such keys need to be manually distributed.