Import/Export Blockchain

A running node requires up-to-date blockchain database for operation. You can speed up (by ~10%) your blockchain synchronization by importing blockchain from binary file rather than synchronizing your blockchain state during regular node operation. Binary files contain chain of transaction blocks in verifiable format (include the original sequence of all the transactions with signatures and blocks with signatures of the block generators).

If you have a running Waves node that is synchronized to current state, you can export your blockchain to a binary file.

Import Blockchain from Binary File

Importing blockchain from binary file causes CPU load and can take 1-3 days to complete. The process implies the same execution of every transaction that happens during normal node operation. That includes validation of signatures, balances etc.

Note: If the directory where node's database is stored is not empty, the import will continue to append new data from the binary file. It is recommended to empty the database directory prior to importing to avoid errors caused by mixing data from different versions. By default, the database is stored in data subdirectory of the base application directory (in particular, in /var/lib/waves/data for a node installed from a DEB package).

To import blockchain, do the following:

1. Stop the node with service waves stop command.

2. Execute the following command:

   Windows

   java -cp waves-all-<version>.jar com.wavesplatform.Importer -c <configuration-file-name> -i <binary-file-name>

   Linux

   Mainnet: sudo -u waves waves import -c /etc/waves/waves.conf -i <binary-file-name>

   Testnet: sudo -u waves-testnet waves-testnet import -c /etc/waves-testnet/waves.conf -i <binary-file-name>

   macOS

   java -cp waves-all-<version>.jar com.wavesplatform.Importer -c <configuration-file-name> -i <binary-file-name>

Use the name of the desired binary file instead of binary-file-name. For example, use mainnet_last to import the latest Mainnet blockchain. Follow the links below to see the names of other binary files available for import.

Latest Downloadable Database (current state from nodes.wavesnodes.com)

• Mainnet: http://blockchain.wavesnodes.com/
• Testnet: http://blockchain-testnet.wavesnodes.com/
• Stagenet: http://blockchain-stagenet.wavesnodes.com/

Note: You can speed up the import by 5-20% at your own risk. To do so, use -no-verify option of the Importer parameter to turn off block and transaction validation. Use with caution and only if you trust the blockchain binary file.

Import Blockchain Up to a Certain Height

It is possible to set target height. If the height parameter is not set, all the blocks will be imported.

To import blockchain up to a certain height, do the following:

1. Stop the node with service waves stop command.

2. Execute the following command:

   Windows

   java com.wavesplatform.Importer -c <configuration-file-name> -i <blockchain_file> -h <height>

   Linux

   Mainnet: sudo -u waves waves import -c /etc/waves/waves.conf -i <blockchain_file> -h <height>

   Testnet: sudo -u waves-testnet waves-testnet import -c /etc/waves-testnet/waves.conf -i <blockchain_file> -h <height>

   macOS

   java com.wavesplatform.Importer -c <configuration-file-name> -i <blockchain_file> -h <height>

Export Blockchain to Binary File

If you have a running Waves node that is synchronized to current state, you can export the node's blockchain to a binary file. Exporting is quite a fast operation, but the resulting binary file can take up to 1/3 of the database directory size.

To export the existing blockchain to a binary file, do the following:

1. Stop the node with service waves stop command.

2. Execute the following command:

   Windows

   java -cp waves-all-<version>.jar com.wavesplatform.Exporter -c <configuration-file-name> -o <output-file-name> -h <height>

   Linux

   Mainnet: sudo -u waves waves export -c /etc/waves/waves.conf -o <output-file-name> -h <height>

   Testnet: sudo -u waves-testnet waves-testnet export -c /etc/waves-testnet/waves.conf -o <output-file-name> -h <height>

   macOS

   java -cp waves-all-<version>.jar com.wavesplatform.Exporter -c <configuration-file-name> -o <output-file-name> -h <height>

The height parameter allows to specify maximum height of the blocks during exporting. If the parameter is not set, all the blocks will be exported.

The output-file-name parameter is optional ('blockchain' is used by default). The resulting export file with the <output-file-name>-<height> name will be created in the database directory.