Lite FullNode Tool¶

Introduction¶

Lite FullNode Tool is used to split the database of a FullNode into a Snapshot dataset and a History dataset.

• Snapshot dataset: the minimum dataset for quick startup of the Lite FullNode.
• History dataset: the archive dataset that used for historical data queries.

Remember stop the FullNode process before any operation. This tool provides the ability to specify which dataset to split. The two datasets are split by the latest_block_number. Lite FullNode that startup by Snapshot dataset does not support query the historical data behind the latest_block_number, this tool also provides a merge function that can merge History dataset into the database of Lite FullNode. For more API details: HTTP&GRPC APIs

Usage¶

Options¶

This tool provides independent cutting of Snapshot Dataset and History Dataset and a merge function.

• --operation | -o: [ split | merge ] specifies the operation as either to split or to merge
• --type | -t: [ snapshot | history ] is used only with split to specify the type of the dataset to be split; snapshot refers to Snapshot Dataset and history refers to History Dataset.
• --fn-data-path: FullNode database directory
• --dataset-path: dataset directory, when operation is split, dataset-path is the path that store the Snapshot Dataset or History Dataset, otherwise dataset-path should be the History Dataset path.

Example¶

Start a new FullNode using the default config, then an output-directory will be produced in the current directory. output-directory contains a sub-directory named database which is the database to be split.

Split and get a Snapshot¶

First, stop the FullNode and execute:

// just for simplify, locate the snapshot into `/tmp` directory,
java -jar LiteFullNodeTool.jar -o split -t snapshot --fn-data-path output-directory/database --dataset-path /tmp

then a snapshot directory will be generated in /tmp, pack this directory and copy it to somewhere that is ready to run a Lite Fullnode. Do not forget rename the directory from snapshot to database. (the default value of the storage.db.directory is database, make sure rename the snapshot to the specified value)

Split a History¶

If historical data query is needed, History dataset should be generated and merged into Lite FullNode.

// just for simplify, locate the history into `/tmp` directory,
java -jar LiteFullNodeTool.jar -o split -t history --fn-data-path output-directory/database --dataset-path /tmp

A history directory will be generated in /tmp, pack this directory and copy it to a Lite Fullnode. History dataset always take a large storage, make sure the disk has enough volume to store the History dataset.

Merge¶

Both History Dataset and Snapshot Dataset have an info.properties file to identify the block height from which they are segmented. Make sure that the split_block_num in History Dataset is not less than the corresponding value in the Snapshot Dataset.

After getting the History dataset, the Lite FullNode can merge the History dataset and become a real FullNode.

// just for simplify, assume `History dataset` is locate in /tmp
java -jar LiteFullNodeTool.jar -o merge --fn-data-path output-directory/database --dataset-path /tmp/history

HTTP&GRPC APIs¶

Some APIs are not supported on lite fullnode, here is the list:

Http¶

GRPC¶

These APIs can open forcibly by set openHistoryQueryWhenLiteFN = true, but not recommended.