Freezer for historical chain data stored as a flat file

[non-fungible-nelson]

Users want historical data to be frozen to reduce overall storage requirements/compaction of the blockchain DB. This will also enable users to move the ancient data to a slower disk than the primary SSD.

Can we also have Backwards sync use the freezer to store old blockchain data during the sync.

https://geth.ethereum.org/docs/fundamentals/databases

https://superlunar.com/post/geth-freezer-files-block-data-done-fast.html

Notes

• Investigate but maybe don't need to do? Probably less impactful than others
  • Expected performance impact would be due to less RocksDB compaction
  • but maybe BlobDB makes this less impactful?
• coordinate with Backward Sync rework
• Can then optimise freezer storage for reads as can assume it will rarely be modified
• Chain data could include items from

  besu/ethereum/core/src/main/java/org/hyperledger/besu/ethereum/storage/keyvalue/KeyValueStoragePrefixedKeyBlockchainStorage.java

  Lines 53 to 58 in 1c261db

  	private static final Bytes BLOCK_HEADER_PREFIX = Bytes.of(2);
  	private static final Bytes BLOCK_BODY_PREFIX = Bytes.of(3);
  	private static final Bytes TRANSACTION_RECEIPTS_PREFIX = Bytes.of(4);
  	private static final Bytes BLOCK_HASH_PREFIX = Bytes.of(5);
  	private static final Bytes TOTAL_DIFFICULTY_PREFIX = Bytes.of(6);
  	private static final Bytes TRANSACTION_LOCATION_PREFIX = Bytes.of(7);

Tasks

• Investigate impact of moving chain data to "freezer" storage in a flat file #5932