ADM Blockchain Recovering Procedure

[al-onyxprotocol]

In ADAMANT blockchain node software, forks may happen if multiple delegate nodes produce blocks at the same time. When this occurs, the network needs to decide which block to keep.

Currently, the consensus rule is:

• Pick the oldest block (assuming the timestamp is trustworthy), or
• If timestamps are equal, choose the block with the smallest ID.

Such short forks happen regularly in blockchains and do not create larger or dangerous forks.

Deleting the Last Block

“Deleting last block” occurs when a fork is detected (either during recovery or upon receiving a new block).

Example case, the fork is caused by reason 5:

The node received a block with the same height and previous block ID, but a different block ID.

Example Log

[WRN] 2025-08-06 00:00:09 | Deleting last block - {"version":0,"totalAmount":12119967437,"totalFee":150000000,"reward":15000000,"payloadHash":"b04ed7f935bec1f74b7a179ff07557a36ca5ea38d6966381f1a5794ca9df7125","timestamp":250066805,"numberOfTransactions":3,"payloadLength":351,"previousBlock":"17914802164676259429","generatorPublicKey":"547919533beb2612d76e3a7d5f38e61145a2b0ecb96d971277f34fb8efd3bcb3","transactions":[{"type":0,"timestamp":250066800,"amount":2893807848,"senderPublicKey":"817c961b57678c2c55bc55358bab9551b7aa65e572a812f50f11c1976aaaebc6","senderId":"U14982290023542615154","asset":{},"recipientId":"U8153746339485828029","signature":"8b9c7f4ac1759f94a5c9cf2a466763bb719cd08bd582c93b8608d395462fdb976fe5194b9e2177d5baee3b7e31489539f3762dc62840f67eaf29b6d57a7f4e05","id":"18272966159919349432","fee":50000000,"relays":3,"receivedAt":"2025-08-06T00:00:03.315Z","blockId":"15500937233239097229","height":48093334,"block_timestamp":250066805},{"type":0,"timestamp":250066800,"amount":3359198799,"senderPublicKey":"817c961b57678c2c55bc55358bab9551b7aa65e572a812f50f11c1976aaaebc6","senderId":"U14982290023542615154","asset":{},"recipientId":"U12130826829283598554","signature":"448b237827ea65288026fb099e74b7b32d6f32ef5986f7bd17dd37ab226c851caa7fcd38f2c566be24f4c458ca4d9318a13557a86a437e993600985f0c2aba03","id":"6994430507695336221","fee":50000000,"relays":3,"receivedAt":"2025-08-06T00:00:03.118Z","blockId":"15500937233239097229","height":48093334,"block_timestamp":250066805},{"type":0,"timestamp":250066800,"amount":5866960790,"senderPublicKey":"817c961b57678c2c55bc55358bab9551b7aa65e572a812f50f11c1976aaaebc6","senderId":"U14982290023542615154","asset":{},"recipientId":"U16963107530576131637","signature":"bd83e38db1ab672be95d669b89b8cf9a1e3d81ad34aa150672abc8ca7d77506d57aac50146403235105b53d610329bbd7d4ad52f3f78f25991b3ba740ef7c305","id":"12712691363231971651","fee":50000000,"relays":3,"receivedAt":"2025-08-06T00:00:03.260Z","blockId":"15500937233239097229","height":48093334,"block_timestamp":250066805}],"blockSignature":"64be4069540ab86f195d3bfb477ac8b2514dc99c33b881d98cdab103101b95e21c3f0cb1d6df5a128977a13992956c5390d7e69b18eb99055250c55d9b734802","height":48093334,"id":"15500937233239097229","relays":3}

Summary

• Forks are resolved automatically by picking the oldest block or the block with the smallest ID
• “Deleting last block” is a normal recovery action when conflicting blocks with the same height are detected
• This ensures the blockchain stays consistent without producing deeper forks

[al-onyxprotocol]

[Bug] Internal Discarded block, a node unable to recover

[adamantmm]

“Deleting last block” ≠ data loss. This action only rolls back the very last block in order to replace it with the correct fork branch. Transactions inside that block are not lost; they are simply re-applied if included in the winning block.

[adamantmm]

@yoxira Do you have something to add?