[Feature Request] Start node with full state in some reasonable time

[astudnev]

Problem is that we need a full state of the lotus node from some pre-defined block. Node is failing very often, due to known bugs of corrupted database, which can not be re-covered.

There are several approaches that we tried:

1. sync from some database, that has synced in the past. It goes very slow, even on a fast server with SSD drives. We have database with 90,000 blocks delayed and it takes around 1 minute (!!!) to sync one block. So it will last very very long

2. sync from the snapshot, it takes more than 10 days to sync full chain

3. once we suceeded to sync lightweight snapshot from a particular date, and then fill. the head block with the full state. However, that method is nowhere described.

What will be helpfull is some method of syncing node for N last blocks only with. full state. How can we do that? We currently stucked in. this problem please help

[astudnev]

i have a fullnode that syncing with Filecoin, and we index the latest data from it. We need the full state for the blocks that we are reading. In case of the node failure ( and it happens already 3 times ) we loosing the ability to catch up to the recent state. Say we indexed to the block 600,000 and node failed. The next day if we start from the light node it will not have state for block 600,000 and we have. start FROM THE 0 BLOCK. Starting from 0 block takes forever

[dd45e640b42e6da7da96faee3996ef7c]

export snapshots as you need it as backup for the node and if it fails import the latest one