[suggestion] WSV snapshot

[mversic]

Feature request

It is in the scope of this ticket to add a way for Iroha to serialize and deserialize wsv.

We can do this:

1. periodically with a configurable dumping period
2. we can implement another endpoint in Torii to force dumping of wsv to the disk.

Once restarted, the node will read the wsv from the disk and reapply any excess transactions from the block store on top of it. The node will try reading a serialized wsv only if it is started with a specific flag, otherwise not

We can also make the network exchange the wsv when started similarly to what we do with broadcasting genesis block. IMO this would require more work and development time for too small gains

Motivation

We need a way to restart Iroha without it having to reapply all transactions from the block store to get to the current WSV. This is a highly requested feature because it takes 3hrs to restart Iroha for Orillion team

Who can help?

@appetrosyan @mversic

[QuentinI]

I vaguely remember this discussed as a possible Kura init mode, where we periodically store snapshots of WSV in blockstore and restart by applying only txns that happened after the snapshot.
I'd say that makes the most sense to me.

[mversic]

you are referring to this discussion

[mversic]

I didn't think taking a wsv snapshot should be mixed with Kura init modes

[appetrosyan]

I would recommend adding a SIGUSR1 handler too, since this is what most programs would do anyway.

[Erigara]

We probably would need to dump finalized_wsv, not wsv because it's guaranteed not to change.
This mean that we will need apply latest block to it in order to obtain original wsv.

[timofeevmd]

Environment: mac m1
iroha2 commit: ee60fc8
setup: on system

step for reproduce:

• ./scripts/test_env.sh setup
  -kill -2 ${pid}
• ./scripts/test_env.sh setup`

console output
`

• BLOCK_COUNT=
• echo -1
  -1
• '[' '' = 1 ']'
• echo 'Sleeping 1 sec...'
  Sleeping 1 sec...
• sleep 1
• for i in $(seq 1 $1)
• echo 'Waiting for genesis block to be created, attempt 16/20'
  Waiting for genesis block to be created, attempt 16/20
  ++ curl --fail -X GET http://127.0.0.1:8180/status/blocks
  % Total % Received % Xferd Average Speed Time Time Time Current
  Dload Upload Total Spent Left Speed
  0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
  curl: (7) Failed to connect to 127.0.0.1 port 8180 after 4 ms: Couldn't connect to server
  `

logs by peers was attached
WSV_SNAPSHOT_3651.txt