batched transactions are not all executed, but no error are thrown

Question

I am doing a balance upload (copying and modifying the balances from a chain to another)

I have a json file containing all i need, i compute the new balance, and i batch calls doing a setBalance().

I have ~16000 calls to batch. Once everything passed, i run a check script that, for every addresses, fetch their balance from the chain, and check if it matches the one i was expected. and, out of my 16000 calls, i get ~500 accounts that doesn't have the right value. and the difference is very big, no not negligible.

why does this happens ? Why doesn't i have an error ? How can i prevent this ?

here is the code (simplified) :

import balances from "./balances.json"
/*
format:
0x000: {
  address: 0x000 // same as key
  free: ...
  reserved: ...
  Total: ...
}
*/

import crowdloan from "./crowdloan.json"
/*
format:
0x000: value
*/

for (balance in balances) {
   let new_balance = (balance.Total / 100) * 10 ** 12

   const deposit = crowdloan[balance.address]
   if (deposit != undefined) {
      new_balance += deposit * kab_per_ksm /* constant */ * 10 ** 12
   }

   const free_balance = parseInt((new_balance * (3 / 10))
   const reserved_balance = parseInt((new_balance * (7 / 10))

   await api.tx.sudo.sudo(
      api.tx.balances.setBalance(address, free_balance.toString(),
      reserved_balance.toString())
   ).signAndSend(sudo, { nonce: -1 })
}

Answer 1

Utility::batch does not return the error but emits a BatchInterrupted event.
Take a look at the related function batch_all which returns the error.
Otherwise there is force_batch which does not interrupt but keeps going and emits ItemFailed events.