HDWalletProvider web3 smart contract connection need to stop or pool

HDWalletProvider engine.stop()

p = HDWalletProvider(MNEMONIC_SYSTEM, "http://ganache:8545", 0);
p.engine.stop();

HDWalletProvider engine.stop() and pool

export function GetHdProvider(id: number, rpcurl: string) {
  //return new HDWalletProvider(MNEMONIC_SYSTEM, url, id);

  return id==0?Provider1Pool.acquire():Provider2Pool.acquire();
}

// Normal use
const hdProvider0 = await GetHdProvider(0, providerUrl).then(function(client) {return client}).catch(function(err) {throw new HttpException(err.toString(), HttpStatus.BAD_REQUEST);});

const hdProvider1 = await GetHdProvider(1, providerUrl).then(function(client) {return client}).catch(function(err) {throw new HttpException(err.toString(), HttpStatus.BAD_REQUEST);});

// Normal release
ReleaseHDProvider1(hdProvider1 );

// Pool code
const genericPool = require("generic-pool");

const opts = {
  max: 10, // maximum size of the pool
  min: 2, // minimum size of the pool
  idleTimeoutMillis: 30000,
  log: true
};

const factory0 = {  // maybe different parms
  create: function() {
    return new HDWalletProvider(MNEMONIC_SYSTEM, RPCURL, 0);
  },
  destroy: function(client) {
    client.engine.stop();
  }
};

const factory1 = {  // maybe different parms
  create: function() {
    return new HDWalletProvider(MNEMONIC_SYSTEM, RPCURL, 1);
  },
  destroy: function(client) {
    client.engine.stop();
  }
};

export function ReleaseHDProvider1(client){
  Provider1Pool.release(client);
  console.log("Provider1Pool status: pool.size %o pool.available %o pool.pending %o", Provider1Pool.size, Provider1Pool.available, Provider1Pool.pending)
}

export function ReleaseHDProvider2(client){
  Provider2Pool.release(client);
  console.log("Provider2Pool status: pool.size %o pool.available %o pool.pending %o", Provider2Pool.size, Provider2Pool.available, Provider2Pool.pending)
}

const Provider1Pool = genericPool.createPool(factory0, opts);
const Provider2Pool = genericPool.createPool(factory1, opts);

truffle truffle-hdwallet-provider Error: Error: the tx doesn't have the correct nonce. account has nonce of: 3 tx has nonce of: 2

What this Error？

Example：

transaction A get nonce 1
transaction B get nonce 2
transaction C get nonce 3

But blockchain package B、C first, then package A. If happen this step, get error.

With truffle？

Because

Normal

const wallet = new HDWalletProvider(mnemonic, url, id);
const AContract = new TruffleContract(Json_contract);
AContract.setProvider(wallet);

wallet.addresses[]
AContract. use contract api

Sometime you call contract "set/write" api two times.

Example：

Create contract first. Write data into contract second. This two step are in one function. This mean is you call two time "new HDWalletProvide".　Usually you think “New“ two time is ok, get "new" instance. But

https://github.com/trufflesuite/truffle-hdwallet-provider/blob/master/index.js

function HDWalletProvider(
  mnemonic,
  provider,
  address_index=0,
  num_addresses=1,
  shareNonce=true,
  wallet_hdpath="m/44'/60'/0'/0/"
) {

shareNonce default is true. new HDWalletProvide use same Nonce.

Answer is shareNonce => false, when you set/update data into to contract use api.