1

I use:
python3.7,
web3==4.9.2,
Infura and/or own Node.
After web3 was initialized it returns isConnected() response only in first time, after that it freezes.

web3.py:

from web3 import Web3
from web3.gas_strategies.rpc import rpc_gas_price_strategy
from web3.providers.auto import load_provider_from_uri  


class Web3NotAvailableException(Exception):
    def __init__(self, rpc_url):
        self.rpc_url = rpc_url

    def __str__(self):
        return f'WEB3_RPC_URL: {self.rpc_url}'


def get_web3():
    logger.debug('Getting web3 instance')
    if hasattr(get_web3, '_web3_instance'):
        logger.warn('Here 1')
        _web3_instance = getattr(get_web3, '_web3_instance')
    else:
        logger.warn('Here 2')
        _web3_instance = Web3(load_provider_from_uri(settings.WEB3_RPC_URL))
        _web3_instance.eth.setGasPriceStrategy(rpc_gas_price_strategy)
        setattr(get_web3, '_web3_instance', _web3_instance)

    logger.warn('Before isConnected()')
    if not _web3_instance.isConnected():
        logger.warn('Here 3')
        _web3_instance = None
        raise Web3NotAvailableException(settings.WEB3_RPC_URL)

    logger.warn('Finish')
    return _web3_instance

logs:

DEBUG 07/06/2021 16:30:13 | [ web3.py:46 ] Getting web3 instance
WARNING 07/06/2021 16:30:13 | [ web3.py:51 ] Here 2
WARNING 07/06/2021 16:30:13 | [ web3.py:56 ] Before isConnected()
WARNING 07/06/2021 16:30:13 | [ web3.py:62 ] Finish
DEBUG 07/06/2021 16:30:15 | [ web3.py:46 ] Getting web3 instance
WARNING 07/06/2021 16:30:15 | [ web3.py:48 ] Here 1
WARNING 07/06/2021 16:30:15 | [ web3.py:56 ] Before isConnected()

and after that docker container freezes and happen nothing. Although celery should pushes tasks every 30 sec.

But if i use ganache locally everything works.

DEBUG 07/06/2021 16:59:37 | [ web3.py:46 ] Getting web3 instance
WARNING 07/06/2021 16:59:37 | [ web3.py:51 ] Here 2
WARNING 07/06/2021 16:59:37 | [ web3.py:56 ] Before isConnected()
WARNING 07/06/2021 16:59:37 | [ web3.py:62 ] Finish
################################################
DEBUG 07/06/2021 17:00:11 | [ web3.py:46 ] Getting web3 instance
WARNING 07/06/2021 17:00:11 | [ web3.py:48 ] Here 1
WARNING 07/06/2021 17:00:11 | [ web3.py:56 ] Before isConnected()
WARNING 07/06/2021 17:00:11 | [ web3.py:62 ] Finish
################################################
DEBUG 07/06/2021 17:00:41 | [ web3.py:46 ] Getting web3 instance
WARNING 07/06/2021 17:00:41 | [ web3.py:48 ] Here 1
WARNING 07/06/2021 17:00:41 | [ web3.py:56 ] Before isConnected()
WARNING 07/06/2021 17:00:41 | [ web3.py:62 ] Finish

What wrong ?

6
  • 1
    Someone had similar problems and it was related to Celery and async issues. They had to switch to gevent or similar to solve it. I am just remembering this from web3.py Discord chat. Commented Jun 7, 2021 at 19:01
  • 1
    @MikkoOhtamaa , thnx, you've just given me decision )
    – Vadim
    Commented Jun 7, 2021 at 20:12
  • 1
    Don't forget to mark your own answer as correct. Commented Jun 11, 2021 at 9:45
  • 1
    @MikkoOhtamaa , "You can't vote for your own post" if you about it
    – Vadim
    Commented Jun 13, 2021 at 11:04
  • 1
    oh, sorry, now i understand, leave the link here -> meta.stackexchange.com/questions/5234/…
    – Vadim
    Commented Jun 13, 2021 at 18:26

1 Answer 1

1

i moved web3 initialization to settings file, now it it's initialize one time and i get the web3-result already for Celery:

settings/production.py:

from web3 import Web3
from web3.gas_strategies.rpc import rpc_gas_price_strategy
from web3.providers.auto import load_provider_from_uri
from django.conf import settings

from eth_watcher.web3 import Web3NotAvailableException


##################
# different variables here
##################
 
def get_web3():
    _web3_instance = Web3(load_provider_from_uri(settings.WEB3_RPC_URL))
    _web3_instance.eth.setGasPriceStrategy(rpc_gas_price_strategy)

    if not _web3_instance.isConnected():
        _web3_instance = None
        raise Web3NotAvailableException(settings.WEB3_RPC_URL)

    return _web3_instance


W3 = get_web3() 

web3.py:

class Web3NotAvailableException(Exception):
    def __init__(self, rpc_url):
        self.rpc_url = rpc_url

    def __str__(self):
        return f'WEB3_RPC_URL: {self.rpc_url}'


def get_web3():
    return settings.W3

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