psycopg2.OperationalError: FATAL: 抱歉，heroku 上已經有太多客戶端了

Question

我試圖將我的 Flask 應用程序推送到 heroku，我的應用程序使用 Postgres 作為數據庫。 但是，當我嘗試使用此命令在 heroku 上遷移數據庫時

heroku run python manage.py db init --app app

它為 psycopg2 和 sqlalchchemy 提供了“客戶端太多”錯誤。

Running python manage.py db migrate on ⬢ petscom... up, run.5707 (Hobby)
Traceback (most recent call last):
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 2285, in _wrap_pool_connect
    return fn()
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool/base.py", line 303, in unique_connection
    return _ConnectionFairy._checkout(self)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool/base.py", line 773, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool/base.py", line 492, in checkout
    rec = pool._do_get()
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool/impl.py", line 238, in _do_get
    return self._create_connection()
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool/base.py", line 308, in _create_connection
    return _ConnectionRecord(self)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool/base.py", line 437, in __init__
    self.__connect(first_connect_check=True)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool/base.py", line 657, in __connect
    pool.logger.debug("Error on connect(): %s", e)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/util/langhelpers.py", line 69, in __exit__
    exc_value, with_traceback=exc_tb,
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 178, in raise_
    raise exception
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/pool/base.py", line 652, in __connect
    connection = pool._invoke_creator(self)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/strategies.py", line 114, in connect
    return dialect.connect(*cargs, **cparams)
  File "/app/.heroku/python/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 488, in connect
    return self.dbapi.connect(*cargs, **cparams)
  File "/app/.heroku/python/lib/python3.6/site-packages/psycopg2/__init__.py", line 126, in connect
    conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: FATAL:  sorry, too many clients already
FATAL:  sorry, too many clients already

經過一番谷歌搜索，我嘗試了：

1. heroku pg:killall
2. heroku restart 這些都不起作用.....

我檢查了heroku pg，它顯示了0/20個連接......

有人說不要將db連接放入循環中，但我必須檢查db中是否有一些數據。 這是我的代碼：

try:
        connection = psycopg2.connect(user="postgres",
                                      password="pass",
                                      host="127.0.0.1",
                                      port="5432",
                                      database="pets")

        cursor = connection.cursor()

        select_all = "select * from pets"
        cursor.execute(select_all)

        # Check if api data in db and save to db
        for index in range(len(myData)):
            # if not exist in db => save to db
            key = myData[index]["animal_id"]
            exists = check_exists(key, cursor)
            if(exists):
                pass
            else:
                doSomething()

我可以連接到我的本地 postgres 數據庫，但不能連接到 heroku 上的數據庫。 我該如何處理這個問題？ 任何建議都會有所幫助:) 謝謝！

Answer 1

我有一個類似的問題。 我能夠通過在環境中設置SQLALCHEMY_TRACK_MODIFICATIONS=False 、破壞數據庫並創建一個新數據庫來修復它。

您可以通過訪問https://data.heroku.com/datastores來銷毀它，打開數據庫，轉到設置，然后選擇“銷毀數據庫”。

然后像往常一樣配置一個新的。