我在PythonAnywhere上托管的Flask应用程序出现内部服务器错误

Question

因此，当我第一次部署我的应用程序时，它的效果非常好。它显示了所有页面，我能够从我的PythonAnywhere MySQL数据库中编写和读取。然后10分钟后我得到internl服务器错误。然后，当我重新加载应用程序时，它工作10分钟，然后回到内部服务器错误。下面的详细信息显示了与我的数据库通信的代码，server.log错误代码以及我得到的error.log代码。

服务器日志：

2019-04-29 01:06:40 Mon Apr 29 01:06:40 2019 - SIGPIPE: writing to a closed pipe/socket/fd (probably the client disconnected) on request / (ip 10.0.0.162) !!!

==============================================================================

错误日志：

2019-04-29 01:06:40,959: Exception on / [GET]
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 2292, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1815, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1718, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1813, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python2.7/dist-packages/flask/app.py", line 1799, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/home/chronic007/TheCronica/index.py", line 21, in home_page
    cursor.execute(query)
  File "/usr/local/lib/python2.7/dist-packages/mysql/connector/cursor.py", line 393, in execute
    self._handle_result(self._connection.cmd_query(stmt))
  File "/usr/local/lib/python2.7/dist-packages/mysql/connector/connection.py", line 586, in cmd_query
statement))
  File "/usr/local/lib/python2.7/dist-packages/mysql/connector/connection.py", line 386, in _send_cmd
packet_number)
  File "/usr/local/lib/python2.7/dist-packages/mysql/connector/network.py", line 104, in send_plain
    raise errors.OperationalError(str(err))
OperationalError: [Errno 32] Broken pipe

=============================================================================

这是我的python烧瓶文件：

from flask import Flask
from flask import render_template
from flask import request
import mysql.connector

app = Flask(__name__)
db = mysql.connector.connect(
    host="xxxx.mysql.pythonanywhere-services.com",
    user="xxxxx",
    passwd="xxxxxx",
    database= "xxxxxx"
)

cursor = db.cursor()

@app.route('/')
def home_page():
    query = "SELECT * FROM Articles"
    cursor.execute(query)
    data = cursor.fetchall()
    return render_template('index.html', value=data)

@app.route('/static/index.html')
def static_home():
    query = "SELECT * FROM Articles"
    cursor.execute(query)
    data = cursor.fetchall()
    return render_template('index.html', value=data)

@app.route('/static/about.html')
def static_about():
    return render_template('about.html')

@app.route('/admin')
def admin_page():
    return render_template('admin.html')

@app.route('/admin', methods=['POST'])
def submit_form():
    query = "INSERT INTO Articles (Title, Author, Date, Description, Content, Link) VALUES (%s, %s, %s, %s, %s, %s)"
    if request.method == 'POST' :
        title = request.form.get('Title')
        author = request.form.get('Author')
        date = request.form.get('Date')
        description = request.form.get('Description')
        content = request.form.get('Content')
        link = request.form.get('Link')
    val = (title, author, date, description, content, link)
    cursor.execute(query, val)
    db.commit()
    return render_template('admin.html')

Answer 1

您正在模块级别（视图函数之外）打开数据库连接，因此在调用视图时它可能不再有效;数据库连接暂时不使用时会关闭，这可以解释您所看到的问题。您应该在使用它们的每个视图函数中创建db和cursor对象，或者甚至更好地使用像SQLAlchemy这样的数据库连接管理器。

This PythonAnywhere help page has more information about connection management和this blog post has a walkthough for creating a database-backed website using Flask and SQLAlchemy on PythonAnywhere。

Answer 2

首先，这段代码在if语句之外

    val = (title, author, date, description, content, link)
        cursor.execute(query, val)
        db.commit()

您不需要两个视图来处理管理员就这样做

@app.route('/admin', methods=['GET', 'POST'])
def submit_form():
    query = "INSERT INTO Articles (Title, Author, Date, Description, Content, Link) VALUES (%s, %s, %s, %s, %s, %s)"
    if request.method == 'POST' :
        title = request.form.get('Title')
        author = request.form.get('Author')
        date = request.form.get('Date')
        description = request.form.get('Description')
        content = request.form.get('Content')
        link = request.form.get('Link')
        val = (title, author, date, description, content, link)
        cursor.execute(query, val)
        db.commit()
        return render_template('admin.html', message="success")
    else:
        return render_template('admin.html')