使用Docker时Socket IO响应慢

Question

我有一个内置在Flask中的Web应用程序，其中tweet被捕获(使用Tweepy库)并显示在前端。我使用Socket IO在前端实时显示tweet。

当我在本地运行时，我的代码工作得很好。推文立即出现。

然而，当我Dockerized web应用程序时，前端不会立即更新。显示更改需要一些时间(有时我认为由于速度缓慢而丢失了tweet)

以下是我网站的代码摘录:

fortsocket.js

$(document).ready(function () {

/************************************/
/*********** My Functions ***********/
/************************************/
function stream_active_setup() {
$("#favicon").attr("href", "/static/icons/fortnite-active.png");
$("#stream-status-ic").attr("src", "/static/icons/stream-active.png");
$("#stream-status-text").text("Live stream active");
}
function stream_inactive_setup() {
$("#favicon").attr("href", "/static/icons/fortnite-inactive.png");
$("#stream-status-ic").attr("src", "/static/icons/stream-inactive.png");
$("#stream-status-text").text("Live stream inactive");
}

/*********************************/
/*********** My Events ***********/
/*********************************/
// Socket connection to server
// Prometheus
//var socket = io.connect('http://104.131.173.145:8083');
// Local
var socket = io.connect(window.location.protocol + '//' + document.domain + ':' + location.port);
// Heroku
//var socket = io.connect('https://fortweet.herokuapp.com/');
// Send a hello to know
// if a stream is already active
socket.on('connect', () => {
socket.emit('hello-stream', 'hello-stream');
});
// Listene for reply from hello
socket.on('hello-reply', function (bool) {
if (bool == true) {
stream_active_setup()
} else {
stream_inactive_setup()
}
});
// Listens for tweets
socket.on('stream-results', function (results) {
// Insert tweets in divs
$('#live-tweet-container').prepend(`
<div class="row justify-content-md-center mt-3">
<div class="col-md-2">
<img width="56px" height="56px"  src="${results.profile_pic !== "" ? results.profile_pic : "/static/icons/profile-pic.png"}" class="mx-auto d-block rounded"  alt="">
</div>
<div class="col-md-8 my-auto">
<div><b>${results.author}</b></div>
<div>${results.message}</div>
</div>
</div>
`);
});
// Listener for when a stream of tweets starts
socket.on('stream-started', function (bool) {
if (bool == true) {
stream_active_setup()
}
});
// Listener for when a stream of tweets ends
socket.on('stream-ended', function (bool) {
if (bool == true) {
stream_inactive_setup()
}
});
});

initpy

# Create the app
app = create_app()
# JWT Configurations
jwt = JWTManager(app)
# Socket IO
socketio = SocketIO(app, cors_allowed_origins="*")
# CORS
CORS(app)
app.config["CORS_HEADERS"] = "Content-Type"
# Creates default admins and insert in db
create_default_admin()
# Main error handlers
@app.errorhandler(404)  # Handling HTTP 404 NOT FOUND
def page_not_found(e):
return Err.ERROR_NOT_FOUND

# Listen for hello emit data
# from client
@socketio.on("hello-stream")
def is_stream_active(hello_stream):
emit("hello-reply", streamer.StreamerInit.is_stream_active(), broadcast=True)

streamer.py

import time
import tweepy
import threading as Coroutine
import app.messages.constants as Const
import app.setup.settings as settings_mod
import app.models.tweet as tweet_mod
import app.services.logger as logger
import app

class FStreamListener(tweepy.StreamListener):
def __init__(self):
self.start_time = time.time()
self.limit = settings_mod.TwitterSettings.get_instance().stream_time
logger.get_logger().debug("Live capture has started")
# Notify client that a live capture will start
app.socketio.emit(
"stream-started", True, broadcast=True,
)
super(FStreamListener, self).__init__()
def on_status(self, status):
if (time.time() - self.start_time) < self.limit:
# Create tweet object
forttweet = tweet_mod.TweetModel(
status.source,
status.user.name,
status.user.profile_background_image_url_https,
status.text,
status.created_at,
status.user.location,
)
# Emit to socket
app.socketio.emit(
"stream-results",
{
"profile_pic": forttweet.profile_pic,
"author": forttweet.author,
"message": forttweet.message,
},
broadcast=True,
)
# Add to database
forttweet.insert()
return True
else:
logger.get_logger().debug("Live capture has ended")
# Notify client that a live capture has ended
app.socketio.emit(
"stream-ended", True, broadcast=True,
)
# Stop the loop of streaming
return False
def on_error(self, status):
logger.get_logger().debug(f"An error occurred while fetching tweets: {status}")
raise Exception(f"An error occurred while fetching tweets: {status}")

class StreamerInit:
# [Private] Twitter configurations
def __twitterInstantiation(self):
# Get settings instance
settings = settings_mod.TwitterSettings.get_instance()
# Auths
auth = tweepy.OAuthHandler(settings.consumer_key, settings.consumer_secret,)
auth.set_access_token(
settings.access_token, settings.access_token_secret,
)
# Get API
api = tweepy.API(auth)
# Live Tweets Streaming
myStreamListener = FStreamListener()
myStream = tweepy.Stream(auth=api.auth, listener=myStreamListener)
myStream.filter(track=settings.filters)
def start(self):
for coro in Coroutine.enumerate():
if coro.name == Const.FLAG_TWEETS_LIVE_CAPTURE:
return False
stream = Coroutine.Thread(target=self.__twitterInstantiation)
stream.setName(Const.FLAG_TWEETS_LIVE_CAPTURE)
stream.start()
return True
@staticmethod
def is_stream_active():
for coro in Coroutine.enumerate():
if coro.name == Const.FLAG_TWEETS_LIVE_CAPTURE:
return True
return False

streamer.py在点击按钮时被调用

Dockerfile

# Using python 3.7 in Alpine
FROM python:3.6.5-stretch
# Set the working directory to /app
WORKDIR /app
# Copy the current directory contents into the container at /app
ADD . /app
RUN apt-get update -y && apt-get upgrade -y && pip install -r requirements.txt
# Run the command
ENTRYPOINT ["uwsgi", "app.ini"]
#ENTRYPOINT ["./entry.sh"]

docker-compose.yml

version: "3.8"
services:
fortweet:
container_name: fortweet
image: mervin16/fortweet:dev
build: ./
env_file:
- secret.env
networks:
plutusnet:
ipv4_address: 172.16.0.10
expose:
- 8083
restart: always
nginx_fortweet:
image: nginx
container_name: nginx_fortweet
ports:
- "8083:80"
networks:
plutusnet:
ipv4_address: 172.16.0.100
volumes:
- ./nginx/nginx.conf:/etc/nginx/conf.d/default.conf
depends_on:
- fortweet
restart: always
networks:
plutusnet:
name: plutus_network
driver: bridge
ipam:
driver: default
config:
- subnet: 172.16.0.0/24
gateway: 172.16.0.1

app.ini

[uwsgi]
module = run:app
master = true
processes = 5
# Local & Prometheus
http-socket = 0.0.0.0:8083
http-websockets = true
chmod-socket = 660
vacuum = true
die-on-term = true

完整的更新代码，可以在dev/mervin

分支下找到。任何帮助都是感激的。

Answer 1

为了查看ipv6是否负责，我建议您关闭所有

打开/etc/sysctl.conf并添加以下行来禁用ipv6

net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1
net.ipv6.conf.lo.disable_ipv6=1

运行sudo sysctl -p使更改生效

重新启动nginx和docker

如果你没有看到任何不同，那么你可以把设置改为0，然后重新运行sysctl -p，然后告诉我

Answer 2

不幸的是，我无法在没有配置的情况下重现这个问题，所以我无法验证我的答案。

我在JP的博客上发现了一个类似的问题:Flask和Docker的性能问题

简而言之，可能是容器上有IPv6和IPv4配置导致了这个问题。为了验证问题:

1. 运行docker
2. 进入正在运行的容器并更改hosts文件，以便它不会将IPv6映射到localhost
3. 在容器内再次运行应用程序

如果应用程序运行顺利，那么你已经确定了你的问题。解决方案是调整uwsgi参数。

作者在博客文章中做了什么:

CMD uwsgi -s /tmp/uwsgi.sock -w project:app --chown-socket=www-data:www-data --enable-threads & nginx -g 'daemon off;'