Questions tagged [connection]
Refers to a connection used to transfer data between two endpoints, such as between a client and a web, database, web service or other server.
connection
10,295
questions
460
votes
5
answers
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How do multiple clients connect simultaneously to one port, say 80, on a server? [duplicate]
I understand the basics of how ports work. However, what I don't get is how multiple clients can simultaneously connect to say port 80. I know each client has a unique (for their machine) port. Does ...
- 18.1k
398
votes
22
answers
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views
Artificially create a connection timeout error
I've had a bug in our software that occurs when I receive a connection timeout. These errors are very rare (usually when my connection gets dropped by our internal network). How can I generate this ...
- 73.1k
384
votes
16
answers
1.1m
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How to connect to MySQL from the command line
How can you connect to MySQL from the command line in a Mac? (i.e. show me the code)
I'm doing a PHP/SQL tutorial, but it starts by assuming you're already in MySQL.
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361
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27
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Login to Microsoft SQL Server Error: 18456
I am getting this error while trying to connect to the SQL Server.
Microsoft SQL Server Error: 18456
Can anybody tell me what the error code means?
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321
votes
9
answers
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MySQL show status - active or total connections?
When I run show status like 'Con%' it shows the number of connections, which is 9972 and constantly growing. Is this an active number of connections or connections made in total?
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270
votes
21
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No internet connection on WSL Ubuntu (Windows Subsystem for Linux) [closed]
Recently I installed WSL Ubuntu 18.04 on my Windows machine, but nothing seems to work properly, because I have no internet access.
I tried a few commands and sudo apt update says 'Connection failed' ...
- 3,097
245
votes
2
answers
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What is the difference between connection and read timeout for sockets?
3 questions:
What is the difference between connection and read timeout for sockets?
What does connection timeout set to "infinity" mean? In what situation can it remain in an infinitive loop? and ...
- 12.1k
241
votes
2
answers
358k
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How to create user for a db in postgresql? [closed]
I have installed PostgreSQL 8.4 on my CentOS server and connected to root user from shell and accessing the PostgreSQL shell.
I created the database and user in PostgreSQL.
While trying to connect ...
user925355
188
votes
22
answers
693k
views
How do I start Mongo DB from Windows?
I have installed MongoDB on my Windows 7 (64 bit) machine. I have created the path data/db too but when I tried to start mongodb using the command 'C:\mongodb\bin\mongod.exe', it is not starting. It ...
- 2,165
186
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17
answers
1.2m
views
java.net.SocketException: Connection reset
I am getting the following error trying to read from a socket. I'm doing a readInt() on that InputStream, and I am getting this error. Perusing the documentation suggests that the client part of the ...
Darryl
167
votes
16
answers
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How to detect the physical connected state of a network cable/connector?
In a Linux environment, I need to detect the physical connected or disconnected state of an RJ45 connector to its socket. Preferably using BASH scripting only.
The following solutions which have ...
- 8,942
160
votes
10
answers
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Using R to download zipped data file, extract, and import data
@EZGraphs on Twitter writes:
"Lots of online csvs are zipped. Is there a way to download, unzip the archive, and load the data to a data.frame using R? #Rstats"
I was also trying to do this today, ...
- 34.6k
157
votes
16
answers
393k
views
Python [Errno 98] Address already in use
In my Python socket program, I sometimes need to interrupt it with Ctrl-C. When I do this, it does close the connection using socket.close().
However, when I try to reopen it I have to wait what ...
- 4,120
155
votes
8
answers
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iPhone Simulator - Simulate a slow connection?
Is there a way to slow down the internet connection to the iPhone Simulator, so as to mimic how the App might react when you are in a slow spot on the cellular network?
- 5,577
155
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16
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"The underlying connection was closed: An unexpected error occurred on a send." With SSL Certificate
Issue
I get this exception
The underlying connection was closed: An unexpected error occurred on a send.
in my logs, and it is breaking our OEM integration with our e-mail marketing system at random ...
- 1,839
153
votes
12
answers
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views
Draw a connecting line between two elements [closed]
How can I draw a line between two or more elements to connect them? Any combination of HTML/CSS/JavaScript/SVG/Canvas is fine.
If your answer supports any of these, then do mention it:
draggable ...
- 7,258
145
votes
24
answers
319k
views
How to test an Internet connection with bash?
How can an internet connection be tested without pinging some website?
I mean, what if there is a connection but the site is down? Is there a check for a connection with the world?
- 4,742
137
votes
11
answers
511k
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How to grant remote access permissions to mysql server for user?
If I do SHOW GRANTS in my mysql database I get
GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost'
IDENTIFIED BY PASSWORD 'some_characters'
WITH GRANT OPTION
If I am not mistaken, root@...
- 26k
129
votes
14
answers
228k
views
How to create a bash script to check the SSH connection?
I am in the process of creating a bash script that would log into the remote machines and create private and public keys.
My problem is that the remote machines are not very reliable, and they are ...
- 13.9k
128
votes
23
answers
427k
views
MySQL connection not working: 2002 No such file or directory
I'm trying to set up WordPress. I have Apache and MySQL running, and the accounts and database are all set up. I tried to make a simple connection:
<?php
$conn = mysql_connect('localhost', '...
- 26.1k
127
votes
20
answers
136k
views
How to fix HttpException: Connection closed before full header was received
I have recently upgraded my flutter version in my app. But when I want to debug the application, it shows me the following error.
Error connecting to the service protocol: HttpException: Connection ...
- 2,407
112
votes
9
answers
358k
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How to determine total number of open/active connections in ms sql server 2005
My PHP/MS Sql Server 2005/win 2003 Application occasionally becomes very unresponsive, the memory/cpu usage does not spike. If i try to open any new connection from sql management studio, then the it ...
jagan
110
votes
8
answers
232k
views
How to close idle connections in PostgreSQL automatically?
Some clients connect to our postgresql database but leave the connections opened.
Is it possible to tell Postgresql to close those connection after a certain amount of inactivity ?
TL;DR
IF you're ...
- 42.6k
101
votes
15
answers
733k
views
Setting up connection string in ASP.NET to SQL SERVER
I'm trying to set up a connecting string in my web.config file (Visual Studio 2008/ASP.NET 3.5) to a local server (SQL server 2008).
In my web.config, how and where do I place the connection string?
...
- 3,429
94
votes
10
answers
544k
views
Why would a "java.net.ConnectException: Connection timed out" exception occur when URL is up?
I'm getting a ConnectException: Connection timed out with some frequency from my code. The URL I am trying to hit is up. The same code works for some users, but not others. It seems like once one ...
- 941
90
votes
5
answers
52k
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How can I programmatically remove the 2 connection limit in WebClient
Those "fine" RFCs mandate from every RFC-client that they beware of not using more than 2 connections per host...
Microsoft implemented this in WebClient. I know that it can be turned off with
App....
- 2,947
89
votes
3
answers
91k
views
How to close a mongodb python connection?
I'm doing a python script that writes some data to a mongodb.
I need to close the connection and free some resources, when finishing.
How is that done in Python?
- 1,100
89
votes
3
answers
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In Java when does a URL connection close?
When does java let go of a connections to a URL? I don't see a close() method on either URL or URLConnection so does it free up the connection as soon as the request finishes? I'm mainly asking to see ...
- 5,317
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votes
15
answers
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Instantly detect client disconnection from server socket
How can I detect that a client has disconnected from my server?
I have the following code in my AcceptCallBack method
static Socket handler = null;
public static void AcceptCallback(IAsyncResult ar)
...
Smart Alec
86
votes
18
answers
147k
views
Apache Server (xampp) doesn't run on Windows 10 (Port 80)
I have installed the Windows 10 Insider Program. Everything works, except Apache. When I try to start it, it says that port 80 is blocked. Is there a way to unblock it or tell Apache to use another ...
- 5,311
84
votes
15
answers
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mySQL Error 1040: Too Many Connection
How to fix these, "SQL Error 1040: Too Many Connection"
even I try to put
max_user_connection=500
still "Too many connection"
- 983
83
votes
11
answers
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views
How to check if a socket is connected/disconnected in C#?
How can you check if a network socket (System.Net.Sockets.Socket) is still connected if the other host doesn't send you a packet when it disconnects (e.g. because it disconnected ungracefully)?
- 3,431
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votes
11
answers
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AWS EC2 Connection closed by when trying ssh into instance
Recently I set up a new EC2 instance. The next day I was not able to connect to my instance via ssh. I could connect and disconnect the day before, I am sure I did nothing. Here is ssh debug info:
...
- 793
78
votes
47
answers
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Failed to connect to mysql at 127.0.0.1:3306 with user root access denied for user 'root'@'localhost'(using password:YES)
I've been trying to create a new database connection on workbench. However, every time I test a connection there is an error message that says
Failed to connect to mysql at 127.0.0.1:3306 with user ...
- 781
78
votes
14
answers
118k
views
How do I connect to mongodb with node.js (and authenticate)?
How do I connect to mongodb with node.js?
I have the node-mongodb-native driver.
There's apparently 0 documentation.
Is it something like this?
var mongo = require('mongodb/lib/mongodb');
var Db= ...
- 33.1k
77
votes
7
answers
281k
views
How to kill MySQL connections
I'm building a website with MySQL. I'm using TOAD for MySQL and suddenly I can't connect to the database as I'm getting an error:
"Too many connections"
Is there any way in Toad for MySQL to view ...
- 194k
75
votes
34
answers
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java.sql.SQLException: Access denied for user 'root'@'localhost' (using password: YES)
The following code:
Class.forName("com.mysql.jdbc.Driver");
Connection m_connection = DriverManager.getConnection("jdbc:mysql://localhost","root","root");
Throws this exception on getConnection():
...
- 21.7k
74
votes
12
answers
156k
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HttpClient 4.0.1 - how to release connection? [duplicate]
I have a loop over a bunch of URLs, for each one I'm doing the following:
private String doQuery(String url) {
HttpGet httpGet = new HttpGet(url);
setDefaultHeaders(httpGet); // static method
...
- 38.8k
74
votes
12
answers
78k
views
How do I shut down a Node.js http(s) server immediately?
I have a Node.js application that contains an http(s) server.
In a specific case, I need to shut down this server programmatically. What I am currently doing is calling its close() function, but this ...
- 147k
73
votes
18
answers
132k
views
How to check if internet connection is present in Java?
How do you check if you can connect to the internet via java? One way would be:
final URL url = new URL("http://www.google.com");
final URLConnection conn = url.openConnection();
... if we got here, ...
- 15.5k
72
votes
2
answers
93k
views
urllib3 connectionpool - Connection pool is full, discarding connection
Does seeing the
urllib3.connectionpool WARNING - Connection pool is full, discarding connection
mean that I am effectively loosing data (because of lost connection)
OR
Does it mean that connection ...
- 1,415
69
votes
2
answers
55k
views
How to increase the timeout for `yarn install`
I'm currently using Yarn on a very unstable internet connection.
Sometimes it takes hours until I can finally download all the packages.
I noticed Yarn retries the download when there is some kind of ...
- 1,374
69
votes
7
answers
143k
views
Cannot connect to MySQL 4.1+ using old authentication
I'm trying to connect to a mySQL database at http://bluesql.net, but when I try to connect, it gives this error:
Connect Error (2000) mysqlnd cannot connect to MySQL 4.1+ using old authentication
I'...
- 59.8k
67
votes
7
answers
42k
views
Hibernate Slow to Acquire Postgres Connection
I'm having a really difficult time debugging this problem. Whenever I try to establish a connection with postgres, it takes a whole minute. After the connection is established, everything is fine. I'...
- 3,877
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votes
2
answers
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views
Is it safe to use a static java.sql.Connection instance in a multithreaded system?
I'm running a web application on Tomcat. I have a class that handles all DB queries.
This class contains the Connection object and methods that returns query results.
This is the connection object:
...
- 4,763
62
votes
3
answers
144k
views
What is the functionality of setSoTimeout and how it works?
I'm trying to learn Socket and I'm confused by following text from Oracle's website:
setSoTimeout
public void setSoTimeout(int timeout) throws SocketException
Enable/disable SO_TIMEOUT with the ...
- 4,420
61
votes
4
answers
100k
views
Android event for internet connectivity state change [duplicate]
I am making an app where a user is uploading information and files to my server on a somewhat frequent basis. This is done in new threads through a dedicated uploader service.
I know from this ...
- 2,313
61
votes
7
answers
57k
views
How to limit speed of internet connection on Android emulator?
I need to test app for work with slow internet connection.
How to simulate slow internet connection on Android emulator?
- 2,308
61
votes
11
answers
241k
views
Oracle - What TNS Names file am I using?
Sometimes I get Oracle connection problems because I can't figure out which tnsnames.ora file my database client is using.
What's the best way to figure this out? ++happy for various platform ...
- 302k
58
votes
15
answers
375k
views
CodeIgniter: Unable to connect to your database server using the provided settings Error Message
I have been using CI just fine using the MySQL driver. I want to use the MySQL driver instead, but as soon as I change it (just add the ‘i’ at the end of MySQL, and added the port number) I get the ...
- 7,532