connection

Direct connection between laptop and arduino via ethernet

て烟熏妆下的殇ゞ 提交于 2019-12-05 00:35:31
问题 I made a project with the Arduino and the ethernet-shield. The Arduino is hosting a website which I can open via the browser on my laptop. The Arduino is connected to the router via ethernet. All of this works just fine. Now I have to present this project at school. To prevent unpleasant surprises I wanted to connect the Arduino directly with the laptop via ethernet. My problem is that I am really not well informed about this topic. Please, if possible, tell me what I should do. 回答1: If you

PHP's PDO is ignoring the ATTR_TIMEOUT option for MySQL when server cannot be reached

孤街醉人 提交于 2019-12-05 00:04:40
I'm testing scenarios where the mysql server cannot be reached by putting in a random IP to try to connect to. I set PDO's options to time out after one second using PDO::ATTR_TIMEOUT => 1 . However, it still takes 30 seconds to throw an exception. I'm guessing this timeout only applies to the actual mysql connection time, not to the server on which mysql is running. What PHP options do I need to change to time out the connection to the mysql server? Just put ini_set("default_socket_timeout", 2); before your PDO() connect string. (Tested on Windows, should also be fine on Linux.) Why? Chasing

C#: How do I terminate a socket before Socket.BeginReceive calls back?

余生长醉 提交于 2019-12-04 23:54:31
问题 I have a server that receives connection requests from clients. This server makes use of the asynchronous Socket.BeginReceive and Socket.EndReceive method. The code is pretty similar to the code found here. In my case, after calling Socket.BeginReceive I need a timeout such that if the client hangs on to the connection but does not transmit any data at all for a fixed amount of time, I need to terminate the connection. How do I go about terminating the connection in this scenario? What is the

To close or not to close an Oracle Connection?

自作多情 提交于 2019-12-04 23:52:39
问题 My application have performance issues, so i started to investigate this from the root: "The connection with the database". The best practices says: "Open a connection, use it and close is as soon as possible", but i dont know the overhead that this causes, so the question is: 1 -"Open, Use, Close connections as soon as possible is the best aproach using ODP.NET?" 2 - Is there a way and how to use connection pooling with ODP.NET? I thinking about to create a List to store some connections

Xcode 8 beta simulator fails to run app after accidentally running Xcode8 simulator

旧时模样 提交于 2019-12-04 23:42:38
"Failed to initiate service connection to simulator" Tried to clean app, reinstall it, delete derived data, reset simulator settings, restart xCode. I've also heard other people solved problems with their simulators by recreating the simulator. I tried that as well. When I press create, I get the very same error message: "Error returned in reply: Connection invalid" Even this occurs on Xcode 8.0 stable version. Got it solved by closing Xcode 7 and its simulator. It seems that when you are working on Xcode 8 and its simulator then Xcode 7 simulator should not remain open. Below is screenshot of

The underlying connection was closed: An unexpected error occurred on a receive

不想你离开。 提交于 2019-12-04 22:56:32
I'm here because I have a problem while downloading some files through ftp protocol. It's weird because it occurs occasionally and even for the same single file. Just a precision: I'm downloading very large files (from 500 Mo to 30Go) Here are the kind of Exceptions returned by my function : (sorry it's in french) System.Net.WebException: La connexion sous-jacente a été fermée : Une erreur inattendue s'est produite lors de la réception. à System.Net.FtpWebRequest.CheckError() à System.Net.FtpWebRequest.SyncRequestCallback(Object obj) à System.IO.Stream.Close() à System.Net.ConnectionPool

Socket single client/server connection, server can send multiple times, client can only once

自古美人都是妖i 提交于 2019-12-04 22:17:40
I have written a client and server application that I need to use to connect a checkers game I made in C#. I have got the client and server to connect and the server can repeatedly send the client messages to update a label but when the client tries to send a message it throws the error "A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied." Here is my client and server so far. CLIENT - public partial class Form1 : Form //main form that establishes connection { Form2 form2 = new

C# Mysql Connection must be valid and open

≯℡__Kan透↙ 提交于 2019-12-04 21:58:17
First of all: I got my code running without using oop. I declared all my variables inside the same class and opened/closed the connection right before and after passing the query to the db. That worked! Now with some new experiences I tried to split my code into different classes. Now it wont work anymore. It tells me "Connection must be valid and open". Enough text, here's my current code: Services.cs public static MySqlConnection conn // Returns the connection itself { get { MySqlConnection conn = new MySqlConnection(Services.ServerConnection); return conn; } } public static string

PHP/MySQL: Create new connection for each query?

寵の児 提交于 2019-12-04 20:34:00
I have a webpage with some mysql querys, I must start new db connection and db close after every query or its more efficiently start an only one db connection at the top of the code and close at the bottom of the script? Thanks! Never create a new connection for every query; it's very wasteful and will overburden your MySQL server. Creating one connection at the top of your script is enough - all subsequent queries will use that connection until the end of the page. You can even use that connection in other scripts that are include() ed into the script with your mysql_connect() call in it. I

Apache Ftp server integration with Android

落花浮王杯 提交于 2019-12-04 20:24:52
I am working on integrating Apache FTP server to my Android app. Follow the instructions here ( Embedding FtpServer in 5 minutes): http://mina.apache.org/ftpserver-project/embedding_ftpserver.html . However, with all the codes included and the jar files imported to my android project, I got two major errors: 1. App crash upon ftp server start claiming class not found 2. Dalvik error 1 Tried every method by researching all related problems and the solution is to keep the minimal subset of the jar files that are listed in the (Embedding FtpServer in 5 minutes) instruction and make the code