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How to properly handle connection persistent things within node-mysql connection pooling
All transactions will happen in the context of a single connection. After you end or terminate the connection, you can no longer operate on that transaction. The general pattern is to open, query, close and unless you have a long running transaction, you won't have any problems of queries or variables bleeding over into other connections. In the event of a long running transaction, you will have to manage that connection object to make sure it exists and is only used by code that operates within that transaction.

Categories : Mysql

Persistent connection or connection pooling in PHP54+ Nginx + PHPFPM + MongoDB
In the 1.4 version all connections are persistent, unless you close them yourself - which you should never do. You will see a connection per IP/username/password/database combination from each PHP processing unit. In your case, per each PHPFPM process. In order to reduce the number of connections, you need to have less username/password/database combinations. However, with 8 boxes, and 50 FPM processes and 3 nodes in your replicaset you're already at 1200 connections - without even taken into account database/username/password differences. There is not much that you can do about that, but it shouldn't have a big influence in performance. You are much more likely to hit RAM/slow disk limitations.

Categories : PHP

Connection pooling is slower than keeping one connection open
If I understand you correctly - the connection is being "new" per session. if you want all instances to share the connection you should make it static. put it in global.asax: public static SqlConnection con; protected void Application_Start(object sender, EventArgs e) { con = new SqlConnection(_connectionString); } in that way you will be sharing the same connection between your sessions.

Categories : C#

Error while using connection pooling
Please use Exception handler. use try catch or Throws because db connection code. Use like this try { Context initContext = new InitialContext(); Context envContext = (Context) initContext.lookup("java:/comp/env"); DataSource datasource = (DataSource) envContext.lookup("jdbc/LocalTestDB"); Connection con = datasource.getConnection(); } catch(Exception ex) { }

Categories : Java

Which is a better way to handle connection pooling?
Either approach of connection pooling is fine. There are many connection pool implementations (each one with advantages and disadvantages), use whatever you feel like using. If you have a list of statements to execute, then I wouldn't open a new connection for each statement. Instead, execute all statements with the same connection (and statement): JdbcConnectionPool cp = JdbcConnectionPool.create( "jdbc:h2:~/test", "sa", "sa"); ... Connection conn = cp.getConnection(); Statement stat = conn.createStatement(); for (String sql : args) { stat.execute(sql); } conn.close(); ... cp.dispose(); The connection pool can be started / stopped: Outside the web application, as a resource (that's a bit more complicated in my view), for example as described in the article "Database Connecti

Categories : JSF

Pooling:more than one connection to a database
Pooling does not guarantee a single connection. For each concurrently active (logical) connection you need one physical connection. So if you have 10 threads each using a connection instance, or for some reason are opening 10 connections on a single thread, you will see 10 physical connections. A single session is assigned to a single connection. Each connection can have at most one session at the same time.

Categories : Sql Server

Connection Pooling in Grails 2.2.x?
No, the pooled attribute configures pooling. If it's set to false then you will create a new connection each time, and this can take hundreds of milliseconds, so it's not advised. You would set pooled = false when using JNDI however, since the JNDI datasource does its own pooling, so there's no need to pool twice.

Categories : Grails

Connection pooling and Appdomain
Different processes (your case #1) do not (and cannot) share database connections, each connection is unique to the process. I do not know whether connection pools are per process or per-appdomain.1 But it is unlikely to make much difference. The model that you should be aiming for is to create, use and then close connections around each functional database operation. Do not try and keep them open, rather try and keep them closed. This maximises the re-use opportunities for re-use. Unless you have a particular will a few excess connections over what is theoretically needed the default pooling while avoiding holding connections open will just work. 1 As connections are reset before being returned from the pool it would be rather hard to determine which of these is the case. Perhaps a t

Categories : C#

How to prevent ADODB.Connection pooling?
In the link you provided, it is said that calling to close returns the connection to the pool: 2.What statement returns the connection to the pool? 2.Conn.Close You might need to destroy/dispose the ADODB.Connection object, so that it is removed from the pool, or, if you are using OLE DB as the provider, configure the OLEDB Services, as explained here: Enabling OLE DB Resource. Pooling Resource pooling can be enabled in several ways: For an ADO-based consumer, by keeping one open instance of a Connection object for each unique user and using the OLEDB_SERVICES connection string attribute to enable or disable pooling. By default, ADO attempts to use pooling, but if you do not keep at least one instance of a Connection object open for each user, there will not b

Categories : Powershell

Connection Pooling with VB.NET and orphaned connections
You need to have the developers implement the Dispose pattern, which is facilitated by the Using statement in VB.NET, like this (this is pertinent to SQL Server, but whatever connection object you are using for DB2 should work as well): Using theConnection As New SqlConnection() '' Command, parameter logic goes here End Using By wrapping the connection object inside of a Using block, it will guarantee that the connection is closed and properly disposed of memory-wise, even if there is an exception in the code within the Using block. Sounds like a code-review is in order for whoever is in charge of the developers.

Categories : Vb.Net

When should I use connection pooling with MySQL in NodeJS
Whether single or multithreaded, pooling can still be beneficial in allowing open connections to be reused rather than being closed only to open another immediately after: When you are done with a connection, just call connection.release() and the connection will return to the pool, ready to be used again by someone else. The added benefit with multithreading is that the pool can also manage multiple, concurrent connections: Connections are lazily created by the pool. If you configure the pool to allow up to 100 connections, but only ever use 5 simultaneously, only 5 connections will be made. Though, to be clear, Node is multithreaded. It just uses a different model than seems to be typical -- 1 "application" thread which executes JavaScript and multiple "worker" threads handli

Categories : Node Js

Selenium Webdriver connection pooling
I agree that WebDriver pooling could enhance performance of the application. On the other hand, if you are using selenium webdriver, the driver becomes stateful making it less reusable. I did a logic something like this: Create a Driver factory that wraps a linked list of size say 10 (which implements a list and a queue). When asked for an instance provide the middle (i==5) one from the list Use another thread to recycle the drivers in the queue, removing ones from the head and adding new ones to the tail. This way you can implement a constantly recycled pool and your code does not have to block on driver.create or driver.quit.

Categories : Selenium

node.js + mysql connection pooling
It's a good approach. If you just want to get a connection add the following code to your module where the pool is in: var getConnection = function(callback) { pool.getConnection(function(err, connection) { callback(err, connection); }); }; module.exports = getConnection; You still have to write getConnection every time. But you could save the connection in the module the first time you get it. Don't forget to end the connection when you are done using it: connection.release();

Categories : Mysql

C3P0 connection Pooling issues
c3p0 has some facilities built-in to debug Connection pool exhaustion. please see http://www.mchange.com/projects/c3p0/index.html#configuring_to_debug_and_workaround_broken_clients

Categories : Misc

Jboss Connection Pooling Configuration
These are the property of connection pool. Add the following XML to the <datasource> element. <pool> <min-pool-size>10</min-pool-size> <max-pool-size>20</max-pool-size> </pool> <statement> <prepared-statement-cache-size>50</prepared-statement-cache-size> </statement> Here is an example (from official JBoss documentation. ) <subsystem xmlns="urn:jboss:domain:datasources:1.0"> <datasources> <datasource jndi-name="java:jboss/datasources/ExampleDS" pool-name="ExampleDS"> <connection-url>jdbc:h2:mem:test;DB_CLOSE_DELAY=-1</connection-url> <driver>h2</driver>

Categories : Java

PHP vs Java MySQL connection pooling
You are misunderstanding the concept and purpose of connection pooling. Connection pooling is meant to maintain a (set of) connections on a single (Java Virtual) machine (typically, an application server). The goal is to allow multiple threads on the same machine to essentially share their connection to the database server without the need to open one everytime they need to query the database. Stand-alone applications cannot share connections as they run on different Java Virtual Machines, or perhaps even on different physical machines. Connection pooling would help in your stand-alone application if you had several threads making concurrent access to the database. However, you can still measure the benefit of connection pooling by wrapping your test (the code inside your try...catch)

Categories : Java

Would a long running sql command using connection pooling cause other command using that same connection to error?
The first statement is locking out all of the other statements at the database level. Are you using SQL Server? In my experience SQL Server locks tables in so many scenarios that the DBA always reverted to dirty reads--any other locking configuration caused too much contention. To get around this problem you can do the long running work in a temporary table, and then copy to the real table when the work is done.

Categories : Sql Server

Can new connection pooling with pymongo2.6 break up a query?
If you mean using skip and limit with multiple cursors to speed up querying, unfortunately, the answer is probably not. Take, for example, if you wanted to return 1000 results in 10 chunks, and thread 10 cursors to each return 100 of the results. Due to the way skip is implemented on the server side, the overhead for each cursor skipping ahead would probably outweigh the benefits of the pooling. However, I'm not sure what you're referring to with regards to the new implementation of max_pool_size-- it's just a hard cap on connection count. Pymongo has no particular features to support breaking up processes across multiple threads.

Categories : Multithreading

what are side effects Connection Pooling with SQL Server
if there is open and usable connection, connection pool provides that you can use them again. So it increases the performance. Use Sql Stored procedure for database process. It is the best way for performance and security! But Don't forget to close the connection =)

Categories : Sql Server

How to Implement connection pooling in Birt reports
We can definitely do this: we need to setup a connection pool in context.xml of the Tomcat server, and declare it in WEB-INF/web.xml of web applications which make use of this pool (BIRT webviewer in your case). See Apache JNDI Datasource HOW-TO for detailed informations. For example, here is "web.xml" given as example in Apache documentation: <web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4"> <description>MySQL Test App</description> <resource-ref> <description>DB Connection</description> <res-ref-name>jdbc/TestDB</res-ref-name> <res-type

Categories : Eclipse

Jboss RestEasy web service connection pooling
If the constructor exists in the JAR you're "exploring" but JBoss can't find it, it means JBoss is not using the JAR you want it to. I suggest using Logback for logging, as it'll add the name of the JAR to the stacktrace in your logs so you know which JAR JBoss is using.

Categories : Misc

JDBC Connection Pooling vs Dependency Injection
In your application context(xml): <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="${jdbc.driverClassName}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> </bean> Then you can inject the dataSource in some DAO: @Repository public class JdbcCorporateEventDao implements CorporateEventDao { private JdbcTemplate jdbcTemplate; @Autowired public void setDataSource(DataSource dataSource) { this.jdbcTemplate = new JdbcTemplate(dataSource); } // JDBC-backed implementations of the methods on the CorporateEven

Categories : Java

Connection pooling issue on Mybatis with Tomcat
Have you considered the Slow Logon issue that occurs with the Teradata JDBC driver when using the TD2 (default) authentication mechanism? This issue has been attributed to a defect in the default random number generator that is used by the Java Virtual Machine. The link provides you with a test script to confirm the problem exists as well as a documented work around to address the defect. EDIT: This would address how your connections in Mybatis are handled with regards to POOLED or UNPOOLED. It would not address the JNDI configuration as that would have to be handled within JNDI. <dataSource type="POOLED"> <property name="driver" value="${driver}"/> <property name="url" value="${url}"/> <property name="username" value="${username}"/> <property name=

Categories : Misc

Does c3p0 connection pooling ensures max pool size?
it is important to distinguish between DataSources and Connection pools. maxPoolSize is enforced by c3p0 on a per-pool basis. but a single DataSource may own multiple Connection pools, as there is (and must be) a distinct pool for each set of authentication credentials. if only the default dataSource.getConnection() method is ever called, then maxPoolSize will be the maximum number of Connections that the pool acquires and manages. However, if Connections are acquired using dataSource.getConnection( user, password ), then the DataSource may hold up to (maxPoolSize * num_distinct_users) Connections. to answer your specific question, if maxPoolSize is 5 and 10 clients hit a c3p0 DataSource simultaneously, no more than 5 of them will get Connections at first. the remaining clients will wait

Categories : Database

Connection Pooling for Oracle in Microsoft enterprise Library
For connection pooling, the complete connection string should be same. ( ie. Either through code or through config the connection information should not be changed.) which means even the userid and password should not be changed. When every thing is same, the connection pooling will automatically happen at the IIS. if not, the connection pooling will not work.

Categories : Dotnet

How to find a reasonable size for connection-pooling? and how to verify it?
you must test it with your actual framework how much minimum and maximum connection pool you will use. according to this article : Small Connection pool : Will have faster access on the connection table. But may not have enough connections to satisfy requests and requests may spend more time in the queue. Large Connection pool: Will have more connections to fulfill requests and requests will spend less (or no) time in the queue at the cost of slower access on the connection table. so you must test with some connection pool, do some load testing. Also consider getting performance/resource usage information on the current load, and doing some transaction cost based analysis. And by the result of the analysis, if the access to the connection table are too slow then you

Categories : Hibernate

Do I need to configure c3p0 connection pooling for Amazon RDS service?
Amazon RDS is exposed as a web-service. Database connection pooling (with c3p0) is needed when the application has the connection object with itself, which is not the case here. Hope this helps!

Categories : Hibernate

How Hibernate pooling works if pooling size is less than concurrent connections?
if you've set things up properly and c3p0's maxPoolSize is 50, then if 1000 clients hit the pool, 50 will get Connections initially and the rest will wait() briefly until Connections are returned by the first cohort. the pool's job, in collaboration with your application which should hold Connections as briefly as possible, is to ensure that a limited number of Connections are efficiently shared. if you are seeing occasional connection reset / socket exception, you probably ought to configure some Connection testing: http://www.mchange.com/projects/c3p0/index.html#configuring_connection_testing the latest prerelease version has some more direct advice about connection testing; you can download that or read the html source starting here: https://github.com/swaldman/c3p0/blob/master/src/

Categories : Mysql

Node.js, Request, MySQL and Connection Pooling leads to Infinite Blocking/Freezing Behavior?
You're using a synchronous loop to deploy an asynchronous resource. You can't do that. Your while loop fills up the database pool and then loops once again and blocks on getConnection which then blocks the whole Node.js event loop. You can use the async package to perform asynchronous while loops. The async#forever call would do what you're trying to achieve. Also, your code is leaking database connections. You should put the connection.end() first in the callback unless you're going to use the same connection again. Otherwise, an error will leak a database connection. pool.getConnection(function (err, connection) { if (err) throw err; connection.query('SELECT 1 + 1 AS solution', function(err, rows, fields) { connection.end(); // return to pool before evaluating err

Categories : Mysql

Pooling connection to mysql database server from django application server
Your approach is not amateur at all. The purpose of bouncer in your case would be to eliminate connection time that happens on each request django handles. For example, on Heroku, which is hosted on AWS servers, this could eat up 40-50ms of each request. Now, if you had a master/slave setup or something like that, a connection pool would also provide you a failover functionality (just an example)

Categories : Mysql

pgpool-II connection pooling - ERROR: "MD5" authentication with pgpool failed
After having hit the same problem the solution was to change ownership of the pool_passwd file to postgres. Even though this file has a 644 permission, if owner isn't postgres you'll always get the aforementioned error. I guess this file's owner and the user running pgpool must match. I'm running PosgreSQL 9.2 and pgpool-II 3.3.2, BTW.

Categories : Postgresql

handling $http.get and $http.post errors in Angularjs
Response interceptors are attached during the config phase of an angularjs app. You can use them to globally respond to any $http request. Be aware, template files also use $http request, so you may wish to filter some requests in your interceptor to only the ones you wish to respond to. A good understanding of the promises pattern is needed to successfully use response interceptors. Heres an example of how they are used: angular.module('services') .config(function($httpProvider){ //Here we're adding our interceptor. $httpProvider.responseInterceptors.push('globalInterceptor'); }) //Here we define our interceptor .factory('globalInterceptor', function($q){ //When the interceptor runs, it is passed a promise object return function(promise){

Categories : Angularjs

Debugging issues in http connection
Here is an article about the exception you're getting. You can also add Log.d(String, String) lines to your code, to follow each step and see exactly where you're getting stuck. The first argument is the tag, the second is a string you define which LogCat will spit back at you when it hits that line of code. It's extremely helpful. I'll bet the article has your answer though. Edit to add the developer doc, looks like running the Network action in your Main thread is the culprit. Edit #2 for the fix: TechBlogIsTech Article Edit #3 for more on AsyncTask from developer docs. Final Edit for more on LogCat debug log writing.

Categories : Android

Express.IO connection keeps failing with HTTP 500
it seems that you are referring to localhost: NSErrorFailingURLStringKey=http://localhost:7076/socket.io/1/?t=16807 in your IOS client, while the node.js server is running on some external Linux box. Try connecting to the server instead.

Categories : IOS

Android repetitive http connection
You can use a static http client (so that gurentees it's created just once) and then reuse it with all requests without having to create new instances of it, you can use this logic for many other fixed variables related to the connection in order to save memory.

Categories : Android

When does an HTTP 1.0 server close the connection?
In HTTP 0.9, the server always closes the connection after sending the response. The client must close its end of the connection after receiving the response. In HTTP 1.0, the server always closes the connection after sending the response UNLESS the client sent a Connection: keep-alive request header and the server sent a Connection: keep-alive response header. If no such response header exists, the client must close its end of the connection after receiving the response. In HTTP 1.1, the server does not close the connection after sending the response UNLESS the client sent a Connection: close request header, or the server sent a Connection: close response header. If such a response header exists, the client must close its end of the connection after receiving the response.

Categories : Http

Opening connection to HTTP server with PHP
The easiest way to interact with an HTTP server from PHP would be to use curl. It's a good library with some great features. It works well. $curl = curl_init(); curl_setopt($curl, CURLOPT_URL, "Your_url_here"); $resp = curl_exec($curl);

Categories : PHP

How to make an HTTP POST URL connection?
You can keep the type as HttpURLConnection instead of URLConnection. It allows to specify HTTP method. HttpURLConnection connection = (HttpURLConnection)url.openConnection(); connection.setRequestMethod("POST");

Categories : Java

Creating an HTTP connection via Android
It would help to know the error. But since I have to guess, my bet is that you are trying to execute this code on the main event thread (a.k.a. the UI thread). That was always wrong and as of API level 11, it will cause a NetworkOnMainThreadException to be thrown. See the document Designing for Responsiveness for the proper way to handle networking in Android.

Categories : Android

open another http connection in java
I'm guessing you can't read from the second URL because you are blocking on the first URL. Two suggestions: Start a new Thread for every new URL you want to read Read all the data in the first URL and add the links that your want to process to a List. Then when you finish reading the main URL you can read each of the other URL's one at a time.

Categories : Java



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