Why updating of dependencies in composer is so slow?

I am using composer (http://getcomposer.org/) to manage installed bundles in the Symfony2 (symfony v 2.1.3). Version of the composer is de3188c.

I have problem that when I add new bundle into the composer.json and execute it the time to show messages about Updating dependencies and next downloading them all is very low.

I have this data in the composer.json (see below) and the executing time is approximately 20 MINUTES!!! The internet connection is fast enough I can download big files very fast...

Is there any trick to make it faster?

{
"name": "symfony/framework-standard-edition",
"description": "The \"Symfony Standard Edition\" distribution",
"autoload": {
    "psr-0": { "": "src/" }
},
"require": {
    "php": ">=5.3.3",
    "symfony/symfony": "2.1.*",
    "doctrine/orm": ">=2.2.3,<2.4-dev",
    "doctrine/doctrine-bundle": "1.0.*",
    "twig/extensions": "1.0.*",
    "symfony/assetic-bundle": "2.1.*",
    "symfony/swiftmailer-bundle": "2.1.*",
    "symfony/monolog-bundle": "2.1.*",
    "sensio/distribution-bundle": "2.1.*",
    "sensio/framework-extra-bundle": "2.1.*",
    "sensio/generator-bundle": "2.1.*",
    "jms/security-extra-bundle": "1.2.*",
    "jms/di-extra-bundle": "1.1.*",
    "doctrine/doctrine-fixtures-bundle": "dev-master",
    "webignition/doctrine-migrations-bundle": "dev-master"
},
"scripts": {
    "post-install-cmd": [
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile"
    ],
    "post-update-cmd": [
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets",
        "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile"
    ]
},
"minimum-stability": "dev",
"extra": {
    "symfony-app-dir": "app",
    "symfony-web-dir": "web"
}

Try to specify a version for each dependency in composer.json and use the option --prefer-dist when calling composer. It will download ZIP files from the repositories (if available) instead of the single files.

php composer.phar install --prefer-dist

Since you accepted an answer, it looks like that solved your problem. Just in case anybody else stumbles across this question though (like I did when I was searching), in my case, a really slow Composer install had to do with my PHP version (word of warning, I am a complete and utter Composer newbie), even though Composer ran through its standard checks and said everything was fine. I run Ubuntu 12.04 LTS and was too lazy to upgrade from the default PHP 5.3.10 (the same version you're running) in the Precise repo.

Installing Twig via Composer originally took me around 30 minutes. I gave up installing Doctrine after it took more than an hour. I upgraded to 5.4.17 (using this PPA https://launchpad.net/~ondrej/+archive/php5) and installing Doctrine was done in a matter of seconds.

I have found that it is also very slow, in the tens of minutes slow.

For me I added -vvv and found it was hanging at stuff like Downloading https://packagist.org/p/provider-active$53cdf887c8d2925b3501f47d6980fb7bda2310716369bf7a84857c6e62bbab0f.json

I then went to the browser and tried to download that JSON file and sure enough. It was packagist.org to be the cause of the slowness.

In my case, the above suggestions didn't make a difference. What did was to use the HTTPS protocol for packagist:

php composer.phar config --global repo.packagist composer https://packagist.org

or

composer config --global repo.packagist composer https://packagist.org

depending on your setup

To diagnose this use I used the require command with -vvv attribute.

composer require larapack/dd -vvv

In my case I've found that the slow speed of composer was because of fxp/composer-asset-plugin.

composer global show
composer global remove fxp/composer-asset-plugin

and voila