composer: Installing / updating dependencies seems very slow

Hi there. I seem to have some issue with the Installing or Updating dependencies steps taking forever. To isolate my issue somewhat, I created a new directory, use the latest composer at the moment (19bfd6c7), and put this composer.json, nothing else:

{
    "require": {
        "php": ">=5.4",
        "zendframework/zendframework": "2.*",
        "doctrine/doctrine-orm-module": "0.*"
    },
    "require-dev": {
        "zendframework/zend-developer-tools": "dev-master"
    }
}

First output:

$ php composer.phar install --profile
[3.1MB/0.37s] Loading composer repositories with package information
[3.4MB/0.90s] Installing dependencies
[37.7MB/64.18s]   - Installing zendframework/zendframework (2.1.4)
[37.7MB/64.19s] [37.7MB/66.89s]     Downloading: 0%[37.7MB/66.89s]              [38.0MB/67.45s]     Downloading:[38.2MB/67.57s]     Downloading:[38.5MB/67.72s]     Downloading:[38.8MB/68.02s]     Downloading:[39.1MB/68.28s]     Downloading:[39.3MB/68.43s]     Downloading:[39.6MB/68.66s]     Downloading:[39.9MB/68.91s]     Downloading:[40.2MB/69.07s]     Downloading:[40.4MB/69.34s]     Downloading:[40.7MB/69.58s]     Downloading:[41.0MB/69.82s]     Downloading:[41.3MB/70.10s]     Downloading:[41.5MB/70.41s]     Downloading:[41.8MB/70.70s]     Downloading:[42.1MB/70.98s]     Downloading:[42.4MB/71.28s]     Downloading:[42.6MB/71.54s]     Downloading: 90%[42.9MB/71.84s]     Downloading:[43.2MB/72.09s]     Downloading:[43.2MB/72.13s]     Downloading: 100%[43.2MB/72.13s] 
[37.7MB/79.99s] 
[37.7MB/80.01s]   - Installing doctrine/common (2.3.0)
[37.7MB/80.01s] [37.7MB/81.07s]     Downloading: 0%[37.7MB/81.07s]              [37.7MB/81.20s]     Downloading:[37.7MB/81.23s]     Downloading:[37.8MB/81.31s]     Downloading:[37.8MB/81.31s]     Downloading:[37.8MB/81.39s]     Downloading:[37.8MB/81.40s]     Downloading:[37.8MB/81.44s]     Downloading:[37.8MB/81.47s]     Downloading:[37.8MB/81.48s]     Downloading:[37.9MB/81.52s]     Downloading:[37.9MB/81.52s]     Downloading:[37.9MB/81.55s]     Downloading:[37.9MB/81.60s]     Downloading:[37.9MB/81.61s]     Downloading:[37.9MB/81.63s]     Downloading:[37.9MB/81.63s]     Downloading:[37.9MB/81.64s]     Downloading: 100%[37.9MB/81.64s] 
[37.7MB/82.17s] 
[37.7MB/82.69s]   - Installing doctrine/dbal (2.3.3)
[37.7MB/82.70s] [37.7MB/83.82s]     Downloading: 0%[37.7MB/83.82s]              [37.7MB/84.06s]     Downloading:[37.8MB/84.12s]     Downloading:[37.8MB/84.20s]     Downloading:[37.8MB/84.22s]     Downloading:[37.8MB/84.36s]     Downloading:[37.9MB/84.37s]     Downloading:[37.9MB/84.52s]     Downloading:[37.9MB/84.53s]     Downloading:[37.9MB/84.61s]     Downloading:[38.0MB/84.62s]     Downloading:[38.0MB/84.69s]     Downloading:[38.0MB/84.76s]     Downloading:[38.0MB/84.77s]     Downloading:[38.0MB/84.84s]     Downloading:[38.1MB/84.85s]     Downloading:[38.1MB/84.92s]     Downloading:[38.1MB/84.93s]     Downloading:[38.1MB/85.00s]     Downloading: 95%[38.1MB/85.01s]     Downloading: 100%[38.1MB/85.02s] 
[37.7MB/85.61s] 
[37.7MB/85.63s]   - Installing symfony/console (v2.2.1)
[37.7MB/85.63s] [37.7MB/86.83s]     Downloading: 0%[37.7MB/86.83s]              [37.7MB/86.99s]     Downloading:[37.8MB/87.02s]     Downloading:[37.8MB/87.10s]     Downloading:[37.8MB/87.15s]     Downloading:[37.8MB/87.15s]     Downloading: 100%[37.8MB/87.15s] 
[37.7MB/87.50s] 
[37.7MB/87.53s]   - Installing doctrine/orm (2.3.3)
[37.7MB/87.53s] [37.7MB/88.60s]     Downloading: 0%[37.7MB/88.61s]              [37.8MB/88.85s]     Downloading:[37.8MB/88.93s]     Downloading:[37.9MB/89.01s]     Downloading:[37.9MB/89.09s]     Downloading:[38.0MB/89.14s]     Downloading:[38.0MB/89.22s]     Downloading:[38.1MB/89.26s]     Downloading:[38.1MB/89.33s]     Downloading:[38.2MB/89.40s]     Downloading:[38.3MB/89.46s]     Downloading:[38.3MB/89.50s]     Downloading:[38.4MB/89.57s]     Downloading:[38.4MB/89.65s]     Downloading:[38.5MB/89.72s]     Downloading:[38.5MB/89.76s]     Downloading:[38.6MB/89.82s]     Downloading:[38.6MB/89.89s]     Downloading:[38.7MB/89.95s]     Downloading: 90%[38.7MB/90.00s]     Downloading:[38.8MB/90.06s]     Downloading:[38.8MB/90.06s]     Downloading: 100%[38.8MB/90.06s] 
[37.7MB/91.28s] 
[37.7MB/91.31s]   - Installing doctrine/doctrine-module (0.7.1)
[37.7MB/91.31s] [37.7MB/92.42s]     Downloading: 0%[37.7MB/92.42s]              [37.7MB/92.58s]     Downloading:[37.8MB/92.75s]     Downloading:[37.8MB/92.78s]     Downloading:[37.8MB/92.83s]     Downloading:[37.8MB/92.86s]     Downloading: 100%[37.8MB/92.86s] 
[37.7MB/93.24s] 
[37.7MB/93.27s]   - Installing doctrine/doctrine-orm-module (0.7.0)
[37.7MB/93.27s] [37.7MB/94.42s]     Downloading: 0%[37.7MB/94.43s]              [37.7MB/94.58s]     Downloading:[37.7MB/94.62s]     Downloading:[37.8MB/94.85s]     Downloading:[37.8MB/94.85s]     Downloading:[37.8MB/94.85s]     Downloading:[37.8MB/94.93s]     Downloading:[37.9MB/95.09s]     Downloading:[37.9MB/95.10s]     Downloading:[37.9MB/95.10s]     Downloading:[37.9MB/95.10s]     Downloading: 100%[37.9MB/95.10s] 
[37.7MB/95.30s] 
[17.8MB/96.57s] zendframework/zendframework suggests installing ircmaxell/random-lib (Fallback random byte generator for Zend\Math\Rand if OpenSSL/Mcrypt extensions are unavailable)
[17.8MB/96.58s] zendframework/zendframework suggests installing pecl-weakref (Implementation of weak references for Zend\Stdlib\CallbackHandler)
[17.8MB/96.59s] zendframework/zendframework suggests installing zendframework/zendpdf (ZendPdf for creating PDF representations of barcodes)
[17.8MB/96.60s] zendframework/zendframework suggests installing zendframework/zendservice-recaptcha (ZendService\ReCaptcha for rendering ReCaptchas in Zend\Captcha and/or Zend\Form)
[17.8MB/96.61s] doctrine/orm suggests installing symfony/yaml (If you want to use YAML Metadata Mapping Driver)
[17.8MB/96.62s] doctrine/doctrine-module suggests installing doctrine/data-fixtures (Data Fixtures if you want to generate test data or bootstrap data for your deployments)
[17.8MB/96.63s] doctrine/doctrine-orm-module suggests installing zendframework/zend-developer-tools (zend-developer-tools if you want to profile operations executed by the ORM during development)
[17.8MB/96.64s] doctrine/doctrine-orm-module suggests installing doctrine/migrations (doctrine migrations if you want to keep your schema definitions versioned)
[17.9MB/96.75s] Writing lock file
[17.9MB/96.75s] Generating autoload files
Memory usage: 17.9MB (peak: 48.73MB), time: 96.77s

Then:

$ php composer.phar update --profile
[3.2MB/0.90s] Loading composer repositories with package information
[3.5MB/1.52s] Updating dependencies (including require-dev)
[38.6MB/65.96s]   - Installing zendframework/zend-developer-tools (dev-master 3994622)
[38.6MB/65.99s]     Cloning 3994622761f496b666a143156b4d21f19205aa66
[38.6MB/67.64s] 
[17.6MB/68.84s] zendframework/zend-developer-tools suggests installing bjyoungblood/bjy-profiler (Version: dev-master, allows the usage of the (Zend) Db collector.)
[17.9MB/69.30s] Writing lock file
[17.9MB/69.31s] Generating autoload files
Memory usage: 17.64MB (peak: 38.7MB), time: 69.37s

And finally

$ php composer.phar update --profile
[3.2MB/0.43s] Loading composer repositories with package information
[3.5MB/0.81s] Updating dependencies (including require-dev)
[39.0MB/58.74s] Nothing to install or update
[18.3MB/60.22s] Generating autoload files
Memory usage: 18.02MB (peak: 39.02MB), time: 60.3s

Is this expected behaviour to take roughly 60 seconds to determine whether there is updates, even if there are no actual updates? I notice in htop that php has very high CPU usage during this time (90-100%)

I don’t suspect a problem with network connectivity or slowness:

$ wget https://packagist.org/p/packages-2013-04.json--2013-04-17 14:58:05--  https://packagist.org/p/packages-2013-04.json
Resolving packagist.org (packagist.org)... 37.59.4.156
Connecting to packagist.org (packagist.org)|37.59.4.156|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [application/json]
Saving to: `packages-2013-04.json'

    [  <=>                                                                                      ] 1,029,324   2.87M/s   in 0.3s    

2013-04-17 14:58:06 (2.87 MB/s) - `packages-2013-04.json' saved [1029324]

Downloading this JSON from packagist took 0.3s. I just did a speedtest.net check, we have 15ms ping, 73 Mbps down and 32 Mbps up.

The environment I’m running in is Ubuntu 12.04 server, running in a VM on ESX servers, 1 CPU with 2GB RAM.