Microbenchmarking Google's Mirror of Maven Central

Last week, Takari announced that Google is Maven Central's New Best Friend. While writing a news article about this for InfoQ, I decided to run a small test to see the speed of the default Maven Central versus the new Google Cloud Storage instance. This micro benchmark didn't seem worthy of including in the article, but I think it's interesting to see the speed improvements I found.

I ran rm -rf ~/.m2/repository, then mvn install with the default repository configured. I ran the commands again with Google Cloud Storage. I found that the downloading of dependencies, compilation and running unit tests on AppFuse's web projects averaged 4 minutes, 30 seconds. With Google Cloud Storage, the same process averaged 3 minutes and 37 seconds. By my calculations, this means you speed up artifact resolution for your Maven projects by 25% by switching to Google. To do that, create a ~/.m2/settings.xml file with the following contents.

<settings>
  <mirrors>
    <mirror>
      <id>google-maven-central</id>
      <name>Google Maven Central</name>
      <url>https://maven-central.storage.googleapis.com</url>
      <mirrorOf>central</mirrorOf>
    </mirror>
  </mirrors>
</settings>

Benchmark Details
My tests were run on a Mac Pro (late 2013) with a 3.5 GHz 6-Core Intel Xeon E5 processor and 32 GB of RAM. Bandwidth speeds during this test averaged 57 Mbps down, 6 Mbps up. Below are the timing numbers (in minutes) from my test:

Default: 4:33, 4:36, 4:32, 4:24, 4:09
Google: 5:13, 3:35, 2:15, 3:38, 3:39

Google had some wide variances in its results, with five minutes and two minutes. Because of this, I dropped the low and high numbers for each service before calculating the average. My math with raw numbers is below.

Default:
273, 276, 272, 264, 213 = 260, 4:20
276, 272, 264 = 270, 4:30

Google:
313, 215, 135, 218, 219 = 220, 3.66 = 3:40
215, 218, 219 = 3:37

Chen Eric commented on the InfoQ article to note that Chinese programmers are blocked from using Google.