Friday, April 1, 2011

Fixing Slow @Grab Dependencies Issue with Groovy/Grape Scripts

Groovy scripts are not only quick to write and powerful but also very flexible because it can download Maven dependencies/artifacts automatically using the @Grab "annotation".

However there is currently an issue being discussed:  @Grab is Unusably Slow in Groovy-User mailing list.

Fortunately there is a solution (actually, workaround) before the powers that be (either Grapes and/or the http-builder guys) implements a proper solution.

The following is a verbatim copy of S├ębastien Launay's post:


I also got the same issue which is a pain because scripting Rest Web Service in Groovy is very powerful especially when it is easy to share with Grape / @Grab.

The dynamic (version range) dependency is actually defined by http-builder himself. IMHO using version range is often a bad practice, at least on production release, because for the same sources the build result can be different when launched again which renders difficult bug analysis and maintenance.

The other thing is that Apache Ivy configuration tries all remote repositories to check for a new version even if it was resolved before but this is appropriate as it is a dynamic dependency. This can be tuned in Ivy with the cache TTL feature.

Indeed, I had the following logs:

== resolving dependencies

downloadGrapes: Checking cache for: dependency:
org.codehaus.groovy#groovy;[1.5,1.7.99] ...
default-cache: cached resolved revision expired for

The default TTL in Ivy 2.1.0 is 10 seconds, by changing it I got
faster startup, this can be done by creating the file ~/.groovy/grapeConfig.xml from the one found in svn and
editing the file to have:

  <property name="ivy.cache.ttl.default" value="15m"/>