GWT -> Scale compilation permutations horizontally

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Jon Kenoyer

Feb 15, 2021, 2:41:39 PM2/15/21
to GWT Users
We are looking to expanding our GWT client to 13 plus locales in addition to our current 5. The current code base takes 16 gigs to compile per permutation (!). I remember at one point I found a blog post/discussion topic where someone had put in an experimental feature to scale workers across machines.

Has anyone successfully done this and if some give some pointers?

Thomas Broyer

Feb 16, 2021, 5:16:21 AM2/16/21
to GWT Users
This may be what you had in mind:

You could also use a custom PermutationWorkerFactory to automate that, that would send the necessary files to another machine, run the CompilePerms there, then get the result back:

Another solution could be to serialize the permutations' compilation rather than parallelize them by using a low localWorkers value ( Build will be longer but put less pressure on memory.
You could also use fewer forked JVMs and more in-process permutation workers by bumping the gwt.jjs.maxThreads system property (if you set it to the same value as  -localWorkers or higher, everything will be done in the same JVM, without ever forking a new one)

Disclaimer: I've never had to deal with such builds, so can't be of much more help.

Jon Kenoyer

Feb 16, 2021, 9:55:04 AM2/16/21
Thanks, that is exactly what I was looking for. I should have mentioned we are trying to keep the GWT compiles to an hour to not bottleneck our CI/CD deployments.

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