My Maven+Java+Kotlin project is getting unbearably slow. Editing Java files is okay but editing Kotl...

# intellij

[poohbar]

My Maven+Java+Kotlin project is getting unbearably slow. Editing Java files is okay but editing Kotlin files is excruciating. Typing anything results in 5+ second freezes where not even the cursor blinks. Everything works correctly, just super slow.

Any quick things I should check? Is there a way to debug IntelliJ performance?

[hudsonb]

Have you tried invalidating caches and restarting? That's my go to when I'm having intellij performance problems.

[Mike]

Latest IntelliJ and latest Kotlin plugin?

Is your project really big? Did you turn on ‘delegate to maven’ for builds? Either of those might lead to the issue too.

[poohbar]

latest everything, project is average size I think, 5 modules, less than 1M LOC

i don't have delegate to maven turned on, i haven't actually tried it but i am guessing it would make it slower

[Mike]

Especially since it’s relatively new… Sometimes if the Kotlin file is large, and there’s an error in it, the IDE gets very slow rendering. But I haven’t seen that for quite awhile personally.

[poohbar]

yeah Mike, I see that too.. let's say 80% of the file is highlighted with errors for some reason, suddenly it's almost impossible to fix the file.. only thing that improves it is turning on Power Saving Mode 😕

[poohbar]

I never have this issue in Kotlin-only project. I really need JetBrains to give Maven + Java + Kotlin combo more love, it's one of the most common paths for companies that are Java-only to move to Kotlin.

[Mike]

I suspect it’s the back-and-forth of the compilers. java interfaces -> kotlin -> java and then with errors…

[ribesg]

Well usually in Kotlin you try to have smaller files, maybe that’s why performance problems with huge files aren’t prioritized? I usually don’t have this problem. My longest Kotlin files are my build.gradle.kts and I could split them in theory

[rocketraman]

I get this periodically as well, though it comes and goes. I'll fire up IJ and things will be fine for a while, but then seemingly randomly things will get really slow and I have to restart IJ. I've tried once or twice to submit perf snapshots on YouTrack but with not much success.

[rocketraman]

It's also difficult to capture the right snapshot, because things aren't consistently slow... they'll be fine for a bit, then really really laggy, then fine for a bit again. Checked all the usual suspects: memory settings, etc. and so far I've got no solutions.

[rocketraman]

And its not specific to one Kotlin file -- it's the whole IDE getting slow for all Kotlin files. @poohbar did you find any solutions?

[poohbar]

Not yet. Restarting IntelliJ improves things a little bit for a little while so I suspect it's some sort of leak.

[rocketraman]

Yup, agreed. I'm running for a while with Activity Monitor open to see if I can notice a pattern/change as IDEA gets slower.

[rocketraman]

It seems to be a Kotlin-related memory leak. I've submitted this issue: https://youtrack.jetbrains.com/issue/KT-31546

[rocketraman]

Looking at the activity monitor, the underlying problem in my case might actually be this: https://youtrack.jetbrains.com/issue/IDEA-207243