Why is IntelliJ IDEA hanging on "Indexing"?

I'm running on Arch Linux, on an i7-5930k 6 core CPU and 64GB of DDR4 RAM, and I'm using IntelliJ IDEA 14.

IDEA was working just fine for me several days ago, but one day, suddenly, it began hanging after opening a project, during the "Indexing" stage. I did not update IDEA and nothing changed about my projects. The IDE's UI hangs after it opens the project, with just a tiny little sliver of the progress bar for "Indexing" complete. Every 5-10 minutes or so it unfreezes and the progress bar crawls forward a little bit, before the IDE freezes again for another few minutes. This happens repeatedly for anywhere between 15 minutes and an hour, until it is finally finished indexing, at which point it hangs for another 5-10 minutes doing nothing, before it finally unlocks and allows me to develop.

While this is happening, my system is fairly unresponsive - Firefox tabs take a long time to switch, and scrolling in them is laggy. Opening a new terminal window takes a long time. Switching windows in general takes awhile. In htop, one of my CPU cores is loaded at 100% while the rest have a normal load, and about 6GB of RAM is used (fairly normal load when this system is idle.)

Things I have tried that have not helped:

• Delete caches folder
• Delete entire ~/.IntelliJIDEA14 folder
• Reinstall IntelliJ package
• Download IntelliJ manually from JetBrains' site and run it from my Downloads folder (to see if there was something wrong with the Arch AUR package)
• Configure IntelliJ to use my system JVM and Maven for importing instead of its embedded tools
• Opening multiple different projects (not just the one I initially experienced the issue on.)

This issue is really hurting my workflow, if anybody has any solution to this I would be very greatful.

Try Invalidating the cache and restarting IntelliJ.

In the File menu, select Invalidate Caches / Restart... and then click the Invalidate and Restart button.

I've finally figured it out. The solution was... Rather odd. TL;DR: Run it under strace. Read on for a more detailed explanation.

I came upon it when I decided to run IntelliJ under strace to see what files it was opening to determine whether or not it was a filesystem bottleneck.

This gave me some very strange results: strace was spewing out a near-constant stream of segfaults. Not only that, but IntelliJ was running just fine, not taking forever to index.

After consulting with a friend, I learned that on Arch Linux, systemd logs a dump of a process's memory every time a segfault occurs, except when a debugger is attached. strace is considered a debugger. Arch was thrashing my disks when it kept logging memory dumps due to all the segfaults, hence why the indexing was taking so long, because it was fighting for disk I/O.

My solution for now is to simply run IntelliJ under strace. I will, however, be looking into the issue further, as I don't think java should be segfaulting that much.

edit Intellij[VERSION]/bin/idea.properties, set idea.max.intellisense.filesize=50

update: Intellij will skip index files that size larger than 50kb.try this if you have many libraries or many large files(too many characters one line or too many lines)

I had this issue as well with version 2016.2 on Mac OS X. I had to do a force quit to end the application, then I deleted the .idea folder. The next time I launched IntelliJ everything worked fine, it had no problem indexing the project.

I was stuck with a similar issue with the latest IntelliJ Idea 2019.3, so maybe it'll help. For me the issue was with one of the plugins, uninstalling/reinstalling, cleaning caches didn't help. My steps were:

1. Kill intellij, start it over
2. When it's starting and about to load a project, be quick and cancel opening the project. This way you'll end up with a small window with a list of previously opened projects and a few menu items.
3. Open menu > plugins, disable them all
4. Restart intellij idea, open any project.

If step 4 above succeeds (which happened to me), one by one try enabling the plugins to see which one is causing error. For me it was Kubernetes plugin from JetBrains.

Select Help -> Debug Log Settings...

Add the following line (note the leading # symbol)

> #com.intellij.util.indexing:trace

Relaunch the IDE (don't need to invalidate cache as that will cause it to start from scratch, whereas restarting from the point of failure, for me anyway, reported the problem file as soon as I restarted):

> Scheduling indexing of file://C:/dev/tools/ruby/lib/ruby/2.2.0/x64-mingw32/win32ole.so by request of index Stubs

Our project doesn't use win32ole so I moved the file to a safe location and restarted my IDE... Bingo, problem gone, indexing finally completed after almost 1 year of effectively using intellij as a slightly-smarter-than-notepad ruby editor.

In my case I found out that Intellij is actually trying to index a 50GB directory with logs that was under the project's root. Make sure that if you have such a directory, it is marked as "Excluded" in the IDE.

You can see which file the IDE is indexing currently in the Indexing Status window (access by clicking on the indexing message in the toolbar). You may need to enlarge this window to see the full path of the file currently being indexed.

In PhpStorm, what solved this for me was excluding folders I didn't need to be indexed from the indexing (specifically the vendor folder, a caches folder, and a few asset folders that contained thousands of images). Instantly it began making progress and completed.

To do this:

1. in the project directory list, right click the folder you want to exclude
2. Mark Directory As
3. Excluded

seems that there might be several reasons for getting into this "indexing" hell. I spent few hours trying to fix it using the ideas above. At the end of the day, with some profiling work, I found that the bad guy in my case was the csv plugin: https://plugins.jetbrains.com/plugin/10037-csv-plugin

I had few (not so large) CSV files serving as input, and although I marked them as not to be indexed, the plugin kept trying to index them. Once I removed the plugin everything worked fine.

I had a similar problem with 2019.1.4. However, mine would change directories and sometimes, eventually, finish. If it did finish, it was somewhere in the 8-10 minute range.

I was all over SO, and even JetBrains' forums. I excluded directories via Project Structure | Modules. I used Invalidate Caches And Restart on multiple occasions. I tried having only 1 project open to let it finish. I installed and tried 2019.2.4 and 2019.3.3 (the latter would crash for other reasons). And best of all, it only seemed to happen on one project!

What ultimately led me to an answer was Help > Activity Monitor... where I found psi.impl.cache.impl.todo was running at nearly 100% CPU and not showing signs of stopping.

It turned out, I had a TODO filter setup with a poorly-defined RegEx. It was something like \b.*wip\b.*; the idea was to find all of our "WIP" values. Well, the leading .* was a huge mistake and one that didn't occur to me until losing many hours blaming a plugin upgrade. I believe the reason this was a bad filter was because the project it was hanging on is in ExtJS, which is JavaScript, which means things are in triplicate with the app.js file and whatnot...

Update In IntelliJ 2020.x and 2021.x, the option has moved to Help > Diagnostic Tools > Activity Monitor.

Disabling unused plugins will improve the indexing. In my case I have disabled Kotlin plugin from File -> Settings->Plugins

if you check the intellij logs (can be found under C:\Users<User Name>.IntelliJIdea2019.1\system\log ) you will get a pointer what is failing. I was getting an error in Kotlin. After disabling the plugin and restarting Intellij fixed my issue

java.lang.RuntimeException: java.io.EOFException
at com.intellij.util.ExceptionUtilRt.rethrow(ExceptionUtilRt.java:31)
at com.intellij.util.ExceptionUtil.rethrow(ExceptionUtil.java:120)
at com.intellij.openapi.vfs.newvfs.persistent.FSRecords$DbConnection.handleError(FSRecords.java:516)
at com.intellij.openapi.vfs.newvfs.persistent.FSRecords$DbConnection.access$000(FSRecords.java:153)
at com.intellij.openapi.vfs.newvfs.persistent.FSRecords.writeAndHandleErrors(FSRecords.java:965)
at com.intellij.openapi.vfs.newvfs.persistent.FSRecords.access$300(FSRecords.java:47)
at com.intellij.openapi.vfs.newvfs.persistent.FSRecords$AttributeOutputStream.close(FSRecords.java:1629)
at kotlin.io.CloseableKt.closeFinally(Closeable.kt:53)
at org.jetbrains.kotlin.idea.caches.FileAttributeServiceImpl.write(FileAttributeServiceImpl.kt:64)
at org.jetbrains.kotlin.idea.caches.FileAttributeServiceImpl.writeBooleanAttribute(FileAttributeServiceImpl.kt:48)
at org.jetbrains.kotlin.idea.caches.IDEKotlinBinaryClassCache.getKotlinBinaryClass(IDEKotlinBinaryClassCache.kt:67)
at org.jetbrains.kotlin.idea.caches.IDEKotlinBinaryClassCache.getKotlinBinaryClassHeaderData(IDEKotlinBinaryClassCache.kt:8

Had the same issue in the past on some Scala project. I have installed IDEA 16 EAP (https://confluence.jetbrains.com/display/IDEADEV/IDEA+16+EAP) and the problem has gone.

I had the same problem with IntelliJ 2017.3.2. When I clicked on the indexing progress bar I noticed it was hung on a directory within my build directory. When I did a gradlew clean which removed that directory then the indexing was able to proceed.

I have encountered this problem, and resolved it:

1. remove idea
2. delete all files and dirs which name regex 'jetbrain' and 'IntelliJ' in my computer(Mac mini)
3. then install idea

I also try just delete idea cache files, it do not work.

There might be another project opened parallelly in new window which is being indexed.

I was using the Elm plugin and installed the elm-bounded-nats package which included a semi-large source file. IntelliJ kept hanging on this file, but did not always report this correctly in the indexing popover dialog (perhaps due to threading). When I exluded this specific file in Settings -> File Types ("Nats.elm") indexing managed to complete successfully. Now the editor renders errors for this package but the compilation process still works.

I ran into this problem today on a Mac. It would hang before I was able to get to the menu and invalidate the cache.

I deleted the cache from command line using the following command and it worked for me.

rm -rf ~/Library/Caches/JetBrains/IntelliJIdea*

After that it started up with no issues.

Invalidate Cache and Restart did not work for me on IntelliJ 2021.3 Ultimate. I was curious to see if the new Repair IDE feature on 2021.3 Ultimate version works on this issue on my mac.

1. On startup, IntelliJ froze on indexing
   • Force quit and relaunched IntelliJ
2. On Startup, manually "paused" the indexing from the status bar at the bottom
3. Invalidated cache and restarted
   • Still froze on indexing
   • Forced quit and relaunched IntelliJ
4. Repeated Step #2 on startup
5. From File Menu, executed Repair IDE, and went through repair steps
   • FIXED; no longer froze on indexing
6. Quit IntelliJ and Relaunch
   • No Index issues

I was also facing freezing issue with intellij 2021.3. Earlier I was using intellij 2021.1 version and that was working fine but since I upgraded intellij version to 2021.3 it started freezing on indexing of files.

Someone in this thread suggested to repair ide using Repair IDE feature. But that didn't worked for me.

So, I went through the thread dumps available in intellij logs folder. After analyzing logs, I found out that calls are blocking on Package Search plugin. So, I disabled that plugin in settings -> plugin. To do that I had to pause indexing at start for time being. After disabling this plugin, it is working fine for me.

This is a known issue and I know disabling it is not a correct fix for it. But I will use it till intellij will release an official fix for this issue.

It looks like the problem can come from many different sources as other answers point out.

In my case, it was the Subversion plugin that had difficulties to communicate with the server and make the IDE to hang on indexing.

I was able to resolve this problem by removing all of my "target" folders from my project.