disk i/o going crazy with latest EAP


I am getting an identical problem with IDEA IU-90.122 from 90.137 on Fedora Core 10 on a dual-core machine with 4GB of ramand getting erattic i/o to disk. All seems fine and then when I do certain actions like compiling, or some other action that causes IDEA to access the disk it carries on accessing the disk for dozens of minutes after! I often stop and restart because this causes IDEA to become almost unusable.

Observations and Notes:
- playing with Xms/Xmx has no effect
- CPU load is very low during this time(total load on both CPUs is between 5-20%)
- I see no background process reported by the UI (indexing, compiling, etc)
- I see thread dumps being created in the system/log directory whose timestamp seem to coincide with the high I/O activity)
- I have removed -ea and the ypagent JVM param
- When the behaviour kicks in it does so for 5-10 minutes


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I am using Maia 90.137 with Ubuntu 09.04 64 bit with JDK 6 update 18ea.  I haven't seen the problem you're describing, although it may make a difference that we use ant scripts to build and deploy our application.

A number of people have run into filedescriptor limit under Linux, causing all kinds of wierd behavior.  It might be worth bumping that up to see if it fixes your problem. See below for details.
Otherwise, the threaddumps in system/log you mentioned might shed further light on the problem.


You can use following command find out number of open file descriptors used by idea (assumes idea is only running java process):
ls -l /proc/`pidof java`/fd | wc -l

If it is close to 1024, then you have a problem. On my system, with a new project containing no files, IDEA already uses 882 file descriptors! Alot of the open files seem related to the plugins. I disabled alot of plugins tha tI don't use, so it could be the total is even higher.  From the number of people that have run into this problem, I suspect the minimum number of file descripters used by IDEA has gone up from last release.

By default, the limit is 1024 (ulimit -n to check) which is kind of low if you are running server applications.

You can try setting "ulimit -n 5000" before launching IDEA to see if it helps.

You can edit  /etc/security/limits.conf and put new permanent defaults (restart required)

*               hard nofile     5000
*               soft nofile     5000

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Thanks.... I think that the file descriptor pointer was the right one. I have one module with 80' 000+  of config files that seemed to cause the problem. I had excluded more than 95% of them in the module definition but it seems that IntelliJ still somehow considered them and cycled through them every so often. So I have not increased the number filedescriptors, instead I have made sure to only add the bits of the whole configuration repository I need.



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