问题
I get this error message as I execute my JUnit tests:
java.lang.OutOfMemoryError: GC overhead limit exceeded
I know what an OutOfMemoryError is, but what does GC overhead limit mean? How can I solve this?
回答1:
This message means that for some reason the garbage collector is taking an excessive amount of time (by default 98% of all CPU time of the process) and recovers very little memory in each run (by default 2% of the heap).
This effectively means that your program stops doing any progress and is busy running only the garbage collection at all time.
To prevent your application from soaking up CPU time without getting anything done, the JVM throws this Error so that you have a chance of diagnosing the problem.
The rare cases where I've seen this happen is where some code was creating tons of temporary objects and tons of weakly-referenced objects in an already very memory-constrained environment.
Check out this article for details (specifically this part).
回答2:
The GC throws this exception when too much time is spent in garbage collection for too little return, eg. 98% of CPU time is spent on GC and less than 2% of heap is recovered.
This feature is designed to prevent applications from running for an extended period of time while making little or no progress because the heap is too small.
You can turn this off with the command line option
-XX:-UseGCOverheadLimit
More info here
EDIT: looks like someone can type faster than me :)
回答3:
If you are sure there are no memory leaks in your program, try to:
- Increase the heap size, for example
-Xmx1g. - Enable the concurrent low pause collector
-XX:+UseConcMarkSweepGC. - Reuse existing objects when possible to save some memory.
If necessary, the limit check can be disabled by adding the option -XX:-UseGCOverheadLimit to the command line.
回答4:
It's usually the code. Here's a simple example:
import java.util.*;
public class GarbageCollector {
public static void main(String... args) {
System.out.printf("Testing...%n");
List<Double> list = new ArrayList<Double>();
for (int outer = 0; outer < 10000; outer++) {
// list = new ArrayList<Double>(10000); // BAD
// list = new ArrayList<Double>(); // WORSE
list.clear(); // BETTER
for (int inner = 0; inner < 10000; inner++) {
list.add(Math.random());
}
if (outer % 1000 == 0) {
System.out.printf("Outer loop at %d%n", outer);
}
}
System.out.printf("Done.%n");
}
}
Using java 1.6.0_24-b07 On a Windows7 32 bit.
java -Xloggc:gc.log GarbageCollector
Then look at gc.log
- Triggered 444 times using BAD method
- Triggered 666 times using WORSE method
- Triggered 354 times using BETTER method
Now granted, this is not the best test or the best design but when faced with a situation where you have no choice but implementing such a loop or when dealing with existing code that behaves badly, choosing to reuse objects instead of creating new ones can reduce the number of times the garbage collector gets in the way...
回答5:
Cause for the error
GC overhead limit exceeded" indicates that the garbage collector is running all the time and Java program is making very slow progress.
After a garbage collection, if the Java process is spending more than approximately 98% of its time doing garbage collection and if it is recovering less than 2% of the heap and has been doing so far the last 5 (compile time constant) consecutive garbage collections, then a java.lang.OutOfMemoryError is thrown
- Increase the heap size if current heap is not enough.
- If you still get this error after increasing heap memory, use memory profiling tools like MAT ( Memory analyzer tool), Visual VM etc and fix memory leaks.
- Upgrade JDK version to latest version ( 1.8.x) or at least 1.7.x and use G1GC algorithm. . The throughput goal for the G1 GC is 90 percent application time and 10 percent garbage collection time
Apart from setting heap memory with -
Xms1g -Xmx2g, try-XX:+UseG1GC -XX:G1HeapRegionSize=n -XX:MaxGCPauseMillis=m -XX:ParallelGCThreads=n -XX:ConcGCThreads=n
Have a look at some more related questions regarding G1GC
Java 7 (JDK 7) garbage collection and documentation on G1
Java G1 garbage collection in production
Oracle technetwork article for GC finetuning
回答6:
Just increase the heap size a little by setting this option in
Run → Run Configurations → Arguments → VM arguments
-Xms1024M -Xmx2048M
Xms - for minimum limit
Xmx - for maximum limit
回答7:
For me, the following steps worked:
- Open the
eclipse.inifile Change
-Xms40m -Xmx512mto
-Xms512m -Xmx1024mRestart Eclipse
See here
回答8:
try this
open the build.gradle file
android {
dexOptions {
javaMaxHeapSize = "4g"
}
}
回答9:
The following worked for me. Just add the following snippet:
android {
compileSdkVersion 25
buildToolsVersion '25.0.1'
defaultConfig {
applicationId "yourpackage"
minSdkVersion 10
targetSdkVersion 25
versionCode 1
versionName "1.0"
multiDexEnabled true
}
dexOptions {
javaMaxHeapSize "4g"
}
}
回答10:
increase javaMaxHeapsize in your build.gradle(Module:app) file
dexOptions {
javaMaxHeapSize "1g"
}
to (Add this line in gradle)
dexOptions {
javaMaxHeapSize "4g"
}
回答11:
Rebooting my MacBook fixed this issue for me.
回答12:
You can also increase memory allocation and heap size by adding this to your gradle.properties file:
org.gradle.jvmargs=-Xmx2048M -XX\:MaxHeapSize\=32g
It doesn't have to be 2048M and 32g, make it as big as you want.
回答13:
Java heap size descriptions (xms, xmx, xmn)
-Xms size in bytes
Example : java -Xms32m
Sets the initial size of the Java heap. The default size is 2097152 (2MB). The values must be a multiple of, and greater than, 1024 bytes (1KB). (The -server flag increases the default size to 32M.)
-Xmn size in bytes
Example : java -Xmx2m
Sets the initial Java heap size for the Eden generation. The default value is 640K. (The -server flag increases the default size to 2M.)
-Xmx size in bytes
Example : java -Xmx2048m
Sets the maximum size to which the Java heap can grow. The default size is 64M. (The -server flag increases the default size to 128M.) The maximum heap limit is about 2 GB (2048MB).
Java memory arguments (xms, xmx, xmn) formatting
When setting the Java heap size, you should specify your memory argument using one of the letters “m” or “M” for MB, or “g” or “G” for GB. Your setting won’t work if you specify “MB” or “GB.” Valid arguments look like this:
-Xms64m or -Xms64M -Xmx1g or -Xmx1G Can also use 2048MB to specify 2GB Also, make sure you just use whole numbers when specifying your arguments. Using -Xmx512m is a valid option, but -Xmx0.5g will cause an error.
This reference can be helpful for someone.
回答14:
You need to increase the memory size in Jdeveloper go to setDomainEnv.cmd.
set WLS_HOME=%WL_HOME%\server
set XMS_SUN_64BIT=**256**
set XMS_SUN_32BIT=**256**
set XMX_SUN_64BIT=**3072**
set XMX_SUN_32BIT=**3072**
set XMS_JROCKIT_64BIT=**256**
set XMS_JROCKIT_32BIT=**256**
set XMX_JROCKIT_64BIT=**1024**
set XMX_JROCKIT_32BIT=**1024**
if "%JAVA_VENDOR%"=="Sun" (
set WLS_MEM_ARGS_64BIT=**-Xms256m -Xmx512m**
set WLS_MEM_ARGS_32BIT=**-Xms256m -Xmx512m**
) else (
set WLS_MEM_ARGS_64BIT=**-Xms512m -Xmx512m**
set WLS_MEM_ARGS_32BIT=**-Xms512m -Xmx512m**
)
and
set MEM_PERM_SIZE_64BIT=-XX:PermSize=**256m**
set MEM_PERM_SIZE_32BIT=-XX:PermSize=**256m**
if "%JAVA_USE_64BIT%"=="true" (
set MEM_PERM_SIZE=%MEM_PERM_SIZE_64BIT%
) else (
set MEM_PERM_SIZE=%MEM_PERM_SIZE_32BIT%
)
set MEM_MAX_PERM_SIZE_64BIT=-XX:MaxPermSize=**1024m**
set MEM_MAX_PERM_SIZE_32BIT=-XX:MaxPermSize=**1024m**
回答15:
I'm working in Android Studio and encountered this error when trying to generate a signed APK for release. I was able to build and test a debug APK with no problem, but as soon as I wanted to build a release APK, the build process would run for minutes on end and then finally terminate with the "Error java.lang.OutOfMemoryError: GC overhead limit exceeded". I increased the heap sizes for both the VM and the Android DEX compiler, but the problem persisted. Finally, after many hours and mugs of coffee it turned out that the problem was in my app-level 'build.gradle' file - I had the 'minifyEnabled' parameter for the release build type set to 'false', consequently running Proguard stuffs on code that hasn't been through the code-shrinking' process (see https://developer.android.com/studio/build/shrink-code.html). I changed the 'minifyEnabled' parameter to 'true' and the release build executed like a dream :)
In short, I had to change my app-level 'build.gradle' file from: //...
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
signingConfig signingConfigs.sign_config_release
}
debug {
debuggable true
signingConfig signingConfigs.sign_config_debug
}
}
//...
to
//...
buildTypes {
release {
minifyEnabled true
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
signingConfig signingConfigs.sign_config_release
}
debug {
debuggable true
signingConfig signingConfigs.sign_config_debug
}
}
//...
回答16:
To increase heap size in IntelliJ IDEA follow the following instructions. It worked for me.
For Windows Users,
Go to the location where IDE is installed and search for following.
idea64.exe.vmoptions
Edit the file and add the following.
-Xms512m
-Xmx2024m
-XX:MaxPermSize=700m
-XX:ReservedCodeCacheSize=480m
That is it !!
回答17:
Solved:
Just addorg.gradle.jvmargs=-Xmx1024m
ingradle.properties
and if it does not exist, create it.
回答18:
I don't know if this is still relevant or not, but just want to share what worked for me.
Update kotlin version to latest available. https://blog.jetbrains.com/kotlin/category/releases/
and it's done.
回答19:
In Netbeans, it may be helpful to design a max heap size. Go to Run => Set Project Configuration => Customise. In the Run of its popped up window, go to VM Option, fill in -Xms2048m -Xmx2048m. It could solve heap size problem.
来源：https://stackoverflow.com/questions/1393486/error-java-lang-outofmemoryerror-gc-overhead-limit-exceeded