Does frequent garbage collection affect performance

Hi,
I have written code in a filter for all the servlets in the application.
Depending on the servlet requested I set the objects to null after
it has finished its work.
My question is that since the filter will be executed each time a
servlet is requested,could it result in affecting performance ?

Styna wrote:
I'm writing off my own experience so take my advice with a grain of salt.
The battery is known to 'degrade' when reaching excessive temperatures. Apple recommends keeping the temperature between to 32 degrees Fahrenheit and 95 degrees Fahrenheit.
I used to game heavily on my phone which would get hot. After a year, I noticed that I had to fully charge my phone 3 times a day in order to make it through a day with light usage. Also, I noticed that the phone would die when the battery percentage display would be at all sorts of numbers, 37%, 43%, 7%, and sometimes stay on 1% for 5 minutes while running a processor-intensive game.
After taking my phone to the Apple store for a diagnostic, Apple confirmed issues with the battery. There's no way to know if having my phone stay hot for long periods of time damaged the battery or if I just had a defective battery.
My recommendation is if you know you will be gaming heavily to take the case (if you have one) off your phone and to be in a cool environment to try to keep the phone from getting too hot.
Your battery failed not because of temperature, but you used it up. The battery is spec'd for 400 full charge/discharge cycles. If you fully drain the battery every day that's about 14 months. If you drain it more than once a day that's less time. The phone has a thermal protection circuit that will shut it down if it gets hot enough to damage anything. And actually Lithium batteries do not degrade at higher temperatures. Electric cars and plugin hybrids use the same battery technology (like the Tesla, Chevy Volt, Prius Plugin, Nissan Leaf) and they run much hotter than iPhones. And last 10 years.

Similar Messages

Frequent Garbage Collection Issues

Hi,
I am using Weblogic 8.1 SP6. Recently we have increase in the traffic and as a result I have seen this pattern w.r.t GC.
While using the monitoring tab of the weblogic console I have seen that at a regular interval of about 20 secs there is a forced GC from JVM and causing the app to not respond for about 5-6 secs. We thought that some of the JVM parameters were not set properly and we raised the parameters.
It worked fine, it is started doing every 1 minute instead of 20 secs. Is there any way we can check if any java objects are not removed from JVM heap or if there are some other configurations we need to check about the system?
John

Regarding objects in the Java heap that are not properly being collected, look
at the trouble shooting guide under memory leaks.
http://java.sun.com/javase/6/webnotes/trouble/index.html

Garbage Collection Problem

Hi All,
I am facing some problem with frequent Garbage Collection application running in the background. Issue in production system. Frequently GC is happening, which is affecting the performance. Is there any work around. Issue is affecting the employees and data is inconsistent.
Please help on this asap.
Regards,
Soorya

Hi,
>>>I am facing some problem with frequent Garbage Collection application running in the background.
usually issues with GC are not that simple
also you need to check what kind of GC is happening first then you can start checking why
but my guess would be there is something wrong with the flow and this is causing the GC to work in a wrong way
(if it was working before)
when I did GC checks for my clients it was at least one day of work sometimes to find out what was wrong + repairs later on
Regards,
Michal Krawczyk

How to encourage jvm to garbage collect?

Hello,
I am working with an application that would benefit from more frequent garbage collection. It is running on a hefty machine, with multiple processors and more than 4 gigs of memory available for the JVM. Right now, we are setting the max heap size to 3 gigs.
The problem is that objects are accumulating, but are not being collected. During a particular operation that I am profiling, over 1 gig of objects are created, but are never collected. If I do a manual garbage collect (using jprofiler), they are all collected. There is no good way to load these objects in another way, or to create fewer objects.
I have spent a few days playing with -XX:MaxNewSize, -XX:NewSize, -XX:MaxHeapFreeRatio, -XX:TargetSurvivorRatio, and even -XX:+UseParNewGC. Unfortunately, I am unable to encourage the JVM to collect these objects automatically.
Are there any tricks that I am missing? Does anyone know any good way to encourage the JVM to collect garbage after a certain threshhold in the new generation?
Thanks,
--Jeff

You can try this!
How do I set the JVM's heap size?
On machines with limited memory (less than 384MB), it is recommended that you set the initial heap size lower than the default. Open the configuration file etc/netbeans.confin a text editor and modify the options in netbeans_default_optionssetting. Decrease the option -J-Xmx128mto -J-Xmx96m and the option -J-XX:MaxPermSize=96mto -J-XX:MaxPermSize=64m. Save the file and restart the IDE.
Bear in mind that UI responsiveness may be affected when the heap utilization gets close to its limit. Should you encounter an OutOfMemoryError, you need to increase Xmx or XX:MaxPermSize back to the default, or even higher.
Similarly when running on a machine with more memory it might be useful to increase the maximum size of the heap, especially when working with larger projects. Use the page linked below to get more details on this topic.
Applies to: NetBeans 4.x, 5.0
Platforms: All

All Tweens randomly halting (Not Garbage Collection)

I am developing a game with some AS3 tweens. I have encountered the problem of garbage collection affecting tweens before so I have all my tweens referenced at the class level now to ensure that isn't a problem. However, randomly all the current tweens in my game will stop. Other, non-tweened, frame by frame animations continue. It's just like the garbage collection problem but the tweens shouldn't be being collected...
The code I am using for tweens:
Var declaration at the top of the class:
private var gateTween:Tween;
This code in a function:
gateTween = new Tween(currentGate, "x", None.easeOut, 800, 380, 1.5, true);
gateTween.addEventListener(TweenEvent.MOTION_FINISH, horseJump);
Any ideas would be appriciated.

I have Swing based java project. Im setting all the
references to null as and when i dont need them, and
then im calling System.gc() also.
However it seems the memory is not being released,
when i check in the task manager, memory usage does
not reduce. It seems garbage collection is not
happening.Actually I have a small class - where in I try to do this:-
public class TestDebug extends Object{
/** Creates a new instance of TestDebug */
public TestDebug() {
* @param args the command line arguments
public static void main(String[] args) {
System.out.println("Trying to debug this");
TestDebug testDebug = new TestDebug();
testDebug.finalize();
System.out.println("Lasting print");
public void finalize(){
System.out.println("Finalize called");
System.gc();
System.out.println("Finalize finished");
But it is also true that you should never try to force it - It has its own way to do it.
For Example try to execute a big code(so that you can find JVM doing the GC) as "java -verbose:gc class-name"
You will find at some points during the execution process - that the JVM actually runs the GC on its own- but when not that is not defined.It is a low priority thread running under JVM.

Garbage Collection Advice

We currently have a garbage collection related performance issue that I could do with some advice on.
We use Jakarta Tomcat with an application that has approximately 1300 jsp's. When a new set of jsp's are rolled out we see a degradation in performance. Using jvmstat I've ascertained that this performance degradation is due to excessive garbage collection partulcarly in the young generation where it appears to be almost constantly collecting. What advice would you give?
ie More young generation space? fewer survivor cycles? bigger eden or survivor space?
Any suggestions would be much appreciated.

Hi
See
http://java.sun.com/docs/hotspot/gc1.4.2/
http://java.sun.com/docs/hotspot/gc1.4.2/example.html
The steps should be, as in example.html
1. Determine the size u would allocate.
2. Then try the alternate collectors.
1300 jsps, do take note of MaxPermSize too.
Hope this helps.

Tracing Garbage Collection

I need to implement a program illustrating the performance loss to java through the automated garbage collection Vs controlling the garbage collection manually using java real time programming.
How can I determine when garbage collection is performed by the virtual machine? For instance could I launch a thread to monitor the garbage collection and return feedback when collection is in progress?
Thanks

I have been using this method on my object to write to a file.
protected void finalize() throws RemoteException {
try{
Date now = new Date();
String s = "Garbage Collection was here\n Date: "+now + " Object: " + this.getName()+"\n";
byte abyte0[] = s.getBytes();
FileOutputStream fileoutputstream = new FileOutputStream("garbageplanner.txt", true);
fileoutputstream.write(abyte0);
fileoutputstream.close();
}catch (Exception e){}
}

BULK COLLECT LIMIT affects performance in any way?

Hi,
I want to know whether BULK COLLECT LIMIT affects performance in any way?
How does one decide what limit to keep?
is there a oracle recommendation on the same?

I agree with Bonist that you should read Tom's article but I am going to disagree, to a minor extent, with Tom's comment about 100 rows.
When developing with BULK COLLECT I always add a parameter to stored procedures that is used to tune the limit clause Then when the code goes to unit testing, and at the beginning of integrated unit testing, the value is varied and the results graphed. For final testing the parameter is dropped. The number I hard code for production is the value at the left side of the top of the bell curve.
What I find is that 100 is sometimes the right number butI have one app I developed recently where 50,000 was the right number (11gR1). As with almost everything Oracle the best answer is always that "it depends." In the case where 50K is the best solution the server has 32G of RAM, and everything processed is an SMS message averaging only 79 bytes.

Does daisy-chaining a Belkin Mac-compatible hub affect performance?

I've had a 7-port Belkin hub plugged into my 13" Macbook and before that a 15" Powerbook for several years and have been pretty satisfied with it. I'd like to get a new one and connect it to the original (or vice-versa). Does anyone know if doing that would affect performance of any kind? (Upload times, wireless mouse interference, etc.?) Belkin doesn't seem to have anyone who knows much--the rep I talked to didn't even know Belkin made a hub that works with Mac.
Thanks for any information anyone has.

That makes sense. My old hub is 2.0, so it should work with the new one I want, which is also 2.0.
I don't know how much power I might ever be using at one time. have a wired keyboard and wireless or USB mice, and at times I probably download something into my printer buffer while at the same time backing up to an external hard drive or flash stick. But I don't think I'd ever be doing more than that, and the present 7-port hub seems to have no problem handling jobs requiring 4 ports at once.
I really just wanted the second hub because the present one is at the back of the desk behind the dictionary (cord is too short to reach the front!), and I'm tired of trying to insert devices into the USB ports without knocking the dictionary off its stand. I figured that plugging a second 7-port hub into the first one would allow me to have a hub at the front of the desk and give me a few extra ports as a bonus. If you have a better idea, I'd be happy to hear it! Meanwhile, thanks so much for the information, and the fast response.

Performance problem due to garbage collection?

Hallo,
we implemented a digital whiteboard with JavaFX: there is a scene (3200 x 2400 px) on which you can draw (insert paths) and add post-its (colored rectangles with paths or string a content). It's possible to drag the post-its around and it's also possible to pan the scene (to reach all parts of the scene which don't fit into the windows).
The application works quite fast even with ca. 50 post-its and lots of skribbles/drawings. But after ca. 20 minutes the application gets a lot slower. Drawing curves (or handwriting) is not really possible anymore as the paths get angular and moving a post-it takes longer and longer.
How is this possible? Is there a problem with the JavaFX garbage collection? Does anyone else have the problem that the application gets slower after a while?
When I close the window and load it again with the same elements it's as quick as in the beginning and slows down after ca. 20 min. again.
Thanks for your help and suggestions what could be the problem!
Raja

I can't really answer...
We can eliminate saturation of scenegraph capabilities since you can reload it again without problem (at start).
Maybe you create lot of temp objects that aren't properly collected?
I suggest to run JVisualVM on your application and watch its memory (and CPU) usage.

Does connection speeds affect performance in Adobe PDF Pack?

Does anyone know if the performance of the Adobe PDF Pack is significantly affected by the local connection speed?

Yes, it is the most important thing,because all files are sent to Adobe for conversion.

Does 5.1 log garbage collection like 4.5.2?

The weblogic 4.5.2 release notes state that the server will log whenever it
garbage collects, see below. Does 5.1 do this?
"We changed the distributed garbage collection server to always indicate
that it is running by adding entries to the Server log file. A typical entry
is:
Thu Aug 19 19:44:28 PDT 1999:<I> <DGCserver>
Freed 1086 objects in 30 ms, 24 exported object remain."

It should. There is a slight possibility that it might not appear as a
feature until service pack No. 4 if the change to version 4.5.2 was not done
until after service pack three was completed.
If you do not see it in service pack No. 4, please report to support.
Thanks,
Michael
Michael Girdley
Product Manager, WebLogic Server & Express
BEA Systems Inc
Mark Johnson <[email protected]> wrote in message
news:396bbb8f$[email protected]..
The weblogic 4.5.2 release notes state that the server will log wheneverit
garbage collects, see below. Does 5.1 do this?
"We changed the distributed garbage collection server to always indicate
that it is running by adding entries to the Server log file. A typicalentry
is:
Thu Aug 19 19:44:28 PDT 1999:<I> <DGCserver>
Freed 1086 objects in 30 ms, 24 exported object remain."

Does DBMS.JOB affect Performance

Dear experts
Please tell me Does DBMS.JOB affect Performance.

Can you detail what performance you are talking about.
DBMS_JOB is simply a scheduler, whcih you can use for your repeated uattended job initiation.which is nt going to impact the performance.
Probably the actual Job if intensive can hit your performance.

When does garbage collection occur?

Answer the question!
thanks

Sometime after a objects become unreachable and before the memory allocator runs out of memory, the garbage collector will run. You have no way of controlling or knowing when that will be. There is no reason to.
For some reason, even though many programming languages have garbage collection, people seem to regard Java's garbage collection as something they need to "understand" and control. Garbage collection is best left up to the garbage collector -- that's its job, and just let it work.

Disabling RMI Explicit Garbage Collection

I have an application that uses RMI. From different articles on the javasoft web site, I have read that RMI explicitly does a Full RMI every minute (default setting). This is undesirable, b/c these full GCs are causing some objects I need to use later to be garbage collected. From the site, the options are to:
1) Disable Full GC
2) Delay Full GC
For point 1), what are the consequences of disabling explicit full GCing that RMI does? Documentation on the javasoft website only says that "this may also cause some objects to take much longer to be reclaimed" etc. To me, I would think that disabling the explicit Full GC is a bad idea for RMI applications (unless they are really short lived, but that is not my case). It would seem safer to go with 2) option to delay the Full GCs since it's not entirely clear what the consequences are of completey disabling explicit GCs, but this still causes objects I still need to use later to be garbage collected. The last option which I feel is not very elegant, would be to just set something to reference or use that object that is being gc'ed so when a Full GC is performed it doesn't get cleaned up. Does anyone have any experience with this or have any better suggestions?
I am using Java 1.4.2 currently, but am also interested in learning what would be good for Java 1.2.X and 1.3.X as well.
Thanks!
These are the links that I have already visited or docs that I have already read on this topic:
1) Java 2 Platform, Standard Edition v 1.4 Performance and Scalability Guide
http://java.sun.com/j2se/1.4/performance.guide.html
2) Frequently Asked Questions about Garbage Collection in the HotspotTM JavaTM Virtual Machine
http://java.sun.com/docs/hotspot/gc1.4.2/faq.html
3) Improving Java Application Performance and Scalability by Reducing Garbage Collection Times and Sizing Memory Using JDK 1.4.1
http://developers.sun.com/techtopics/mobility/midp/articles/garbagecollection2/#11.1.3.15
4) Garbage Collection for Remote Objects (1.4.2)
http://java.sun.com/j2se/1.4.2/docs/guide/rmi/spec/rmi-arch4.html

Towards the end of my pot I wrote:
The last option which I feel is not very elegant, would be to just set something to reference or use that object that is being gc'ed so when a Full GC is performed it doesn't get cleaned up. Does anyone have any experience with this or have any better suggestions?
I realize that I can reference these objects, but I don't think that is really a great solution. This would mean deliberately referencing them (a hack at a solution in my view) when really it's the explicity GC running every minute (b/c of RMI) that is collecting them. If I turn the explicit GC off, my objects are not collected like this.
My question was really does anyone have any better ideas or experience with RMI's explicit garbage collecting? I don't need to read a tutorial to tell me how to keep my objects alive by referencing them. Thanks.

Does frequent garbage collection affect performance

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