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Tutorial Addendum on JVM - Anamnesis Administration

 Output on JRockit JVM with -Xms2m -Xmx64m Having 0 MB and abacus 10 MB... Chargeless memory: 8717040Total memory: 19419136Having 10 MB and abacus 10 MB... Chargeless memory: 8698800Total memory: 29904896Having 20 MB and abacus 10 MB... Chargeless memory: 7607344Total memory: 39297024Having 30 MB and abacus 10 MB... Chargeless memory: 6951960Total memory: 49127424Having 40 MB and abacus 10 MB... Chargeless memory: 6558720Total memory: 59219968Having 50 MB and abacus 10 MB...java.lang.OutOfMemoryErrorNote that My 10MB arrangement is hardly added than 10MB because of the arrangement overhead. I aswell activated with JRockit with -Xmx512m, it got 200MB afore runningout of memory. My arrangement has: 128MB concrete memory, and 288MB paging filesize.Garbage CollectionI wrote the afterward program to watch how the debris accumulating processworks: /** * GarbageCollection.java * Absorb (c) 2002 by Dr. Yang */class GarbageCollection { accessible changeless abandoned main(String a) { int max = 1... Read More by user

Tutorial Addendum on JVM - Anamnesis Administration

 OverviewGenerally, a JVM is using the afterward rules to administer memory: When a JVM is invoked to run an application, it will ask the operating arrangement for abundant anamnesis to run the JVM itself and some chargeless anamnesis for the applicationto make new objects. When a new item is created, the JVM will admeasure anamnesis for that item outof the chargeless anamnesis area.When the chargeless anamnesis breadth is accepting too small, the JVM will ask the operatingsystem for more.When a item is no best acclimated by the application, it will be destroyed. Itsmemory will be freed up and alloyed aback to the chargeless anamnesis area.When the chargeless anamnesis breadth is acclimated up, and there is no added added memoryavailable from the operating system, the JVM will stop the appliance and issuethe "Out of anamnesis error".Out of Anamnesis ErrorI wrote the afterward program to try to advance JVM for added anamnesis in a loop: /** * MemoryCrash.java * Absorb (c) 2002 by Dr. Yan... Read More by user

Tutorial Addendum on JVM - JRockit JVM 7.0

 Let s use the afterward simple program to see how the Administration Animate works: /** * LongWhile.java * Absorb (c) 2002 by Dr. Yang */class LongWhile { accessible changeless abandoned main(String[] a) { Runtime rt = Runtime.getRuntime(); System.out.println(" Chargeless memory: " + rt.freeMemory()); System.out.println("Total memory: " + rt.totalMemory()); while (true); }}Compile this program with J2SDK 1.4.0_02 and run it in JRockit JVM withthe Administration Animate server basic angry on: progra~1jrockit7.01.4.0injava -cp . "-Djrockit.managementserver=true" LongWhile[JRockit] Administration Server started on anchorage 7090. Chargeless memory: 62665048Total memory: 73363465Now my sample appliance is active in JRockit JVM with the Administration Console server angry on accessible to consign advice on anchorage 7090.Use the afterward command to run the JRockit Administration Animate clientcomponent: cd progra~1jrockit7.01.4.0console..injava -jar ManagementConsole.jarUnfortunately, th... Read More by user

Tutorial Addendum on JVM - JRockit JVM 8.0

 Test 6: Active LongSleep with HotSpotFor allegory purposes, I launched LongSleep with HotSpot JVM: localj2sdk1.4.1_01injava LongSleep Chargeless memory: 1781480Total memory: 2031616On the Windows Assignment Manager: Before active LongWhile: Achievement tab: CPU: 1%, MEM: 133052KOnce LongSleep started: Achievement tab: CPU: 1%, MEM: 141424K Processes tab - java: CPU: 0%, MEM: 4716K10 account later: about the same.Results looked ok.Test 7: Active LongSleep with JRockit additional ManagementNow, aback to JRockit, but with Administration advantage angry on this time: localeajrockit80_141_32injava -Xmanagement LongSleep[JRockit] Administration Server started on anchorage 7090. Chargeless memory: 66912936Total memory: 77594624On the Windows Assignment Manager: Before active LongWhile: Achievement tab: CPU: 1%, MEM: 132032KOnce LongWhile started: Achievement tab: CPU: 1%, MEM: 233220K Processes tab - java: CPU: 0%, MEM: 12852K10 account later: about the same. Results looked ok too.Test 8: ... Read More by user

Tutorial Addendum on JVM - JRockit JVM 8.0

 Test 3: Active LongWhile with JRockit additional ManagementIn this test, I capital to seewhat s the appulse of active JRockit with the Administration advantage angry on: localeajrockit80_141_32injava -Xmanagement LongWhile[JRockit] Administration Server started on anchorage 7090. Chargeless memory: 66912936Total memory: 77594624On the Windows Assignment Manager: Before active LongWhile: Achievement tab: CPU: 1%, MEM: 132032KOnce LongWhile started: Achievement tab: CPU: 100%, MEM: 231876K Processes tab - java: CPU: 99%, MEM: 12582K10 account later: about the same. The Administration advantage alone added the anamnesis acceptance by about 2MB, comparing to Analysis 1.Test 4: Active LongWhile and JRockit Administration Animate ClientIn this test, I capital to echo the aforementioned analysis I did with JRockit 7.0, see my addendum on JRockit7.0. In that test, I empiric that the Administration Animate Applicant comatose anon on my laptopwith 128MB RAM. It aswell comatose on my desktop wi... Read More by user

Tutorial Addendum on JVM - JRockit JVM 8.0

 Installing JRockit JVM 8.0One of the JRockit developers saw my addendum on JRockit 7.0 on the Web, and appropriate me to try JRockit 8.0. So I downloaded the appraisal adaptation of JRockit 8.0, anddid a brace of quick tests.To try JRockit 8.0, I went to http://commerce.bea.com/showallversions.jsp?family=WLJR.Then using my registered name and password, I got the download page. There, I called WebLogic JRockit 8.0 SDK, then Microsoft Windows (32 bit). At the end of download process, I gotjrockit-8.0-j2se1.4.1-win32.exe (35,864KB).The accession action was beeline advanced by bifold beat on the downloaded file. At the end, JRockit was installed atlocaleaJRockit80_141_32. To analysis the installation, I did the afterward in a command window: localeaJRockit80_141_32injava -versionjava adaptation "1.4.1_01"Java(TM) 2 Runtime Environment, Accepted Copy (build 1.4.1_01)BEA WebLogic JRockit(R) Basic Apparatus (build 8.0-1.4.1_01-win32-CROSIS-20030124-1058, Built-in Threads, Generational Circ... Read More by user
Tags: started, windows, minutes, performance, memory, notes, manager, later

Tutorial Addendum on JVM - JRockit JVM 7.0

 OverviewJRockit JVM is developed by BEA Systems, and declared by them as:BEA WebLogic JRockit is the alone aboveboard top achievement Java Basic Machine (JVM) developed abnormally for server-side applications and optimized for Intel architectures advised to ensure reliability, scalability, manageability, and adaptability for Java applications. A acute basic of the BEA WebLogic Action Platform, WebLogic JRockit delivers a new level of achievement for Java applications deployed on any affectionate of accouterments architecture at decidedly lower costs to the enterprise. With JRockit, customers will be able to accomplish top ROI at all levels of the basement stack. It is the alone enterprise-class JVM alms that is optimized for Intel Architecture, accouterment seamless interoperability beyond assorted hardware and operating arrangement configurations.One actual absorbing affection of JRockit is the Administration Animate which connects to the active JVM, and provides real-time advice abou... Read More by user

Tutorial Addendum on JVM - Debris Accumulating

 I aswell approved to ability 7.5 MB, but failed: java -Xms2m -Xmx8m GCTest 16 44 > tail_16_44.out Time Absolute Chargeless Chargeless Absolute Act. Asleep Oversec. Mem. Mem. Per. Obj. Obj. Obj. Head 0 1984 1815 91% 0 0 0 169 0 1984 1682 84% 128 128 0 174 1 1984 1552 78% 256 256 0 176.... 20 5484 390 7% 4992 4992 0 102 20 5484 260 4% 5120 5120 0 104 21 8128 2780 34% 5248 5248 0 100 21 8128 2652 32% 5376 5376 0 100.... 51 8128 272 3% 7680 2432 5248 176 51 8128 270 3% 7680 2304 5376 178 52 8128 268 3% 7680 2176 5504 180 52 8128 266 3% 7680 2048 5632 182 53 8128 136 1% 7808 2176 5632 184Exception in cilia "main" java.lang.OutOfMemoryErrorIt is actual absorbing to see that the JVM died out of memory, but therewas 5632KB anamnesis as garbage. Why did the JVM not collectthe garbages at that time?Comparing with JDK 1.4.0, JDK 1.3.1 did a acceptable job in accession garbages.JDK 1.3.1 allowedGCTest to use upto 88% of the absolute memory, while JDK 1.4.0 comatose if GCTesttring to get 63% of the... Read More by user
Tags: client, memory, collection

Tutorial Addendum on JVM - Debris Accumulating

 Comparing with the aforementioned analysis with JDK 1.4.0, JDK 1.3.1 added the totalmemory in abate amounts. Additional than this the achievement sames to be identical.Outputs tail_16_08 and tail_16_16 were aswell actual agnate to JDK 1.3.1.However, tail_16_24 had a abruptness for me. The program ran to the end withoutany anamnesis problem: Time Absolute Chargeless Chargeless Absolute Act. Asleep Oversec. Mem. Mem. Per. Obj. Obj. Obj. Head 0 1984 1815 91% 0 0 0 169 1 1984 1682 84% 128 128 0 174 1 1984 1552 78% 256 256 0 176.... 31 5484 220 4% 5120 2304 2816 144 32 5484 218 3% 5120 2176 2944 146 32 5484 216 3% 5120 2048 3072 148 33 8128 2780 34% 2176 2176 0 3172 33 8128 2780 34% 2304 2176 128 3044 34 8128 2651 32% 2304 2304 0 3173 34 8128 2521 31% 2432 2432 0 3175.... 41 8128 856 10% 4096 4096 0 3176 42 8128 731 8% 4224 4224 0 3173 42 8128 601 7% 4352 4352 0 3175 43 8128 472 5% 4480 4480 0 3176 43 8128 3421 42% 4608 4608 0 99 44 8128 3291 40% 4736 4736 0 101 44 8128 3161 38% 4864 4864 0... Read More by user

Tutorial Addendum on JVM - Debris Accumulating

 Obviously, we had a problem here. My program comatose at additional 42 with the "out of memory" exception.At that time, the chargeless anamnesis decreased to 2%. But there were 3072KB of dead altar that could be calm to accretion added chargeless memory. Why the JVM did not aggregate the asleep objects? Can anyone advice to explain?I accept the the acknowledgment is accompanying my estimated aphorism that the JVM will reservethe aforementioned bulk of anamnesis as the calm garbages.At additional 42 in our test, 8128 (total memory) - 4608 (active objects) - 3072 (reserved memory) = 448 (free memory), not abundant to plan with.Comparison - Absolution Old vs. New ObjectsIn the antecedent tests, altar were appear from the appendage of the list. So old altar were appear first. To see if there are any differences between absolution old altar and new objects, I afflicted the cipher to usethe objList.removedHead() method. 4 tests were conducted to analyze withthe antecedent tests: java -Xms2m ... Read More by user
Tags: tests, memory, collection, second, conducted

Tutorial Addendum on JVM - Debris Accumulating

 I got the afterward output: Time Absolute Chargeless Chargeless Absolute Act. Asleep Oversec. Mem. Mem. Per. Obj. Obj. Obj. Head 0 1984 1727 87% 0 0 0 257 0 1984 1593 80% 128 128 0 263 1 1984 1464 73% 256 256 0 264 1 1984 1334 67% 384 384 0 266 2 1984 1204 60% 512 512 0 268 2 1984 1074 54% 640 640 0 270 .... 15 5256 1265 24% 3840 3840 0 151 16 5256 1135 21% 3968 3968 0 153 16 5256 1005 19% 4096 4096 0 155 17 5256 1003 19% 4096 3968 128 157 17 5256 1002 19% 4096 3840 256 158 .... 26 5256 588 11% 4480 2432 2048 188 26 5256 459 8% 4608 2560 2048 189 27 5256 329 6% 4736 2688 2048 191 27 5256 199 3% 4864 2816 2048 193 28 8128 2998 36% 2944 2944 0 2186 28 8128 2868 35% 3072 3072 0 2188 29 8128 2738 33% 3200 3200 0 2190 29 8128 2608 32% 3328 3328 0 2192.... 45 8128 634 7% 5248 3200 2048 2246 45 8128 504 6% 5376 3328 2048 2248 46 8128 375 4% 5504 3456 2048 2249 46 8128 245 3% 5632 3584 2048 2251 47 8128 2230 27% 3712 3712 0 2186 47 8128 2100 25% 3840 3840 0 2188 48 8128 1970 24% 3968 3968 0 21... Read More by user

Tutorial Addendum on JVM - Debris Accumulating

 GCTest Program Achievement - Journal Anamnesis RequirementIn this test, I ran the aforementioned program un J2SDK 1.4.0_02 with a altered parameter: java -Xms2m -Xmx8m GCTest 16 8 > tail_16_08.outI got the afterward output: Time Absolute Chargeless Chargeless Absolute Act. Asleep Oversec. Mem. Mem. Per. Obj. Obj. Obj. Head 0 1984 1727 87% 0 0 0 257 0 1984 1593 80% 128 128 0 263 1 1984 1464 73% 256 256 0 264 1 1984 1334 67% 384 384 0 266 .... 5 1984 425 21% 1280 1280 0 279 5 1984 296 14% 1408 1408 0 280 6 3124 1451 46% 1536 1408 128 137 6 3124 1450 46% 1536 1536 0 138 .... 10 3124 412 13% 2560 2560 0 152 11 3124 282 9% 2688 2688 0 154 11 5256 2303 43% 2816 2816 0 137 12 5256 2173 41% 2944 2944 0 139 12 5256 2043 38% 3072 3072 0 141 .... 27 5256 329 6% 4736 2688 2048 191 27 5256 199 3% 4864 2816 2048 193 28 8128 2998 36% 2944 2944 0 2186 28 8128 2868 35% 3072 3072 0 2188 29 8128 2866 35% 3072 2944 128 2190 29 8128 2864 35% 3072 2816 256 2192 30 8128 2863 35% 3072 2688 384 2193 30 8128 28... Read More by user

Tutorial Addendum on JVM - Debris Accumulating

 .... 142 8128 358 4% 5120 2176 2944 2650 143 8128 356 4% 5120 2048 3072 2652 143 8128 226 2% 5248 2176 3072 2654 144 8128 224 2% 5248 2048 3200 2656 144 8128 2614 32% 2176 2176 0 3338 145 8128 2612 32% 2176 2048 128 3340 145 8128 2482 30% 2304 2176 128 3342 146 8128 2481 30% 2304 2048 256 3343 146 8128 2351 28% 2432 2176 256 3345 147 8128 2349 28% 2432 2048 384 3347.... 161 8128 378 4% 4352 2176 2176 3398 162 8128 376 4% 4352 2048 2304 3400 162 8128 247 3% 4480 2176 2304 3401 163 8128 245 3% 4480 2048 2432 3403 163 8128 3382 41% 2176 2176 0 2570 164 8128 3380 41% 2176 2048 128 2572 164 8128 3251 39% 2304 2176 128 2573 165 8128 3249 39% 2304 2048 256 2575 165 8128 3119 38% 2432 2176 256 2577 166 8128 3117 38% 2432 2048 384 2579.... 186 8128 358 4% 5120 2176 2944 2650 187 8128 356 4% 5120 2048 3072 2652 187 8128 226 2% 5248 2176 3072 2654 188 8128 224 2% 5248 2048 3200 2656 188 8128 2614 32% 2176 2176 0 3338 189 8128 2612 32% 2176 2048 128 3340 189 8128 2482 30% 2304 2176 128 3342 190 81... Read More by user

Tutorial Addendum on JVM - Debris Accumulating

 Note that An close chic MyObject is acclimated to represent a all-encompassing object. It has a anchored admeasurement of 128KB additional some overhead.Another close chic MyList is acclimated to as a administrator to registerand absolution objects. It uses a affiliated account data anatomy to do the job.A third close chic Adviser is acclimated to sample anamnesis acceptance and objectcounts data.The capital test, myTest(), is disconnected two sections: the initialization section, area a amount of altar are added to the list; the bend section, where altar are added to the list, then removed from the list. Two paramters are supported. The first one, initSteps, is acclimated to control how some altar we wish to put into the account initially. The secondone, testSteps, is acclimated to ascendancy the amount altar to be added to the listbefore removing the aforementioned amount of altar from the list. Two types of data are calm by the program: anamnesis acceptance data, includingtotal memo... Read More by user
Tags: added, program, class, collection, object

Tutorial Addendum on JVM - Debris Accumulating

 GCTest ProgramWe all understand that altar that are not referenced will be removed from anamnesis by the garbage collector. But we don t understand how this action works exactly. I wrote thefollowing program to try to amount this out. /** * GCTest.java * Testing debris accumulating behavior. * Appropriate JVM options: -Xms2m -Xmx8m * Absorb (c) 2003 by Dr. Yang */import java.util.*;class GCTest { changeless MyList objList = null; changeless int delay = 500; // milliseconds changeless int initSteps = 16; // 2 MB changeless int testSteps = 1; changeless int objSize = 128; // 1/8 MB accessible changeless abandoned main(String[] arg) { if (arg.length>0) initSteps = Integer.parseInt(arg[0]); if (arg.length>1) testSteps = Integer.parseInt(arg[1]); objList = new MyList(); Adviser m = new Monitor(); m.setDaemon(true); m.start(); myTest(); } accessible changeless abandoned myTest() { for (int m=0; m<initSteps; m++) { mySleep(wait); objList.add(new MyObject()); } for (int n=0; n<10*8*8/te... Read More by user

Tutorial Addendum on JVM - Chic Data Administration

 Here is how I did my tests: j2sdk1.4.2injavac Hello.javaperl StartupTimeTest.pl jdk142Hello world!Hello world!...Command: j2sdk1.4.2injava -cp . HelloTotal time: 24 seconds.Average time: 0.24 seconds.j2sdk1.5.0injavac Hello.javaperl StartupTimeTest.pl jdk150_offHello world!Hello world!...Command: j2sdk1.5.0injava -cp . -Xshare:off HelloTotal time: 31 seconds.Average time: 0.31 seconds.perl StartupTimeTest.pl jdk150_onHello world!Hello world!...Command: j2sdk1.5.0injava -cp . -Xshare:on HelloTotal time: 18 seconds.Average time: 0.18 seconds.The analysis aftereffect is actual interest:With JDK 1.5.0, CDS absolutely bargain the startup time of active Hello.java from 0.31 abnormal to 0.18 seconds.However, the startup time of active Hello.java added from 0.24 secondsto 0.31 abnormal amid JDK 1.4.2 and JDK 1.5.0. Test 2 - Startup Time Extenuative with Assorted JVM ProcessesBased on the CDS affection document, some data will be aggregate by assorted JVM processes. To verify this, I am pl... Read More by user
Tags: world, windows, class, shows, average, memory, command, startup, manager, seconds

Tutorial Addendum on JVM - Chic Data Administration

 This affiliate explains:What is chic data administration (CDS).How to change the aggregate annal file.Startup time bigger by CDS.Footprint afflicted by CDS.What Is Chic Data SharingClass Data Administration (CDS) is a new affection alien in JDK 1.5.0. CDS is advised to abate the startup time and brand of Java applications.The basal abstraction of CDS is to:Select a set of arrangement classes that are frequently acclimated by Java applications.Load the called classes into memory.Dump the loaded classes to a book alleged a "shared archive".When a consecutive Java appliance is launched, JVM will restore the aggregate annal book into memory.When assorted Java applications are launched on the machine, a allocation of the aggregate annal will be aggregate by assorted JVM processes.The startup time is bargain because of abating aggregate annal is abundant fasterthan loading classes.The brand is bargain because of some data is aggregate by assorted JVM processes."java" command options accompan... Read More by user

 

 

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