JJUG JavaOne 2012 San Francisco 報告会 LT(G1GC)

JJUG JavaOne 2012 San Francisco 報告会

(LT) G1GC チューニングと G1GC Visualizer

～ CON6583 – G1 Garbage Collector Performance Tuning より～

2012/11/9

木村英一(@kimuchi583)

© 2012 EIICHI KIMURA All Rights Reserved. 1 2012/11/9

木村英一って、誰 ? 武蔵小杉駅横須賀線口の前に立つビルで Java案件支援, チューニング諸々に対応してます。

Twitter : @kimuchi583

URL : http://kimuchi583.at.webry.info/

http://blog.kimu2.jp/

本セッションの内容は、

http://www.myexpospace.com/JavaOne2012/SessionFiles/CON6583_PDF_6583_0001.pdf


http://kimuchi583.at.webry.info/





オプションは、これだけ !!

‐Xms6g ‐Xmx6g

‐XX:+UseG1GC ‐XX:MaxGCPauseMillis=200


これらのオプションはダメ !!

‐Xmn ‐XX:MaxNewSize

‐XX:NewSize

‐XX:NewRatio ‐XX:SurvivorRatio

Young 領域は目標達成のために自動的に調整される (ヒープ全体の20%～80%の範囲で)


Young 領域サイズを指定をすると …

Young 領域のサイズを自動調整しない

一時停止時間の目標設定は無視する

私のほうが Java VM より上手くチューニングできる

!! 宣言 !! © 2012 EIICHI KIMURA All Rights Reserved. 5 2012/11/9

G1GC の動作状況を分析するにはログ出力用

[‐verbosegc | ‐XLoggc:<gc.log>]

‐XX:+PrintGC

‐XX:+PrintGCTimeStamps

‐XX:+PrintGCDateStamps

‐XX:+PrintGCDetails

‐XX:+PrintAdaptiveSizePolicy

‐XX:+UnlockExperimentalVMOptions –XX:G1LogLevel=[fine | finer | finest]

チューニング用

‐XX:InitiatingHeapOccupancyPercent=<percent>

‐XX:G1OldCSetRegionLiveThresholdPercent=<percent>

‐XX:G1MixedGCCountTarget=<N>

‐XX:G1HeapWastePercent=<N>

(http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html)


でも使えるのは、これだけログ出力用

[‐verbosegc | ‐XLoggc:<gc.log>]

‐XX:+PrintGC

‐XX:+PrintGCTimeStamps

‐XX:+PrintGCDateStamps

‐XX:+PrintGCDetails

‐XX:+PrintAdaptiveSizePolicy

‐XX:+UnlockExperimentalVMOptions –XX:G1LogLevel=[fine | finer | finest]

チューニング用

‐XX:InitiatingHeapOccupancyPercent=<percent>

‐XX:G1OldCSetRegionLiveThresholdPercent=<percent>

‐XX:G1MixedGCCountTarget=<N>

‐XX:G1HeapWastePercent=<N>

(http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html)


G1GC のサイクル Initial Mark – STW

Root Region Scanning – Concurrent

Concurrent Marking – Concurrent

Remark – STW

Cleanup – STW + Concurrent

Copying(Young GC/Mixed GC) - STW © 2012 EIICHI KIMURA All Rights Reserved. 8 2012/11/9

2012/11/9 © 2012 EIICHI KIMURA All Rights Reserved. 9

高

低低

低低

高

高高

高

高高

高高

低

高

高高

高高

高高

高高

低低低

低

高

高高

高高

高高

高高

Non-Allocated Eden Survivor Recently copied in Survivor Recently copied in Old

Old

You

ng

mo

de

M

ixed

mo

de

Mark Phase Copy phase

Mark /Remark Phase Cleanup Phase Copy Phase

{Heap before GC invocations=0 (full 0): garbage-first heap total 16384K, used 5120K [0x03600000, 0x04600000, 0x05a00000) region size 1024K, 5 young (5120K), 0 survivors (0K) compacting perm gen total 12288K, used 6053K [0x05a00000, 0x06600000, 0x09a00000) the space 12288K, 49% used [0x05a00000, 0x05fe9478, 0x05fe9600, 0x06600000) No shared spaces configured. 2012-08-22T16:37:32.445+0900: G1HR #StartGC 1 0.911: [GC pause (young) Desired survivor size 524288 bytes, new threshold 15 (max 15) 0.911: [G1Ergonomics (CSet Construction) start choosing CSet, predicted base time: 83.70 ms, remaining time: 116.30 ms, target pause time: 200.00 ms] 0.911: [G1Ergonomics (CSet Construction) add young regions to CSet, eden: 5 regions, survivors: 0 regions, predicted young region time: 127.33 ms] 0.911: [G1Ergonomics (CSet Construction) finish choosing CSet, eden: 5 regions, survivors: 0 regions, old: 0 regions, predicted pause time: 211.03 ms, target pause time: 200.00 ms] G1HR CSET 0x03a00000 : G1HR ALLOC(Survivor) 0x03b00000 G1HR ALLOC(Old) 0x03c00000 G1HR RETIRE 0x03c00000 0x03ccee20, 0.01186911 secs] [Parallel Time: 11.0 ms] [GC Worker Start (ms): 911.1 911.1 911.1 911.1 Avg: 911.1, Min: 911.1, Max: 911.1, Diff: 0.0] [Ext Root Scanning (ms): 2.6 3.5 3.6 4.6 Avg: 3.6, Min: 2.6, Max: 4.6, Diff: 2.0] [Update RS (ms): 0.0 0.1 0.0 0.0 Avg: 0.0, Min: 0.0, Max: 0.1, Diff: 0.1] [Processed Buffers : 0 14 0 0 Sum: 14, Avg: 3, Min: 0, Max: 14, Diff: 14] [Scan RS (ms): 0.0 0.0 0.0 0.0 Avg: 0.0, Min: 0.0, Max: 0.0, Diff: 0.0] [Object Copy (ms): 8.2 7.0 7.0 6.0 Avg: 7.1, Min: 6.0, Max: 8.2, Diff: 2.2] [Termination (ms): 0.0 0.0 0.0 0.0 Avg: 0.0, Min: 0.0, Max: 0.0, Diff: 0.0] [Termination Attempts : 2 2 1 1 Sum: 6, Avg: 1, Min: 1, Max: 2, Diff: 1] [GC Worker End (ms): 921.9 921.9 921.9 921.9 Avg: 921.9, Min: 921.9, Max: 921.9, Diff: 0.0] [GC Worker (ms): 10.9 10.9 10.9 10.8 Avg: 10.9, Min: 10.8, Max: 10.9, Diff: 0.0] [GC Worker Other (ms): 0.2 0.3 0.3 0.3 Avg: 0.3, Min: 0.2, Max: 0.3, Diff: 0.2] [Clear CT: 0.1 ms] [Other: 0.7 ms] [Choose CSet: 0.0 ms] [Ref Proc: 0.5 ms] [Ref Enq: 0.0 ms] [Free CSet: 0.0 ms] G1HR #EndGC 1 [Eden: 5120K(5120K)->0B(5120K) Survivors: 0B->1024K Heap: 5120K(16M)->1851K(16M)] [Times: user=0.02 sys=0.02, real=0.02 secs] Heap after GC invocations=1 (full 0): garbage-first heap total 16384K, used 1851K [0x03600000, 0x04600000, 0x05a00000) region size 1024K, 1 young (1024K), 1 survivors (1024K) compacting perm gen total 12288K, used 6053K [0x05a00000, 0x06600000, 0x09a00000) the space 12288K, 49% used [0x05a00000, 0x05fe9478, 0x05fe9600, 0x06600000) No shared spaces configured. }


こんな GC ログ、読むのは大変

そこで – JavaOne 2012 になかったネタ

G1GC ログの可視化したい


Fin.

本セッションの内容は、

http://www.myexpospace.com/JavaOne2012/SessionFiles/CON6583_PDF_6583_0001.pdf


JJUG JavaOne 2012 San Francisco 報告会 LT(G1GC)

Documents

Transcript of JJUG JavaOne 2012 San Francisco 報告会 LT(G1GC)