我目前正在将Adobe Experience Manager(AEM，也称为CQ)用于客户站点(Java平台)。它使用OpenJDK:
java version "1.7.0_65"
OpenJDK Runtime Environment (rhel-2.5.1.2.el6_5-x86_64 u65-b17)
OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)
它在Rackspace上运行并具有以下内容:
vCPU: 4
Memory: 16GB
Guest OS: Red Hat Enterprise Linux 6 (64-bit)
由于它已经投入生产，因此我在应用程序方面一直遇到非常慢的性能。就像这样，我启动了该应用程序，一切都很顺利，然后7到10天后，CPU使用率飙升至400％(每天有4000个用户访问该网站)。该站点变得异常缓慢，并且永远不会成为OOM异常。
由于我是Java内存管理的新手，因此我开始阅读有关它的工作原理的信息，并找到了jstat和jmap之类的工具。当第二次系统不堪重负时，我得到了一个堆转储并将其挖进去。
似乎所有这些都指向org.slf4j.helpers.BasicMarkerFactory和org.slf4j.helpers.BasicMarker，因为当我使用MAT Eclipse分析它时，我看到按保留大小最大的保留对象是:
org.slf4j.helpers.BasicMarkerFactory @ 0x6021a4f00
Shallow Size: 16 B Retained Size: 6.8 GB
和
当我运行泄漏嫌疑人报告时，我得到以下结果:
Description
One instance of "org.slf4j.helpers.BasicMarkerFactory" loaded by "org.apache.felix.framework.BundleWiringImpl$BundleClassLoaderJava5 @ 0x60219a878" occupies 7,263,024,848 (96.71%) bytes. The memory is accumulated in one instance of "java.util.concurrent.ConcurrentHashMap$Segment[]" loaded by "<system class loader>".
Keywords
java.util.concurrent.ConcurrentHashMap$Segment[]
org.apache.felix.framework.BundleWiringImpl$BundleClassLoaderJava5 @ 0x60219a878
org.slf4j.helpers.BasicMarkerFactory
和
Shortest Paths To the Accumulation Point
Class Name Shallow Heap Retained Heap
java.util.concurrent.ConcurrentHashMap$Segment[16] @ 0x6021a4f40 80 7,263,024,784
.
... segments java.util.concurrent.ConcurrentHashMap @ 0x6021a4f10 48 7,263,024,832
.
... markerMap org.slf4j.helpers.BasicMarkerFactory @ 0x6021a4f00 16 7,263,024,848
.
... markerFactory org.slf4j.impl.StaticMarkerBinder @ 0x6021d3970 16 16
.
... SINGLETON class org.slf4j.impl.StaticMarkerBinder @ 0x6021d38f8 8 24
.
... [328] java.lang.Object[640] @ 0x6021d2ee8 2,576 9,592
.
... elementData java.util.Vector @ 0x6021d0fe0 32 9,624
.
... classes org.apache.felix.framework.BundleWiringImpl$
BundleClassLoaderJava5 @ 0x6021c32e0 96 26,888
.
... <classloader> class ch.qos.logback.classic.Logger @
0x600be4310 16 16
. .
. ...<class> ch.qos.logback.classic.Logger @ 0x600282a78 48 48
.
... <Java Local> java.lang.Thread @ 0x60077b450
pool-9-thread-1 Thread 104 3,344
.
... <class> ch.qos.logback.classic.Logger @ 0x60025b850 48 48
.
... <class> ch.qos.logback.classic.Logger @ 0x604b0a708 48 48
.
... <class> ch.qos.logback.classic.Logger @ 0x604b0a6d8 48 48
.
... <class> ch.qos.logback.classic.Logger @ 0x6049debe0 48 48
.
... <class> ch.qos.logback.classic.Logger @ 0x604535228 48 48
.
... <class> ch.qos.logback.classic.Logger @ 0x604124248 48 48
另外，当我运行时:
$ sudo -u aem jmap -histo PID
num #instances #bytes class name
----------------------------------------------
1: 11460084 950827248 [C
2: 10740160 257763840 java.lang.String
3: 7681495 245807840 java.util.concurrent.ConcurrentHashMap$HashEntry
4: 7563527 181524648 org.slf4j.helpers.BasicMarker
5: 217007 173568376 [I
6: 177602 158721184 [B
7: 60611 69739136 [Ljava.util.concurrent.ConcurrentHashMap$HashEntry;
8: 1147481 69348496 [Ljava.lang.Object;
9: 1797107 43130568 org.apache.jackrabbit.oak.plugins.segment.RecordId
10: 208912 33824544 <constMethodKlass>
11: 570143 31928008 org.mozilla.javascript.ast.Name
12: 22350 27643920 <constantPoolKlass>
13: 208912 26752544 <methodKlass>
14: 821217 26278944 java.util.UUID
15: 793800 25401600 java.util.HashMap$Entry
16: 532946 21317840 org.mozilla.javascript.Node
17: 792296 19015104 java.lang.Long
18: 191294 18335600 [Ljava.util.HashMap$Entry;
19: 22350 16133328 <instanceKlassKlass>
20: 173883 15855152 [Ljava.lang.String;
21: 635690 15256560 org.apache.sling.engine.impl.request.SlingRequestProgressTracker$TrackingEntry
22: 18509 14662848 <constantPoolCacheKlass>
23: 911112 14577792 java.lang.Integer
24: 255426 14303856 org.apache.jackrabbit.oak.plugins.segment.SegmentNodeBuilder
25: 519324 12463776 java.util.ArrayList
26: 254643 12222864 org.apache.jackrabbit.oak.core.SecureNodeBuilder
27: 137703 11016240 java.lang.reflect.Method
28: 312116 9987712 org.apache.jackrabbit.oak.plugins.segment.SegmentNodeState
29: 19236 9828448 [Lorg.apache.jackrabbit.oak.plugins.segment.SegmentId;
30: 242179 9687160 java.util.TreeMap$Entry
31: 197121 9461808 java.util.HashMap
32: 15041 9416328 <methodDataKlass>
33: 387927 9310248 org.apache.jackrabbit.oak.plugins.segment.MapRecord
34: 250049 8001568 org.apache.jackrabbit.oak.plugins.memory.MemoryNodeBuilder$UnconnectedHead
35: 248586 7954752 org.apache.jackrabbit.oak.core.MutableTree
36: 107865 7948112 [S
37: 191950 7678000 java.util.LinkedHashMap$Entry
38: 102212 6541568 org.mozilla.javascript.ast.PropertyGet
39: 37021 6515696 org.mozilla.javascript.ast.FunctionNode
40: 161905 6476200 org.mozilla.javascript.ScriptableObject$Slot
.....
8210: 1 16 org.slf4j.helpers.BasicMarkerFactory
我注意到:
4: 7563527 181524648 org.slf4j.helpers.BasicMarker
和
8210: 1 16 org.slf4j.helpers.BasicMarkerFactory
当我进入org.slf4j.helpers.BasicMarkerFacotry的文档时，看到以下内容引起了我的注意:
detachMarker
public boolean detachMarker(String name)
Description copied from interface: IMarkerFactory
Detach an existing marker.
Note that after a marker is detached, there might still be "dangling" references to the detached marker.
Specified by:
detachMarker in interface IMarkerFactory
Parameters:
name - The name of the marker to detach
Returns:
whether the marker could be detached or not
特别是:
Note that after a marker is detached, there might still be "dangling" references to the detached marker.
欢迎任何建议。
提前致谢。
最佳答案
您是否正在使用 MarkerFactory 创建 Marker 实例？
听起来很明显，保存您的标记的ConcurrentHashMap一直在增长。例如，情况就是如此。如果您创建的标记每次都有不同的名称(例如，使用日期)。标记用于标记您的日志，以便您可以相应地对其进行过滤。您可能需要将代码的一部分发布到创建标记的位置。
关于java - AEM性能问题(内存泄漏缓慢)org.slf4j.helpers.BasicMarker和org.slf4j.helpers.BasicMarkerFactory，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/31524084/