Bug 13250244 - Shared pool leak of "KGLHD" memory when using multiple subpools (文档 ID 13250244.8)

心已赠人 2022-05-28 09:07 101阅读 0赞

### Bug 13250244  Shared pool leak of "KGLHD" memory when using multiple subpools ###

This note gives a brief overview of bug 13250244.   
 The content was last updated on: 05-JUL-2013  
 *Click [here][] for details of each of the sections below.*

### Affects: ###

> <table> 
>  <tbody> 
>   <tr> 
>    <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;"><strong>Product (<em>Component</em>)</strong></span></td> 
>    <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;">Oracle Server (Rdbms)</span></td> 
>   </tr> 
>   <tr> 
>    <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;"><strong>Range of versions&nbsp;<em>believed</em>&nbsp;to be affected</strong></span></td> 
>    <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;">Versions &gt;= 11.1 but BELOW 12.1</span></td> 
>   </tr> 
>   <tr> 
>    <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;"><strong>Versions&nbsp;<em>confirmed</em>&nbsp;as being affected</strong></span></td> 
>    <td style="font-family:'YaHei Consolas Hybrid';"> 
>     <ul> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#AFFECTS_11.2.0.3" rel="nofollow">11.2.0.3</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#AFFECTS_11.2.0.2" rel="nofollow">11.2.0.2</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#AFFECTS_11.2.0.1" rel="nofollow">11.2.0.1</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#AFFECTS_11.1.0.7" rel="nofollow">11.1.0.7</a></span></li> 
>     </ul></td> 
>   </tr> 
>   <tr> 
>    <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;"><strong>Platforms affected</strong></span></td> 
>    <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;">Generic (all / most platforms affected)</span></td> 
>   </tr> 
>  </tbody> 
> </table>

### Fixed: ###

> <table> 
>  <tbody> 
>   <tr> 
>    <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;"><strong>This issue is fixed in</strong></span></td> 
>    <td style="font-family:'YaHei Consolas Hybrid';"> 
>     <ul> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#FIXED_12.1.0.1" rel="nofollow">12.1.0.1 (Base Release)</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#FIXED_11.2.0.4" rel="nofollow">11.2.0.4 (Future Patch Set)</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=14275605.8" rel="nofollow">11.2.0.3.4 Database Patch Set Update</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=14352236.8" rel="nofollow">11.2.0.3 Bundle Patch 10 for Exadata Database</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=14275621.8" rel="nofollow">11.2.0.2.8 Database Patch Set Update</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=14461970.8" rel="nofollow">11.2.0.2 Bundle Patch 18 for Exadata Database</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=1114533.1" rel="nofollow">11.2.0.3 Patch 10 on Windows Platforms</a></span></li> 
>      <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=1114533.1" rel="nofollow">11.2.0.2 Patch 21 on Windows Platforms</a></span></li> 
>     </ul></td> 
>   </tr> 
>  </tbody> 
> </table>

<table> 
 <tbody> 
  <tr> 
   <td style="font-family:'YaHei Consolas Hybrid';"><h3><span style="font-size:16px;"><u>Symptoms:</u></span></h3></td> 
   <td style="font-family:'YaHei Consolas Hybrid';"><h3><span style="font-size:16px;"><u>Related To:</u></span></h3></td> 
  </tr> 
  <tr> 
   <td style="font-family:'YaHei Consolas Hybrid';"> 
    <ul> 
     <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#TAGS_ERROR" rel="nofollow">Error May Occur</a></span></li> 
     <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#TAGS_LEAK_MEM" rel="nofollow">Leak (Memory Leak / Growth)</a></span></li> 
     <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1#TAGS_POOL" rel="nofollow">Shared Pool Affected</a></span></li> 
     <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=4031.1" rel="nofollow">ORA-4031</a></span></li> 
    </ul></td> 
   <td style="font-family:'YaHei Consolas Hybrid';"> 
    <ul> 
     <li><span style="font-size:16px;">_kghdsidx_count</span></li> 
     <li><span style="font-size:16px;"><a href="https://support.oracle.com/epmos/faces/DocumentDisplay?id=68642.1" rel="nofollow">USE_STORED_OUTLINES</a></span></li> 
    </ul></td> 
  </tr> 
 </tbody> 
</table>

### Description ###

>     Shared pool memory of type "KGLHD" may be leaker, potentially
>     leading to ORA-4031 errors when multiple shared pool subpools
>     are in use. 
>      
>     The problem is easily triggered if stored outlines are used, but the use
>     of stored outlines is not required to hit this problem.
>      
>     Rediscovery Notes:
>     This problem may be being seen of both of the following are true:
>      (a) Hitting ORA-4031 or shared pool usage increases due 
>          to many "KGLHD" allocations
>      (b) Multiple shared pool subpools are in use.
>          (eg the internal parameter _kghdsidx_count set to a value greater than 1)
>      
>     Workaround
>       Set "_kghdsidx_count"=1 so that only one shared pool subpool is used.
>       Note that in highly concurrent environments this workaround may cause 
>       shared pool and library cache latch related contention issues.
> 
>     Getting a Fix
>      Use one of the "Fixed" versions listed above
>      (for Patch Sets / bundles use the latest version available as contents are cumulative - the "Fixed" version listed above is the first version where the fix is included)
>      or
>      You can check for existing interim patches here: Patch:13250244

<table> 
 <tbody> 
  <tr> 
   <td style="font-family:'YaHei Consolas Hybrid';"><span style="font-size:16px;"><strong>Please note:</strong>&nbsp;The above is a summary description only. Actual symptoms can vary. Matching to any symptoms here does not confirm that you are encountering this problem. For questions about this bug please consult Oracle Support.</span></td> 
  </tr> 
 </tbody> 
</table>

### References ###

> [Bug:13250244][Bug_13250244] (This link will only work for PUBLISHED bugs)  
> 
> 
> [Note:245840.1][here] Information on the sections in this article
> 
> \+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 
> \+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++  
> 
> 
> KGLHD is not Function   
>   
> KGL ->  Kernel Generic Library   
> KGLHD  Library cache Handle structure  
> KGLOB - Object structure  
> KGLNA - Name structure  
>   
>   
>   
> KGLHD -> KGLOB  
>                ->  KGLNA -> KGLNA->KGLNA  
>   
>   
>   
>   
> Object Handles  
>   
> All objects that are stored in the library cache are accessed by using handles (kglhd). The handle stores the name of the object, its namespace, some flags that are used to get information about the object (if the object is read-only, remote or local, in CGA memory, marked to be kept pinned in memory, and so on), and statistical information regarding the object. The handle is also used by the library cache to keep a list of all users who have locks, pins, or references to the object as well as those who are waiting to acquire locks or pins on it.  
> Object handles are placed in linked lists according to a hashing algorithm, which is a function of the object’s name and namespace.  
>   
>   
> When a process requests an object, the library cache manager applies the hashing algorithm to determine the linked list (hash bucket) to be searched. If the object is in cache, the appropriate object handle will be found. It is possible for the handle to be in memory but the object heaps have been aged out. The object handle will tell us that. In this case, the required object heaps are reloaded. Finally, it is possible that the object handle is not found. In this case, a new one must be allocated, it must be populated with the object information, and the object heaps must be loaded.   
>   
>   
> Handles: kglhd  
>   
> Files kgl.c kgl2.c kgl.h  
>

[here]: https://support.oracle.com/epmos/faces/DocumentDisplay?id=245840.1
[Bug_13250244]: https://support.oracle.com/epmos/faces/BugDisplay?id=13250244