DB2 db2mtrk用法总结

   当我们对db2内存使用清理进行监控检查的时候，经常需要知道db2当前的内存使用情况。通过参数instance_memory并不能准确的看到这些信息，因为instance_memory包括了mon_heap, audit_buf_sz and FCM, database shared memory segment (bufferpool, locklist, dbheap, pckcache, util_heap, catalogcache）这些内存池集合，而db2mtrk就可以指定数据库和实例级别查看实时的内存使用情况

所以在DB2中，db2mtrk工具就是一个查看当前内存使用情况的非常好的的工具。

 db2mtrk的命令语法：（unix,linux,window平台之间可能有稍许差异）
db2inst1@marven ~]$ db2mtrk -h
Usage: db2mtrk -i | -d | -a | -p [-m | -w] [-v] [-r interval [count]] [-h]


   -i  Display instance level memory usage
   -d  Display database level memory usage
   -a  Display application level memory usage
   -p  Display agent private memory usage
   -m  Display maximum usage information
   -w  Display watermark usage information
   -v  Display verbose memory usage information
   -r  Run in repeat mode
          interval  Amount of seconds to wait between reports
          count     Number of reports to generate before quitting
   -h  Display this help screen

Notes:

   1. One of -i -d -a -p must be specified.
   2. The -w and -m flags are optional.  An invocation of the application
      is invalid if both flags are specified.
   3. The -m flag reports the maximum allowable size for a given heap
      while the -w flag reports the largest amount of memory allocated
      from a given heap at some point in its history.

Usage scenarios:

   db2mtrk -i -d

      Report current memory usage for instance and all databases

   db2mtrk -i -p -m

      Report maximum allowable size for instance and agent private memory

   db2mtrk -p -r 1 5

      Report agent private memory five times at one second intervals

Heap Legend:

   When running in normal mode (i.e. -v flag not specified) heaps are named
   using the following codes:

   agsh      - Application Group Shared Heap   lockh     - Lock Manager Heap
   appctlh   - Application Control Heap        monh      - Database Monitor Heap
   apph      - Application Heap                other     - Other Memory
   appshrh   - Applications Shared Heap        pckcacheh - Package Cache
   bph       - Buffer Pool Heap                queryh    - Query Heap
   catcacheh - Catalog Cache Heap              shsorth   - Shared Sort Heap
   dbh       - Database Heap                   sorth     - Sort Heap
   dlfmh     - DFM Heap                        stath     - Statistics Heap
   fcmbp     - FCMBP Heap                      stmth     - Statement Heap
   ip        - Import Pool                     utilh     - Backup/Restore/Util Heap



-m 参数选项是显示最大的内存使用上线
-w 参数选项是显示使用过程中内存达到的最大值，既watermark

-r  参数选项是重复显示 interval是重复显示的时间间隔数 count是要重复显示的次数

如下使用示例结果输出：

[db2inst1@marven ~]$ db2 list active databases

                           Active Databases

Database name                              = SAMPLE
Applications connected currently           = 0
Database path                              = /home/db2inst1/db2inst1/NODE0000/SQL00002/

Database name                              = ORACLE
Applications connected currently           = 0
Database path                              = /home/db2inst1/db2inst1/NODE0000/SQL00004/
如上我的实例中存在两个激活的数据库，如下分别显示数据库的内存使用情况：
[db2inst1@marven ~]$ db2mtrk -i -d
Tracking Memory on: 2012/02/13 at 09:38:24

Memory for instance

   other       fcmbp       monh        
   17.1M       832.0K      576.0K      

Memory for database: SAMPLE  

   utilh       pckcacheh   other       catcacheh   bph (1)     bph (S32K)  
   64.0K       256.0K      192.0K      192.0K      8.2M        832.0K      

   bph (S16K)  bph (S8K)   bph (S4K)   shsorth     lockh       dbh         
   576.0K      448.0K      384.0K      0           16.8M       18.9M       

   apph (258)  apph (257)  apph (256)  apph (255)  apph (254)  apph (253)  
   64.0K       64.0K       64.0K       192.0K      64.0K       64.0K       

   apph (252)  appshrh     
   64.0K       320.0K      

Memory for database: ORACLE  

   utilh       pckcacheh   other       catcacheh   bph (1)     bph (S32K)  
   64.0K       256.0K      192.0K      192.0K      40.3M       832.0K      

   bph (S16K)  bph (S8K)   bph (S4K)   shsorth     lockh       dbh         
   576.0K      448.0K      384.0K      128.0K      16.8M       18.9M       

   apph (267)  apph (266)  apph (265)  apph (264)  apph (263)  apph (262)  
   64.0K       64.0K       64.0K       192.0K      64.0K       64.0K       

   apph (261)  appshrh     
   64.0K       320.0K