Extended trace analysis and perf. problem.

  • From: Brian Wisniewski <brian_wisniewski@xxxxxxxxx>
  • To: oracle-l@xxxxxxxxxxxxx
  • Date: Fri, 13 May 2005 05:49:46 -0700 (PDT)

We are in process of moving from a 2-node (4 CPU per node Xeon 1.6GHz) RAC to a 
3-node (2 CPU per node 3.0GHz) RAC.  The 2 CPU machines are hyper-threaded so 
it appears as 4-CPU's.  We're splitting databases that currently sit on the 
2-node into seperate RAC's.  Going from RHAS 2.1 to RHAS 3.0.  Also going from 
a mix of raw devices and OCFS in the existing environment to complete OCFS and 
from a dedicated switch to a VLAN interconnect.  Is it possible to change 
anything else? :-)
 
This is a 600gb database that stores a lot of blobs.  I copied a backup over to 
the new server, restored it and applied some archive logs from production and 
then opened it for testing.
 
Doing performance testing on the new machine and of course it is abysmal - it 
would have been too good to be true for it to actually work!  Loads are about 
1/2 as fast.  I've extended trace'd loads in the current production and in the 
new production and that where I'm lost.  All of the wait time averages for the 
new setup are right in line with current production.  If this was database 
related I'd expect to see some wait-time averages way off the chart somewhere - 
wouldn't you?  Am I missing something if this is database related - shouldn't 
it show in the extended traces if it was?
 
I don't know what this is going to come across like but I'll give it a shot.  
This is my table holding the wait stats of the loads.  The 1st column is the 
avg wait time (microseconds), the 2nd column is the number of events it pulled 
out of the trace file, 3rd is the wait event and 4th is the name of the run.  
RAC 'C' is the new cluster - all the others are current production runs.
 
Any help is appreciated or if my assumptions are incorrect I'd be happy to know.
 
Thanks - Brian
 
       AVG   COUNT(*) WAIT_EVENT                               LOAD_TXT
---------- ---------- ---------------------------------------- 
------------------------------
     27.50          2 KJC Wait for msg sends to complete       Prod run 25464 
05/09
    152.00         12 KJC Wait for msg sends to complete       Prod run 8317
    172.61         33 KJC Wait for msg sends to complete       Prod run 14892
    201.77         13 KJC Wait for msg sends to complete       Prod run amcc
    359.33          6 KJC Wait for msg sends to complete       RAC C 3node async
   1407.40          5 buffer busy global CR                    Prod run 14892
   3833.00          9 buffer busy global CR                    Prod run 25464 
05/09
  16060.80          5 buffer busy global cache                 Prod run 14892
     50.00          1 buffer busy waits                        Prod run 14892
     72.40         15 buffer busy waits                        Prod run 25464 
05/09
   1753.50          8 buffer busy waits                        Prod run 8317
   3218.38      23297 db file sequential read                  Prod run 25464 
05/09
   5741.80     117792 db file sequential read                  Prod run 14892
   6326.64      85276 db file sequential read                  Prod run 8317
   7326.37      60987 db file sequential read                  RAC C 3node 
async cert client
   7626.50      57413 db file sequential read                  Prod run amcc
   8002.31      46649 db file sequential read                  RAC C 3node async
   8243.14      57986 db file sequential read                  RAC C 1node async
   8907.66      20778 db file sequential read                  RAC C 3node 
noasync initial
      5.50         12 direct path write (lob)                  RAC C 3node async
      6.17         12 direct path write (lob)                  RAC C 1node async
      6.50         14 direct path write (lob)                  RAC C 3node 
async cert client
     10.09       5998 direct path write (lob)                  Prod run amcc
     10.59      13329 direct path write (lob)                  Prod run 14892
     10.80       6893 direct path write (lob)                  Prod run 8317
     15.00          4 direct path write (lob)                  Prod run 25464 
05/09
    123.00          2 enqueue                                  RAC C 3node 
async cert client
    133.00         44 enqueue                                  Prod run amcc
    181.73        143 enqueue                                  RAC C 3node 
noasync initial
    225.75        215 enqueue                                  RAC C 3node async
    232.69         55 enqueue                                  Prod run 8317
    233.93        151 enqueue                                  Prod run 25464 
05/09
   1429.65        142 enqueue                                  Prod run 14892
    336.00          2 global cache busy                        Prod run 14892
  14982.00          2 global cache busy                        Prod run 25464 
05/09
    111.22      58269 global cache cr request                  Prod run amcc
    134.23     123907 global cache cr request                  Prod run 14892
    135.20      84376 global cache cr request                  Prod run 8317
    184.61      25831 global cache cr request                  Prod run 25464 
05/09
    239.21      99254 global cache cr request                  RAC C 3node 
async cert client
    251.68      62661 global cache cr request                  RAC C 3node async
    281.58      27544 global cache cr request                  RAC C 3node 
noasync initial
    152.00          2 global cache null to s                   Prod run amcc
    160.50          2 global cache null to s                   Prod run 8317
    176.04         28 global cache null to s                   Prod run 25464 
05/09
    135.64         28 global cache null to x                   Prod run amcc
    147.58         12 global cache null to x                   Prod run 8317
   6870.91       1154 global cache null to x                   Prod run 25464 
05/09
  12296.99        467 global cache null to x                   Prod run 14892
    129.13          8 global cache open s                      Prod run 8317
    172.40         10 global cache open s                      RAC C 3node async
    183.60         10 global cache open s                      Prod run 14892
    216.66        376 global cache open s                      RAC C 3node 
async cert client
    608.91         43 global cache open s                      Prod run 25464 
05/09
     92.74       1007 global cache open x                      RAC C 3node async
    119.83        192 global cache open x                      Prod run amcc
    121.28        648 global cache open x                      RAC C 3node 
noasync initial
    125.09        733 global cache open x                      Prod run 8317
    298.99       5641 global cache open x                      RAC C 3node 
async cert client
    548.07       1363 global cache open x                      Prod run 14892
    553.81       1238 global cache open x                      Prod run 25464 
05/09
    109.86       3145 global cache s to x                      Prod run amcc
    132.11       8585 global cache s to x                      Prod run 14892
    133.69       5958 global cache s to x                      Prod run 8317
    137.21       1286 global cache s to x                      Prod run 25464 
05/09
    219.80       2205 global cache s to x                      RAC C 3node 
async cert client
    245.66       2344 global cache s to x                      RAC C 3node async
    277.20       1236 global cache s to x                      RAC C 3node 
noasync initial
     36.67          3 latch free                               Prod run amcc
     80.46         13 latch free                               Prod run 25464 
05/09
    200.56         16 latch free                               Prod run 8317
   2074.43         23 latch free                               Prod run 14892
    125.80        246 library cache lock                       Prod run amcc
    181.92        637 library cache lock                       Prod run 14892
    189.28        276 library cache lock                       Prod run 8317
    208.26         61 library cache lock                       Prod run 25464 
05/09
    213.79         66 library cache lock                       RAC C 3node 
async cert client
    230.29          7 library cache lock                       RAC C 3node async
    244.17         18 library cache lock                       RAC C 3node 
noasync initial
     80.00          1 library cache pin                        RAC C 1node async
    499.00          1 library cache pin                        RAC C 3node async
    866.00          1 library cache pin                        RAC C 3node 
async cert client
  81776.00          2 log file switch completion               Prod run 14892
 106827.50          2 log file switch completion               Prod run 8317
   6249.67         12 log file sync                            Prod run 14892
   6257.25          4 log file sync                            RAC C 1node async
   6409.80          5 log file sync                            Prod run amcc
  11107.67          3 log file sync                            RAC C 3node 
async cert client
  11291.33          3 log file sync                            Prod run 25464 
05/09
  11633.60         10 log file sync                            RAC C 3node async
  12709.00          7 log file sync                            Prod run 8317
  13767.50          2 log file sync                            RAC C 3node 
noasync initial
     83.00          1 rdbms ipc reply                          RAC C 1node async
    358.00          1 rdbms ipc reply                          RAC C 3node async
    449.00          1 rdbms ipc reply                          RAC C 3node 
async cert client
     92.50          8 row cache lock                           RAC C 1node async
     96.00          1 row cache lock                           RAC C 3node 
noasync initial
    307.29          7 row cache lock                           RAC C 3node async
    320.17          6 row cache lock                           Prod run amcc
    343.45         11 row cache lock                           Prod run 8317
    419.29          7 row cache lock                           Prod run 25464 
05/09
    616.82         11 row cache lock                           RAC C 3node 
async cert client
   1155.74         19 row cache lock                           Prod run 14892
 
 
 


                
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