Monday, March 29, 2010

Setup StatsPack to monitor standby database performance

AWR/ADDM are not supported (and don't work) against a read only standby database, so they are not useful for diagnostic for an Active Data Guard environment.

A modifed version of statspack availabe on metalink (note 454848.1) can be deployed on the primary production database. This modified version uses a STDBYPERF schema which writes locally but reads remotely from PERFSTAT@standbydb.

Initial Setup (Oracle 11.1.0.7)

export ORACLE_SID=standbydb
cd $ORACLE_HOME/rdbms/admin
sql
CREATE SMALLFILE TABLESPACE PERFSTAT DATAFILE '+DATA1/perfstat01.dbf' SIZE 4G
 LOGGING 
 EXTENT MANAGEMENT LOCAL 
 SEGMENT SPACE MANAGEMENT AUTO;
@spdrop
@spcreate
exit;

sql
@sbcreate

--wait a second or two, the account has to propagate to the standby

@sbaddins


Configure Snapshots

Remember that PERFSTAT is not automatically purged/managed by the database, so this must be done by the DBA or scheduled.

-- workaround to avoid serious performance problem due to Bug 8323663
. setdb ordprod2
sql
execute dbms_stats.gather_table_stats(ownname => 'SYS',tabname => 'X$KCCTS', estimate_percent => 20 );
execute dbms_stats.gather_table_stats(ownname => 'SYS',tabname => 'X$KCFIO', estimate_percent => 20 );
execute dbms_stats.gather_table_stats(ownname => 'SYS',tabname => 'X$KCBFWAIT', estimate_percent => 20 );
execute dbms_stats.gather_table_stats(ownname => 'SYS',tabname => 'X$KCCFN', estimate_percent => 20 );
execute dbms_stats.gather_table_stats(ownname => 'SYS',tabname => 'X$KCCFE', estimate_percent => 20 );


grant create job to stdbyperf;
grant manage scheduler to stdbyperf;

conn stdbyperf/***

-- if this takes more than ~40 seconds there is a performance issue that will need to be traced
exec statspack_ordprod1.snap;

-- automate stats collection every 30 min during Mon-Fri 7am-5pm

exec dbms_scheduler.disable('ordrpt_statspack_snap_daily');

begin
   dbms_scheduler.create_job
   (
      job_name => 'ordrpt_statspack_snap_daily',
      job_type => 'PLSQL_BLOCK',
      job_action => 'begin statspack_ordprod1.snap; end;',
      repeat_interval => 'FREQ=MINUTELY; INTERVAL=30; BYHOUR=7,8,9,10,11,12,13,14,15,16,17; BYDAY=MON,TUE,WED,THU,FRI',
      enabled => true,
      comments => 'Take statspack snapshot on remote standby db ordrpt daily Mon to Fri 7am to 5pm'
   );
end;
/

exec dbms_scheduler.enable('ordrpt_statspack_snap_daily');


Create Reports

Similar to AWR reports, run reports from caldbrac02

SQL> conn stbyperf/***

SQL> @?/rdbms/admin/sbreport

-- follows prompts to enter dbid, instanceid, snapshot intervals, output is text file

Author: Blair Boadway  |  Production DBA

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