Friday 27 July 2018

General Possible Problem Oracle Database


General Possible Problem


1.  Event after killing session, Sessions are keep on regenerating and lead to  database in hang state

Check session which is coming continuously

set head on feed on pagesize 500 linesize 1000
col  machine for a40
col module for a40
col program for a40
select count(*) , module , status, program, machine, username from v$session
group by status, module, program, machine, username;


SET LINESIZE 500
SET PAGESIZE 1000
SET VERIFY OFF
 SELECT a.sql_text,b.sid,b.serial#,username,b.status,b.sql_id,to_char(b.logon_time,'dd-mon:hh24:mi'),b.machine,b.module
FROM   v$sqltext a,
       v$session b
WHERE  a.address = b.sql_address
AND    a.hash_value = b.sql_hash_value
AND    b.username = &1

Check if any problematic event on Database

select count(1),event from v$session group by event;

Map database session with OS process if you got any top consumer process from OS end.

select s.sid,s.serial#,s.username,to_char(s.logon_time,'dd-mon:hh24:mi'),machine,module,sql_id  from v$session s, v$process p
where p.addr=s.paddr and p.spid in ('41484692','49021256');

kill the new/upcoming incoming session

alter system kill session 'sid,serial#' immediate;
ALTER SYSTEM KILL SESSION '2777,32093' immediate

OR

Kill session at OS level

kill -9 <pid>


if require kill session module wise as below

ps -eaf | grep DTLBS1 | grep "LOCAL=NO" | awk '{ print "kill -9 " $2 }' > kill211a.log


ps -eaf | grep RCC1 | grep "ora_j" | awk '{ print "kill -9 " $2 }' > kill41.log


select 'ALTER SYSTEM KILL SESSION'''||SID||','||SERIAL#||'''IMMEDIATE;' from v$session where username like 'U%'


select '!kill -9 '||spid from v$process where addr in (select paddr from v$session where username ='SERVRECO' and status='INACTIVE');


Check database status and try to switch log on database

   
alter system switch logfile;
alter system archive log current

Check alert log if any other issue.








Database is not getting shutdown due to active session


Investigation for issue.:

As part of investigation, check  alert log of database
if you find active sessions from alert log as below mean PMON process is unable to clear any uncommited transaction and oracle hung for long time and DBA will not be able to login on database via SQL*Plus to release the source of the hanging.

Massege from alert log

Active call for process 60228112 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 46662294 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 14877444 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 16188536 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 33555092 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 29360252 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 58655778 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 6816242 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 27329312 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 11600716 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 12649448 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 1246730 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 59507126 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 60424736 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
Active call for process 11993870 user 'lprd001' program 'oracle@linwood (TNS V1-V3)'
SHUTDOWN: waiting for active calls to complete.

Workaround/Solution


The workaround in such a situation will be to kill such processes

1. Now check if there are any connection present at the database as:

$ ps -eaf | grep LOCAL
  or
ps -eaf | grep <Database Name> | grep "LOCAL=NO" | awk '{ print "kill -9 " $2 }' > kill211a.log

It will give  the OSPIDs of the client connected to database.

2 Manually kill them as:

# Kill -9 <OSPID>
or
  
# sh kill211a.log

3. Issue shutdown immediate now or  As the shutdown was in progress ,the base automatically may came down

Or
The other workaround in this case will be to shutdown with:

shutdown abort
startup restrict
shutdown normal



 I would suspect that there might be some long running transaction going on in any of the sessions that were present at the time of shutdown. This could have caused because the shutdown was waiting for this transaction to roll back completely.
The other possibility of this could be that there are some blocking processes present in the system, which caused some of the other sessions to hang







SWAP USAGE Analysis on DB server



SWAP USAGE Analysis


Issue with High SWAP

Swap/paging is used when there is no sufficient free space available on physical memory. Excessive SGA and PGA usage can lead to memory swapping issue and have impact on the database  performance .Most of environment, Monitoring is set to get alert on high usage on swap.

Therefore, We started investigation and found that SIX Databases are running on this server and Total Memory on this server is Approx 24 GB and Most of memory is used by Oracle PGA and SGA and causing consistent high usages of swap and optimal value of SGA and PGA cannot decreased
Therefore, We require capacity analysis to smooth functioning and to reduce memory and swap usage within threshold on Production Server.

Memory Allocation from Each Database
easy44ppt =600 MB
intern02ppt =3GB
cca44ppt =1GB
abcppt =8GB
testppt =8GB
=========
Total=21 GB approx
internserver:dummy:/home/oracle $
internserver:dummy:/home/oracle $ps -ef|grep pmon
 oracle 20250704        1   0   Jun 10      -  9:39 ora_pmon_easy44ppt
 oracle 30671020        1   0   Mar 04      - 23:22 ora_pmon_intern02ppt
 oracle 35979502        1   0   Aug 02      -  5:25 ora_pmon_cca44ppt
 oracle 42860754        1   0   Jul 13      -  3:44 ora_pmon_abcppt
 oracle 54198338        1   0   Sep 12      -  0:14 ora_pmon_testppt
internserver:dummy:/home/oracle $ 










Determine the free physical memory usage of an AIX system

Use the commands  Nmon then press m





Determine the memory/swap usage of an AIX system

Use the commands  lsps -s.




Job Slowness issue


We got job slowness with server and job name details


Servrer =easyserver
Job=  udmd4090

Search job location and log

easyserver:easyprd:/home/oracle $cd /prod
easyserver:easyprd:/prod $find . -name udmd409* 2>/dev/null
./dmdata/log/udmd4090.sh.out
./dmprod/jobs_exec/udmd4090.sh
./dmprod/jobs_mast/udmd4090.sh
easyserver:easyprd:/prod $


check any problematic event at database level


SQL> select count(1),event from v$session group by event;

  COUNT(1) EVENT
---------- ----------------------------------------------------------------
        10 PL/SQL lock timer
       228 SQL*Net message from client
         1 SQL*Net message from dblink
         1 SQL*Net message to client
         1 Streams AQ: qmn coordinator idle wait
         1 Streams AQ: qmn slave idle wait
         1 Streams AQ: waiting for time management or cleanup tasks
         1 TCP Socket (KGAS)
         1 db file scattered read
         1 db file sequential read
         2 pipe get

  COUNT(1) EVENT
---------- ----------------------------------------------------------------
         1 pmon timer
        14 rdbms ipc message
         1 smon timer

14 rows selected.


SQL>  select count(1) ,username,event from v$session group by username,event

  COUNT(1) USERNAME                       EVENT
---------- ------------------------------ ----------------------------------------------------------------
         1                                pmon timer
         1                                smon timer
        14                                rdbms ipc message
         1                                Streams AQ: qmn slave idle wait
         1                                Streams AQ: qmn coordinator idle wait
         1                                Streams AQ: waiting for time management or cleanup tasks
         1 SYS                            SQL*Net message to client
         3 DBSNMP                         SQL*Net message from client
         5 PICPRD                         SQL*Net message from client
         2 SYSTEM                         SQL*Net message from client
         1 TIVOLI                         SQL*Net message from client

  COUNT(1) USERNAME                       EVENT
---------- ------------------------------ ----------------------------------------------------------------
        44 WMSPRD                         SQL*Net message from client
       173 DMS_USER                       SQL*Net message from client
         2 CLOUD_USER                     SQL*Net message from client
         1 DMS_BROWSE                     SQL*Net message from client
         1 OPS$BPRD001                    pipe get
        10 OPS$BPRD001                    PL/SQL lock timer
         1 OPS$BPRD001                    TCP Socket (KGAS)
         2 OPS$BPRD001                    db file scattered read


 10158450



If you found top process from OS command topas command then map it with
database session as below

SQL>
select s.sql_id,s.sql_hash_value,s.prev_hash_value,s.sid,s.serial#,s.username,s.event,to_char(s.logon_time,'dd-mon:hh24:mi')  from v$session s, v$process p
where p.addr=s.paddr and p.spid=10158450


check login time and sql id from below command.

SQL>
SQL> select to_char(logon_time,'dd-mon:hh24:mi'),sid,serial#,username,status,sql_id,event from v$session where sid =1631 order by 1;

TO_CHAR(LOGO        SID    SERIAL# USERNAME                       STATUS   SQL_ID        EVENT
------------ ---------- ---------- ------------------------------ -------- ------------- ----------------------------------------------------------------
06-may:15:40       1631      31917 OPS$BPRD001                    ACTIVE   d3rcjjtj06xy0 TCP Socket (KGAS)

SQL>

Generate explain Plan  as below

We can create explain plan with different command
  • awrsqrpt.sql
  • select * from table(dbms_xplan.display_cursor('&sql_id',null,'AdVanced ALLSTATS LAST'));
  • select * from table(dbms_xplan.display_awr('&sql_id',null,null,'advanced'));
  • select * from table(dbms_xplan.display_awr('&SQL_ID',NULL,NULL,'ALL'));
  • select substr(value_string,1,40) from v$sql_bind_capture where sql_id='dup0ph9mdm3fc';
  • select substr(value_string,1,40) from DBA_HIST_SQLBIND  where sql_id='dup0ph9mdm3fc';
  • select substr(value_string,1,40) from DBA_HIST_SQLBIND  where sql_id='dup0ph9mdm3fc';

To check Bind variable
  • select sn.END_INTERVAL_TIME,sb.NAME,sb.VALUE_STRING from DBA_HIST_SQLBIND sb,DBA_HIST_SNAPSHOT sn where sb.sql_id='dup0ph9mdm3fc' and sb.WAS_CAPTURED='YES' and sn.snap_id=sb.snap_id order by  sb.snap_id,sb.NAME;

  • SELECT a.sql_text,b.name,b.position,b.datatype_string,b.value_string  FROM v$sql_bind_capture b,v$sqlarea  a WHERE b.sql_id = 'dup0ph9mdm3fc' AND b.sql_id = a.sql_id;

We fetch complete scrip with below sql


SELECT a.sql_text  FROM v$sqlarea  a WHERE a.sql_id = 'dup0ph9mdm3fc' ;

if require generate trace for session

exec dbms_support.start_trace_in_session (1631,31917,binds=>true,waits=>true);

-rw-r--r--    1 oracle   dba             836 Mar 04 18:01 easyprd_ora_22675482.trc
-rw-r--r--    1 oracle   dba            3754 Mar 06 05:46 easyprd_ora_30474446.trc
-rw-r--r--    1 oracle   dba            3566 Mar 16 15:30 easyprd_ora_63635668.trc
-rw-rw-r--    1 oracle   dba             781 Apr 01 14:00 easyprd_ora_44695754.trc
-rw-r--r--    1 oracle   dba           64959 May 03 23:14 easyprd_ora_37880058.log
-rw-r--r--    1 oracle   dba         4171471 May 03 23:34 easyprd_ora_37880058.trc
-rw-r--r--    1 oracle   dba           77447 May 03 23:35 easyprd_ora_37880058-longer.log
easyserver:easyprd:/ora/easyprd/trace/udump $

OS process id will help in identify newly generate trace file.

SQL>   select p.PID,p.SPID,s.SID
  from v$process p,v$session s
  where s.paddr = p.addr
  and s.sid = &SESSION_ID  2    3    4
  5  ;
Enter value for session_id: 1631
old   4:   and s.sid = &SESSION_ID
new   4:   and s.sid = 1631

       PID SPID                SID
---------- ------------ ----------
       195 58851386           1631

SQL>


Stop trace file


exec dbms_support.stop_trace_in_session (1631,31917);


exec dbms_system.set_sql_trace_in_session(1279,62705,true);
EXEC DBMS_SYSTEM.set_sql_trace_in_session(sid=>123, serial#=>1234, sql_trace=>FALSE);


exec dbms_system.set_sql_trace_in_session(1631,31917,true);
EXEC DBMS_SYSTEM.set_sql_trace_in_session(sid=>1631, serial#=>31917, sql_trace=>FALSE);


EXEC DBMS_SYSTEM.set_sql_trace_in_session(sid=>123, serial#=>1234, sql_trace=>FALSE);


To check logon time for oracle session

SQL>  select to_char(logon_time,'dd-mon:hh24:mi'),sid,serial#,username,status,sql_id,event from v$session where sid =1631 order by 1;

TO_CHAR(LOGO        SID    SERIAL# USERNAME                       STATUS   SQL_ID        EVENT
------------ ---------- ---------- ------------------------------ -------- ------------- ----------------------------------------------------------------
06-may:15:40       1631      31917 OPS$BPRD001                    ACTIVE   d3rcjjtj06xy0 TCP Socket (KGAS)



Generate trace file in readable format for further ananlysis

tkprof rcc1_ora_3695308.trc rcc1_ora_3695308.prf SYS=NO SORT= EXECPU,FCHCPU

  or

tkprof rcc2_ora_1294546.trc thirdnewelapsechela.txt waits=yes sys=no sort=exeela,fchela explain='system/'

For database level analysis 
check PGA and SGA value and generate AWR report as well

show parameter max

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
lock_sga                             boolean     FALSE
pre_page_sga                         boolean     FALSE
sga_max_size                         big integer 2G
sga_target                           big integer 2G
SQL> show parameter pga
SQL> show parameter pga

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_target                 big integer 691M
SQL>

Database (easypprd)


Current Value

1,382== Pga
3,072 == Sga           


Recommended value
-----------------------
sga_max_size =5,740        
sga_target =2,419
shared_pool_size= 896


check table size if require



SQL> select sum(bytes/1024/1024) from dba_segments where segment_name='GAZ_DESTINATION_STATION';

SUM(BYTES/1024/1024)
--------------------
              51.625

SQL>

Run SQLtrpt -It will help DBA to get  recommendation for particular s

SQL>
SQL> @?/rdbms/admin/sqltrpt.sql

15 Most expensive SQL in the cursor cache
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SQL_ID           ELAPSED SQL_TEXT_FRAGMENT
------------- ---------- -------------------------------------------------------
5rf0k04hs5491 ########## SELECT * FROM GAZ_DESTINATION_STATION WHERE VERSION_NO
gdy0dnwknz384 ########## BEGIN CARRIER_ROUTING_DETAILS.PC_MAIN(CA_META_CLOB=>:1
avufag1k1k5fk ########## BEGIN DC_ROUTING.PC_MAIN(CA_META_CLOB=>:1 , CA_DATA_CLO
7b4r2t7vn5t4h ########## BEGIN get_atp_carrier_label_details.pc_main(:1, :2, :3,
d2w3a132p21f7  69,137.34 BEGIN GET_ATP_TRACKING_DETAILS.PC_MAIN(CA_META_CLOB=>:1
drvqacc5j0ta8  48,054.86 BEGIN ATP_DBA.PACK_GAZ0004.pc_main('I'); END;
cx99x6vjnz1p6  26,062.83 BEGIN GETTRACKINGMESSAGES.PC_MAIN(CA_IN_REQ_META_DATA=>
873742mkttpu1  24,543.07 BEGIN GET_ATP_DELIVERY_STATUS.PC_MAIN(CA_META_CLOB=>:1
0hqrdn4gwvwxa  15,782.96 BEGIN CARRIER_ROUTING_DETAILS.PC_MAIN(:1, :2, :3, :4);
7j6n2v74q4bm2  12,916.31 BEGIN PACK_CALCULATE_DC_DEL_PROMISE.PC_MAIN(CA_ATG_SITE
bg71sruhqpxta  12,285.01 SELECT PT.TIMESTAMP_CREATED, PT.LOG_DATE, PT.EVENT_CODE

SQL_ID           ELAPSED SQL_TEXT_FRAGMENT
------------- ---------- -------------------------------------------------------
03ns1wz1nx4r2  12,098.69 BEGIN ATP_DBA.PACK_PAN_DATA_EXTRACT.pc_main('ALL'); END
2wz9rpn84kw1c  11,445.90 SELECT * FROM ( SELECT PAR_T.* FROM PARCEL PAR , PARCEL
03135qyarm618   9,973.96 SELECT EXTRACTVALUE(VALUE(PARAM_ARRAY),'//TrackingDetai
bhyf4zy55r2rx   8,544.46 INSERT INTO PARCEL_TRACKING (         LOG_DATE,UPI,CARR

15 Most expensive SQL in the workload repository
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



Specify the Sql id
~~~~~~~~~~~~~~~~~~
Enter value for sqlid: 5rf0k04hs5491

Sql Id specified: 5rf0k04hs5491

Tune the sql
~~~~~~~~~~~~

GENERAL INFORMATION SECTION
-------------------------------------------------------------------------------
Tuning Task Name   : TASK_162079
Tuning Task Owner  : SYS
Workload Type      : Single SQL Statement
Scope              : COMPREHENSIVE
Time Limit(seconds): 1800
Completion Status  : COMPLETED
Started at         : 05/06/2016 17:45:37
Completed at       : 05/06/2016 17:45:46

-------------------------------------------------------------------------------
Schema Name: ATP_DBA

SQL ID     : 5rf0k04hs5491
SQL Text   : SELECT * FROM GAZ_DESTINATION_STATION WHERE VERSION_NO = :B5 AND
             :B4 ||:B3 ||:B2 ||:B1 BETWEEN FROM_AREA||FROM_DISTRICT||FROM_SECT
             OR||FROM_STREET AND TO_AREA||TO_DISTRICT||TO_SECTOR||TO_STREET
Bind Variables :
 1 -  (NUMBER):136
 2 -  (VARCHAR2(32)):BA
 3 -  (VARCHAR2(32)):13
 4 -  (NUMBER):3
 5 -  (VARCHAR2(32)):HF

-------------------------------------------------------------------------------
FINDINGS SECTION (2 findings)

-------------------------------------------------------------------------------

1- SQL Profile Finding (see explain plans section below)
--------------------------------------------------------
  A potentially better execution plan was found for this statement.

  Recommendation (estimated benefit: 93.89%)
  ------------------------------------------
  - Consider accepting the recommended SQL profile.
    execute dbms_sqltune.accept_sql_profile(task_name => 'TASK_162079',
            task_owner => 'SYS', replace => TRUE);

  Validation results

  ------------------
  The SQL profile was tested by executing both its plan and the original plan
  and measuring their respective execution statistics. A plan may have been
  only partially executed if the other could be run to completion in less time.

                           Original Plan  With SQL Profile  % Improved
                           -------------  ----------------  ----------
  Completion Status:            COMPLETE          COMPLETE
  Elapsed Time (s):            3.224566           .529278      83.58 %
  CPU Time (s):                 .351035           .084862      75.82 %
  User I/O Time (s):           2.679023           .396901      85.18 %
  Buffer Gets:                   107149              6540      93.89 %
  Physical Read Requests:          2462                63      97.44 %

  Physical Write Requests:            0                 0
  Physical Read Bytes:         20168704           5963776      70.43 %
  Physical Write Bytes:               0                 0
  Rows Processed:                     1                 1
  Fetches:                            1                 1
  Executions:                         1                 1

  Notes
  -----
  1. Statistics for the original plan were averaged over 1 executions.
  2. Statistics for the SQL profile plan were averaged over 2 executions.

2- Alternative Plan Finding

---------------------------
  Some alternative execution plans for this statement were found by searching
  the system's real-time and historical performance data.

  The following table lists these plans ranked by their average elapsed time.
  See section "ALTERNATIVE PLANS SECTION" for detailed information on each
  plan.

  id plan hash  last seen            elapsed (s)  origin          note
  -- ---------- -------------------- ------------ --------------- ----------------
   1 4282425958  2016-05-04/03:00:35        0.265 AWR
   2 2850782741  2016-05-06/09:13:24        0.519 Cursor Cache    original plan


  Recommendation
  --------------
  - Consider creating a SQL plan baseline for the plan with the best average
    elapsed time.
    execute dbms_sqltune.create_sql_plan_baseline(task_name => 'TASK_162079',
            owner_name => 'SYS', plan_hash_value => 4282425958);

-------------------------------------------------------------------------------
EXPLAIN PLANS SECTION
-------------------------------------------------------------------------------

1- Original With Adjusted Cost
------------------------------

Plan hash value: 2850782741

-------------------------------------------------------------------------------------------------------
| Id  | Operation                   | Name                    | Rows  | Bytes | Cost (%CPU)| Time     |
-------------------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT            |                         |     1 |    63 |  1781   (1)| 00:00:22 |
|*  1 |  TABLE ACCESS BY INDEX ROWID| GAZ_DESTINATION_STATION |     1 |    63 |  1781   (1)| 00:00:22 |
|*  2 |   INDEX RANGE SCAN          | GA_DE_ST_PK             |   174K|       |   625   (1)| 00:00:08 |
-------------------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------


   1 - filter("FROM_AREA"||"FROM_DISTRICT"||"FROM_SECTOR"||"FROM_STREET"<=:B4||:B3||TO_CHAR(:B2
              )||:B1 AND "TO_AREA"||"TO_DISTRICT"||"TO_SECTOR"||"TO_STREET">=:B4||:B3||TO_CHAR(:B2)||:B1)
   2 - access("VERSION_NO"=:B5)

2- Using SQL Profile
--------------------
Plan hash value: 4282425958

-----------------------------------------------------------------------------
| Id  | Operation         | Name                    | Rows  | Bytes | Cost  |
-----------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |                         |     1 |    63 |   987 |
|*  1 |  TABLE ACCESS FULL| GAZ_DESTINATION_STATION |     1 |    63 |   987 |

-----------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter("VERSION_NO"=:B5 AND "FROM_AREA"||"FROM_DISTRICT"||"FROM_S
              ECTOR"||"FROM_STREET"<=:B4||:B3||TO_CHAR(:B2)||:B1 AND
              "TO_AREA"||"TO_DISTRICT"||"TO_SECTOR"||"TO_STREET">=:B4||:B3||TO_CHAR(:B
              2)||:B1)

-------------------------------------------------------------------------------
ALTERNATIVE PLANS SECTION
-------------------------------------------------------------------------------