Help: Triangle Tennis Trust Tournament Web Registration

Manufacturing Logistics Control has developed a web application to assist the process of registration the annual tennis tournament by Triangle Tennis Trust, Chennai. The application has been deployed on Microsoft's Silverlight platform and the participants registering for the event will be required to have a silverlight plug-in for their browsers.
Following are the steps that will assist you in the registration process.

1. Step 1: Go to the registration website - http://ttt.mlcmds.com/
2. Step 2: Install Silverlight plug-in. (If the plug-in is already installed skip to Step 7)
   
   Click on the icon to initiate the download of Silverlight from Microsoft's website.
3. Step 3: You will be prompted to 'Run' or 'Save' the installer file. Click on 'Save' and save the file to a local folder. In case, you have subsequent problems with installation you can utilise this file later.
   
4. Step 4: Run the downloaded file.
   
5. Step 5: Install Silverlight to your computer.
   
   
6. Step 6: The browser will refresh automatically to launch the website. If it does not, then close your browser and try to log on to the website http://ttt.mlcmds.com/ again.
7. Step 7: Click on the button 'Registration' at the bottom, or click 'Registration' link available on the right under "Quick Links"
   
8. Step 8: Pre-registration screen appears requesting the details of the participant.
   
   
   • Provide the first name. Do not use a blank space in first name.
   • Provide the last name (or initials). No blank spaces here either.
   • Select the Date of birth (DOB). If you find it difficult to use the buttons available to select date, specify your date in the following format - 12-04-1999 (For a DOB of 12 April, 1999).
   • Select Gender of participant. (M- Male and F-Female)
   
9. Step 9: Click the button labeled 'New' to continue with registration.
   
   A window pops up as shown above. (Note: If you are not able to view the buttons 'OK' and 'Cancel' at the bottom of the screen, reduce the zoom level of the browser to less than 100%)
10. Step 10: Provide further details of the participant.
    
    
    • Under 'Tournament Details' select the events for which the participant wishes to register. Use the drop down box for selecting the event.
    • Participant can appear for two events. (For e.g. Boys Under 12 and Boys Under 14). If second event is necessary, select Event 2. Else, leave it blank. You can always correct it using the option 'Clear Selection'.
    • Provide the AITA and TNTA points of the participant for each event.
    • Fill in the Contact Information of the participant.
    • Mention 10-digit Mobile number, E-mail address and postal address
    • Select city of residence of the participant.
    • Select the training centre of the participant. If it doesn't appear in the list, choose 'OTHERS'.
    • Provide a password. (Must contain atleast 6 alphanumeric characters and one number). Password will be required if you wish to edit/change any information provided here, at a later time.
    • Note: Errors, if any, will be shown at the bottom as a summary. On every field a red box will appear next to it, if it is erroneous.
11. Step 11: After required information is provided, click 'OK' to save the registration details. A window will appear confirming the completion of registration.
    
12. Changing Registration details: To change any information provided in your registration details
    
    • Enter First Name
    • Enter Surname/Initials
    • Select Date of Birth
    • Select Gender
    • Provide the password created during registration
    • Click the button 'Edit'
    
    
    Edit the information you have provided and click 'OK' to save the changes made.
    

And Good luck to the participant for the tournament!

Recovering Oracle Block corruption

Occurence of Problem:
While trying to login to our application running on Oracle 10g R2 (10.2.0.4) we received the following error:

ORA-01115: IO error reading block from file 1 (block # 94697)
ORA-01110: data file 1: '(...)\SYSTEM01.DBF'
ORA-27091: unable to queue I/O
ORA-27070: async read/write failed
OSD-04006: ReadFile() failure, unable to read from file
O/S-Error: (OS 23) Data error (cyclic redundancy check).

Investigation:

• Oracle's Metalink pointed out that the problem was a block corruption on the disk.


• It is a 500GB Seagate SATA disk. The Event Viewer of Windows Server 2008 also gave the 'disk' block corrupt error.


• A DBVERIFY was done on the corrupted datafile and it returned an O/S Error 0RA-01115.


• A complete Check Disk was run on the disk and the corrupted block were fixed.


• DBVERIFY now gave the following error for the datafile
  

  
  Corrupt block relative dba: 0x004171e8 (file 1, block 94696)
  Fractured block found during buffer read
  Data in bad block:
  type: 6 format: 2 rdba: 0x004171e8
  last change scn: 0x0000.01c61503 seq: 0x1 flg: 0x06
  spare1: 0x0 spare2: 0x0 spare3: 0x0
  consistency value in tail: 0x00000000
  check value in block header: 0xa06b
  computed block checksum: 0xdfa7
  Reread of rdba: 0x004171e8 (file 1, block 94696) found same corrupted data
  

  
  Same error also appears in the alert.log file


• Attempting to login into the application gave a block corruption error in Oracle in the datafile.
  

  
  ORA-01578: ORACLE data block corrupted (file # 1, block # 94696)
  ORA-01110: data file 1: '(...)\SYSTEM01.DBF'
  

  
  Do note that it is the previous block ID from last error message


• Alert.log contained the following information
  

  
  Corrupt Block Found
  TSN = 0, TSNAME = SYSTEM
  RFN = 1, BLK = 94696, RDBA = 4289000
  OBJN = 331, OBJD = 331, OBJECT = I_PROCEDUREPLSQL$, SUBOBJECT =
  SEGMENT OWNER = SYS, SEGMENT TYPE = Index Segment
  

  
  

Resolution:
Refer to Oracle's documentation on Detecting and Repairing Data Block Corruption.

1. Logon to SYS user and create a REPAIR Table:
   

   
   BEGIN
   DBMS_REPAIR.ADMIN_TABLES (
   TABLE_NAME => 'REPAIR_TABLE',
   TABLE_TYPE => dbms_repair.repair_table,
   ACTION => dbms_repair.create_action,
   TABLESPACE => 'USERS');
   END;
   



2. Check the Object for corruption
   

   
   DECLARE num_corrupt INT;
   BEGIN
   num_corrupt := 0;
   DBMS_REPAIR.CHECK_OBJECT (
   SCHEMA_NAME => 'SYS',
   OBJECT_NAME => 'I_PROCEDUREPLSQL$',
   OBJECT_TYPE => dbms_repair.index_object,
   REPAIR_TABLE_NAME => 'REPAIR_TABLE',
   CORRUPT_COUNT => num_corrupt);
   DBMS_OUTPUT.PUT_LINE('number corrupt: ' || TO_CHAR (num_corrupt));
   END;
   

   
   Note: If parameter Object Type is ignored, it takes the default as TABLE_OBJECT and the query will return a table or view not found error. The object turned out to be an INDEX OBJECT.


3. Command - "select * from repair_object" will show the corrupt blocks and associated information


4. Fix the errors using the following code:
   

   
   DECLARE num_fix INT;
   BEGIN
   num_fix := 0;
   DBMS_REPAIR.FIX_CORRUPT_BLOCKS (
   SCHEMA_NAME => 'SYS',
   OBJECT_NAME=> 'I_PROCEDUREPLSQL$',
   OBJECT_TYPE => dbms_repair.INDEX_OBJECT,
   REPAIR_TABLE_NAME => 'REPAIR_TABLE',
   FIX_COUNT=> num_fix);
   DBMS_OUTPUT.PUT_LINE('num fix: ' || TO_CHAR(num_fix));
   END;
   

   
   num fix: 0 was returned.
   Corrupt block could not be fixed


5. It was a UNIQUE index on procedures. The index was dropped!


6. Trying to recreate the index failed due to duplicate records


7. From the object ID, the problematic procedure (from our application) was located and dropped.


8. Index creation was successful.


9. Application procedure which was dropped was re-created.


10. Login to the application was successful.


11. DB Verify still gives the same error informing that a block has been marked as corrupt and is not usable.

Using AWE to improve Oracle performance

Problem:
Hardware:

1. 4 x Dual core Intel Xeon processors


2. 12 GB of physical RAM


3. 2 x 74 GB SATA Disks configured as RAID-0 (RAID-1 removed to increase performance. Data security done using archiving and automated backups).

Despite having a high performance configuration, Oracle Database 10g R2 (Version 10.2.0.4) was reporting problems with speed. Typical user complaints were as follows

• Startup time for login screen is high.


• Transition between screens is slow.


• Execution of programs within a screen is fast.


• Time lag (Freeze) experienced (anything between 0.5 second to 5 seconds) while traversing between multiple records in one screen.

Analysis:
The Oracle Database was tuned manually. All the values for Pool size and SGA, PGA targets were provided manually in the SPFILE during installation.
Some of them were as follows:

• _db_cache_size=989855744


• _large_pool_size=25165824


• java_pool_size=512165824


• shared_pool_size=233554432


• sga_max_size=2500016000


• sga_target=2500016000


• pga_aggregate_target=262144000

The /3gb switch was turned on for the Operating system. oracle.exe process was able to acquire upto 2.5 GB physical memory. But the performance problems continued. The complete 12GB of physical RAM was also unutilised most of the time.

Solution:
Windows Address Windowing Extension (AWE) was used to increase the Oracle Data Buffer size. The Windows AWE is actually a set of extensions that allows applications like Oracle Database to manipulate physical memory greater than 4GB on 32-bit Operating systems. AWE allows fast memory management.

How To:
To use the Windows AWE, the following was done.

1. Turn on /PAE (Physical Address Extension) and /3gb switch on the Operating System so that more than 2GB of addressable space is available to applications.


2. Set the parameter AWE_WINDOW_MEMORY to a suitable value in the registry.
   Parameter is set in HKEY_LOCAL_MACHINE\Software\Oracle\(Oracle_Home)
   Value used: 536870912


3. In the init.ora set USE_INDIRECT_DATA_BUFFERS=TRUE


4. In the init.ora set DB_BLOCK_BUFFERS to a suitable value.
   Value used: 850000


5. The above should be sufficient for most databases. But we use poi Java utilities to import/export data to excel that requires a minimum of 500 MB Java Pool size.
   Hence, in init.ora JAVA_POOL_SIZE=512165824


6. An error was encountered on starting up the database that said that there was insufficient Streams Pool size. For which in init.ora, we set
   STREAMS_POOL_SIZE=100M

Note: Oracle's Metalink note - 225349.1 has a detailed description on using AWE and the calculations needed to arrive at appropriate values for AWE_WINDOW_MEMORY and DB_BLOCK_BUFFERS.

On starting up the database, we can see that Oracle acquired upto 9GB of physical memory and all the performance related problems from users were addressed.

Problems encountered:

• If the DB_BLOCK_BUFFERS or AWE_WINDOW_MEMORY value is incorrect, we get an
  ORA-27102: out of memory Error followed by
  O/S-Error: (OS 8) Not enough storage is available to process this command

The init.ora used is attached herewith:

_db_block_lru_latches=32
audit_file_dest='C:\admin\(db_name)\adump'
background_dump_dest='C:\admin\(db_name)\bdump'
compatible='10.2.0.3.0'
control_files='D:\(db_name)\CONTROLFILE\(controlfilename).CTL'
core_dump_dest='C:\admin\(db_name)\cdump'
db_block_buffers=850000
db_block_size=8192
db_create_file_dest='D:\(db_name)'
db_domain=''
db_file_multiblock_read_count=16
db_name=(db_name)
dispatchers='(protocol=TCP)'
java_pool_size=512165824
job_queue_processes=10
log_buffer=8388608
open_cursors=3000
processes=150
remote_login_passwordfile='EXCLUSIVE'
shared_pool_size=1468006400
shared_servers=5
streams_pool_size=100M
undo_management='AUTO'
undo_tablespace='UNDOTBS1'
use_indirect_data_buffers=TRUE
user_dump_dest='C:\admin\(db_name)\udump'
log_archive_format=Log_%s_%t_%r.arc
log_archive_dest='D:\(db_name)\ARCHIVE'