Adabas Recovery using

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Adabas Recoveryusing fast backup software

• by
• Rich Crumley
• Keane, Inc

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SAG disclaimer

• Software AG does not recommend using such a
  database fastcopy as a substitute for a regular
  Software AG database (or delta) save. Not only
  does Software AG have no control over the
  datasets that are included in the database
  fastcopy, but it also cannot vouch for the
  success of the fastcopy. Moreover, delta saves
  cannot sensibly be run on a copy of the database,
  as the DSF status change effected by the delta
  save would occur on the database copy instead of
  the original.

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Agenda

• Backup process
• Recovery process
• Some possibilities

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The Backup Process

• Suspend update transactions
• Execute fastcopy
• Resume update transactions

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ADABAS 7.4 Release Notes
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SUSPEND UPDATE TRANSACTIONS
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TRANSACTIONS SUSPEND

• Optional Parameter - TTSYN
• Use this parameter to specify the maximum
  amount of time the nucleus is to wait for all ET
  users to reach ET status before it forcibly ends
  and backs out update transactions that are still
  running in order to quiesce the system. If this
  parameter is not specified, the default is the
  ADARUN TT value.

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TRANSACTIONS SUSPEND

• Optional Parameter - TRESUME
• Use this parameter to specify the amount of
  time in seconds the system is to remain quiesced
  after being suspended before the nucleus
  automatically resumes normal update transaction
  processing. If this parameter is not specified,
  the default is 120 seconds and the maximum is
  86400 seconds or about 24 hours. The count begins
  when the nucleus has been successfully quiesced.
  

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TRANSACTIONS SUSPEND

• Behind the scenes
• New update transactions held in the user queue.
• In-flight transactions are allowed to complete
  (within TTSYN)
• Buffer flush
• Write checkpoint SYNC-73
• ADADBS notified

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TRANSACTIONS SUSPEND

• Issues
• Read processing continues
• Utility conflicts (collisions)
• TTSYN value
• TRESUME value

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Execute fastcopy
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RESUME UPDATE TRANSACTIONS
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TRANSACTIONS RESUME

• Behind the scenes
• Write checkpoint SYNS-74
• Suspended transactions released from the user
  queue
• ADADBS notified

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TRANSACTIONS RESUME

• Issues
• Database not in SUSPEND status

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Agenda

• Backup process
• Recovery process
• Some possibilities

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The Recovery Process

• Database recovery
• Ensure database inactive
• Execute copyback process
• Start database in utility only mode
• Regenerate transactions
• Start database for normal processing

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The Recovery Process

• File recovery
• Disable original file
• Regenerate transactions on snap DB
• Save file on snap database
• Restore file to original database
• Enable file for normal processing

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Agenda

• Backup process
• Recovery process
• Some possibilities

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Some Possibilities

• How might the snap database be used?
• Offline Save
• Diagnostic utilities (ACK, ICK, VAL)
• Static copy of Production database
• Recovery purposes
• ???