B3: Putting OpenEdge Auditing to Work: Dump and Load with (Almost) No Downtime

1. B3: Putting OpenEdge Auditing to Work: Dump and Load with (Almost) No Downtime David EDDY Senior Solution Consultant

2. Why?

3. Why? • Get access to Type-II storage areas • Reorganise database • Can’t afford to have DB off-line!

4. So What’s the Big Deal? • Dump and load with 2 small downtime slots: • A few minutes at front end • As little as 5 min at back end – YMMV • Old DB continues in live use while building new • No lost data

5. Agenda Introduction The Dump/Load Process Techniques: Turning Auditing to this Purpose Techniques: Offline Dump and Load Other Issues

6. Introduction • Why is this important? • The plan • Why it works • Why it might not work • Why auditing?

7. Why is this Important? • Type II Storage Areas • 15-20% performance boost • Removal of limits • On-line maintainability • Future capabilities (e.g. per-area backups)

8. Plan Timeline Old DB New DB Add storage ares for auditing data Enable auditing Add auditing policy & enable Copy live DB via backup/restore Dump Build new structure Load & index build Initial replication Second replication • Changeover: • Final replication • Verification test (db content comparison) • Signoff • Make new DB live 

9. Why It Works • Bulk of DB activity is reads • Updates small proportion of total • Batch update can be done in << real time • Multiple updates per row • Only interested in the last • Further decreases total work replicating changes • ...for most databases

10. Why It Might Not Work • Update rate too high / no duplication of activity • Cost of change capture too high • No unique key • Record replication needs unique key

11. Why Auditing • Reliable, light-weight change capture • Implemented in DB engine core • Easy to set up • Can use GUI tool for policy set up if desired • No code impact • See OpenEdge Core Services manual for more detail about auditing

12. Agenda Introduction The Dump/Load Process Techniques: Turning Auditing to this Purpose Techniques: Offline Dump and Load Other Issues

13. The Dump/Load Process Old DB New DB • Migrate to OpenEdge 10.1C in-situ • Prepare auditing policy • Initiate auditing • Offline dump/load • Repeated batch replication to “catch up” • Verification of database contents & signoff • Changeover 

14. The Dump/Load Process:Migrate to OpenEdge 10.1C In-Situ • Auditing requires 10.1 • OpenEdge 10.1C+ ideally • Must run 10.1 in production during change capture • If this represents a migration, you must first: • Do a trial migration in your test environment • Test & get signoff • Migrate clients to 10.1 if needed

15. Migration In-Situ (continued) • Convert database to 10.1 if not already there • First disable JTA, Replication, AI if enabled • Thenproutil db –C truncate bi $DLC10/bin/proutil db –C conv910 • New DB will have 64-bit features enabled • So we will also enable them in migrated DB to catch problems early proutil db –C enableseq64 proutil db –C enablelargekeys

16. The Dump/Load Process:Prepare Auditing Policy • Nominate tables to be replicated • Omit any scratch/work tables • Specify unique key for each table • Ideally corresponding with an index • Create auditing policy • APMT (from DB Admin Tool) • Direct policy data creation • Automation • Extract key field list from DB • Load policy without using APMT

17. The Dump/Load Process:Initiation of Auditing • Add storage areas to contain auditing datad “AuditData”,128;512 /path/to/extents d “AuditIndex”,16;64 /path/to/extents prostrct add[online] db audit.st • Enable auditing (and create auditing tables)proutil db –C enableauditing area AuditData indexarea AuditIndex deactivateidx • Consider enabling large file supportproutil db –C enablelargefiles • Load and enable the policies • APMT or bespoke tool

18. The Dump/Load Process:Offline Dump/Load • Take online backup of production DB • Restore in working area • Dump contents • Don’t dump scratch/work tables • Delete old DB • Build new structure for DB • Modify schema to suit (and load into new DB) • Load dumped data • Procedural details later

19. The Dump/Load Process:Batch Replication • Gather committed changes • Record timestamp of last change gathered • Eliminate duplicates • Only interested in last change for each row • Split list of changes into multiple lists • Use multiple loaders to load changes • Write a script to do all this

20. Batch Replication – Catching Up • Initial run will take some time • 3 days work might take 4 hours to apply • Next run will be faster • 4 hours work might take 15 minutes to apply • Once caught up, replicate periodically • Keep replication execution time low • Replication interval is a trade-off • Less frequent means more data reduction through duplicate elimination • Too infrequent means replication takes too long

21. The Dump/Load Process:Verification of Contents • You should have a basis for certifying that new DB is a good copy of the old • proutil tabanalys • Application reports e.g. trial balance • Everyone must agree that tests are valid basis for certification • Tests should not take too long to run

22. The Dump/Load Process:Changeover • Block user access to live DB • Perform final replication • Dump users, sequence values from old DB • Verify content equality (& signoff) • Make new DB live • Load users, seqvals into new DB • Shut down old DB • Change references in startup scripts, OR move or delete old DB and replace with new DB • Allow users access • Initiate backup

23. Agenda Introduction The Dump/Load Process Techniques: Turning Auditing to this Purpose Techniques: Offline Dump and Load Other Issues

24. Techniques: Auditing for Dump/Load • Audit policy • Audit data tables • Extracting key data • Data reduction • Applying changes

25. Audit Policy • Defines auditing: • What tables/fields are audited • What data is recorded • Can be multiple policies active • DB will merge at runtime to generate “effective” policy • Report available through APMT • Contained in tables • _aud-*-policy

26. Audit Policy Starting Point • You must know the name of each table you will replicate • You must know for each replicated table the list of fields you will use to uniquely identify each row in that table • Suggest automatic generation from schema (unique indexes) # Table keys for dump/load auditing policy – # C:\oebin\oework\tmp\test Salesrep: SalesRep Vacation: StartDate Department: DeptCode State: State ...

27. Audit Policy with APMT • GUI tool provided with OpenEdge distribution • How to use: • Define a new policy • Add tables • Add fields • Add events • Enable policy • Export new policy to XML (for later upload to live)

28. Audit Policy with APMT: Policy These values are default

29. Audit Policy with APMT: Tables Note “standard” audit level

30. Audit Policy with APMT: Fields List of key fields (for the Customer table in this example). Don’t forget to set the identifying seq num for each field in unique key.

31. Audit Policy with APMT: Events You need to define audit events, which describe the events used by this policy.Events 5100-5102 are the standard events for capturing creates, updates, and deletes in the database.Don’t forget to do this or no changes will be captured.

32. Audit Policy Tables • If you’re not using APMT, you need to set: • _aud-audit-policy • _aud-file-policy • _aud-field-policy • _aud-event-policy

33. Audit Policy Tables: _aud-audit-policy One record per policy (i.e. we add 1 record) _audit-policy-guid = base64-encode(generate-uuid) _audit-data-security-level = 0 _audit-custom-detail-level = 0 _audit-policy-active = true

34. Audit Policy Tables: _aud-file-policy One record for each table being audited _audit-policy-guid = _aud-audit-policy._audit-policy-guid _file-name = “table name” _owner = “PUB” /* usually */ _audit-create-level = 12 _audit-update-level = 12 _audit-delete-level = 12 _create-event-id = 5100 _update-event-id = 5101 _delete-event-id = 5102

35. Audit Policy Tables: _aud-field-policy One record for each key field of each table _audit-policy-guid = _aud-audit-policy._audit-policy-guid _file-name = “table name” _owner = “PUB” /* usually */ _field-name = “field name” _audit-identifying-field =seq_num_of_field_in_unique_key _audit-create-level = 12 _audit-update-level = 12 _audit-delete-level = 12

36. Audit Policy Tables: _aud-event-policy Three records per policy (one for each event used) _audit-policy-guid = _aud-audit-policy._audit-policy-guid _event-id = {5100|5101|5102} _event-level = 1

37. Audit Data Tables • Only interested in _aud-audit-data • Key fields: • _audit-date-time • _event-id • _event-context • Some indexes present even after deactivateidx: • _Audit-data-guid • _Audit-date-time

38. Audit Data Tables: _aud-audit-data • _audit-date-time is a datetime-tz field • _event-id tells you whether it was a create, update or delete • _audit-event-context contains the table name and key field values • _audit-event-data contains changed field values but can be safely ignored

39. _audit-event-context _audit-event-context = Tablename + chr(6) + list-of-key-field-values List-of-key-field-values = key-value-1 [ + chr(7) + key-value-2 ] … Order of key field values is dictated by identifying field sequence number

40. Extracting key data • Pull data from _aud-audit-data in _audit-date-time order • Want only those rows which can be share-locked • Unlockable audit data means transaction still in progress • Must not replicate uncommitted data • Dump only up to last row time time stamp different to last lockable row • Order not guaranteed within same date/time value • Need only 3 fields: • _event-context • _event-id • _audit-date-time

41. Data reduction • Need only last change for each row mentioned • Ignore or discard earlier changes

42. Applying changes • Changes can be applied in any order • Recommend multi-threading load • OpenEdge performance best with multiple threads • Tune new DB for heavy transaction activity • Write program to read event data and emulate in new DB fail-safe • Create/Update = Create if row does not exist in new; copy row from live DB if does exist in new • Delete = do nothing if target row does not exist • Batch transactions for performance • Run multiple threads e.g. 4-8

43. Agenda Introduction The Dump/Load Process Techniques: Turning Auditing to this Purpose Techniques: Offline Dump and Load Other Issues

44. Techniques: Off-Line Dump and Load • Planning the new database • Adjusting the schema • Dumping • Loading • Index rebuild

45. Planning the New Database • Plan to use Type II storage areas everywhere • Rows per block not that critical • Type-II areas have no max size (>1PB @ 128) • Use 128 or 256 for all table areas • Use 8 or 16 for all indexes • Blocks per cluster more important • Use 512 bpc only for objects 20MB+ • Use 8bpc otherwise • Distinct data & index areas • Try to equalise area sizes • Index build is parallel across areas

46. Adjusting the Schema • Old .df has old storage areas encoded • Manual editing is error prone • Recommended technique: • Build empty DB with both old & new areas (only 1 var extent for each area) • Load old schema • Build & execute script which tablemove’s to new schema • Dump new .df • New .st and .df define the new database

47. Dumping • Use binary dump • No size limit • No data corruption risk • Self-balancing parallel technique: • List tables in descending order of size • Start multiple dump threads • Each thread takes 1st table from list and dumps it • Speed is nice but not critical • Dump multithreaded might be useful for very large tables

48. Loading • Use binary load • Difficult to go faster than offline load as follows:proutil db –C truncate bi –bi 512 –biblocksize 8for f in *.bd* ; do proutil db –C load $f –r –B 500done • Don’t bother with “build indexes” • Multithreaded idxbuild is faster

49. Index Rebuild • Set up sort file dbname.srt • Invoke index build in multi-threaded mode:proutil db –C idxbuild all –TB 31 –TM 32 –SS db.srt –SG 64 –B 500 –thread 1 –threadnum cpus*1.5 • IDXBUILD is multi-threaded by default • No need to specify –thread, –threadnum if happy with 1 thread per CPU

50. Agenda Introduction The Dump/Load Process Techniques: Turning Auditing to this Purpose Techniques: Offline Dump and Load Other Issues