® IBM Software Group © 2005 IBM Corporation Informix High Availability Features John F. Miller III

IBM Software Group 2 Overview  Backup and Restore  New & Recent Features  Backup Options  Restore Options  Best Practices  High Availability Data Replication  Archive Validation  New and Recent HA Feature

IBM Software Group 3 Recent Backup & Restore Features  Point in Time Restore of a table from a backup  Ontape improvements  No tape size  Large file support in ontape  Backup/restore using STDIO  Support of External Backup & Restore  New option to salvage log using ontape  Onbar Improvements  More accurate space calculation for onbar backup  Reading and dumping logical log using onbar  Improved messages in bar activity log  Better handling of command line options in onbar  Sync Emergency boot file and sysutil database (onsmsync)  Progress Feedback  Re Directed Restore  Backup Verification  Parallel Log Cleaning

IBM Software Group 4 Backup Types  Serial Backup  Archives the entire system at a single point in time using only one data stream  Parallel Backup  Archives the requested dbspace one at a time to N data streams  External Backup  Allows a third party application to backup the database server while maintain logical consistency

IBM Software Group 5 Physical Backup  Level 0 (Full Backup)  Backup of all used pages  Level 1 (Incremental Backup)  Backup of all modified pages since last level-0 backup  Level 2 (Delta Backup)  Backup of all modified pages since last level-1 backup  Level 1 and 2 backup is not supported using EBR

IBM Software Group 6 Overview  Backup and Restore  New & Recent Features  Backup Options  Restore Options  Best Practices  High Availability Data Replication  Archive Validation  New and Recent HA Feature

IBM Software Group 7 Restore Options  Cold Restore  Restoring the server when the database engine is offline  Warm Restore  Restore of dbspaces which occur while the database engine is online  Mixed Restore  A cold restore of set dbspaces followed by a warm restore of other dbspaces  Logical Restore  Follows physical restore  Required  After onbar restore from parallel backup  Warm Restore  After cold whole system restore it is optional  Parallel logical recovery  ON_RECVRY_THREADS  OFF_RECVRY_THREADS

IBM Software Group 8 Restore Options  Point-in-time Table and/or column Level Restore  Imported Restore  Transferring an archive taken on one computer and restoring it on a second computer  Point-in-Time Restore  Restoring the entire system to a single point in time  Suspended Restore  Ability to continue the restore if a restore client fails  Restartable Restore  Allows the DBA to pickup the restore from the failure point  Re-Directed Restore  Allows chunk pathnames to be changed while doing the restore

IBM Software Group 9 Backup and Restore Tools ontape On-Bar External Backup and Restore archecker

IBM Software Group 10 Point in Time Table Level Restore (PITTLR)  Provide the customer with the ability to easily extract a set of tables, a table or a portion of a table from a level 0 archive to a user specified point in time.  The extracted data can be placed in an external table or on a table on the server of the user’s choice regardless of server version or machine type as long as the database server is listed in the sqlhost file.

IBM Software Group 11 Benefits  Extract a table or set of tables  Filter the retrieved data  Retrieve just a subset of columns  Repartition the data  Data may be placed in the same version database or on a different database version with a different machine architecture

IBM Software Group 12 Recovery of Lost Table  Extracts a table called test1:tlr from the most recent backup of dbspace1 and places the data in table test1:tlr database test1; create table tlr ( a_serial serial, b_integer integer, c_char char(20), d_decimal decimal ) in dbspace1; insert into tlr select * from tlr;

IBM Software Group 13 Using External Tables  Extracts a table called dl:source_tab from the most recent backup of dbspace1 and sends the data in ASCII format with fields delimited to the file named /TMP/PIPE. database d1; create table source_tab (cola int) in dbspace1; create external table target_tab (cola int) USING (‘/TMP/PIPE’, ‘DELIMITED’); insert into target_tab select * from source_tab;

IBM Software Group 14 Distributed Restore  Extracts a table called test:source_tab from the most recent backup of dbspace1 and places the data on the database server rem_srv in the table target_dbs:tlr_1 database target_dbs; create table target_tab ( columns ); database test; create table source_tab ( columns ) in dbspace1; insert into select * from source_tab;

IBM Software Group 15 Ontape Features  Backup at the Server level  Support for incremental backups  Manual or continuous logical log backup  Restore entire system or single dbspace  Backup is self describing  All data backup is from the archive start time or before  No longer required to set TAPESIZE  Backup & Restore using STDIO  Large file support in ontape  Support of External Backup & Restore  New option to salvage log using ontape

IBM Software Group 16 Ontape Database server Physical Log Logical Logs reserve pages ontape Backup Media onconfig online log

IBM Software Group 17 On-Bar Features  Parallel backup and restore  System and dbspace level backup and restore  Support for incremental backups  Manual or automatic backup of logical logs  Instance point-in time recovery  Open interface for communication with storage managers (XBSA)  Re-Directed Restore

IBM Software Group 18 OnBar Architecture Storage Manager XBSAXBSA onbar_d onbar sysutils Database server Backup Media onconfig debug log activity log emergency Boot file emergency Boot file online log

IBM Software Group 19 External Backup & Restore (EBR) Features  External Backup and Restore  EBR allows administrators to make a consistent copy of their dbspaces using external tools  Used with many 3rd party backup products  Allows for both cold and warm restores  Basic Steps  Block server at checkpoint  Backup dbspace(s) using third party tools  Unblock server

IBM Software Group 20 Flash Copy IDS Informix Host Storage Spaces and logs FlashCopy Backups IDS ISM Backup logs on-bar Production Server A  Requires Storage System Capability  Use EBR technique to block server for copy

IBM Software Group 21 Remote copy using PPRC  Requires Storage System Capability  Uses EBR technique to block server for copy  Makes a flash copy on local storage  Establishes PPRC relationship between local and remote site  Makes multiple flash copy on remote site

IBM Software Group 22 Remote Copy using PPRC

IBM Software Group 23 Overview  Backup and Restore  New & Recent Features  Backup Options  Restore Options  Best Practices  High Availability Data Replication  Archive Validation  New and Recent HA Feature

IBM Software Group 24 Best Practices 1.Planning 2.Planning 3.Planning

IBM Software Group 25 What is a Successful Recovery?  “Successful” recovery is defined by your business needs

IBM Software Group 26 Goals For Recovery  Determine acceptable recovery time  How long can your business function without the data?  How long can your production system be down during a restore?

IBM Software Group 27 Right, Fast or Cheap? Choose Two!

IBM Software Group 28 Recovery Strategy Tune the Strategy Analyze/Test the Strategy Implement The Strategy Select Tools Plan Recovery Goals

IBM Software Group 29 Overview  Backup and Restore  New & Recent Features  Backup Options  Restore Options  Best Practices  High Availability Data Replication  Archive Validation  New and Recent HA Feature

IBM Software Group 30 What Is HDR (High Availability Data Replication)?  Two identical servers on two identical machines  Primary server  Fully functional server  All database activity – insert/update/deletes, are performed on this instance  Automatically sends logs to secondary server  Secondary server  Read only server : allows read only query  Always in recovery mode  Receives logs from primary and replay them to keep in sync with primary  When Primary server goes down, secondary server takes over as Standard server

IBM Software Group 31 HDR – Key points  Easy of administration and setup  Reduced downtime using DR switchover  Update interval  Automatic client redirection using DBPATH  Improved performance by using secondary as report server  Independent of geographic location  Indexes are locked when created on primary (till they are shipped to secondary)  No Replication of Blobspace blobs (only)  Non logged databases are not replicated BenefitsLimitations

IBM Software Group 32 ontape –p / onbar –r -ponmode –d secondary Server-A ontape –s –L 0 / onbar –b –L 0onmode –d primary Server-B HDR Setup B Primary Logs 1) Backup made of primary server 2) Notify primary server identity of secondary 3) Physical restore backup on secondary server 4) Notify secondary server identity of primary 5) Logical log transmission begins PrimarySecondary A

IBM Software Group 33 HDR – Normal Operations B Read-only Primary Secondary A Users reading and updating database Can be Updated Network Link For log Transmission Running Reports Log Buffers are transferred to Secondary

IBM Software Group 34 HDR – How it works AcctTable Logical Log Buffer Logical Logs Written to Disk PrimarySecondary Reception Buffer Recovery Buffer Logical Logs Written to Disk AcctTable LogRecvr drsecapply HDR Buffer DRINTERVAL Sets maximum time lag in seconds for HDR buffer transmission Set to ‘-1’ for synchronous.

IBM Software Group 35 PrimaryDown SecondaryStandard Read-only HDR Availability - Failover B Users reading and updating database A onmode –d standard Running Reports (Not Any More!!)

IBM Software Group 36 Down B A 1) Switch Server-B to primary mode Standard onmode –d primary Server-A Primary 5) Automatically transfers current logs from primary and resume 4) Possibly restore offline/backed up logs 2) Physical restore of failed system (if media failure) or restart Server-A to last checkpoint time ontape -p oninit -PHY 3) Notify Secondary server-A identity of Primary server onmode –d secondary Server-B Recovery ontape -l Secondary HDR Restart with NO Downtime

IBM Software Group 37 HDR Configuration Parameters  DRINTERVAL  Also decides sync or non-sync configuration  DRTIMEOUT  Actual value is 4 times of this  DRAUTO  Controls how the secondary should changes modes  DRLOSTFOUND

IBM Software Group 38 HDR Threads  Main thread  Primary: dr_prsend  Secondary: dr_secrecv  Ping thread  Primary: dr_prping  Secondary: dr_secping  Index thread  Primary: dr_idx_send (dr_btsend)  Secondary: dr_idx_recv(dr_btrecv)

IBM Software Group 39 Overview  Backup and Restore  New & Recent Features  Backup Options  Restore Options  Best Practices  High Availability Data Replication  Archive Validation  New and Recent HA Feature

IBM Software Group 40 Validating Archives  Does not have to be run on the same computer as the archive was taken  Uses very little space ~50MB  Both onbar and ontape

IBM Software Group 41 Validation  onbar -v [ other options ]  Are my backups usable?  Run a verification before you need to restore  After a restore fails  Get some idea why the restore failed  Perhaps the data was inconsistent  Perhaps the data was incomplete

IBM Software Group 42 What is actually validated  Format of each page on the archive is check (similar to oncheck -cd)  Tape control pages are sanity check  Each table is checked ensuring all pages of the table exist on the archive tape  Reserve page format is validated  Each chunk free list is verified  Table extents are checked for overlap

IBM Software Group 43 Example of Archive Validation Backup Validation onbar -r -v(IDS 7.3) onbar -v(IUS 9.X) Sample Output: /spare2/9.20/bin/onbar_d -v …Successfully connected to Storage Manager. …Begin backup verification of level 0 for rootdbs (Storage Manager copy ID 102). …Completed level 0 backup verification successfully. …/spare2/9.20/bin/onbar_d complete, returning 0 (0x00)

IBM Software Group 44 Overview  Backup and Restore  New & Recent Features  Backup Options  Restore Options  Best Practices  High Availability Data Replication  Archive Validation  New and Recent HA Feature

IBM Software Group 45 Other Recent HA Features  Fast Restart  Ensure logical recovery is limited in time  External Directives  The ability to add directives to SQL statements without modifying the program  Re-Send Index  In an HDR environment copy an index from the primary to correct a corrupted index on the secondary  Drop and Create an index online  Dropping or creating an index without locking the table while user are modifying the table  Redundant Network Listeners  Multiple listener can now monitor a single network port  Single User Mode  An administration mode in which only user informix can connect to the database  HDR setup using EBR  Using External Backup and Restore to setup HDR  ER auto resync  Automatically resync or repair tables in ER

IBM Software Group 46 Other HA Features  Database mirroring  Thread suspension  Online configuration tuning  Online index checking  Dynamic lock table allocation (avoiding out of locks)  Event Alarms – automatic notification of database events  Enterprise Replication  InPlace Alter Table

IBM Software Group 47 Questions