DB-3: OpenEdge® Replication How-To David Eddy Senior Consultant

© 2006 Progress Software Corporation2 DB-3: OpenEdge Replication How-To Agenda  What is OpenEdge Replication?  Planning for your installation  First-time setup  Common procedures  Things you need to know  Things you should think about  Summary

© 2006 Progress Software Corporation3 DB-3: OpenEdge Replication How-To What is OpenEdge Replication?  Optional component of OpenEdge RDBMS  Maintains 1 or 2 copies of a database  In near-real-time synchronization  Basically a tap on the After-Image log Client BI AI ReplAgent ReplServ BI

© 2006 Progress Software Corporation4 DB-3: OpenEdge Replication How-To “Ordinary” Replication vs. Role Reversal source (live) target Client live Client  transition (drop replication) source (live) target Client target source (live) Client transition (role reversal) 10.1A automates “back-replication” and similar tasks

© 2006 Progress Software Corporation5 DB-3: OpenEdge Replication How-To Agenda  What is OpenEdge Replication?  Planning for your installation  First-time setup  Common procedures  Things you need to know  Things you should think about  Summary

© 2006 Progress Software Corporation6 DB-3: OpenEdge Replication How-To Planning for your Installation: OS Versions and Management  Must have same operating system on source and target machines Ideally, patch levels synchronized as well  Other combinations may work but are not supported  Develop a plan to maintain both systems Synchronised Staged with planned fail-over/fail-back for continuous availability

© 2006 Progress Software Corporation7 DB-3: OpenEdge Replication How-To Planning for your Installation: The Network Link  Must have enough bandwidth to handle AI data Otherwise source DB might be throttled back  How much is “sufficient”? diagram here concept: “bottleneck”

© 2006 Progress Software Corporation8 DB-3: OpenEdge Replication How-To Computing Required Network Bandwidth  Examine BI block writes promon R&D/2/5 or _ActBI VST  Net replication traffic will be 1.5x BI data rate  E.g. 10 8k BI block writes second  15 x 8k = 120kB/sec replication traffic  1.2Mbits/sec network bandwidth required If Ethernet hardware, allow 1.5-2x utilisation fudge factor due to CSMA/CD inefficiency

© 2006 Progress Software Corporation9 DB-3: OpenEdge Replication How-To Computing Required Network Bandwidth Considering Peaks

© 2006 Progress Software Corporation10 DB-3: OpenEdge Replication How-To Computing Required Network Bandwidth  Consider peaks when measuring BI block writes Are you willing to sacrifice performance for cost? When do peaks occur? Can they be handled by buffering? –-pica broker parameter specifies replication buffers Is buffering a desirable policy option? –buffering = falling behind Considering Peaks

© 2006 Progress Software Corporation11 DB-3: OpenEdge Replication How-To Computing Required Network Bandwidth  Average volume 2 BI writes/sec 256kb/sec sufficient for average  Peaks: 7/sec for 5 mins; 3.3/sec for 25 mins BI write rateDuration (s)Total blocks written Considering Peaks – case study Blocks to transmit256kb/s512kb/s1Mb/s2Mb/s Blocks/sec seconds to transmit cost-effective performance-oriented

© 2006 Progress Software Corporation12 DB-3: OpenEdge Replication How-To Planning for your Installation: DB Backup and After Image Log Management  On-line backup is preferable Implications for target DB if source is shut down  Must plan how to handle AI data Back up DB AI extents Typically just throw away AI data after backup Some people choose to archive AI logs Use AI File Archiver if OpenEdge 10.1A

© 2006 Progress Software Corporation13 DB-3: OpenEdge Replication How-To Replica DB Setup  Need to plan replica DB(s) Layout, extent size, memory usage Recommend same as production  “Ordinary” replication: Source DB needs to know host and port of target DB(s)  Role reversal replication (OpenEdge 10.1A only): Source and Target DBs need to know each other’s host/port

© 2006 Progress Software Corporation14 DB-3: OpenEdge Replication How-To Agenda  What is OpenEdge Replication?  Planning for your installation  First-time setup  Common procedures  Things you need to know  Things you should think about  Summary

© 2006 Progress Software Corporation15 DB-3: OpenEdge Replication How-To First Time Setup: Recommended Workflow Plan Implement infrastructure Install Progress® Prepare DB structure and property files Review / alter DB start parameters & backup scripts Enable source DB for replication Backup source & move to target system Create target DB & enable Verify replication running brief (5 min) downtime

© 2006 Progress Software Corporation16 DB-3: OpenEdge Replication How-To First Time Setup: Prepare Structure Files  Source database needs After Image extents Recommend 5-7 extents Must be “enough” to cope with issues  Target database needs structure description Recommend it’s the same as source DB At least make extents same size if you can

© 2006 Progress Software Corporation17 DB-3: OpenEdge Replication How-To First Time Setup: Prepare Property Files  Replication requires property file dbname.repl.properties in.db directory Both source and target databases  Template files located in $DLC/properties source.repl.properties target.repl.properties  Can be combined if you wish Not recommended for “ordinary” replication

© 2006 Progress Software Corporation18 DB-3: OpenEdge Replication How-To First Time Setup: Prepare Property Files – Source [server] control-agents=agent1 database=dbname transition=manual transition-timeout=1200 defer-agent-startup=1400 schema-lock-action=wait [control-agent.agent1] name=agent1 database=dbname host=targetdb_host port=targetdb_port connect-timeout=120 replication-method=async critical=0 Changes from source template are shown in red Unlikely these will need changing, but possible

© 2006 Progress Software Corporation19 DB-3: OpenEdge Replication How-To First Time Setup: Prepare Property Files – Target [agent] name=agent1 database=db-name listener-minport=1500# adjust if needed listener-maxport=4500# adjust if needed  This file usually does not need to be changed from template $DLC/properties/target.repl.properties

© 2006 Progress Software Corporation20 DB-3: OpenEdge Replication How-To First Time Setup: Review / Change Backup Scripts  Need to empty any full AI extents Might even want to archive first  probkup and rfutil mark backedup force AI extent switch May as well deal with AI in backup script  Simple addition to current script

© 2006 Progress Software Corporation21 DB-3: OpenEdge Replication How-To First Time Setup: Changed Backup Scripts – Some Examples while f=`rfutil dbname –C aimage extent full` ; do # archive $f here if you want to rfutil dbname –C aimage extent empty $f done rfutil dbname –C aimage extent empty 1 rfutil dbname –C aimage extent empty 2 rfutil dbname –C aimage extent empty 3 rfutil dbname –C aimage extent empty 4 rfutil dbname –C aimage extent empty 5 rfutil dbname –C aimage extent empty 6 rfutil dbname –C aimage extent empty 7 One Unix site did this… One Windows site did this…

© 2006 Progress Software Corporation22 DB-3: OpenEdge Replication How-To First Time Setup: Enable Source DB for Replication (1 of 2)  Shut down broker  Add after-image log extents if not already present prostrct add dbname ai.st  Enable after-imaging if not already enabled rfutil dbname –C mark backedup rfutil dbname –C aimage begin  Remove any dbname.repl.recovery file (if present)  Enable DB as replication source proutil dbname –C enablesitereplication source

© 2006 Progress Software Corporation23 DB-3: OpenEdge Replication How-To First Time Setup: Enable Source DB for Replication (2 of 2)  Ensure broker parameters present: –DBService replserv  Start the broker (and use DB normally) The BI has been truncated; you may wish to perform a proutil bigrow first  Take a full online backup probkup online dbname backup_file -REPLTargetCreation  Don’t forget –REPLTargetCreation! If you do, you won’t be able to establish a replication database from the backup It’s case sensitive – beware

© 2006 Progress Software Corporation24 DB-3: OpenEdge Replication How-To First Time Setup: Transport Backup to Target System  Use a method that suits your needs and resources Send via network Walk tape across room Drive tape to remote site Set up replica system at source site then transport to remote site  There’s no particular hurry  Reliability is critical

© 2006 Progress Software Corporation25 DB-3: OpenEdge Replication How-To First Time Setup: Create Target DB (1 of 2)  Make sure dbname.st file is in.db directory  Restore backup prorest dbname backup_file This will implicitly call prostrct create with the correct block size Eliminates a source of error  Remove any dbname.repl.recovery file (if present)

© 2006 Progress Software Corporation26 DB-3: OpenEdge Replication How-To First Time Setup: Create Target DB (2 of 2)  Convert repl. source DB to repl. target proutil dbname –C enablesitereplication target  Ensure broker parameters present: –DBService replagent  Start the target DB broker

© 2006 Progress Software Corporation27 DB-3: OpenEdge Replication How-To First Time Setup: Verify Replication is Running  Check source db.lg file, or  Use dsrutil dbname –C monitor  Might have to wait up to 5 minutes defer_agent_startup checks every 5 minutes, tries for 1 minute each time

© 2006 Progress Software Corporation28 DB-3: OpenEdge Replication How-To First Time Setup: Common Mistakes (1 of 2)  Source/target port mismatch e.g. source.repl.properties says to expect target DB to be listening on 7001, but target actually listening on 7701  Firewall in the way Connection between ReplServ and ReplAgent is independent of initial connection to DB Manipulate port range using agent listener- minport and listener-maxport parameters

© 2006 Progress Software Corporation29 DB-3: OpenEdge Replication How-To First Time Setup: Common Mistakes (2 of 2)  db.repl.recovery file left behind This file is used for recovery processing Must be deleted if initialising replication anew Seldom an issue in first-time install but common when re-establishing replication  –DBService parameter issue Required parameter in replication Mode must agree with database mode Must not be present if not replicating

© 2006 Progress Software Corporation30 DB-3: OpenEdge Replication How-To First Time Setup: Optimising Performance  Configure / tune target DB as though it were live Likely needs less –B but otherwise the same Don’t forget BI block and cluster size  Ensure you start APW & BIW  If you get slowdowns on source system, try adding replication buffers Max is –pica 256  Should not be necessary to tweak Replication polling properties

© 2006 Progress Software Corporation31 DB-3: OpenEdge Replication How-To Agenda  What is OpenEdge Replication?  Planning for your installation  First-time setup  Common procedures  Things you need to know  Things you should think about  Summary Subtitle Goes Here - Arial Italic 24 pt.

© 2006 Progress Software Corporation32 DB-3: OpenEdge Replication How-To Common procedures  Using a DB copy or restored backup  Handling throughput spikes  Failing over  Failing back

© 2006 Progress Software Corporation33 DB-3: OpenEdge Replication How-To Common Procedures: Using a DB Copy or Restored Backup  It’s common to restore a backup or copy a live DB for analysis or reporting purposes.  If you copy or restore a replication-enabled DB, it will still be replication-enabled afterwards.  You need to disable the replication before you use it (specify the appropriate mode): proutil dbname –C disablesitereplication {source | target}

© 2006 Progress Software Corporation34 DB-3: OpenEdge Replication How-To Common Procedures: Throughput Spikes  Spikes in transaction throughput are common Usually associated with batch processing  Can overwhelm capacity of network between source and target Replication buffers fill up Transaction activity paused until a replication buffer becomes available  Might also be caused by competition for bandwidth

© 2006 Progress Software Corporation35 DB-3: OpenEdge Replication How-To Common Procedures: Handling Throughput Spikes  If objectionable slowdown occurs: Stop replication server dsrutil dbname –C terminate server Wait a short time Restart the replication server dsrutil dbname –C restart server  Replication will move to ‘catchup’ mode Reading from AI file, not AI buffers Will resume using buffers when caught up (when surge passes)

© 2006 Progress Software Corporation36 DB-3: OpenEdge Replication How-To Common Procedures: Failing Over (1 of 2)  First, decide to fail over May prefer to recover/roll forward local DB if remote system or network is slow Recommend never allow automatic transition  If source system still available, copy AI log files to target system Use rfutil db –C aimage scan to determine log(s) to transport/apply Apply logs using dsrutil db –C applyextent aifile

© 2006 Progress Software Corporation37 DB-3: OpenEdge Replication How-To Common Procedures Failing Over (2 of 2)  Transition target DB to allow updates dsrutil targetdb –C transition  Check broker startup parameters  Enable AI, source replication if you wish Done as part of transition in OpenEdge 10.1A  Start DB

© 2006 Progress Software Corporation38 DB-3: OpenEdge Replication How-To Common Procedures: Other Aspects of Failing Over  Failing DB over is easy part  You must manage client connections to new live system  Many use a “virtual” DNS entry for DB / application server Hostname has no physical existence Change IP addr to suit current live host Requires no user training and no multiple icons (etc).  User authentication, application currency, etc.

© 2006 Progress Software Corporation39 DB-3: OpenEdge Replication How-To Common Procedures: Failing Back  “Fail back” is resuming normal operation after the reason for a fail-over has gone away  Is a planned fail-over  Are a number of techniques Backup-restore-reinitialise Back-replication  Recommend back-replication technique More complex but less downtime

© 2006 Progress Software Corporation40 DB-3: OpenEdge Replication How-To Common Procedures: Failing Back  Set up replication to repaired primary system Manual form of OpenEdge 10.1A role reversal  Once synchronised, “fail over” to primary At a convenient time e.g. weekend  Re-establish replication once failed over OpenEdge 10.1A role reversal removes need to transport backup to secondary all over again

© 2006 Progress Software Corporation41 DB-3: OpenEdge Replication How-To Agenda  What is OpenEdge Replication?  Planning for your installation  First-time setup  Common procedures  Things you need to know  Things you should think about  Summary

© 2006 Progress Software Corporation42 DB-3: OpenEdge Replication How-To Things You Need to Know  Replication and AdminServer-managed DBs  Schema updates  Effect of DB stops and starts  Effect of network failures  Moving tables and indexes  Truncating a storage area

© 2006 Progress Software Corporation43 DB-3: OpenEdge Replication How-To Things You Need to Know: Replication and AdminServer-Managed DBs  AdminServer detects replication status of a database Shows properties in Progress Explorer Allows you to update properties  Detection of mode is based on.repl.properties file, not DB master block [server] section means it’s a source DB [agent] section means it’s a target DB

© 2006 Progress Software Corporation44 DB-3: OpenEdge Replication How-To Things You Need to Know: Replication and AdminServer-Managed DBs  AdminServer will automatically supply a –DBService parameter(s) based on detected mode(s) Convenient! Will supply both –DBService replserv and -DBService replagent if both ‘modes’ detected  Will supply –DBService even if a transitioned database Result: DB won’t start Workaround: Rename.repl.properties file

© 2006 Progress Software Corporation45 DB-3: OpenEdge Replication How-To Things You Need to Know: Schema Updates  You have to have an active replication connection established to perform a schema update Progress requires schema locks in both source and target databases simultaneously.  Implications for DBA practise Keeping users out of a multiuser-enabled database.

© 2006 Progress Software Corporation46 DB-3: OpenEdge Replication How-To Things You Need to Know: Effect of DB Stops and Starts  Source DB is shut down Target DB sees this as normal exit Replication agent exits Source DB restart does not cause agent to restart Must bounce target DB as it’s not possible to restart the replication agent. If OpenEdge 10.1A, can configure away replic agent shutdown [server] agent-shutdown-action=recovery

© 2006 Progress Software Corporation47 DB-3: OpenEdge Replication How-To Things You Need to Know: Effect of DB Stops and Starts  Target DB is shut down Source DB sees this as normal exit Replication server ends if this was the only target After restarting target DB, need to restart replication server: dsrutil dbname –C server restart

© 2006 Progress Software Corporation48 DB-3: OpenEdge Replication How-To Things You Need to Know: Effect of DB Stops and Starts  Source DB crashes All is well; replication agent remains running Will resync when source DB is restarted If wait too long replication agent may exit –Restart target DB; or –Use dsrutil sourcedb –C connectagent database all  Target DB crashes All is well; replication server remains running Will resync when target DB is restarted Replication data will build up in AI log files until replicated

© 2006 Progress Software Corporation49 DB-3: OpenEdge Replication How-To Things You Need to Know: Effect of Network Failures  All is well; both replication server and agent remain running  When connection re-established replication will resync  Replication data will build up in AI log files until replicated  Depends on hardware connection sensing Networks that spoof this can cause problems worked around with repl-keep-alive property

© 2006 Progress Software Corporation50 DB-3: OpenEdge Replication How-To Agenda  What is OpenEdge Replication?  Planning for your installation  First-time setup  Common procedures  Things you need to know  Things you should think about  Summary

© 2006 Progress Software Corporation51 DB-3: OpenEdge Replication How-To Things You Should Think About  Handling extended replication outage  Managing database extents  Managing database parameters  Automation

© 2006 Progress Software Corporation52 DB-3: OpenEdge Replication How-To Things You Should Think About: Extended Replication Outage  Problem: Unreplicated data in AI logs cause logs to be “Locked” not “Full” Cannot be cleared while replication still enabled and no connection established  Extended outage will cause AI logs to fill  You need to plan what do to if this happens: Disable replication? Add AI extents? Relocate replication target until outage fixed? etc

© 2006 Progress Software Corporation53 DB-3: OpenEdge Replication How-To Things You Should Think About: Managing Database Extents  Replica database is an ordinary database with usage constraints Grows just like the source DB  Plan how you’re going to monitor free space in the replica DB Periodic login? Automated scripts with ? OpenEdge Management?  Avoid the problem: Same structure as source Perform all prostrct operations on both DBs

© 2006 Progress Software Corporation54 DB-3: OpenEdge Replication How-To Things You Should Think About: Managing Database Parameters  Target DB needs to support same transaction activity as source Most broker parameters should be the same  Target system may be smaller (memory) Requires smaller –B parameter  Care must be taken in replicating application files if they include.pf’s or scripts

© 2006 Progress Software Corporation55 DB-3: OpenEdge Replication How-To Things You Should Think About: Automation  Automation is the DBA’s friend  Especially in this case Use scripts to coordinate local/remote DB stops and starts via remote execution Use scripts to hide details of –DBService provision  Hide messy details of Replication Don’t forget to document, though!

© 2006 Progress Software Corporation56 DB-3: OpenEdge Replication How-To In Summary  Replication is simple to install and use  Gives near real-time replica for reporting or D.R.

© 2006 Progress Software Corporation57 DB-3: OpenEdge Replication How-To Questions?

© 2006 Progress Software Corporation58 DB-3: OpenEdge Replication How-To Thank you for your time

© 2006 Progress Software Corporation59 DB-3: OpenEdge Replication How-To

© 2006 Progress Software Corporation60 DB-3: OpenEdge Replication How-To Appendix: Setting up Role-Reversal Replication  Differs mainly in setup of property files Both primary and secondary files have both source and target components  Some terminology differences Primary: Normal source (acts as target in fail- over situation) Secondary: Normal target (acts as source in fail-over)  Secondary DB should have AI extents Not needed in “ordinary” replication

© 2006 Progress Software Corporation61 DB-3: OpenEdge Replication How-To Prepare Property Files – OpenEdge 10.1A (1 of 2) [server] control-agents=agent1 database=dbname transition=manual transition-timeout=600 defer-agent-startup=1440 schema-lock-action=wait [control-agent.agent1] name=agent1 database=dbname host=partner_db_host port=partner_db_port connect-timeout=120 replication-method=async critical=0...

© 2006 Progress Software Corporation62 DB-3: OpenEdge Replication How-To Prepare Property Files – OpenEdge 10.1A (2 of 2)... [transition] database-role=reverse responsibility=primary restart-after-transition=0 auto-begin-ai=1 auto-add-ai-areas=0 backup-method=mark [agent] name=agent1 database=dbname listener-minport=minport listener-maxport=maxport connect-timeout=120

© 2006 Progress Software Corporation63 DB-3: OpenEdge Replication How-To Enable Primary DB for Replication (1 of 2)  Shut down broker  Add after-image log extents if not already present prostrct add dbname ai.st  Enable after-imaging if not already enabled rfutil dbname –C mark backedup rfutil dbname –C aimage begin rfutil dbname –C aiarchiver enable  Enable DB as replication source proutil dbname –C enablesitereplication source

© 2006 Progress Software Corporation64 DB-3: OpenEdge Replication How-To Enable Primary DB for Replication (2 of 2)  Add to broker parameters: –DBService replserv –aiarcinterval 0 –aiarcdir /dev/null  Start the broker (and use DB normally) The BI has been truncated; you may wish to perform a proutil bigrow first  Take a full online backup probkup online dbname backup_file -REPLTargetCreation  Don’t forget –REPLTargetCreation! If you do, you won’t be able to establish a replication database from the backup It’s case sensitive – beware

© 2006 Progress Software Corporation65 DB-3: OpenEdge Replication How-To Create Secondary DB (1 of 2)  Make sure dbname.st file is in.db directory  Make sure dbname.repl.properties is present and correct  Restore backup prorest dbname backup_file -REPLTransition This will implicitly call prostrct create with the correct block size Eliminates a source of error  Enable AI archiver: rfutil dbname –C aiarchiver enable

© 2006 Progress Software Corporation66 DB-3: OpenEdge Replication How-To Create Secondary DB (2 of 2)  Remove any dbname.repl.recovery file (if present)  Ensure broker parameters present: –DBService replagent –aiarcinterval 0 -aiarcdir /dev/null  Start the target DB broker

© 2006 Progress Software Corporation67 DB-3: OpenEdge Replication How-To Other Issues in Role-Reversal  It is possible to automatically trigger both halves of a transition Personally, I recommend against this Better to have the ability to decide whether to transition the source after seeing whether the target transition succeeded  It is possible to have the database automatically started after transition I also recommend against this as it constrains your DB parameter specification choices

© 2006 Progress Software Corporation68 DB-3: OpenEdge Replication How-To Computing Required Network Bandwidth  Latency is time required for round trip Effectively 0 in modern LAN Typically 30ms for trans-continental WAN link –But can vary widely >>100ms depending on traffic, QoS, etc, etc, etc  Replication agent also uses some time  AI blocks must be buffered until ACK reaches server Network Latency

© 2006 Progress Software Corporation69 DB-3: OpenEdge Replication How-To Computing Required Network Bandwidth Buffering needed to support network latency Round-trip latency including replication processing (ms) Data rate Number of buffers needed to support network latency