Transaction-based Grid Data Replication Using OGSA-DAI Presented by Yin Chen February 2007.
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Transcript of Transaction-based Grid Data Replication Using OGSA-DAI Presented by Yin Chen February 2007.
![Page 1: Transaction-based Grid Data Replication Using OGSA-DAI Presented by Yin Chen February 2007.](https://reader035.fdocuments.net/reader035/viewer/2022062321/56649f2f5503460f94c4964b/html5/thumbnails/1.jpg)
Transaction-based Grid Data Transaction-based Grid Data
ReplicationReplication Using OGSA-DAI Using OGSA-DAI
Presented by Yin Chen Presented by Yin Chen
February 2007February 2007
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• Initial copying of data & synchronization of updating
• Is not Cashing
– Client phenomenon
– Only for improving response time
• Is not a Backup
– Not automatically overwritten when the original data is modified
– Normally, cannot directly access
What is replication?What is replication?
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• Data consolidation (central audit & analyse)
• Data distribution (for branch labs)
• Performance– Access efficiency (moving data near processing)– Load balancing (distributing access load)– Security (data protection)– Availability (off-line access)– Reliability (disaster recovery, avoiding single point of failure)
Why do we need it?Why do we need it?
![Page 4: Transaction-based Grid Data Replication Using OGSA-DAI Presented by Yin Chen February 2007.](https://reader035.fdocuments.net/reader035/viewer/2022062321/56649f2f5503460f94c4964b/html5/thumbnails/4.jpg)
• How to copy the large data among heterogeneous DBs• How to maintain the consistency of data in a highly
distributed network environment• How to discover & self-repair the dead parts
Challenges of Grid database Challenges of Grid database replicationreplication
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• Existing Grid “replication” systems E.g. the EDG replica manager/ the Globus data replication
service/ SRB Support large dataset copying Yet, merely deal with files Too simple (e.g. not support updating, database replication, etc.) Not consistent
• Relational database replication tools E.g. Oracle/ Sybase/ DB2/ MySQL replication Very flexible (e.g., portion copy, bi-direction update) Yet, not suit for virtual organizations (e.g. can’t copy large data/
difficult to search for replicas)
Problems of existing Problems of existing technologiestechnologies
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ArchitectureArchitecture
Metadata Catalogue
Relational Database Replication Mechanism
ReplicationControl Service
Transfer Service
Data Resource
Data Replica
Data flow directions
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Request
Replication Control Service
MetadataSearchEngine
Metadata Register
Initiator
Selector
Starter
Metadata Catalogue
Relational Database Replication Mechanism
Transfer Service
Data Resource
ReplicationTarget
Replication control Replication control workflowworkflow
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OGSA-DAI activities OGSA-DAI activities (ongoing)(ongoing)
• High-level APIs to interact with relational replication mechanisms:
CreateReplicaDatabase() DropReplicaDatabase() ConfigReplication() CleanUp() -- to clean up replication configuration StartReplication() StopReplication() MonitorReplication() -- to check the status of each process
• Control the workflow of data replication, i.e.sequence.addChild(createDB2RelicaDB);sequence.addChild(configDB2Replication);sequence.addChild(startDB2Replication);
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IBM DB2 SQL IBM DB2 SQL ReplicationReplication
IBM Replication
• Admin: create replication criteria control table
• Capture: use log/trigger to capture the changes temp table
• Apply: scheduled apply transactions accumulated target DB
• Alert Monitor: monitor and notify users
• Supports: after-image copy / before-image copy (can rollback)
• Allows subset/simple view/ complex joins & unions copy
• Asynchronous replication, allows specifying schedule
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FeaturesFeatures
• Combine Relational Database Replication with Grid technologies, to gain benefits from both
Keep the features of relational database replication
Supporting more scalable, secure, high performance data access
• Explore the abilities of OGSA-DAI to control workflows
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InformationInformation• Project members:
• Dave Berry (NeSC, UK)
• Patrick Dantressangle (IBM, Hursley)
• Yin Chen (NeSC, UK)
• Simon Laws (IBM, Hursley)
• Project website:
http://www.aiai.ed.ac.uk/~ychen/ibm_ogsadai/ibm-ogsadai-index.html