Derby
  1. Derby
  2. DERBY-2852

Derby: Replication and Availability

    Details

    • Type: Improvement Improvement
    • Status: Closed
    • Priority: Major Major
    • Resolution: Duplicate
    • Affects Version/s: 10.2.2.0
    • Fix Version/s: None
    • Component/s: Network Server, Services, SQL, Store
    • Labels:
      None

      Description

      This paper and attached source code describes the work done to add hot standby replication functionality to the Apache Derby Database Management System.

      By implementing a hot standby scheme in Apache Derby several features are added. The contents of the database is replicated at run time to another site providing online runtime backup. As the hot standby takes over on faults availability is added in that a client can connect to the hot standby after a crash. Thus the crash is masked from the clients. In addition to this, online upgrades of software and hardware can be done by taking down one database at the time. Then when
      the upgrade is completed the upgraded server is synchronized and back online with no downtime.

      A fully functional prototype of the Apache Derby hot standby scheme has been created in this project using logical logs, fail-fast takeovers and logical catchups after an internal up-to-crash recovery and reconnection. This project builds on the ideas that are presented in my earlier project: Derby: Write to Neighbor Mode.

      To enable the features described above some changes have been made to the Derby base system. The following classes have been changed or added:

      The Logical Log System
      org.apache.derby.iapi.store.logical.log.LogicalImage
      org.apache.derby.iapi.store.logical.log.LogicalLoggable
      org.apache.derby.impl.store.logical.log.LogicalLog
      org.apache.derby.impl.store.logical.log.LogicalLogger
      org.apache.derby.impl.store.logical.log.LogicalLogRecord
      org.apache.derby.impl.store.logical.opearations.LogicalAbortOperation
      org.apache.derby.impl.store.logical.opearations.LogicalCommitOperation
      org.apache.derby.impl.store.logical.opearations.LogicalDeleteOperation
      org.apache.derby.impl.store.logical.opearations.LogicalImage
      org.apache.derby.impl.store.logical.opearations.LogicalInsertOperation
      org.apache.derby.impl.store.logical.opearations.LogicalOperation
      org.apache.derby.impl.store.logical.opearations.LogicalOperationFactory
      org.apache.derby.impl.store.logical.opearations.LogicalUpdateOperation

      The SQL Layer
      org.apache.impl.sql.execute.RowChangerImpl
      org.apache.impl.sql.conn.GenericLanguageConnectionContext

      The Communications Service
      org.apache.derby.impl.services.net.LogicalServer
      org.apache.derby.impl.services.net.LogicalClient
      org.apache.derby.impl.services.net.NetworkPayload
      org.apache.derby.impl.services.net.receiver.LogReceiver
      org.apache.derby.impl.services.net.shipper.LogShipper
      org.apache.derby.impl.services.net.shipper.LogicalCatchUp

      The Hot Standby Service
      org.apache.derby.impl.services.hotstandby.HotStandbyController
      org.apache.derby.impl.services.hotstandby.Database

      The Network Server
      org.apache.derby.impl.drda.NetworkServerControlImpl
      org.apache.derby.impl.drda.HotStandbyPoller
      org.apache.derby.impl.drda.net.LogicalClient
      org.apache.derby.imp.drda.net.LogicalServer

      See the added paper for more thorough documentation on design choices and implementation along with some benchmarking results

      1. svn.diff
        32 kB
        Egil Sørensen
      2. soereeg07
        1.33 MB
        Egil Sørensen
      3. repl_trunk.stat
        3 kB
        Jørgen Løland
      4. repl_trunk.diff
        124 kB
        Jørgen Løland
      5. repl_trunk_ignored.diff
        8 kB
        Jørgen Løland
      6. derby-rep.zip
        91 kB
        Egil Sørensen

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            • Assignee:
              Unassigned
              Reporter:
              Egil Sørensen
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              • Created:
                Updated:
                Resolved:

                Development