Maintenance Notification:
On next Monday August 5th 2019 starting at 7am CEST we will conduct some maintenance. You might encounter some issues using the Exasol User Portal and Issue Tracker! We will restore the Exasol User Portal and Issue Tracker before 9am CEST on Monday August 5th 2019.

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EXASOL cluster consists of multiple service layers, which fulfill different roles


  • EXASOL database runs on active nodes (A)
  • Reserve node (R) is not a part of computations and does not store any data. It will be automatically pushed in, in case an active node fails and gets restored from the slave segments in the background. The reserve node needs to have exactly the same configuration as active nodes
  • EXASOL database can use any number of reserve nodes
  • The database connection string includes active and reserve nodes

EXAStorage Layer

  • Data will be stored in four different types of EXAStorage volumes
    • Data Volume
    • Local Archive Volume
    • Temporary Volume
    • Remote Archive Volume
  • If redundancy is set, active computation nodes (M) store their data additionally in slave segments (S), which reside on other nodes
    • Redundancy is supported for Data and Local Archive Volumes
  • Archive Volumes are used to store database backups

EXAClusterOS Layer

  • A management node (LS) is required for cluster administration and boot strapping (cold boot) the data nodes (N)
  • Is used to operate and manage the cluster
  • Build to implement cluster services and fail-safety mechanisms
  • Cluster operations need a quorum
  • Applying software updates

Networking Layer

  • Used for sharing cluster vitality information
  • Booting the cluster
  • Database communication
  • EXAStorage communication
  • EXAClusterOS communication