Terracotta 10.11 | Glossary
 
Glossary
This glossary includes key terms and concepts in the context of Dynamic Configuration and using the Config Tool to manage a Terracotta cluster.
KeyWords
Description
The process of persisting an in-memory configuration of a set of nodes in order to form a valid cluster which can now perform operations and accept clients.
Activated node
A node that has been activated and has a persisted configuration in its configuration directory.
Add a node to an existing Terracotta cluster. You can either add a node to an existing stripe as a passive node or you can add a node as a new stripe to the cluster.
Change
An abstraction or logical representation for any actions that are performed on cluster. For example, activation, adding/deleting nodes/stripes, or setting/unsetting any configuration.
Cluster
An arrangement of constituent stripes forming the cluster.
Commit phase
Applying the change to the current configuration, which can then take effect at runtime or may require a restart.
Configuration
Values for various attributes applicable to Terracotta cluster.
Configuration consistency
Validity of the cluster configuration installed on all the nodes: the configuration is consistent when the nodes are all using the same committed configuration and no restart is required (runtime configuration used by all nodes is the same as the last configuration saved on disk and used at startup).
Configuration directory
The folder which contains the various configuration files, and is used to read the current configuration at startup time.
Remove a node from an existing Terracotta cluster. You can either remove a passive node from an existing stripe or remove an entire stripe from the cluster.
Diagnostic port
The port that is used to reassemble diagnostic information. It is the same port on which server is listening for making a normal connection.
Discovery phase
Sanity check of the cluster configuration on all the nodes.
Create a snapshot of the written configuration or runtime configuration for a node. Note that the written configuration of a node can be different to the runtime configuration if a change was made to the node that requires a restart, but the restart has not yet been done.
Look up the values for a particular configuration (written on disk, or currently at runtime).
Configure/initialize nodes with the provided configuration file.
Mutative Operation
An operation or command that when executed will change the state of the underlying system/cluster. For example: attach, detach, set, unset, and activate are mutative Config Tool commands.
Prepare phase
Validation phase where targeted nodes verify whether the change can be applied or not.
Perform actions to achieve configuration consistency.
Rollback phase
If for some reason a change fails to be applied on some nodes, they are restored to their previous state.
Runtime configuration
The configuration that is currently in use by the node.
Apply the specified configuration values to the node, stripe, or cluster.
Stripe
Arrangement of constituent nodes in which one of them is active and rest passive.
Unconfigured node
A node that has not been activated yet.
Remove a user-defined configuration value that was previously set. The configuration will use the default value, if one is available.
Upcoming configuration
The latest configuration which is written on disk. Various changes require some nodes or the entire cluster to be restarted for those changes to take effect. This on-disk configuration is the configuration that will take effect immediately after restart and will always represent the latest changes.