Package io.camunda.zeebe.dynamic.config

Interface ClusterConfigurationInitializer

All Known Implementing Classes:

ClusterConfigurationInitializer.FileInitializer, ClusterConfigurationInitializer.GossipInitializer, ClusterConfigurationInitializer.StaticInitializer, ClusterConfigurationInitializer.SyncInitializer

public interface ClusterConfigurationInitializer

Initializes configuration using different strategies.

Initialization Process

Each member is configured with a static configuration with initial set of cluster members and partition distribution.

Both coordinator and other members first check the local persisted configuration to determine the configuration. If one exists, that is used to initialize the configuration. See ClusterConfigurationInitializer.FileInitializer. On bootstrap of the cluster, the local persisted configuration is empty.

When the local configuration is empty, the coordinator queries cluster members in the static configuration for the current configuration. See ClusterConfigurationInitializer.SyncInitializer. If any member replies with a valid configuration, coordinator uses that one. If any member replies with an uninitialized configuration, coordinator generates a new configuration from the provided static configuration. See ClusterConfigurationInitializer.StaticInitializer.

When the local configuration is empty, a non-coordinating member waits until it receives a valid configuration from the coordinator via gossip. See ClusterConfigurationInitializer.GossipInitializer.

After initialization, the configuration can be modified using ClusterConfigurationModifier. For example, ExporterStateInitializer overwrites the local member's state to keep it in sync with the statically configured exporters.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	ClusterConfigurationInitializer.FileInitializer	Initialized configuration from the locally persisted configuration
static class	ClusterConfigurationInitializer.GossipInitializer	Initializes local configuration from the configuration received from other members via gossip.
static interface	ClusterConfigurationInitializer.InitializerError
static class	ClusterConfigurationInitializer.StaticInitializer	Initialized configuration from the given static partition distribution
static class	ClusterConfigurationInitializer.SyncInitializer	Initializes configuration by sending sync requests to other members.

Field Summary

Fields

Modifier and Type	Field	Description
static final org.slf4j.Logger	LOG

Method Summary

Modifier and Type	Method	Description
default ClusterConfigurationInitializer	andThen(ClusterConfigurationModifier modifier)	Chain a modifier that updates the configuration after it is initialized.
ActorFuture<ClusterConfiguration>	initialize()	Initializes the cluster configuration.
default ClusterConfigurationInitializer	orThen(ClusterConfigurationInitializer after)	Chain initializers in oder.
default ClusterConfigurationInitializer	recover(Class<? extends ClusterConfigurationInitializer.InitializerError> exception, ClusterConfigurationInitializer recovery)	If this initializer completed exceptionally with the given exception, the recovery initializer is used instead.

Field Details

LOG

static final org.slf4j.Logger LOG

Method Details

initialize

ActorFuture<ClusterConfiguration> initialize()

Initializes the cluster configuration.

Returns:

a future that completes with a configuration which can be initialized or uninitialized

orThen

default ClusterConfigurationInitializer orThen(ClusterConfigurationInitializer after)

Chain initializers in oder. If this initializer returns an uninitialized configuration, the provided initializer is tried instead. If this initializer completes exceptionally, the exceptions propagates. See recover(Class, ClusterConfigurationInitializer) to handle exceptions.

Parameters:

after - the next initializer used to initialize configuration if the current one did not succeed with an initialized configuration.

Returns:

a chained ClusterConfigurationInitializer

andThen

default ClusterConfigurationInitializer andThen(ClusterConfigurationModifier modifier)

Chain a modifier that updates the configuration after it is initialized.

Parameters:

modifier - a modifier that updates the configuration

Returns:

the chained initializer

recover

default ClusterConfigurationInitializer recover(Class<? extends ClusterConfigurationInitializer.InitializerError> exception,
 ClusterConfigurationInitializer recovery)

If this initializer completed exceptionally with the given exception, the recovery initializer is used instead. If this initializer completed exceptionally with a different exception, the recovery is not used and the exception is propagated.

Parameters:

exception - The class of the exceptions to recover from. If the exception is assignable from the given class, the recovery initializer is used.

recovery - A regular ClusterConfigurationInitializer.

Returns:

a ClusterConfigurationInitializer that can be used for further chaining with orThen(ClusterConfigurationInitializer).