Package org.elasticsearch.gateway

Class PersistedClusterStateService

java.lang.Object

org.elasticsearch.gateway.PersistedClusterStateService

public class PersistedClusterStateService
extends Object

Stores cluster metadata in a bare Lucene index (per data path) split across a number of documents. This is used by master-eligible nodes to record the last-accepted cluster state during publication. The metadata is written incrementally where possible, leaving alone any documents that have not changed. The index has the following fields: +------------------------------+-----------------------------+----------------------------------------------+ | "type" (string field) | "index_uuid" (string field) | "data" (stored binary field in SMILE format) | +------------------------------+-----------------------------+----------------------------------------------+ | GLOBAL_TYPE_NAME == "global" | (omitted) | Global metadata | | INDEX_TYPE_NAME == "index" | Index UUID | Index metadata | +------------------------------+-----------------------------+----------------------------------------------+ Additionally each commit has the following user data: +---------------------------+-------------------------+-------------------------------------------------------------------------------+ | Key symbol | Key literal | Value | +---------------------------+-------------------------+-------------------------------------------------------------------------------+ | CURRENT_TERM_KEY | "current_term" | Node's "current" term (≥ last-accepted term and the terms of all sent joins) | | LAST_ACCEPTED_VERSION_KEY | "last_accepted_version" | The cluster state version corresponding with the persisted metadata | | NODE_ID_KEY | "node_id" | The (persistent) ID of the node that wrote this metadata | | NODE_VERSION_KEY | "node_version" | The (ID of the) version of the node that wrote this metadata | +---------------------------+-------------------------+-------------------------------------------------------------------------------+ (the last-accepted term is recorded in Metadata → CoordinationMetadata so does not need repeating here)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PersistedClusterStateService.OnDiskState
static class	PersistedClusterStateService.Writer

Field Summary

Fields

Modifier and Type	Field	Description
static String	METADATA_DIRECTORY_NAME
static Setting<org.elasticsearch.core.TimeValue>	SLOW_WRITE_LOGGING_THRESHOLD

Constructor Summary

Constructors

Constructor	Description
PersistedClusterStateService(Path[] dataPaths, String nodeId, org.elasticsearch.common.xcontent.NamedXContentRegistry namedXContentRegistry, BigArrays bigArrays, ClusterSettings clusterSettings, LongSupplier relativeTimeMillisSupplier)
PersistedClusterStateService(NodeEnvironment nodeEnvironment, org.elasticsearch.common.xcontent.NamedXContentRegistry namedXContentRegistry, BigArrays bigArrays, ClusterSettings clusterSettings, LongSupplier relativeTimeMillisSupplier)

Method Summary

Modifier and Type	Method	Description
PersistedClusterStateService.Writer	createWriter()	Creates a new disk-based writer for cluster states
static void	deleteAll(Path[] dataPaths)	Remove all persisted cluster states from the given data paths, for use in tests.
Path[]	getDataPaths()
String	getNodeId()
PersistedClusterStateService.OnDiskState	loadBestOnDiskState()	Loads the best available on-disk cluster state.
static NodeMetadata	nodeMetadata(Path... dataPaths)	Returns the node metadata for the given data paths, and checks if the node ids are unique
static void	overrideVersion(Version newVersion, Path... dataPaths)	Overrides the version field for the metadata in the given data path

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

METADATA_DIRECTORY_NAME

public static final String METADATA_DIRECTORY_NAME

See Also:

Constant Field Values

SLOW_WRITE_LOGGING_THRESHOLD

public static final Setting<org.elasticsearch.core.TimeValue> SLOW_WRITE_LOGGING_THRESHOLD

Constructor Details

PersistedClusterStateService

public PersistedClusterStateService(NodeEnvironment nodeEnvironment,
 org.elasticsearch.common.xcontent.NamedXContentRegistry namedXContentRegistry,
 BigArrays bigArrays,
 ClusterSettings clusterSettings,
 LongSupplier relativeTimeMillisSupplier)

PersistedClusterStateService

public PersistedClusterStateService(Path[] dataPaths,
 String nodeId,
 org.elasticsearch.common.xcontent.NamedXContentRegistry namedXContentRegistry,
 BigArrays bigArrays,
 ClusterSettings clusterSettings,
 LongSupplier relativeTimeMillisSupplier)

Method Details

getNodeId

public String getNodeId()

createWriter

public PersistedClusterStateService.Writer createWriter()
                                                 throws IOException

Creates a new disk-based writer for cluster states

Throws:

IOException

deleteAll

public static void deleteAll(Path[] dataPaths)
                      throws IOException

Remove all persisted cluster states from the given data paths, for use in tests. Should only be called when there is no open PersistedClusterStateService.Writer on these paths.

Throws:

IOException

getDataPaths

public Path[] getDataPaths()

nodeMetadata

@Nullable
public static NodeMetadata nodeMetadata(Path... dataPaths)
                                 throws IOException

Returns the node metadata for the given data paths, and checks if the node ids are unique

Parameters:

dataPaths - the data paths to scan

Throws:

IOException

overrideVersion

public static void overrideVersion(Version newVersion,
 Path... dataPaths)
                            throws IOException

Overrides the version field for the metadata in the given data path

Throws:

IOException

loadBestOnDiskState

public PersistedClusterStateService.OnDiskState loadBestOnDiskState()
                                                             throws IOException

Loads the best available on-disk cluster state. Returns PersistedClusterStateService.OnDiskState.NO_ON_DISK_STATE if no such state was found.

Throws:

IOException