Package org.apache.hadoop.ozone.container.keyvalue

Class KeyValueContainerMetadataInspector

java.lang.Object

org.apache.hadoop.ozone.container.keyvalue.KeyValueContainerMetadataInspector

All Implemented Interfaces:

ContainerInspector

public class KeyValueContainerMetadataInspector
extends Object
implements ContainerInspector

Container inspector for key value container metadata. It is capable of logging metadata information about a container, and repairing the metadata database values of #BLOCKCOUNT and #BYTESUSED. To enable this inspector in inspect mode, pass the java system property -Dozone.datanode.container.metadata.inspector=inspect on datanode startup. This will cause the inspector to log metadata information about all containers on datanode startup whose aggregate values of #BLOCKCOUNT and #BYTESUSED do not match the sum of their parts in the database at the ERROR level, and information about correct containers at the TRACE level. Changing the `inspect` argument to `repair` will update these aggregate values to match the database. When run, the inspector will output json to the logger named in the REPORT_LOG variable. The log4j configuration can be modified to send this output to a separate file without log information prefixes interfering with the json. For example: log4j.logger.ContainerMetadataInspectorReport=INFO,inspectorAppender log4j.appender.inspectorAppender=org.apache.log4j.FileAppender log4j.appender.inspectorAppender.File=${hadoop.log.dir}/\ containerMetadataInspector.log log4j.appender.inspectorAppender.layout=org.apache.log4j.PatternLayout

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	KeyValueContainerMetadataInspector.Mode	The mode to run the inspector in.

Field Summary

Fields

Modifier and Type	Field	Description
static final org.slf4j.Logger	REPORT_LOG
static final String	SYSTEM_PROPERTY

Constructor Summary

Constructors

Constructor	Description
KeyValueContainerMetadataInspector()
KeyValueContainerMetadataInspector(KeyValueContainerMetadataInspector.Mode mode)

Method Summary

Modifier and Type	Method	Description
boolean	isReadOnly()	Determines whether the inspector will be modifying containers as part of the process method.
boolean	load()	Validate configuration here so that an invalid config value is only logged once, and not once per container.
void	process(ContainerData containerData, DatanodeStore store)	Operates on the container as the inspector is configured.
String	process(ContainerData containerData, DatanodeStore store, org.slf4j.Logger log)
void	unload()	Removes configurations to run the inspector, so that the process method becomes a no-op.

Methods inherited from class java.lang.Object

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

Field Details

REPORT_LOG

public static final org.slf4j.Logger REPORT_LOG

SYSTEM_PROPERTY

public static final String SYSTEM_PROPERTY

See Also:

• Constant Field Values

Constructor Details

KeyValueContainerMetadataInspector

public KeyValueContainerMetadataInspector(KeyValueContainerMetadataInspector.Mode mode)

KeyValueContainerMetadataInspector

public KeyValueContainerMetadataInspector()

Method Details

load

public boolean load()

Validate configuration here so that an invalid config value is only logged once, and not once per container.

Specified by:

load in interface ContainerInspector

Returns:

true if the inspector will operate when process is called. False otherwise.

unload

public void unload()

Description copied from interface: ContainerInspector

Removes configurations to run the inspector, so that the process method becomes a no-op.

Specified by:

unload in interface ContainerInspector

isReadOnly

public boolean isReadOnly()

Description copied from interface: ContainerInspector

Determines whether the inspector will be modifying containers as part of the process method.

Specified by:

isReadOnly in interface ContainerInspector

Returns:

true if the inspector will only read the container, false if it will be making modifications/repairs.

process

public void process(ContainerData containerData,
 DatanodeStore store)

Description copied from interface: ContainerInspector

Operates on the container as the inspector is configured. This may involve logging information or fixing errors. Multiple containers may be processed in parallel by calling this method on the same inspector instance, but only one process call will be invoked per container at a time. Implementations must ensure that: 1. Information they log is batched so that log output from other inspectors working on other containers is not interleaved. 2. Multiple process calls to the same inspector instance with different containers are thread safe.

Specified by:

process in interface ContainerInspector

Parameters:

containerData - Container data for the container to process.

store - The metadata store for this container.

process

public String process(ContainerData containerData,
 DatanodeStore store,
 org.slf4j.Logger log)