org.apache.hadoop.registry.server.services

Class MicroZookeeperService

java.lang.Object

org.apache.hadoop.service.AbstractService

org.apache.hadoop.registry.server.services.MicroZookeeperService

All Implemented Interfaces:

Closeable, AutoCloseable, RegistryConstants, RegistryBindingSource, ZookeeperConfigOptions, MicroZookeeperServiceKeys, org.apache.hadoop.service.Service

@InterfaceStability.Evolving
public class MicroZookeeperService
extends org.apache.hadoop.service.AbstractService
implements RegistryBindingSource, RegistryConstants, ZookeeperConfigOptions, MicroZookeeperServiceKeys

This is a small, localhost Zookeeper service instance that is contained in a YARN service...it's been derived from Apache Twill.

It implements RegistryBindingSource and provides binding information, once started. Until AbstractService.start() is called, the hostname and port may be undefined. Accordingly, the service raises an exception in this condition.

If you wish to chain together a registry service with this one under the same CompositeService, this service must be added as a child first.

It also sets the configuration parameter RegistryConstants.KEY_REGISTRY_ZK_QUORUM to its connection string. Any code with access to the service configuration can view it.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.service.Service

org.apache.hadoop.service.Service.STATE

Field Summary

Fields inherited from interface org.apache.hadoop.registry.client.api.RegistryConstants

DEFAULT_REGISTRY_CLIENT_JAAS_CONTEXT, DEFAULT_REGISTRY_ENABLED, DEFAULT_REGISTRY_SECURE, DEFAULT_REGISTRY_SYSTEM_ACCOUNTS, DEFAULT_REGISTRY_USER_ACCOUNTS, DEFAULT_REGISTRY_ZK_QUORUM, DEFAULT_ZK_CONNECTION_TIMEOUT, DEFAULT_ZK_REGISTRY_ROOT, DEFAULT_ZK_RETRY_CEILING, DEFAULT_ZK_RETRY_INTERVAL, DEFAULT_ZK_RETRY_TIMES, DEFAULT_ZK_SESSION_TIMEOUT, KEY_REGISTRY_CLIENT_AUTH, KEY_REGISTRY_CLIENT_AUTHENTICATION_ID, KEY_REGISTRY_CLIENT_AUTHENTICATION_PASSWORD, KEY_REGISTRY_CLIENT_JAAS_CONTEXT, KEY_REGISTRY_ENABLED, KEY_REGISTRY_KERBEROS_REALM, KEY_REGISTRY_SECURE, KEY_REGISTRY_SYSTEM_ACCOUNTS, KEY_REGISTRY_USER_ACCOUNTS, KEY_REGISTRY_ZK_CONNECTION_TIMEOUT, KEY_REGISTRY_ZK_QUORUM, KEY_REGISTRY_ZK_RETRY_CEILING, KEY_REGISTRY_ZK_RETRY_INTERVAL, KEY_REGISTRY_ZK_RETRY_TIMES, KEY_REGISTRY_ZK_ROOT, KEY_REGISTRY_ZK_SESSION_TIMEOUT, PATH_SYSTEM_SERVICES, PATH_USER_SERVICES, PATH_USERS, REGISTRY_CLIENT_AUTH_ANONYMOUS, REGISTRY_CLIENT_AUTH_DIGEST, REGISTRY_CLIENT_AUTH_KERBEROS, REGISTRY_PREFIX, SUBPATH_COMPONENTS, ZK_PREFIX

Fields inherited from interface org.apache.hadoop.registry.client.impl.zk.ZookeeperConfigOptions

DEFAULT_ZK_ENABLE_SASL_CLIENT, PROP_ZK_ALLOW_FAILED_SASL_CLIENTS, PROP_ZK_ENABLE_SASL_CLIENT, PROP_ZK_KINIT_PATH, PROP_ZK_SASL_CLIENT_CONTEXT, PROP_ZK_SASL_CLIENT_USERNAME, PROP_ZK_SERVER_MAINTAIN_CONNECTION_DESPITE_SASL_FAILURE, PROP_ZK_SERVER_REALM, PROP_ZK_SERVER_SASL_CONTEXT, SCHEME_DIGEST, SCHEME_SASL

Fields inherited from interface org.apache.hadoop.registry.server.services.MicroZookeeperServiceKeys

DEFAULT_ZKSERVICE_HOST, KEY_REGISTRY_ZKSERVICE_JAAS_CONTEXT, KEY_ZKSERVICE_ALLOW_FAILED_SASL_CLIENTS, KEY_ZKSERVICE_DIR, KEY_ZKSERVICE_HOST, KEY_ZKSERVICE_PORT, KEY_ZKSERVICE_TICK_TIME, ZKSERVICE_PREFIX

Constructor Summary

Constructors

Constructor and Description
MicroZookeeperService(String name) Create an instance

Method Summary

Modifier and Type	Method and Description
protected void	addDiagnostics(String text, Object... args) Append a formatted string to the diagnostics.
InetSocketAddress	getConnectionAddress() Get the connection address
String	getConnectionString() Get the connection string.
String	getDiagnostics() Get the diagnostics info
protected void	serviceInit(org.apache.hadoop.conf.Configuration conf) Initialize the service, including choosing a path for the data
protected void	serviceStart() Startup: start ZK.
protected void	serviceStop() When the service is stopped, it deletes the data directory and its contents
boolean	setupSecurity() set up security.
BindingInformation	supplyBindingInformation() Supply the binding information for this registry

Methods inherited from class org.apache.hadoop.service.AbstractService

close, getBlockers, getConfig, getFailureCause, getFailureState, getLifecycleHistory, getName, getServiceState, getStartTime, init, isInState, noteFailure, putBlocker, registerGlobalListener, registerServiceListener, removeBlocker, setConfig, start, stop, toString, unregisterGlobalListener, unregisterServiceListener, waitForServiceToStop

Methods inherited from class java.lang.Object

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

Constructor Detail

MicroZookeeperService

public MicroZookeeperService(String name)

Create an instance

Parameters:

name - service name

Method Detail

getConnectionString

public String getConnectionString()

Get the connection string.

Returns:

the string

Throws:

IllegalStateException - if the connection is not yet valid

getConnectionAddress

public InetSocketAddress getConnectionAddress()

Get the connection address

Returns:

the connection as an address

Throws:

IllegalStateException - if the connection is not yet valid

serviceInit

protected void serviceInit(org.apache.hadoop.conf.Configuration conf)
                    throws Exception

Initialize the service, including choosing a path for the data

Overrides:

serviceInit in class org.apache.hadoop.service.AbstractService

Parameters:

conf - configuration

Throws:

Exception

addDiagnostics

protected void addDiagnostics(String text,
                              Object... args)

Append a formatted string to the diagnostics.

A newline is appended afterwards.

Parameters:

text - text including any format commands

args - arguments for the forma operation.

getDiagnostics

public String getDiagnostics()

Get the diagnostics info

Returns:

the diagnostics string built up

setupSecurity

public boolean setupSecurity()
                      throws IOException

set up security. this must be done prior to creating the ZK instance, as it sets up JAAS if that has not been done already.

Returns:

true if the cluster has security enabled.

Throws:

IOException

serviceStart

protected void serviceStart()
                     throws Exception

Startup: start ZK. It is only after this that the binding information is valid.

Overrides:

serviceStart in class org.apache.hadoop.service.AbstractService

Throws:

Exception

serviceStop

protected void serviceStop()
                    throws Exception

When the service is stopped, it deletes the data directory and its contents

Overrides:

serviceStop in class org.apache.hadoop.service.AbstractService

Throws:

Exception

supplyBindingInformation

public BindingInformation supplyBindingInformation()

Description copied from interface: RegistryBindingSource

Supply the binding information for this registry

Specified by:

supplyBindingInformation in interface RegistryBindingSource

Returns:

the binding information data