org.opennms.netmgt.dnsresolver.netty

Class NettyDnsResolver

java.lang.Object

org.opennms.netmgt.dnsresolver.netty.NettyDnsResolver

All Implemented Interfaces:

DnsResolver

public class NettyDnsResolver
extends Object
implements DnsResolver

Asynchronous DNS resolution using Netty. Creates multiple resolvers (aka contexts) (defaults to 2*num cores) against which the queries are randomized in order to improve performance. Uses a circuit breaker in order to ensure that callers do not continue to be bogged down if resolution fails.

Author:

jwhite

Field Summary

Fields

Modifier and Type	Field and Description
static String	CIRCUIT_BREAKER_STATE_CHANGE_EVENT_UEI

Constructor Summary

Constructors

Constructor and Description
NettyDnsResolver(EventForwarder eventForwarder, com.codahale.metrics.MetricRegistry metrics)

Method Summary

Modifier and Type	Method and Description
void	destroy()
boolean	getBreakerEnabled()
int	getBreakerFailureRateThreshold()
int	getBreakerRingBufferSizeInClosedState()
int	getBreakerRingBufferSizeInHalfOpenState()
int	getBreakerWaitDurationInOpenState()
int	getBulkheadMaxConcurrentCalls()
long	getBulkheadMaxWaitDurationMillis()
io.github.resilience4j.circuitbreaker.CircuitBreaker	getCircuitBreaker()
long	getMaxCacheSize()
int	getMaxTtlSeconds()
int	getMinTtlSeconds()
io.netty.resolver.dns.DnsServerAddressStreamProvider	getNameServerProvider()
String	getNameservers()
int	getNegativeTtlSeconds()
int	getNumContexts()
long	getQueryTimeoutMillis()
void	init()
CompletableFuture<Optional<InetAddress>>	lookup(String hostname) Perform a DNS lookup for the given hostname.
CompletableFuture<Optional<String>>	reverseLookup(InetAddress inetAddress) Perform a reverse DNS lookup for the given IP address.
void	setBreakerEnabled(boolean breakerEnabled)
void	setBreakerFailureRateThreshold(int breakerFailureRateThreshold)
void	setBreakerRingBufferSizeInClosedState(int breakerRingBufferSizeInClosedState)
void	setBreakerRingBufferSizeInHalfOpenState(int breakerRingBufferSizeInHalfOpenState)
void	setBreakerWaitDurationInOpenState(int breakerWaitDurationInOpenState)
void	setBulkheadMaxConcurrentCalls(int bulkheadMaxConcurrentCalls)
void	setBulkheadMaxWaitDurationMillis(long bulkheadMaxWaitDurationMillis)
void	setMaxCacheSize(long maxCacheSize)
void	setMaxTtlSeconds(int maxTtlSeconds)
void	setMinTtlSeconds(int minTtlSeconds)
void	setNameservers(String nameservers)
void	setNegativeTtlSeconds(int negativeTtlSeconds)
void	setNumContexts(int numContexts)
void	setQueryTimeoutMillis(long queryTimeoutMillis)
static List<InetSocketAddress>	toSocketAddresses(String commaSeparatedAddressesWithPorts)

Methods inherited from class java.lang.Object

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

Field Detail

CIRCUIT_BREAKER_STATE_CHANGE_EVENT_UEI

public static final String CIRCUIT_BREAKER_STATE_CHANGE_EVENT_UEI

See Also:

Constant Field Values

Constructor Detail

NettyDnsResolver

public NettyDnsResolver(EventForwarder eventForwarder,
                        com.codahale.metrics.MetricRegistry metrics)

Method Detail

init

public void init()

destroy

public void destroy()

lookup

public CompletableFuture<Optional<InetAddress>> lookup(String hostname)

Description copied from interface: DnsResolver

Perform a DNS lookup for the given hostname. Returns a future that contains the lookup results. If the optional is empty the lookup was completed but no result was found.

Specified by:

lookup in interface DnsResolver

Parameters:

hostname - hostname to lookup

Returns:

a future

reverseLookup

public CompletableFuture<Optional<String>> reverseLookup(InetAddress inetAddress)

Description copied from interface: DnsResolver

Perform a reverse DNS lookup for the given IP address. Returns a future that contains the lookup results. If the optional is empty the lookup was completed but no result was found.

Specified by:

reverseLookup in interface DnsResolver

Parameters:

inetAddress - IP address to lookup

Returns:

a future

getBreakerEnabled

public boolean getBreakerEnabled()

setBreakerEnabled

public void setBreakerEnabled(boolean breakerEnabled)

getBreakerFailureRateThreshold

public int getBreakerFailureRateThreshold()

setBreakerFailureRateThreshold

public void setBreakerFailureRateThreshold(int breakerFailureRateThreshold)

getBreakerWaitDurationInOpenState

public int getBreakerWaitDurationInOpenState()

setBreakerWaitDurationInOpenState

public void setBreakerWaitDurationInOpenState(int breakerWaitDurationInOpenState)

getBreakerRingBufferSizeInHalfOpenState

public int getBreakerRingBufferSizeInHalfOpenState()

setBreakerRingBufferSizeInHalfOpenState

public void setBreakerRingBufferSizeInHalfOpenState(int breakerRingBufferSizeInHalfOpenState)

getBreakerRingBufferSizeInClosedState

public int getBreakerRingBufferSizeInClosedState()

setBreakerRingBufferSizeInClosedState

public void setBreakerRingBufferSizeInClosedState(int breakerRingBufferSizeInClosedState)

getBulkheadMaxConcurrentCalls

public int getBulkheadMaxConcurrentCalls()

setBulkheadMaxConcurrentCalls

public void setBulkheadMaxConcurrentCalls(int bulkheadMaxConcurrentCalls)

getBulkheadMaxWaitDurationMillis

public long getBulkheadMaxWaitDurationMillis()

setBulkheadMaxWaitDurationMillis

public void setBulkheadMaxWaitDurationMillis(long bulkheadMaxWaitDurationMillis)

getNumContexts

public int getNumContexts()

setNumContexts

public void setNumContexts(int numContexts)

getNameservers

public String getNameservers()

setNameservers

public void setNameservers(String nameservers)

getQueryTimeoutMillis

public long getQueryTimeoutMillis()

setQueryTimeoutMillis

public void setQueryTimeoutMillis(long queryTimeoutMillis)

getMinTtlSeconds

public int getMinTtlSeconds()

setMinTtlSeconds

public void setMinTtlSeconds(int minTtlSeconds)

getMaxTtlSeconds

public int getMaxTtlSeconds()

setMaxTtlSeconds

public void setMaxTtlSeconds(int maxTtlSeconds)

getNegativeTtlSeconds

public int getNegativeTtlSeconds()

setNegativeTtlSeconds

public void setNegativeTtlSeconds(int negativeTtlSeconds)

getMaxCacheSize

public long getMaxCacheSize()

setMaxCacheSize

public void setMaxCacheSize(long maxCacheSize)

getCircuitBreaker

public io.github.resilience4j.circuitbreaker.CircuitBreaker getCircuitBreaker()

getNameServerProvider

public io.netty.resolver.dns.DnsServerAddressStreamProvider getNameServerProvider()

toSocketAddresses

public static List<InetSocketAddress> toSocketAddresses(String commaSeparatedAddressesWithPorts)