Package org.opennms.netmgt.dnsresolver.netty

Class CaffeineDnsCache

  • All Implemented Interfaces:
    io.netty.resolver.dns.DnsCache, ExtendedDnsCache
    public class CaffeineDnsCache
extends Object
implements ExtendedDnsCache
    DNS cache implementation largely copied from Netty's https://github.com/netty/netty/blob/netty-4.1.38.Final/resolver-dns/src/main/java/io/netty/resolver/dns/DefaultDnsCache.java but adapted slightly to work with our CaffeineCache.

    • Constructor Summary

      Constructors 
      Constructor Description
      CaffeineDnsCache()
      Create a cache that respects the TTL returned by the DNS server and doesn't cache negative responses.
      CaffeineDnsCache​(int minTtl, int maxTtl, int negativeTtl, long maxSize)
      Create a cache.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      ExtendedDnsCacheEntry cache​(String hostname, io.netty.handler.codec.dns.DnsPtrRecord ptrRecord, io.netty.channel.EventLoop loop)
      Positive caching for reverse lookups.
      io.netty.resolver.dns.DnsCacheEntry cache​(String hostname, io.netty.handler.codec.dns.DnsRecord[] additionals, Throwable cause, io.netty.channel.EventLoop loop)
      Negative caching for failures (or empty reverse lookups).
      io.netty.resolver.dns.DnsCacheEntry cache​(String hostname, io.netty.handler.codec.dns.DnsRecord[] additionals, InetAddress address, long originalTtl, io.netty.channel.EventLoop loop)
      Positive caching for normal lookups.
      void clear()  
      boolean clear​(String hostname)  
      List<? extends io.netty.resolver.dns.DnsCacheEntry> get​(String hostname, io.netty.handler.codec.dns.DnsRecord[] additionals)  
      long getSize()  
      long maxSize()
      Returns the maximum number of elements allows in the cache.
      int maxTtl()
      Returns the maximum TTL of the cached DNS resource records (in seconds).
      int minTtl()
      Returns the minimum TTL of the cached DNS resource records (in seconds).
      int negativeTtl()
      Returns the TTL of the cache for the failed DNS queries (in seconds).
      void registerMetrics​(com.codahale.metrics.MetricRegistry metrics)  
      String toString()  
      void unregisterMetrics​(com.codahale.metrics.MetricRegistry metrics)  

    • Field Detail

      • MAX_SUPPORTED_TTL_SECS

        protected static final int MAX_SUPPORTED_TTL_SECS

      • DEFAULT_NEGATIVE_TTL_SECS

        protected static final int DEFAULT_NEGATIVE_TTL_SECS

    • Constructor Detail

      • CaffeineDnsCache

        public CaffeineDnsCache()
        Create a cache that respects the TTL returned by the DNS server and doesn't cache negative responses.

      • CaffeineDnsCache

        public CaffeineDnsCache​(int minTtl,
                        int maxTtl,
                        int negativeTtl,
                        long maxSize)
        Create a cache.
        Parameters:
        minTtl - the minimum TTL
        maxTtl - the maximum TTL
        negativeTtl - the TTL for failed queries

    • Method Detail

      • minTtl

        public int minTtl()
        Returns the minimum TTL of the cached DNS resource records (in seconds).
        See Also:
        maxTtl()

      • maxTtl

        public int maxTtl()
        Returns the maximum TTL of the cached DNS resource records (in seconds).
        See Also:
        minTtl()

      • negativeTtl

        public int negativeTtl()
        Returns the TTL of the cache for the failed DNS queries (in seconds). The default value is 0, which disables the cache for negative results.

      • maxSize

        public long maxSize()
        Returns the maximum number of elements allows in the cache.

      • clear

        public void clear()
        Specified by:
        clear in interface io.netty.resolver.dns.DnsCache

      • clear

        public boolean clear​(String hostname)
        Specified by:
        clear in interface io.netty.resolver.dns.DnsCache

      • get

        public List<? extends io.netty.resolver.dns.DnsCacheEntry> get​(String hostname,
                                                               io.netty.handler.codec.dns.DnsRecord[] additionals)
        Specified by:
        get in interface io.netty.resolver.dns.DnsCache

      • cache

        public io.netty.resolver.dns.DnsCacheEntry cache​(String hostname,
                                                 io.netty.handler.codec.dns.DnsRecord[] additionals,
                                                 InetAddress address,
                                                 long originalTtl,
                                                 io.netty.channel.EventLoop loop)
        Positive caching for normal lookups.
        Specified by:
        cache in interface io.netty.resolver.dns.DnsCache

      • cache

        public ExtendedDnsCacheEntry cache​(String hostname,
                                   io.netty.handler.codec.dns.DnsPtrRecord ptrRecord,
                                   io.netty.channel.EventLoop loop)
        Positive caching for reverse lookups.
        Specified by:
        cache in interface ExtendedDnsCache

      • cache

        public io.netty.resolver.dns.DnsCacheEntry cache​(String hostname,
                                                 io.netty.handler.codec.dns.DnsRecord[] additionals,
                                                 Throwable cause,
                                                 io.netty.channel.EventLoop loop)
        Negative caching for failures (or empty reverse lookups).
        Specified by:
        cache in interface io.netty.resolver.dns.DnsCache

      • getSize

        public long getSize()

      • registerMetrics

        public void registerMetrics​(com.codahale.metrics.MetricRegistry metrics)

      • unregisterMetrics

        public void unregisterMetrics​(com.codahale.metrics.MetricRegistry metrics)