Package io.vertx.core.dns

Class AddressResolverOptions

  • public class AddressResolverOptions
extends Object
    Configuration options for Vert.x hostname resolver. The resolver uses the local hosts file and performs DNS A and AAAA queries.
    Author:
    Julien Viet

    • Field Detail

      • DEFAULT_SERVERS

        public static final List<String> DEFAULT_SERVERS
        The default list of DNS servers = null (uses system name server's list like resolve.conf otherwise Google Public DNS)

      • DEFAULT_CACHE_MIN_TIME_TO_LIVE

        public static final int DEFAULT_CACHE_MIN_TIME_TO_LIVE
        The default value for the cache min TTL = 0
        See Also:
        Constant Field Values

      • DEFAULT_CACHE_MAX_TIME_TO_LIVE

        public static final int DEFAULT_CACHE_MAX_TIME_TO_LIVE
        The default value for the cache max TTL = 0x7fffffff
        See Also:
        Constant Field Values

      • DEFAULT_CACHE_NEGATIVE_TIME_TO_LIVE

        public static final int DEFAULT_CACHE_NEGATIVE_TIME_TO_LIVE
        The default value for the negative cache TTL = 0
        See Also:
        Constant Field Values

      • DEFAULT_QUERY_TIMEOUT

        public static final int DEFAULT_QUERY_TIMEOUT
        The default value for the query timeout in millis = 5000
        See Also:
        Constant Field Values

      • DEFAULT_HOSTS_REFRESH_PERIOD

        public static final int DEFAULT_HOSTS_REFRESH_PERIOD
        The default value for the hosts refresh value in millis = 0 (disabled)
        See Also:
        Constant Field Values

      • DEFAULT_MAX_QUERIES

        public static final int DEFAULT_MAX_QUERIES
        The default value for the max dns queries per query = 4
        See Also:
        Constant Field Values

      • DEFAULT_RD_FLAG

        public static final boolean DEFAULT_RD_FLAG
        The default value of the rd flag = true
        See Also:
        Constant Field Values

      • DEFAULT_SEARCH_DOMAINS

        public static final List<String> DEFAULT_SEARCH_DOMAINS
        The default value of search domains = null

      • DEFAULT_NDOTS

        public static final int DEFAULT_NDOTS
        The default ndots value = loads the value from the OS on Linux otherwise use the value 1

      • DEFAULT_ROTATE_SERVERS

        public static final boolean DEFAULT_ROTATE_SERVERS
        The default servers rotate value = loads the value from the OS on Linux otherwise use the value false

      • DEFAULT_ROUND_ROBIN_INET_ADDRESS

        public static final boolean DEFAULT_ROUND_ROBIN_INET_ADDRESS
        The default round robin inet address = false
        See Also:
        Constant Field Values

    • Constructor Detail

      • AddressResolverOptions

        public AddressResolverOptions()

      • AddressResolverOptions

        public AddressResolverOptions​(JsonObject json)

    • Method Detail

      • getHostsPath

        public String getHostsPath()
        Returns:
        the path to the alternate hosts configuration file

      • setHostsPath

        public AddressResolverOptions setHostsPath​(String hostsPath)
        Set the path of an alternate hosts configuration file to use instead of the one provided by the os.

        The default value is null, so the operating system hosts config is used.

        Parameters:
        hostsPath - the hosts path
        Returns:
        a reference to this, so the API can be used fluently

      • getHostsValue

        public Buffer getHostsValue()
        Returns:
        the hosts configuration file value

      • setHostsValue

        public AddressResolverOptions setHostsValue​(Buffer hostsValue)
        Set an alternate hosts configuration file to use instead of the one provided by the os.

        The value should contain the hosts content literaly, for instance 127.0.0.1 localhost

        The default value is null, so the operating system hosts config is used.

        Parameters:
        hostsValue - the hosts content
        Returns:
        a reference to this, so the API can be used fluently

      • getHostsRefreshPeriod

        public int getHostsRefreshPeriod()
        Returns:
        the hosts configuration refresh period in millis

      • setHostsRefreshPeriod

        public AddressResolverOptions setHostsRefreshPeriod​(int hostsRefreshPeriod)
        Set the hosts configuration refresh period in millis, 0 disables it.

        The resolver caches the hosts configuration file after it has read it. When the content of this file can change, setting a positive refresh period will load the configuration file again when necessary.

        Parameters:
        hostsRefreshPeriod - the hosts configuration refresh period

      • getServers

        public List<String> getServers()
        Returns:
        the list of dns server

      • setServers

        public AddressResolverOptions setServers​(List<String> servers)
        Set the list of DNS server addresses, an address is the IP of the dns server, followed by an optional colon and a port, e.g 8.8.8.8 or {code 192.168.0.1:40000}. When the list is empty, the resolver will use the list of the system DNS server addresses from the environment, if that list cannot be retrieved it will use Google's public DNS servers "8.8.8.8" and "8.8.4.4".
        Parameters:
        servers - the list of DNS servers
        Returns:
        a reference to this, so the API can be used fluently

      • addServer

        public AddressResolverOptions addServer​(String server)
        Add a DNS server address.
        Parameters:
        server - the server to add
        Returns:
        a reference to this, so the API can be used fluently

      • isOptResourceEnabled

        public boolean isOptResourceEnabled()
        Returns:
        true if an optional record is automatically included in DNS queries

      • setOptResourceEnabled

        public AddressResolverOptions setOptResourceEnabled​(boolean optResourceEnabled)
        Set to true to enable the automatic inclusion in DNS queries of an optional record that hints the remote DNS server about how much data the resolver can read per response.
        Parameters:
        optResourceEnabled - true to enable, false otherwise
        Returns:
        a reference to this, so the API can be used fluently

      • getCacheMinTimeToLive

        public int getCacheMinTimeToLive()
        Returns:
        the cache min TTL in seconds

      • setCacheMinTimeToLive

        public AddressResolverOptions setCacheMinTimeToLive​(int cacheMinTimeToLive)
        Set the cache minimum TTL value in seconds. After resolution successful IP addresses are cached with their DNS response TTL, use this to set a minimum value to all responses TTL.
        Parameters:
        cacheMinTimeToLive - the cache min TTL in seconds
        Returns:
        a reference to this, so the API can be used fluently

      • getCacheMaxTimeToLive

        public int getCacheMaxTimeToLive()
        Returns:
        the cache max TTL in seconds

      • setCacheMaxTimeToLive

        public AddressResolverOptions setCacheMaxTimeToLive​(int cacheMaxTimeToLive)
        Set the cache maximum TTL value in seconds. After successful resolution IP addresses are cached with their DNS response TTL, use this to set a maximum value to all responses TTL.
        Parameters:
        cacheMaxTimeToLive - the cache max TTL in seconds
        Returns:
        a reference to this, so the API can be used fluently

      • getCacheNegativeTimeToLive

        public int getCacheNegativeTimeToLive()
        Returns:
        the cache negative TTL in seconds

      • setCacheNegativeTimeToLive

        public AddressResolverOptions setCacheNegativeTimeToLive​(int cacheNegativeTimeToLive)
        Set the negative cache TTL value in seconds. After a failed hostname resolution, DNS queries won't be retried for a period of time equals to the negative TTL. This allows to reduce the response time of negative replies and reduce the amount of messages to DNS servers.
        Parameters:
        cacheNegativeTimeToLive - the cache negative TTL in seconds
        Returns:
        a reference to this, so the API can be used fluently

      • getQueryTimeout

        public long getQueryTimeout()
        Returns:
        the query timeout in milliseconds

      • setQueryTimeout

        public AddressResolverOptions setQueryTimeout​(long queryTimeout)
        Set the query timeout in milliseconds, i.e the amount of time after a query is considered to be failed.
        Parameters:
        queryTimeout - the query timeout in milliseconds
        Returns:
        a reference to this, so the API can be used fluently

      • getMaxQueries

        public int getMaxQueries()
        Returns:
        the maximum number of queries to be sent during a resolution

      • setMaxQueries

        public AddressResolverOptions setMaxQueries​(int maxQueries)
        Set the maximum number of queries when an hostname is resolved.
        Parameters:
        maxQueries - the max number of queries to be sent
        Returns:
        a reference to this, so the API can be used fluently

      • getRdFlag

        public boolean getRdFlag()
        Returns:
        the DNS queries Recursion Desired flag value

      • setRdFlag

        public AddressResolverOptions setRdFlag​(boolean rdFlag)
        Set the DNS queries Recursion Desired flag value.
        Parameters:
        rdFlag - the flag value
        Returns:
        a reference to this, so the API can be used fluently

      • getSearchDomains

        public List<String> getSearchDomains()
        Returns:
        the list of search domains

      • setSearchDomains

        public AddressResolverOptions setSearchDomains​(List<String> searchDomains)
        Set the lists of DNS search domains.

        When the search domain list is null, the effective search domain list will be populated using the system DNS search domains.

        Parameters:
        searchDomains - the search domains

      • addSearchDomain

        public AddressResolverOptions addSearchDomain​(String searchDomain)
        Add a DNS search domain.
        Parameters:
        searchDomain - the search domain to add
        Returns:
        a reference to this, so the API can be used fluently

      • getNdots

        public int getNdots()
        Returns:
        the ndots value

      • setNdots

        public AddressResolverOptions setNdots​(int ndots)
        Set the ndots value used when resolving using search domains, the default value is -1 which determines the value from the OS on Linux or uses the value 1.
        Parameters:
        ndots - the new ndots value
        Returns:
        a reference to this, so the API can be used fluently

      • isRotateServers

        public boolean isRotateServers()
        Returns:
        the value true when the dns server selection uses round robin

      • setRotateServers

        public AddressResolverOptions setRotateServers​(boolean rotateServers)
        Set to true to enable round-robin selection of the dns server to use. It spreads the query load among the servers and avoids all lookup to hit the first server of the list.
        Returns:
        a reference to this, so the API can be used fluently

      • isRoundRobinInetAddress

        public boolean isRoundRobinInetAddress()
        Returns:
        the value true when the inet address selection uses round robin

      • setRoundRobinInetAddress

        public AddressResolverOptions setRoundRobinInetAddress​(boolean roundRobinInetAddress)
        Set to true to enable round-robin inet address selection of the ip address to use.
        Returns:
        a reference to this, so the API can be used fluently