package envoy.extensions.common.dynamic_forward_proxy.v3
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dns_cache.proto:28Configuration of circuit breakers for resolver.
Used in:
optional max_pending_requests = 1
The maximum number of pending requests that Envoy will allow to the resolver. If not specified, the default is 1024.
message
dns_cache.proto:37Configuration for the dynamic forward proxy DNS cache. See the :ref:`architecture overview <arch_overview_http_dynamic_forward_proxy>` for more information. [#next-free-field: 16]
Used in: , , , ,
string name = 1
The name of the cache. Multiple named caches allow independent dynamic forward proxy configurations to operate within a single Envoy process using different configurations. All configurations with the same name *must* otherwise have the same settings when referenced from different configuration components. Configuration will fail to load if this is not the case.
config.cluster.v3.Cluster.DnsLookupFamily dns_lookup_family = 2
The DNS lookup family to use during resolution. [#comment:TODO(mattklein123): Figure out how to support IPv4/IPv6 "happy eyeballs" mode. The way this might work is a new lookup family which returns both IPv4 and IPv6 addresses, and then configures a host to have a primary and fall back address. With this, we could very likely build a "happy eyeballs" connection pool which would race the primary / fall back address and return the one that wins. This same method could potentially also be used for QUIC to TCP fall back.]
optional dns_refresh_rate = 3
The DNS refresh rate for unresolved DNS hosts. If not specified defaults to 60s. The refresh rate is rounded to the closest millisecond, and must be at least 1ms. Once a host has been resolved, the refresh rate will be the DNS TTL, capped at a minimum of ``dns_min_refresh_rate``.
optional dns_min_refresh_rate = 14
The minimum rate that DNS resolution will occur. Per ``dns_refresh_rate``, once a host is resolved, the DNS TTL will be used, with a minimum set by ``dns_min_refresh_rate``. ``dns_min_refresh_rate`` defaults to 5s and must also be >= 1s.
optional host_ttl = 4
The TTL for hosts that are unused. Hosts that have not been used in the configured time interval will be purged. If not specified defaults to 5m. .. note: The TTL is only checked at the time of DNS refresh, as specified by ``dns_refresh_rate``. This means that if the configured TTL is shorter than the refresh rate the host may not be removed immediately. .. note: The TTL has no relation to DNS TTL and is only used to control Envoy's resource usage.
optional max_hosts = 5
The maximum number of hosts that the cache will hold. If not specified defaults to 1024. .. note: The implementation is approximate and enforced independently on each worker thread, thus it is possible for the maximum hosts in the cache to go slightly above the configured value depending on timing. This is similar to how other circuit breakers work.
bool disable_dns_refresh_on_failure = 15
Disable the DNS refresh on failure. If this field is set to true, it will ignore the :ref:`typed_dns_resolver_config <envoy_v3_api_field_extensions.common.dynamic_forward_proxy.v3.DnsCacheConfig.dns_failure_refresh_rate>`. If not specified, it defaults to false. By enabling this feature, the failed hosts will now be treated as a cache miss, allowing the failed hosts to be resolved on demand.
optional dns_failure_refresh_rate = 6
If the DNS failure refresh rate is specified, this is used as the cache's DNS refresh rate when DNS requests are failing. If this setting is not specified, the failure refresh rate defaults to the dns_refresh_rate.
optional dns_cache_circuit_breaker = 7
The config of circuit breakers for resolver. It provides a configurable threshold. Envoy will use dns cache circuit breakers with default settings even if this value is not set.
bool use_tcp_for_dns_lookups = 8
Always use TCP queries instead of UDP queries for DNS lookups. This field is deprecated in favor of ``dns_resolution_config`` which aggregates all of the DNS resolver configuration in a single message.
optional dns_resolution_config = 9
DNS resolution configuration which includes the underlying dns resolver addresses and options. This field is deprecated in favor of :ref:`typed_dns_resolver_config <envoy_v3_api_field_extensions.common.dynamic_forward_proxy.v3.DnsCacheConfig.typed_dns_resolver_config>`.
optional typed_dns_resolver_config = 12
DNS resolver type configuration extension. This extension can be used to configure c-ares, apple, or any other DNS resolver types and the related parameters. For example, an object of :ref:`CaresDnsResolverConfig <envoy_v3_api_msg_extensions.network.dns_resolver.cares.v3.CaresDnsResolverConfig>` can be packed into this ``typed_dns_resolver_config``. This configuration replaces the :ref:`dns_resolution_config <envoy_v3_api_field_extensions.common.dynamic_forward_proxy.v3.DnsCacheConfig.dns_resolution_config>` configuration. During the transition period when both ``dns_resolution_config`` and ``typed_dns_resolver_config`` exists, when ``typed_dns_resolver_config`` is in place, Envoy will use it and ignore ``dns_resolution_config``. When ``typed_dns_resolver_config`` is missing, the default behavior is in place. [#extension-category: envoy.network.dns_resolver]
repeated preresolve_hostnames = 10
Hostnames that should be preresolved into the cache upon creation. This might provide a performance improvement, in the form of cache hits, for hostnames that are going to be resolved during steady state and are known at config load time.
optional dns_query_timeout = 11
The timeout used for DNS queries. This timeout is independent of any timeout and retry policy used by the underlying DNS implementation (e.g., c-areas and Apple DNS) which are opaque. Setting this timeout will ensure that queries succeed or fail within the specified time frame and are then retried using the standard refresh rates. Setting it to 0 will disable the Envoy DNS query timeout and use the underlying DNS implementation timeout. Defaults to 5s if not set.
optional key_value_config = 13
Configuration to flush the DNS cache to long term storage.