diff options
Diffstat (limited to 'src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc')
| -rw-r--r-- | src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc | 101 |
1 files changed, 57 insertions, 44 deletions
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc index 01796ca08f..abacd0c960 100644 --- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc +++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc @@ -33,6 +33,7 @@ #include "src/core/ext/filters/client_channel/lb_policy_registry.h" #include "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h" #include "src/core/ext/filters/client_channel/resolver_registry.h" +#include "src/core/ext/filters/client_channel/server_address.h" #include "src/core/lib/backoff/backoff.h" #include "src/core/lib/channel/channel_args.h" #include "src/core/lib/gpr/env.h" @@ -117,9 +118,13 @@ class AresDnsResolver : public Resolver { /// retry backoff state BackOff backoff_; /// currently resolving addresses - grpc_lb_addresses* lb_addresses_ = nullptr; + UniquePtr<ServerAddressList> addresses_; /// currently resolving service config char* service_config_json_ = nullptr; + // has shutdown been initiated + bool shutdown_initiated_ = false; + // timeout in milliseconds for active DNS queries + int query_timeout_ms_; }; AresDnsResolver::AresDnsResolver(const ResolverArgs& args) @@ -157,10 +162,15 @@ AresDnsResolver::AresDnsResolver(const ResolverArgs& args) grpc_combiner_scheduler(combiner())); GRPC_CLOSURE_INIT(&on_resolved_, OnResolvedLocked, this, grpc_combiner_scheduler(combiner())); + const grpc_arg* query_timeout_ms_arg = + grpc_channel_args_find(channel_args_, GRPC_ARG_DNS_ARES_QUERY_TIMEOUT_MS); + query_timeout_ms_ = grpc_channel_arg_get_integer( + query_timeout_ms_arg, + {GRPC_DNS_ARES_DEFAULT_QUERY_TIMEOUT_MS, 0, INT_MAX}); } AresDnsResolver::~AresDnsResolver() { - gpr_log(GPR_DEBUG, "destroying AresDnsResolver"); + GRPC_CARES_TRACE_LOG("resolver:%p destroying AresDnsResolver", this); if (resolved_result_ != nullptr) { grpc_channel_args_destroy(resolved_result_); } @@ -172,7 +182,8 @@ AresDnsResolver::~AresDnsResolver() { void AresDnsResolver::NextLocked(grpc_channel_args** target_result, grpc_closure* on_complete) { - gpr_log(GPR_DEBUG, "AresDnsResolver::NextLocked() is called."); + GRPC_CARES_TRACE_LOG("resolver:%p AresDnsResolver::NextLocked() is called.", + this); GPR_ASSERT(next_completion_ == nullptr); next_completion_ = on_complete; target_result_ = target_result; @@ -197,6 +208,7 @@ void AresDnsResolver::ResetBackoffLocked() { } void AresDnsResolver::ShutdownLocked() { + shutdown_initiated_ = true; if (have_next_resolution_timer_) { grpc_timer_cancel(&next_resolution_timer_); } @@ -213,9 +225,15 @@ void AresDnsResolver::ShutdownLocked() { void AresDnsResolver::OnNextResolutionLocked(void* arg, grpc_error* error) { AresDnsResolver* r = static_cast<AresDnsResolver*>(arg); + GRPC_CARES_TRACE_LOG( + "resolver:%p re-resolution timer fired. error: %s. shutdown_initiated_: " + "%d", + r, grpc_error_string(error), r->shutdown_initiated_); r->have_next_resolution_timer_ = false; - if (error == GRPC_ERROR_NONE) { + if (error == GRPC_ERROR_NONE && !r->shutdown_initiated_) { if (!r->resolving_) { + GRPC_CARES_TRACE_LOG( + "resolver:%p start resolving due to re-resolution timer", r); r->StartResolvingLocked(); } } @@ -300,53 +318,40 @@ void AresDnsResolver::OnResolvedLocked(void* arg, grpc_error* error) { r->resolving_ = false; gpr_free(r->pending_request_); r->pending_request_ = nullptr; - if (r->lb_addresses_ != nullptr) { - static const char* args_to_remove[2]; + if (r->addresses_ != nullptr) { + static const char* args_to_remove[1]; size_t num_args_to_remove = 0; - grpc_arg new_args[3]; + grpc_arg args_to_add[2]; size_t num_args_to_add = 0; - new_args[num_args_to_add++] = - grpc_lb_addresses_create_channel_arg(r->lb_addresses_); - grpc_core::UniquePtr<grpc_core::ServiceConfig> service_config; + args_to_add[num_args_to_add++] = + CreateServerAddressListChannelArg(r->addresses_.get()); char* service_config_string = nullptr; if (r->service_config_json_ != nullptr) { service_config_string = ChooseServiceConfig(r->service_config_json_); gpr_free(r->service_config_json_); if (service_config_string != nullptr) { - gpr_log(GPR_INFO, "selected service config choice: %s", - service_config_string); + GRPC_CARES_TRACE_LOG("resolver:%p selected service config choice: %s", + r, service_config_string); args_to_remove[num_args_to_remove++] = GRPC_ARG_SERVICE_CONFIG; - new_args[num_args_to_add++] = grpc_channel_arg_string_create( + args_to_add[num_args_to_add++] = grpc_channel_arg_string_create( (char*)GRPC_ARG_SERVICE_CONFIG, service_config_string); - service_config = - grpc_core::ServiceConfig::Create(service_config_string); - if (service_config != nullptr) { - const char* lb_policy_name = - service_config->GetLoadBalancingPolicyName(); - if (lb_policy_name != nullptr) { - args_to_remove[num_args_to_remove++] = GRPC_ARG_LB_POLICY_NAME; - new_args[num_args_to_add++] = grpc_channel_arg_string_create( - (char*)GRPC_ARG_LB_POLICY_NAME, - const_cast<char*>(lb_policy_name)); - } - } } } result = grpc_channel_args_copy_and_add_and_remove( - r->channel_args_, args_to_remove, num_args_to_remove, new_args, + r->channel_args_, args_to_remove, num_args_to_remove, args_to_add, num_args_to_add); gpr_free(service_config_string); - grpc_lb_addresses_destroy(r->lb_addresses_); + r->addresses_.reset(); // Reset backoff state so that we start from the beginning when the // next request gets triggered. r->backoff_.Reset(); - } else { + } else if (!r->shutdown_initiated_) { const char* msg = grpc_error_string(error); - gpr_log(GPR_DEBUG, "dns resolution failed: %s", msg); + GRPC_CARES_TRACE_LOG("resolver:%p dns resolution failed: %s", r, msg); grpc_millis next_try = r->backoff_.NextAttemptTime(); grpc_millis timeout = next_try - ExecCtx::Get()->Now(); - gpr_log(GPR_INFO, "dns resolution failed (will retry): %s", - grpc_error_string(error)); + GRPC_CARES_TRACE_LOG("resolver:%p dns resolution failed (will retry): %s", + r, grpc_error_string(error)); GPR_ASSERT(!r->have_next_resolution_timer_); r->have_next_resolution_timer_ = true; // TODO(roth): We currently deal with this ref manually. Once the @@ -355,9 +360,10 @@ void AresDnsResolver::OnResolvedLocked(void* arg, grpc_error* error) { RefCountedPtr<Resolver> self = r->Ref(DEBUG_LOCATION, "retry-timer"); self.release(); if (timeout > 0) { - gpr_log(GPR_DEBUG, "retrying in %" PRId64 " milliseconds", timeout); + GRPC_CARES_TRACE_LOG("resolver:%p retrying in %" PRId64 " milliseconds", + r, timeout); } else { - gpr_log(GPR_DEBUG, "retrying immediately"); + GRPC_CARES_TRACE_LOG("resolver:%p retrying immediately", r); } grpc_timer_init(&r->next_resolution_timer_, next_try, &r->on_next_resolution_); @@ -383,10 +389,10 @@ void AresDnsResolver::MaybeStartResolvingLocked() { if (ms_until_next_resolution > 0) { const grpc_millis last_resolution_ago = grpc_core::ExecCtx::Get()->Now() - last_resolution_timestamp_; - gpr_log(GPR_DEBUG, - "In cooldown from last resolution (from %" PRId64 - " ms ago). Will resolve again in %" PRId64 " ms", - last_resolution_ago, ms_until_next_resolution); + GRPC_CARES_TRACE_LOG( + "resolver:%p In cooldown from last resolution (from %" PRId64 + " ms ago). Will resolve again in %" PRId64 " ms", + this, last_resolution_ago, ms_until_next_resolution); have_next_resolution_timer_ = true; // TODO(roth): We currently deal with this ref manually. Once the // new closure API is done, find a way to track this ref with the timer @@ -403,7 +409,6 @@ void AresDnsResolver::MaybeStartResolvingLocked() { } void AresDnsResolver::StartResolvingLocked() { - gpr_log(GPR_DEBUG, "Start resolving."); // TODO(roth): We currently deal with this ref manually. Once the // new closure API is done, find a way to track this ref with the timer // callback as part of the type system. @@ -411,13 +416,15 @@ void AresDnsResolver::StartResolvingLocked() { self.release(); GPR_ASSERT(!resolving_); resolving_ = true; - lb_addresses_ = nullptr; service_config_json_ = nullptr; pending_request_ = grpc_dns_lookup_ares_locked( dns_server_, name_to_resolve_, kDefaultPort, interested_parties_, - &on_resolved_, &lb_addresses_, true /* check_grpclb */, - request_service_config_ ? &service_config_json_ : nullptr, combiner()); + &on_resolved_, &addresses_, true /* check_grpclb */, + request_service_config_ ? &service_config_json_ : nullptr, + query_timeout_ms_, combiner()); last_resolution_timestamp_ = grpc_core::ExecCtx::Get()->Now(); + GRPC_CARES_TRACE_LOG("resolver:%p Started resolving. pending_request_:%p", + this, pending_request_); } void AresDnsResolver::MaybeFinishNextLocked() { @@ -425,7 +432,8 @@ void AresDnsResolver::MaybeFinishNextLocked() { *target_result_ = resolved_result_ == nullptr ? nullptr : grpc_channel_args_copy(resolved_result_); - gpr_log(GPR_DEBUG, "AresDnsResolver::MaybeFinishNextLocked()"); + GRPC_CARES_TRACE_LOG("resolver:%p AresDnsResolver::MaybeFinishNextLocked()", + this); GRPC_CLOSURE_SCHED(next_completion_, GRPC_ERROR_NONE); next_completion_ = nullptr; published_version_ = resolved_version_; @@ -463,11 +471,16 @@ static grpc_error* blocking_resolve_address_ares( static grpc_address_resolver_vtable ares_resolver = { grpc_resolve_address_ares, blocking_resolve_address_ares}; +static bool should_use_ares(const char* resolver_env) { + return resolver_env != nullptr && gpr_stricmp(resolver_env, "ares") == 0; +} + void grpc_resolver_dns_ares_init() { char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER"); /* TODO(zyc): Turn on c-ares based resolver by default after the address sorter and the CNAME support are added. */ - if (resolver_env != nullptr && gpr_stricmp(resolver_env, "ares") == 0) { + if (should_use_ares(resolver_env)) { + gpr_log(GPR_DEBUG, "Using ares dns resolver"); address_sorting_init(); grpc_error* error = grpc_ares_init(); if (error != GRPC_ERROR_NONE) { @@ -487,7 +500,7 @@ void grpc_resolver_dns_ares_init() { void grpc_resolver_dns_ares_shutdown() { char* resolver_env = gpr_getenv("GRPC_DNS_RESOLVER"); - if (resolver_env != nullptr && gpr_stricmp(resolver_env, "ares") == 0) { + if (should_use_ares(resolver_env)) { address_sorting_shutdown(); grpc_ares_cleanup(); } |