diff --git a/include/grpc/impl/codegen/grpc_types.h b/include/grpc/impl/codegen/grpc_types.h index 993fc97adb6..d5ec2fedd82 100644 --- a/include/grpc/impl/codegen/grpc_types.h +++ b/include/grpc/impl/codegen/grpc_types.h @@ -202,8 +202,12 @@ typedef enum grpc_call_error { /* Initial metadata flags */ /** Signal that the call is idempotent */ #define GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST (0x00000010u) +/** Signal that the call should not return UNAVAILABLE before it has started */ +#define GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY (0x00000020u) /** Mask of all valid flags */ -#define GRPC_INITIAL_METADATA_USED_MASK GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST +#define GRPC_INITIAL_METADATA_USED_MASK \ + (GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST | \ + GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY) /** A single metadata element */ typedef struct grpc_metadata { diff --git a/src/core/channel/client_channel.c b/src/core/channel/client_channel.c index f021a8ae329..e229a15260e 100644 --- a/src/core/channel/client_channel.c +++ b/src/core/channel/client_channel.c @@ -114,6 +114,22 @@ static void watch_lb_policy(grpc_exec_ctx *exec_ctx, channel_data *chand, grpc_lb_policy *lb_policy, grpc_connectivity_state current_state); +static void set_channel_connectivity_state_locked(grpc_exec_ctx *exec_ctx, + channel_data *chand, + grpc_connectivity_state state, + const char *reason) { + if ((state == GRPC_CHANNEL_TRANSIENT_FAILURE || + state == GRPC_CHANNEL_FATAL_FAILURE) && + chand->lb_policy != NULL) { + /* cancel fail-fast picks */ + grpc_lb_policy_cancel_picks( + exec_ctx, chand->lb_policy, + /* mask= */ GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY, + /* check= */ 0); + } + grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, state, reason); +} + static void on_lb_policy_state_changed_locked( grpc_exec_ctx *exec_ctx, lb_policy_connectivity_watcher *w) { grpc_connectivity_state publish_state = w->state; @@ -127,8 +143,8 @@ static void on_lb_policy_state_changed_locked( GRPC_LB_POLICY_UNREF(exec_ctx, w->chand->lb_policy, "channel"); w->chand->lb_policy = NULL; } - grpc_connectivity_state_set(exec_ctx, &w->chand->state_tracker, publish_state, - "lb_changed"); + set_channel_connectivity_state_locked(exec_ctx, w->chand, publish_state, + "lb_changed"); if (w->state != GRPC_CHANNEL_FATAL_FAILURE) { watch_lb_policy(exec_ctx, w->chand, w->lb_policy, w->state); } @@ -200,8 +216,8 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg, } if (iomgr_success && chand->resolver) { - grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, state, - "new_lb+resolver"); + set_channel_connectivity_state_locked(exec_ctx, chand, state, + "new_lb+resolver"); if (lb_policy != NULL) { watch_lb_policy(exec_ctx, chand, lb_policy, state); } @@ -216,8 +232,8 @@ static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg, GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel"); chand->resolver = NULL; } - grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, - GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone"); + set_channel_connectivity_state_locked( + exec_ctx, chand, GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone"); gpr_mu_unlock(&chand->mu_config); } @@ -272,8 +288,8 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx, } if (op->disconnect && chand->resolver != NULL) { - grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, - GRPC_CHANNEL_FATAL_FAILURE, "disconnect"); + set_channel_connectivity_state_locked( + exec_ctx, chand, GRPC_CHANNEL_FATAL_FAILURE, "disconnect"); grpc_resolver_shutdown(exec_ctx, chand->resolver); GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel"); chand->resolver = NULL; @@ -290,6 +306,7 @@ static void cc_start_transport_op(grpc_exec_ctx *exec_ctx, typedef struct { grpc_metadata_batch *initial_metadata; + uint32_t initial_metadata_flags; grpc_connected_subchannel **connected_subchannel; grpc_closure *on_ready; grpc_call_element *elem; @@ -298,6 +315,7 @@ typedef struct { static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *arg, grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, grpc_connected_subchannel **connected_subchannel, grpc_closure *on_ready); @@ -308,6 +326,7 @@ static void continue_picking(grpc_exec_ctx *exec_ctx, void *arg, bool success) { } else if (cpa->connected_subchannel == NULL) { /* cancelled, do nothing */ } else if (cc_pick_subchannel(exec_ctx, cpa->elem, cpa->initial_metadata, + cpa->initial_metadata_flags, cpa->connected_subchannel, cpa->on_ready)) { grpc_exec_ctx_enqueue(exec_ctx, cpa->on_ready, true, NULL); } @@ -316,6 +335,7 @@ static void continue_picking(grpc_exec_ctx *exec_ctx, void *arg, bool success) { static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp, grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, grpc_connected_subchannel **connected_subchannel, grpc_closure *on_ready) { grpc_call_element *elem = elemp; @@ -349,7 +369,8 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp, GRPC_LB_POLICY_REF(lb_policy, "cc_pick_subchannel"); gpr_mu_unlock(&chand->mu_config); r = grpc_lb_policy_pick(exec_ctx, lb_policy, calld->pollset, - initial_metadata, connected_subchannel, on_ready); + initial_metadata, initial_metadata_flags, + connected_subchannel, on_ready); GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "cc_pick_subchannel"); return r; } @@ -362,6 +383,7 @@ static int cc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *elemp, } cpa = gpr_malloc(sizeof(*cpa)); cpa->initial_metadata = initial_metadata; + cpa->initial_metadata_flags = initial_metadata_flags; cpa->connected_subchannel = connected_subchannel; cpa->on_ready = on_ready; cpa->elem = elem; diff --git a/src/core/channel/client_uchannel.c b/src/core/channel/client_uchannel.c index 83fcc3a87f5..cafbc4fd894 100644 --- a/src/core/channel/client_uchannel.c +++ b/src/core/channel/client_uchannel.c @@ -126,6 +126,7 @@ static void cuc_start_transport_op(grpc_exec_ctx *exec_ctx, static int cuc_pick_subchannel(grpc_exec_ctx *exec_ctx, void *arg, grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, grpc_connected_subchannel **connected_subchannel, grpc_closure *on_ready) { channel_data *chand = arg; diff --git a/src/core/channel/http_client_filter.c b/src/core/channel/http_client_filter.c index 32c808cf6aa..79abfd2102e 100644 --- a/src/core/channel/http_client_filter.c +++ b/src/core/channel/http_client_filter.c @@ -111,10 +111,12 @@ static void hc_mutate_op(grpc_call_element *elem, elem); /* Send : prefixed headers, which have to be before any application layer headers. */ - grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->method, - op->send_idempotent_request - ? GRPC_MDELEM_METHOD_PUT - : GRPC_MDELEM_METHOD_POST); + grpc_metadata_batch_add_head( + op->send_initial_metadata, &calld->method, + op->send_initial_metadata_flags & + GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST + ? GRPC_MDELEM_METHOD_PUT + : GRPC_MDELEM_METHOD_POST); grpc_metadata_batch_add_head(op->send_initial_metadata, &calld->scheme, channeld->static_scheme); grpc_metadata_batch_add_tail(op->send_initial_metadata, &calld->te_trailers, diff --git a/src/core/channel/subchannel_call_holder.c b/src/core/channel/subchannel_call_holder.c index 9c087dc2a1d..788d3ab21b8 100644 --- a/src/core/channel/subchannel_call_holder.c +++ b/src/core/channel/subchannel_call_holder.c @@ -127,7 +127,7 @@ retry: break; case GRPC_SUBCHANNEL_CALL_HOLDER_PICKING_SUBCHANNEL: holder->pick_subchannel(exec_ctx, holder->pick_subchannel_arg, NULL, - &holder->connected_subchannel, NULL); + 0, &holder->connected_subchannel, NULL); break; } gpr_mu_unlock(&holder->mu); @@ -145,7 +145,8 @@ retry: GRPC_CALL_STACK_REF(holder->owning_call, "pick_subchannel"); if (holder->pick_subchannel( exec_ctx, holder->pick_subchannel_arg, op->send_initial_metadata, - &holder->connected_subchannel, &holder->next_step)) { + op->send_initial_metadata_flags, &holder->connected_subchannel, + &holder->next_step)) { holder->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING; GRPC_CALL_STACK_UNREF(exec_ctx, holder->owning_call, "pick_subchannel"); } diff --git a/src/core/channel/subchannel_call_holder.h b/src/core/channel/subchannel_call_holder.h index 9cf72c6cf76..acb35a8283a 100644 --- a/src/core/channel/subchannel_call_holder.h +++ b/src/core/channel/subchannel_call_holder.h @@ -42,6 +42,7 @@ called when the subchannel is available) */ typedef int (*grpc_subchannel_call_holder_pick_subchannel)( grpc_exec_ctx *exec_ctx, void *arg, grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, grpc_connected_subchannel **connected_subchannel, grpc_closure *on_ready); typedef enum { diff --git a/src/core/client_config/lb_policies/pick_first.c b/src/core/client_config/lb_policies/pick_first.c index 81167b31c8c..20c2dd8bf34 100644 --- a/src/core/client_config/lb_policies/pick_first.c +++ b/src/core/client_config/lb_policies/pick_first.c @@ -42,6 +42,7 @@ typedef struct pending_pick { struct pending_pick *next; grpc_pollset *pollset; + uint32_t initial_metadata_flags; grpc_connected_subchannel **target; grpc_closure *on_complete; } pending_pick; @@ -151,6 +152,32 @@ static void pf_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, gpr_mu_unlock(&p->mu); } +static void pf_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, + uint32_t initial_metadata_flags_mask, + uint32_t initial_metadata_flags_eq) { + pick_first_lb_policy *p = (pick_first_lb_policy *)pol; + pending_pick *pp; + gpr_mu_lock(&p->mu); + pp = p->pending_picks; + p->pending_picks = NULL; + while (pp != NULL) { + pending_pick *next = pp->next; + if ((pp->initial_metadata_flags & initial_metadata_flags_mask) == + initial_metadata_flags_eq) { + grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties, + pp->pollset); + *pp->target = NULL; + grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL); + gpr_free(pp); + } else { + pp->next = p->pending_picks; + p->pending_picks = pp; + } + pp = next; + } + gpr_mu_unlock(&p->mu); +} + static void start_picking(grpc_exec_ctx *exec_ctx, pick_first_lb_policy *p) { p->started_picking = 1; p->checking_subchannel = 0; @@ -173,7 +200,8 @@ void pf_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset, grpc_metadata_batch *initial_metadata, - grpc_connected_subchannel **target, grpc_closure *on_complete) { + uint32_t initial_metadata_flags, grpc_connected_subchannel **target, + grpc_closure *on_complete) { pick_first_lb_policy *p = (pick_first_lb_policy *)pol; pending_pick *pp; @@ -200,6 +228,7 @@ int pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset, pp->next = p->pending_picks; pp->pollset = pollset; pp->target = target; + pp->initial_metadata_flags = initial_metadata_flags; pp->on_complete = on_complete; p->pending_picks = pp; gpr_mu_unlock(&p->mu); @@ -378,8 +407,9 @@ void pf_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, } static const grpc_lb_policy_vtable pick_first_lb_policy_vtable = { - pf_destroy, pf_shutdown, pf_pick, pf_cancel_pick, pf_ping_one, pf_exit_idle, - pf_check_connectivity, pf_notify_on_state_change}; + pf_destroy, pf_shutdown, pf_pick, pf_cancel_pick, pf_cancel_picks, + pf_ping_one, pf_exit_idle, pf_check_connectivity, + pf_notify_on_state_change}; static void pick_first_factory_ref(grpc_lb_policy_factory *factory) {} diff --git a/src/core/client_config/lb_policies/round_robin.c b/src/core/client_config/lb_policies/round_robin.c index 98d9acc75bf..6fa5b03d8cd 100644 --- a/src/core/client_config/lb_policies/round_robin.c +++ b/src/core/client_config/lb_policies/round_robin.c @@ -48,6 +48,7 @@ int grpc_lb_round_robin_trace = 0; typedef struct pending_pick { struct pending_pick *next; grpc_pollset *pollset; + uint32_t initial_metadata_flags; grpc_connected_subchannel **target; grpc_closure *on_complete; } pending_pick; @@ -274,6 +275,32 @@ static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, gpr_mu_unlock(&p->mu); } +static void rr_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, + uint32_t initial_metadata_flags_mask, + uint32_t initial_metadata_flags_eq) { + round_robin_lb_policy *p = (round_robin_lb_policy *)pol; + pending_pick *pp; + gpr_mu_lock(&p->mu); + pp = p->pending_picks; + p->pending_picks = NULL; + while (pp != NULL) { + pending_pick *next = pp->next; + if ((pp->initial_metadata_flags & initial_metadata_flags_mask) == + initial_metadata_flags_eq) { + grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties, + pp->pollset); + *pp->target = NULL; + grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL); + gpr_free(pp); + } else { + pp->next = p->pending_picks; + p->pending_picks = pp; + } + pp = next; + } + gpr_mu_unlock(&p->mu); +} + static void start_picking(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) { size_t i; p->started_picking = 1; @@ -302,7 +329,8 @@ void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset, grpc_metadata_batch *initial_metadata, - grpc_connected_subchannel **target, grpc_closure *on_complete) { + uint32_t initial_metadata_flags, grpc_connected_subchannel **target, + grpc_closure *on_complete) { round_robin_lb_policy *p = (round_robin_lb_policy *)pol; pending_pick *pp; ready_list *selected; @@ -328,6 +356,7 @@ int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset, pp->pollset = pollset; pp->target = target; pp->on_complete = on_complete; + pp->initial_metadata_flags = initial_metadata_flags; p->pending_picks = pp; gpr_mu_unlock(&p->mu); return 0; @@ -483,8 +512,9 @@ static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, } static const grpc_lb_policy_vtable round_robin_lb_policy_vtable = { - rr_destroy, rr_shutdown, rr_pick, rr_cancel_pick, rr_ping_one, rr_exit_idle, - rr_check_connectivity, rr_notify_on_state_change}; + rr_destroy, rr_shutdown, rr_pick, rr_cancel_pick, rr_cancel_picks, + rr_ping_one, rr_exit_idle, rr_check_connectivity, + rr_notify_on_state_change}; static void round_robin_factory_ref(grpc_lb_policy_factory *factory) {} diff --git a/src/core/client_config/lb_policy.c b/src/core/client_config/lb_policy.c index 0d8b0073369..d67505e618c 100644 --- a/src/core/client_config/lb_policy.c +++ b/src/core/client_config/lb_policy.c @@ -101,10 +101,11 @@ void grpc_lb_policy_weak_unref(grpc_exec_ctx *exec_ctx, int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_pollset *pollset, grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, grpc_connected_subchannel **target, grpc_closure *on_complete) { return policy->vtable->pick(exec_ctx, policy, pollset, initial_metadata, - target, on_complete); + initial_metadata_flags, target, on_complete); } void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, @@ -112,6 +113,14 @@ void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, policy->vtable->cancel_pick(exec_ctx, policy, target); } +void grpc_lb_policy_cancel_picks(grpc_exec_ctx *exec_ctx, + grpc_lb_policy *policy, + uint32_t initial_metadata_flags_mask, + uint32_t initial_metadata_flags_eq) { + policy->vtable->cancel_picks(exec_ctx, policy, initial_metadata_flags_mask, + initial_metadata_flags_eq); +} + void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy) { policy->vtable->exit_idle(exec_ctx, policy); } diff --git a/src/core/client_config/lb_policy.h b/src/core/client_config/lb_policy.h index 34573906068..922b0d36722 100644 --- a/src/core/client_config/lb_policy.h +++ b/src/core/client_config/lb_policy.h @@ -60,9 +60,13 @@ struct grpc_lb_policy_vtable { /** implement grpc_lb_policy_pick */ int (*pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_pollset *pollset, grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, grpc_connected_subchannel **target, grpc_closure *on_complete); void (*cancel_pick)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_connected_subchannel **target); + void (*cancel_picks)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, + uint32_t initial_metadata_flags_mask, + uint32_t initial_metadata_flags_eq); void (*ping_one)(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_closure *closure); @@ -122,6 +126,7 @@ void grpc_lb_policy_init(grpc_lb_policy *policy, int grpc_lb_policy_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_pollset *pollset, grpc_metadata_batch *initial_metadata, + uint32_t initial_metadata_flags, grpc_connected_subchannel **target, grpc_closure *on_complete); @@ -131,6 +136,14 @@ void grpc_lb_policy_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, void grpc_lb_policy_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, grpc_connected_subchannel **target); +/** Cancel all pending picks which have: + (initial_metadata_flags & initial_metadata_flags_mask) == + initial_metadata_flags_eq */ +void grpc_lb_policy_cancel_picks(grpc_exec_ctx *exec_ctx, + grpc_lb_policy *policy, + uint32_t initial_metadata_flags_mask, + uint32_t initial_metadata_flags_eq); + void grpc_lb_policy_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy); void grpc_lb_policy_notify_on_state_change(grpc_exec_ctx *exec_ctx, diff --git a/src/core/surface/call.c b/src/core/surface/call.c index a369795ac83..07a6c1a2dbd 100644 --- a/src/core/surface/call.c +++ b/src/core/surface/call.c @@ -1229,8 +1229,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx, call->metadata_batch[0][0].deadline = call->send_deadline; stream_op.send_initial_metadata = &call->metadata_batch[0 /* is_receiving */][0 /* is_trailing */]; - stream_op.send_idempotent_request = - (op->flags & GRPC_INITIAL_METADATA_IDEMPOTENT_REQUEST) != 0; + stream_op.send_initial_metadata_flags = op->flags; break; case GRPC_OP_SEND_MESSAGE: if (!are_write_flags_valid(op->flags)) { diff --git a/src/core/transport/transport.h b/src/core/transport/transport.h index 0374c98087b..ca7f60fa039 100644 --- a/src/core/transport/transport.h +++ b/src/core/transport/transport.h @@ -84,9 +84,9 @@ typedef struct grpc_transport_stream_op { /** Send initial metadata to the peer, from the provided metadata batch. idempotent_request MUST be set if this is non-null */ grpc_metadata_batch *send_initial_metadata; - /** Iff send_initial_metadata != NULL, flags if this is an idempotent request - or not */ - bool send_idempotent_request; + /** Iff send_initial_metadata != NULL, flags associated with + send_initial_metadata: a bitfield of GRPC_INITIAL_METADATA_xxx */ + uint32_t send_initial_metadata_flags; /** Send trailing metadata to the peer, from the provided metadata batch. */ grpc_metadata_batch *send_trailing_metadata; diff --git a/test/core/end2end/dualstack_socket_test.c b/test/core/end2end/dualstack_socket_test.c index 58e13a4098b..f6531ea523d 100644 --- a/test/core/end2end/dualstack_socket_test.c +++ b/test/core/end2end/dualstack_socket_test.c @@ -39,9 +39,9 @@ #include #include -#include "src/core/support/string.h" #include "src/core/iomgr/resolve_address.h" #include "src/core/iomgr/socket_utils_posix.h" +#include "src/core/support/string.h" #include "test/core/end2end/cq_verifier.h" #include "test/core/util/port.h" @@ -237,7 +237,7 @@ void test_connect(const char *server_host, const char *client_host, int port, cq_expect_completion(cqv, tag(1), 1); cq_verify(cqv); - GPR_ASSERT(status == GRPC_STATUS_DEADLINE_EXCEEDED); + GPR_ASSERT(status == GRPC_STATUS_UNAVAILABLE); } grpc_call_destroy(c); diff --git a/test/core/end2end/tests/simple_delayed_request.c b/test/core/end2end/tests/simple_delayed_request.c index 0afef7503b7..ad8bce55413 100644 --- a/test/core/end2end/tests/simple_delayed_request.c +++ b/test/core/end2end/tests/simple_delayed_request.c @@ -120,7 +120,7 @@ static void simple_delayed_request_body(grpc_end2end_test_config config, op = ops; op->op = GRPC_OP_SEND_INITIAL_METADATA; op->data.send_initial_metadata.count = 0; - op->flags = 0; + op->flags = GRPC_INITIAL_METADATA_IGNORE_CONNECTIVITY; op->reserved = NULL; op++; op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;