diff options
Diffstat (limited to 'src/core/ext/lb_policy/grpclb/grpclb.c')
| -rw-r--r-- | src/core/ext/lb_policy/grpclb/grpclb.c | 106 |
1 files changed, 76 insertions, 30 deletions
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c index 36f0a90bb8..6da4febf26 100644 --- a/src/core/ext/lb_policy/grpclb/grpclb.c +++ b/src/core/ext/lb_policy/grpclb/grpclb.c @@ -343,6 +343,21 @@ static bool is_server_valid(const grpc_grpclb_server *server, size_t idx, return true; } +/* vtable for LB tokens in grpc_lb_addresses. */ +static void *lb_token_copy(void *token) { + return token == NULL ? NULL : GRPC_MDELEM_REF(token); +} +static void lb_token_destroy(void *token) { + if (token != NULL) GRPC_MDELEM_UNREF(token); +} +static int lb_token_cmp(void *token1, void *token2) { + if (token1 > token2) return 1; + if (token1 < token2) return -1; + return 0; +} +static const grpc_lb_user_data_vtable lb_token_vtable = { + lb_token_copy, lb_token_destroy, lb_token_cmp}; + /* Returns addresses extracted from \a serverlist. */ static grpc_lb_addresses *process_serverlist( const grpc_grpclb_serverlist *serverlist) { @@ -354,7 +369,8 @@ static grpc_lb_addresses *process_serverlist( } if (num_valid == 0) return NULL; - grpc_lb_addresses *lb_addresses = grpc_lb_addresses_create(num_valid); + grpc_lb_addresses *lb_addresses = + grpc_lb_addresses_create(num_valid, &lb_token_vtable); /* second pass: actually populate the addresses and LB tokens (aka user data * to the outside world) to be read by the RR policy during its creation. @@ -415,11 +431,6 @@ static grpc_lb_addresses *process_serverlist( return lb_addresses; } -/* A plugin for grpc_lb_addresses_destroy that unrefs the LB token metadata. */ -static void lb_token_destroy(void *token) { - if (token != NULL) GRPC_MDELEM_UNREF(token); -} - /* perform a pick over \a rr_policy. Given that a pick can return immediately * (ignoring its completion callback) we need to perform the cleanups this * callback would be otherwise resposible for */ @@ -459,20 +470,27 @@ static grpc_lb_policy *create_rr_locked( glb_lb_policy *glb_policy) { GPR_ASSERT(serverlist != NULL && serverlist->num_servers > 0); + if (glb_policy->addresses != NULL) { + /* dispose of the previous version */ + grpc_lb_addresses_destroy(glb_policy->addresses); + } + glb_policy->addresses = process_serverlist(serverlist); + grpc_lb_policy_args args; memset(&args, 0, sizeof(args)); - args.server_name = glb_policy->server_name; args.client_channel_factory = glb_policy->cc_factory; - args.addresses = process_serverlist(serverlist); - args.additional_args = glb_policy->args; - grpc_lb_policy *rr = grpc_lb_policy_create(exec_ctx, "round_robin", &args); + // Replace the LB addresses in the channel args that we pass down to + // the subchannel. + static const char *keys_to_remove[] = {GRPC_ARG_LB_ADDRESSES}; + const grpc_arg arg = + grpc_lb_addresses_create_channel_arg(glb_policy->addresses); + args.args = grpc_channel_args_copy_and_add_and_remove( + glb_policy->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &arg, + 1); - if (glb_policy->addresses != NULL) { - /* dispose of the previous version */ - grpc_lb_addresses_destroy(glb_policy->addresses, lb_token_destroy); - } - glb_policy->addresses = args.addresses; + grpc_lb_policy *rr = grpc_lb_policy_create(exec_ctx, "round_robin", &args); + grpc_channel_args_destroy(args.args); return rr; } @@ -568,6 +586,12 @@ static void glb_rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg, static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx, grpc_lb_policy_factory *factory, grpc_lb_policy_args *args) { + /* Get server name. */ + const grpc_arg *arg = + grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME); + const char *server_name = + arg != NULL && arg->type == GRPC_ARG_STRING ? arg->value.string : NULL; + /* Count the number of gRPC-LB addresses. There must be at least one. * TODO(roth): For now, we ignore non-balancer addresses, but in the * future, we may change the behavior such that we fall back to using @@ -575,24 +599,27 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx, * time, this should be changed to allow a list with no balancer addresses, * since the resolver might fail to return a balancer address even when * this is the right LB policy to use. */ + arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES); + GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER); + grpc_lb_addresses *addresses = arg->value.pointer.p; size_t num_grpclb_addrs = 0; - for (size_t i = 0; i < args->addresses->num_addresses; ++i) { - if (args->addresses->addresses[i].is_balancer) ++num_grpclb_addrs; + for (size_t i = 0; i < addresses->num_addresses; ++i) { + if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs; } if (num_grpclb_addrs == 0) return NULL; glb_lb_policy *glb_policy = gpr_malloc(sizeof(*glb_policy)); memset(glb_policy, 0, sizeof(*glb_policy)); - /* All input addresses in args->addresses come from a resolver that claims + /* All input addresses in addresses come from a resolver that claims * they are LB services. It's the resolver's responsibility to make sure * this * policy is only instantiated and used in that case. * * Create a client channel over them to communicate with a LB service */ - glb_policy->server_name = gpr_strdup(args->server_name); + glb_policy->server_name = gpr_strdup(server_name); glb_policy->cc_factory = args->client_channel_factory; - glb_policy->args = grpc_channel_args_copy(args->additional_args); + glb_policy->args = grpc_channel_args_copy(args->args); GPR_ASSERT(glb_policy->cc_factory != NULL); /* construct a target from the addresses in args, given in the form @@ -600,19 +627,19 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx, * TODO(dgq): support mixed ip version */ char **addr_strs = gpr_malloc(sizeof(char *) * num_grpclb_addrs); size_t addr_index = 0; - for (size_t i = 0; i < args->addresses->num_addresses; i++) { - if (args->addresses->addresses[i].user_data != NULL) { + for (size_t i = 0; i < addresses->num_addresses; i++) { + if (addresses->addresses[i].user_data != NULL) { gpr_log(GPR_ERROR, "This LB policy doesn't support user data. It will be ignored"); } - if (args->addresses->addresses[i].is_balancer) { + if (addresses->addresses[i].is_balancer) { if (addr_index == 0) { addr_strs[addr_index++] = - grpc_sockaddr_to_uri(&args->addresses->addresses[i].address); + grpc_sockaddr_to_uri(&addresses->addresses[i].address); } else { - GPR_ASSERT(grpc_sockaddr_to_string( - &addr_strs[addr_index++], - &args->addresses->addresses[i].address, true) > 0); + GPR_ASSERT(grpc_sockaddr_to_string(&addr_strs[addr_index++], + &addresses->addresses[i].address, + true) > 0); } } } @@ -620,10 +647,29 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx, char *target_uri_str = gpr_strjoin_sep((const char **)addr_strs, num_grpclb_addrs, ",", &uri_path_len); - /* will pick using pick_first */ + /* Create a channel to talk to the LBs. + * + * We strip out the channel arg for the LB policy name, since we want + * to use the default (pick_first) in this case. + * + * We also strip out the channel arg for the resolved addresses, since + * that will be generated by the name resolver used in the LB channel. + * Note that the LB channel will use the sockaddr resolver, so this + * won't actually generate a query to DNS (or some other name service). + * However, the addresses returned by the sockaddr resolver will have + * is_balancer=false, whereas our own addresses have is_balancer=true. + * We need the LB channel to return addresses with is_balancer=false + * so that it does not wind up recursively using the grpclb LB policy, + * as per the special case logic in client_channel.c. + */ + static const char *keys_to_remove[] = {GRPC_ARG_LB_POLICY_NAME, + GRPC_ARG_LB_ADDRESSES}; + grpc_channel_args *new_args = grpc_channel_args_copy_and_remove( + args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove)); glb_policy->lb_channel = grpc_client_channel_factory_create_channel( exec_ctx, glb_policy->cc_factory, target_uri_str, - GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, NULL); + GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, new_args); + grpc_channel_args_destroy(new_args); gpr_free(target_uri_str); for (size_t i = 0; i < num_grpclb_addrs; i++) { @@ -664,7 +710,7 @@ static void glb_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { grpc_grpclb_destroy_serverlist(glb_policy->serverlist); } gpr_mu_destroy(&glb_policy->mu); - grpc_lb_addresses_destroy(glb_policy->addresses, lb_token_destroy); + grpc_lb_addresses_destroy(glb_policy->addresses); gpr_free(glb_policy); } |