| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/string_util.h> |
| |
| #include <grpc/grpc_zookeeper.h> |
| #include <zookeeper/zookeeper.h> |
| |
| #include "src/core/ext/client_config/lb_policy_registry.h" |
| #include "src/core/ext/client_config/resolver_registry.h" |
| #include "src/core/lib/iomgr/resolve_address.h" |
| #include "src/core/lib/json/json.h" |
| #include "src/core/lib/support/string.h" |
| #include "src/core/lib/surface/api_trace.h" |
| |
| /** Zookeeper session expiration time in milliseconds */ |
| #define GRPC_ZOOKEEPER_SESSION_TIMEOUT 15000 |
| |
| typedef struct { |
| /** base class: must be first */ |
| grpc_resolver base; |
| /** refcount */ |
| gpr_refcount refs; |
| /** name to resolve */ |
| char *name; |
| /** subchannel factory */ |
| grpc_client_channel_factory *client_channel_factory; |
| /** load balancing policy name */ |
| char *lb_policy_name; |
| |
| /** mutex guarding the rest of the state */ |
| gpr_mu mu; |
| /** are we currently resolving? */ |
| int resolving; |
| /** which version of resolved_config have we published? */ |
| int published_version; |
| /** which version of resolved_config is current? */ |
| int resolved_version; |
| /** pending next completion, or NULL */ |
| grpc_closure *next_completion; |
| /** target config address for next completion */ |
| grpc_client_config **target_config; |
| /** current (fully resolved) config */ |
| grpc_client_config *resolved_config; |
| |
| /** zookeeper handle */ |
| zhandle_t *zookeeper_handle; |
| /** zookeeper resolved addresses */ |
| grpc_resolved_addresses *resolved_addrs; |
| /** total number of addresses to be resolved */ |
| int resolved_total; |
| /** number of addresses resolved */ |
| int resolved_num; |
| } zookeeper_resolver; |
| |
| static void zookeeper_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *r); |
| |
| static void zookeeper_start_resolving_locked(zookeeper_resolver *r); |
| static void zookeeper_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx, |
| zookeeper_resolver *r); |
| |
| static void zookeeper_shutdown(grpc_exec_ctx *exec_ctx, grpc_resolver *r); |
| static void zookeeper_channel_saw_error(grpc_exec_ctx *exec_ctx, |
| grpc_resolver *r); |
| static void zookeeper_next(grpc_exec_ctx *exec_ctx, grpc_resolver *r, |
| grpc_client_config **target_config, |
| grpc_closure *on_complete); |
| |
| static const grpc_resolver_vtable zookeeper_resolver_vtable = { |
| zookeeper_destroy, zookeeper_shutdown, zookeeper_channel_saw_error, |
| zookeeper_next}; |
| |
| static void zookeeper_shutdown(grpc_exec_ctx *exec_ctx, |
| grpc_resolver *resolver) { |
| zookeeper_resolver *r = (zookeeper_resolver *)resolver; |
| grpc_closure *call = NULL; |
| gpr_mu_lock(&r->mu); |
| if (r->next_completion != NULL) { |
| *r->target_config = NULL; |
| call = r->next_completion; |
| r->next_completion = NULL; |
| } |
| zookeeper_close(r->zookeeper_handle); |
| gpr_mu_unlock(&r->mu); |
| if (call != NULL) { |
| call->cb(exec_ctx, call->cb_arg, 1); |
| } |
| } |
| |
| static void zookeeper_channel_saw_error(grpc_exec_ctx *exec_ctx, |
| grpc_resolver *resolver) { |
| zookeeper_resolver *r = (zookeeper_resolver *)resolver; |
| gpr_mu_lock(&r->mu); |
| if (r->resolving == 0) { |
| zookeeper_start_resolving_locked(r); |
| } |
| gpr_mu_unlock(&r->mu); |
| } |
| |
| static void zookeeper_next(grpc_exec_ctx *exec_ctx, grpc_resolver *resolver, |
| grpc_client_config **target_config, |
| grpc_closure *on_complete) { |
| zookeeper_resolver *r = (zookeeper_resolver *)resolver; |
| gpr_mu_lock(&r->mu); |
| GPR_ASSERT(r->next_completion == NULL); |
| r->next_completion = on_complete; |
| r->target_config = target_config; |
| if (r->resolved_version == 0 && r->resolving == 0) { |
| zookeeper_start_resolving_locked(r); |
| } else { |
| zookeeper_maybe_finish_next_locked(exec_ctx, r); |
| } |
| gpr_mu_unlock(&r->mu); |
| } |
| |
| /** Zookeeper global watcher for connection management |
| TODO: better connection management besides logs */ |
| static void zookeeper_global_watcher(zhandle_t *zookeeper_handle, int type, |
| int state, const char *path, |
| void *watcher_ctx) { |
| if (type == ZOO_SESSION_EVENT) { |
| if (state == ZOO_EXPIRED_SESSION_STATE) { |
| gpr_log(GPR_ERROR, "Zookeeper session expired"); |
| } else if (state == ZOO_AUTH_FAILED_STATE) { |
| gpr_log(GPR_ERROR, "Zookeeper authentication failed"); |
| } |
| } |
| } |
| |
| /** Zookeeper watcher triggered by changes to watched nodes |
| Once triggered, it tries to resolve again to get updated addresses */ |
| static void zookeeper_watcher(zhandle_t *zookeeper_handle, int type, int state, |
| const char *path, void *watcher_ctx) { |
| if (watcher_ctx != NULL) { |
| zookeeper_resolver *r = (zookeeper_resolver *)watcher_ctx; |
| if (state == ZOO_CONNECTED_STATE) { |
| gpr_mu_lock(&r->mu); |
| if (r->resolving == 0) { |
| zookeeper_start_resolving_locked(r); |
| } |
| gpr_mu_unlock(&r->mu); |
| } |
| } |
| } |
| |
| /** Callback function after getting all resolved addresses |
| Creates a subchannel for each address */ |
| static void zookeeper_on_resolved(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_resolved_addresses *addresses) { |
| zookeeper_resolver *r = arg; |
| grpc_client_config *config = NULL; |
| grpc_lb_policy *lb_policy; |
| |
| if (addresses != NULL) { |
| grpc_lb_policy_args lb_policy_args; |
| config = grpc_client_config_create(); |
| lb_policy_args.addresses = addresses; |
| lb_policy_args.client_channel_factory = r->client_channel_factory; |
| lb_policy = |
| grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args); |
| |
| if (lb_policy != NULL) { |
| grpc_client_config_set_lb_policy(config, lb_policy); |
| GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction"); |
| } |
| grpc_resolved_addresses_destroy(addresses); |
| } |
| gpr_mu_lock(&r->mu); |
| GPR_ASSERT(r->resolving == 1); |
| r->resolving = 0; |
| if (r->resolved_config != NULL) { |
| grpc_client_config_unref(exec_ctx, r->resolved_config); |
| } |
| r->resolved_config = config; |
| r->resolved_version++; |
| zookeeper_maybe_finish_next_locked(exec_ctx, r); |
| gpr_mu_unlock(&r->mu); |
| |
| GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "zookeeper-resolving"); |
| } |
| |
| /** Callback function for each DNS resolved address */ |
| static void zookeeper_dns_resolved(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_resolved_addresses *addresses) { |
| size_t i; |
| zookeeper_resolver *r = arg; |
| int resolve_done = 0; |
| |
| gpr_mu_lock(&r->mu); |
| r->resolved_num++; |
| r->resolved_addrs->addrs = |
| gpr_realloc(r->resolved_addrs->addrs, |
| sizeof(grpc_resolved_address) * |
| (r->resolved_addrs->naddrs + addresses->naddrs)); |
| for (i = 0; i < addresses->naddrs; i++) { |
| memcpy(r->resolved_addrs->addrs[i + r->resolved_addrs->naddrs].addr, |
| addresses->addrs[i].addr, addresses->addrs[i].len); |
| r->resolved_addrs->addrs[i + r->resolved_addrs->naddrs].len = |
| addresses->addrs[i].len; |
| } |
| |
| r->resolved_addrs->naddrs += addresses->naddrs; |
| grpc_resolved_addresses_destroy(addresses); |
| |
| /** Wait for all addresses to be resolved */ |
| resolve_done = (r->resolved_num == r->resolved_total); |
| gpr_mu_unlock(&r->mu); |
| if (resolve_done) { |
| zookeeper_on_resolved(exec_ctx, r, r->resolved_addrs); |
| } |
| } |
| |
| /** Parses JSON format address of a zookeeper node */ |
| static char *zookeeper_parse_address(const char *value, size_t value_len) { |
| grpc_json *json; |
| grpc_json *cur; |
| const char *host; |
| const char *port; |
| char *buffer; |
| char *address = NULL; |
| |
| buffer = gpr_malloc(value_len); |
| memcpy(buffer, value, value_len); |
| json = grpc_json_parse_string_with_len(buffer, value_len); |
| if (json != NULL) { |
| host = NULL; |
| port = NULL; |
| for (cur = json->child; cur != NULL; cur = cur->next) { |
| if (!strcmp(cur->key, "host")) { |
| host = cur->value; |
| if (port != NULL) { |
| break; |
| } |
| } else if (!strcmp(cur->key, "port")) { |
| port = cur->value; |
| if (host != NULL) { |
| break; |
| } |
| } |
| } |
| if (host != NULL && port != NULL) { |
| gpr_asprintf(&address, "%s:%s", host, port); |
| } |
| grpc_json_destroy(json); |
| } |
| gpr_free(buffer); |
| |
| return address; |
| } |
| |
| static void zookeeper_get_children_node_completion(int rc, const char *value, |
| int value_len, |
| const struct Stat *stat, |
| const void *arg) { |
| char *address = NULL; |
| zookeeper_resolver *r = (zookeeper_resolver *)arg; |
| int resolve_done = 0; |
| grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT; |
| |
| if (rc != 0) { |
| gpr_log(GPR_ERROR, "Error in getting a child node of %s", r->name); |
| grpc_exec_ctx_finish(&exec_ctx); |
| return; |
| } |
| |
| address = zookeeper_parse_address(value, (size_t)value_len); |
| if (address != NULL) { |
| /** Further resolves address by DNS */ |
| grpc_resolve_address(&exec_ctx, address, NULL, zookeeper_dns_resolved, r); |
| gpr_free(address); |
| } else { |
| gpr_log(GPR_ERROR, "Error in resolving a child node of %s", r->name); |
| gpr_mu_lock(&r->mu); |
| r->resolved_total--; |
| resolve_done = (r->resolved_num == r->resolved_total); |
| gpr_mu_unlock(&r->mu); |
| if (resolve_done) { |
| zookeeper_on_resolved(&exec_ctx, r, r->resolved_addrs); |
| } |
| } |
| |
| grpc_exec_ctx_finish(&exec_ctx); |
| } |
| |
| static void zookeeper_get_children_completion( |
| int rc, const struct String_vector *children, const void *arg) { |
| char *path; |
| int status; |
| int i; |
| zookeeper_resolver *r = (zookeeper_resolver *)arg; |
| |
| if (rc != 0) { |
| gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name); |
| return; |
| } |
| |
| if (children->count == 0) { |
| gpr_log(GPR_ERROR, "Error in resolving zookeeper address %s", r->name); |
| return; |
| } |
| |
| r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses)); |
| r->resolved_addrs->addrs = NULL; |
| r->resolved_addrs->naddrs = 0; |
| r->resolved_total = children->count; |
| |
| /** TODO: Replace expensive heap allocation with stack |
| if we can get maximum length of zookeeper path */ |
| for (i = 0; i < children->count; i++) { |
| gpr_asprintf(&path, "%s/%s", r->name, children->data[i]); |
| status = zoo_awget(r->zookeeper_handle, path, zookeeper_watcher, r, |
| zookeeper_get_children_node_completion, r); |
| gpr_free(path); |
| if (status != 0) { |
| gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", path); |
| } |
| } |
| } |
| |
| static void zookeeper_get_node_completion(int rc, const char *value, |
| int value_len, |
| const struct Stat *stat, |
| const void *arg) { |
| int status; |
| char *address = NULL; |
| zookeeper_resolver *r = (zookeeper_resolver *)arg; |
| r->resolved_addrs = NULL; |
| r->resolved_total = 0; |
| r->resolved_num = 0; |
| |
| if (rc != 0) { |
| gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name); |
| return; |
| } |
| |
| /** If zookeeper node of path r->name does not have address |
| (i.e. service node), get its children */ |
| address = zookeeper_parse_address(value, (size_t)value_len); |
| if (address != NULL) { |
| r->resolved_addrs = gpr_malloc(sizeof(grpc_resolved_addresses)); |
| r->resolved_addrs->addrs = NULL; |
| r->resolved_addrs->naddrs = 0; |
| r->resolved_total = 1; |
| /** Further resolves address by DNS */ |
| grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT; |
| grpc_resolve_address(&exec_ctx, address, NULL, zookeeper_dns_resolved, r); |
| gpr_free(address); |
| grpc_exec_ctx_finish(&exec_ctx); |
| return; |
| } |
| |
| status = zoo_awget_children(r->zookeeper_handle, r->name, zookeeper_watcher, |
| r, zookeeper_get_children_completion, r); |
| if (status != 0) { |
| gpr_log(GPR_ERROR, "Error in getting zookeeper children of %s", r->name); |
| } |
| } |
| |
| static void zookeeper_resolve_address(zookeeper_resolver *r) { |
| int status; |
| status = zoo_awget(r->zookeeper_handle, r->name, zookeeper_watcher, r, |
| zookeeper_get_node_completion, r); |
| if (status != 0) { |
| gpr_log(GPR_ERROR, "Error in getting zookeeper node %s", r->name); |
| } |
| } |
| |
| static void zookeeper_start_resolving_locked(zookeeper_resolver *r) { |
| GRPC_RESOLVER_REF(&r->base, "zookeeper-resolving"); |
| GPR_ASSERT(r->resolving == 0); |
| r->resolving = 1; |
| zookeeper_resolve_address(r); |
| } |
| |
| static void zookeeper_maybe_finish_next_locked(grpc_exec_ctx *exec_ctx, |
| zookeeper_resolver *r) { |
| if (r->next_completion != NULL && |
| r->resolved_version != r->published_version) { |
| *r->target_config = r->resolved_config; |
| if (r->resolved_config != NULL) { |
| grpc_client_config_ref(r->resolved_config); |
| } |
| grpc_exec_ctx_enqueue(exec_ctx, r->next_completion, true, NULL); |
| r->next_completion = NULL; |
| r->published_version = r->resolved_version; |
| } |
| } |
| |
| static void zookeeper_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) { |
| zookeeper_resolver *r = (zookeeper_resolver *)gr; |
| gpr_mu_destroy(&r->mu); |
| if (r->resolved_config != NULL) { |
| grpc_client_config_unref(exec_ctx, r->resolved_config); |
| } |
| grpc_client_channel_factory_unref(exec_ctx, r->client_channel_factory); |
| gpr_free(r->name); |
| gpr_free(r->lb_policy_name); |
| gpr_free(r); |
| } |
| |
| static grpc_resolver *zookeeper_create(grpc_resolver_args *args, |
| const char *lb_policy_name) { |
| zookeeper_resolver *r; |
| size_t length; |
| char *path = args->uri->path; |
| |
| if (0 == strcmp(args->uri->authority, "")) { |
| gpr_log(GPR_ERROR, "No authority specified in zookeeper uri"); |
| return NULL; |
| } |
| |
| /** Removes the trailing slash if exists */ |
| length = strlen(path); |
| if (length > 1 && path[length - 1] == '/') { |
| path[length - 1] = 0; |
| } |
| |
| r = gpr_malloc(sizeof(zookeeper_resolver)); |
| memset(r, 0, sizeof(*r)); |
| gpr_ref_init(&r->refs, 1); |
| gpr_mu_init(&r->mu); |
| grpc_resolver_init(&r->base, &zookeeper_resolver_vtable); |
| r->name = gpr_strdup(path); |
| |
| r->client_channel_factory = args->client_channel_factory; |
| grpc_client_channel_factory_ref(r->client_channel_factory); |
| |
| r->lb_policy_name = gpr_strdup(lb_policy_name); |
| |
| /** Initializes zookeeper client */ |
| zoo_set_debug_level(ZOO_LOG_LEVEL_WARN); |
| r->zookeeper_handle = |
| zookeeper_init(args->uri->authority, zookeeper_global_watcher, |
| GRPC_ZOOKEEPER_SESSION_TIMEOUT, 0, 0, 0); |
| if (r->zookeeper_handle == NULL) { |
| gpr_log(GPR_ERROR, "Unable to connect to zookeeper server"); |
| return NULL; |
| } |
| |
| return &r->base; |
| } |
| |
| /* |
| * FACTORY |
| */ |
| |
| static void zookeeper_factory_ref(grpc_resolver_factory *factory) {} |
| |
| static void zookeeper_factory_unref(grpc_resolver_factory *factory) {} |
| |
| static char *zookeeper_factory_get_default_hostname( |
| grpc_resolver_factory *factory, grpc_uri *uri) { |
| return NULL; |
| } |
| |
| static grpc_resolver *zookeeper_factory_create_resolver( |
| grpc_resolver_factory *factory, grpc_resolver_args *args) { |
| return zookeeper_create(args, "pick_first"); |
| } |
| |
| static const grpc_resolver_factory_vtable zookeeper_factory_vtable = { |
| zookeeper_factory_ref, zookeeper_factory_unref, |
| zookeeper_factory_create_resolver, zookeeper_factory_get_default_hostname, |
| "zookeeper"}; |
| |
| static grpc_resolver_factory zookeeper_resolver_factory = { |
| &zookeeper_factory_vtable}; |
| |
| static grpc_resolver_factory *zookeeper_resolver_factory_create() { |
| return &zookeeper_resolver_factory; |
| } |
| |
| static void zookeeper_plugin_init() { |
| grpc_register_resolver_type(zookeeper_resolver_factory_create()); |
| } |
| |
| void grpc_zookeeper_register() { |
| GRPC_API_TRACE("grpc_zookeeper_register(void)", 0, ()); |
| grpc_register_plugin(zookeeper_plugin_init, NULL); |
| } |