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Diffstat (limited to 'src/core/client_config/resolvers/zookeeper_resolver.c')
-rw-r--r--src/core/client_config/resolvers/zookeeper_resolver.c501
1 files changed, 501 insertions, 0 deletions
diff --git a/src/core/client_config/resolvers/zookeeper_resolver.c b/src/core/client_config/resolvers/zookeeper_resolver.c
new file mode 100644
index 0000000000..a8397a3da1
--- /dev/null
+++ b/src/core/client_config/resolvers/zookeeper_resolver.c
@@ -0,0 +1,501 @@
+/*
+ *
+ * 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 "src/core/client_config/resolvers/zookeeper_resolver.h"
+
+#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/client_config/lb_policies/pick_first.h"
+#include "src/core/client_config/resolver_registry.h"
+#include "src/core/iomgr/resolve_address.h"
+#include "src/core/support/string.h"
+#include "src/core/json/json.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_subchannel_factory *subchannel_factory;
+ /** load balancing policy factory */
+ grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
+ size_t num_subchannels);
+
+ /** 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_iomgr_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_resolver *r);
+
+static void zookeeper_start_resolving_locked(zookeeper_resolver *r);
+static void zookeeper_maybe_finish_next_locked(zookeeper_resolver *r);
+
+static void zookeeper_shutdown(grpc_resolver *r);
+static void zookeeper_channel_saw_error(grpc_resolver *r,
+ struct sockaddr *failing_address,
+ int failing_address_len);
+static void zookeeper_next(grpc_resolver *r, grpc_client_config **target_config,
+ grpc_iomgr_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_resolver *resolver) {
+ zookeeper_resolver *r = (zookeeper_resolver *)resolver;
+ gpr_mu_lock(&r->mu);
+ if (r->next_completion != NULL) {
+ *r->target_config = NULL;
+ grpc_iomgr_add_callback(r->next_completion);
+ r->next_completion = NULL;
+ }
+ zookeeper_close(r->zookeeper_handle);
+ gpr_mu_unlock(&r->mu);
+}
+
+static void zookeeper_channel_saw_error(grpc_resolver *resolver,
+ struct sockaddr *sa, int len) {
+ 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_resolver *resolver,
+ grpc_client_config **target_config,
+ grpc_iomgr_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(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(void *arg,
+ grpc_resolved_addresses *addresses) {
+ zookeeper_resolver *r = arg;
+ grpc_client_config *config = NULL;
+ grpc_subchannel **subchannels;
+ grpc_subchannel_args args;
+ grpc_lb_policy *lb_policy;
+ size_t i;
+ if (addresses != NULL) {
+ config = grpc_client_config_create();
+ subchannels = gpr_malloc(sizeof(grpc_subchannel *) * addresses->naddrs);
+ for (i = 0; i < addresses->naddrs; i++) {
+ memset(&args, 0, sizeof(args));
+ args.addr = (struct sockaddr *)(addresses->addrs[i].addr);
+ args.addr_len = addresses->addrs[i].len;
+ subchannels[i] = grpc_subchannel_factory_create_subchannel(
+ r->subchannel_factory, &args);
+ }
+ lb_policy = r->lb_policy_factory(subchannels, addresses->naddrs);
+ grpc_client_config_set_lb_policy(config, lb_policy);
+ GRPC_LB_POLICY_UNREF(lb_policy, "construction");
+ grpc_resolved_addresses_destroy(addresses);
+ gpr_free(subchannels);
+ }
+ gpr_mu_lock(&r->mu);
+ GPR_ASSERT(r->resolving == 1);
+ r->resolving = 0;
+ if (r->resolved_config != NULL) {
+ grpc_client_config_unref(r->resolved_config);
+ }
+ r->resolved_config = config;
+ r->resolved_version++;
+ zookeeper_maybe_finish_next_locked(r);
+ gpr_mu_unlock(&r->mu);
+
+ GRPC_RESOLVER_UNREF(&r->base, "zookeeper-resolving");
+}
+
+/** Callback function for each DNS resolved address */
+static void zookeeper_dns_resolved(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(r, r->resolved_addrs);
+ }
+}
+
+/** Parses JSON format address of a zookeeper node */
+static char *zookeeper_parse_address(const char *value, int 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;
+
+ if (rc != 0) {
+ gpr_log(GPR_ERROR, "Error in getting a child node of %s", r->name);
+ return;
+ }
+
+ address = zookeeper_parse_address(value, value_len);
+ if (address != NULL) {
+ /** Further resolves address by DNS */
+ grpc_resolve_address(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(r, r->resolved_addrs);
+ }
+ }
+}
+
+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, 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_resolve_address(address, NULL, zookeeper_dns_resolved, r);
+ gpr_free(address);
+ 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(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_iomgr_add_callback(r->next_completion);
+ r->next_completion = NULL;
+ r->published_version = r->resolved_version;
+ }
+}
+
+static void zookeeper_destroy(grpc_resolver *gr) {
+ zookeeper_resolver *r = (zookeeper_resolver *)gr;
+ gpr_mu_destroy(&r->mu);
+ if (r->resolved_config != NULL) {
+ grpc_client_config_unref(r->resolved_config);
+ }
+ grpc_subchannel_factory_unref(r->subchannel_factory);
+ gpr_free(r->name);
+ gpr_free(r);
+}
+
+static grpc_resolver *zookeeper_create(
+ grpc_uri *uri,
+ grpc_lb_policy *(*lb_policy_factory)(grpc_subchannel **subchannels,
+ size_t num_subchannels),
+ grpc_subchannel_factory *subchannel_factory) {
+ zookeeper_resolver *r;
+ size_t length;
+ char *path = uri->path;
+
+ if (0 == strcmp(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->subchannel_factory = subchannel_factory;
+ r->lb_policy_factory = lb_policy_factory;
+ grpc_subchannel_factory_ref(subchannel_factory);
+
+ /** Initializes zookeeper client */
+ zoo_set_debug_level(ZOO_LOG_LEVEL_WARN);
+ r->zookeeper_handle = zookeeper_init(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;
+}
+
+static void zookeeper_plugin_init() {
+ grpc_register_resolver_type("zookeeper",
+ grpc_zookeeper_resolver_factory_create());
+}
+
+void grpc_zookeeper_register() {
+ grpc_register_plugin(zookeeper_plugin_init, NULL);
+}
+
+/*
+ * FACTORY
+ */
+
+static void zookeeper_factory_ref(grpc_resolver_factory *factory) {}
+
+static void zookeeper_factory_unref(grpc_resolver_factory *factory) {}
+
+static grpc_resolver *zookeeper_factory_create_resolver(
+ grpc_resolver_factory *factory, grpc_uri *uri,
+ grpc_subchannel_factory *subchannel_factory) {
+ return zookeeper_create(uri, grpc_create_pick_first_lb_policy,
+ subchannel_factory);
+}
+
+static const grpc_resolver_factory_vtable zookeeper_factory_vtable = {
+ zookeeper_factory_ref, zookeeper_factory_unref,
+ zookeeper_factory_create_resolver};
+static grpc_resolver_factory zookeeper_resolver_factory = {
+ &zookeeper_factory_vtable};
+
+grpc_resolver_factory *grpc_zookeeper_resolver_factory_create() {
+ return &zookeeper_resolver_factory;
+}