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/*
*
* 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 */
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 for handling updates to watched nodes */
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);
}
}
}
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_all = 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_all = (r->resolved_num == r->resolved_total);
gpr_mu_unlock(&r->mu);
if (resolve_all) {
zookeeper_on_resolved(r, r->resolved_addrs);
}
}
/** Parse json format address of a zookeeper node */
static char *zookeeper_parse_address(char *buffer, int buffer_len) {
const char *host;
const char *port;
char *address;
grpc_json *json;
grpc_json *cur;
address = NULL;
json = grpc_json_parse_string_with_len(buffer, buffer_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) {
address = gpr_malloc(GRPC_MAX_SOCKADDR_SIZE);
memset(address, 0, GRPC_MAX_SOCKADDR_SIZE);
strcat(address, host);
strcat(address, ":");
strcat(address, port);
}
grpc_json_destroy(json);
}
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;
char *buffer = NULL;
zookeeper_resolver *r = (zookeeper_resolver *)arg;
int resolve_all = 0;
if (rc != 0) {
gpr_log(GPR_ERROR, "Error in getting a child node of %s", r->name);
return;
}
buffer = gpr_malloc(value_len);
memcpy(buffer, value, value_len);
address = zookeeper_parse_address(buffer, value_len);
gpr_free(buffer);
if (address != NULL) {
/** Further resolve address by DNS */
grpc_resolve_address(address, NULL, zookeeper_dns_resolved, r);
gpr_free(address);
} else {
gpr_mu_lock(&r->mu);
r->resolved_total--;
resolve_all = (r->resolved_num == r->resolved_total);
gpr_mu_unlock(&r->mu);
if (resolve_all) {
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 path_length;
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, "Fail to resolve 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;
for (i = 0; i < children->count; i++) {
path_length = strlen(r->name) + strlen(children->data[i]) + 2;
path = gpr_malloc(path_length);
memset(path, 0, path_length);
strcat(path, r->name);
strcat(path, "/");
strcat(path, 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;
char *buffer = 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 */
buffer = gpr_malloc(value_len);
memcpy(buffer, value, value_len);
address = zookeeper_parse_address(buffer, value_len);
gpr_free(buffer);
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 resolve 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;
const char *path = uri->path;
if (0 == strcmp(uri->authority, "")) {
gpr_log(GPR_ERROR, "No authority specified in zookeeper uri");
return NULL;
}
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);
if (r->name[strlen(r->name) - 1] == '/') {
r->name[strlen(r->name) - 1] = 0;
}
r->subchannel_factory = subchannel_factory;
r->lb_policy_factory = lb_policy_factory;
grpc_subchannel_factory_ref(subchannel_factory);
/** Initialize 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;
}
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