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arcus_zk.c
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arcus_zk.c
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/* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* arcus-memcached - Arcus memory cache server
* Copyright 2010-2014 NAVER Corp.
* Copyright 2015 JaM2in Co., Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
Arcus incorporates memcached instance as a ephemeral entity
Here's how memcached participates in Arcus cluster
1. get local IP address
2. connect to Zookeeper ensemble
3. sync "/arcus/cache_server_mapping"
for latest provisioned cache server
4. get child of "/arcus/cache_server_mapping/{ip}:{port}" znode
to get service code
this service code is a string that indicates which service this
cache server belongs to
ie. /arcus/cache_server_mapping/10.0.0.1:11211/{svc}
5. create an ephemeral "/arcus/cache_list/{svc}/{ip}:{port}-{hostname}" znode
to indicate that this server is participating in Arcus {svc} cluster
{port} is the memcached listen port
hostname is a redudant information to easily identify the server
the memcached memory capacity is stored in the znode's data
6. create "/arcus/cache_server_log/{date}/{ip}:{port}-{hostname}-" sequential znode
this is to log join and leave activity for later debugging or post-mortem
In global watcher callback routine, we chose not to restart/reconnect to
Zookeeper ensemble (when session expires), because this may create stale cache
entry access. We need to restart the whole memcached process to flush its content
before rejoin the Arcus cluster. We need to force restart of memcached (/etc/inittab)
*/
#include <config.h>
#ifdef ENABLE_ZK_INTEGRATION
#include <assert.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <time.h>
#include <unistd.h>
#include <string.h>
#include <zookeeper.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdbool.h>
#include <sysexits.h>
#include <limits.h>
#include "arcus_zk.h"
#ifdef ENABLE_CLUSTER_AWARE
#include "cluster_config.h"
#endif
/* zookeeper.h unfortunately includes a lot of other headers. One of
* them (recordio.h) unconditionally defines htonll. memcached.h also
* includes so many headers. util.h defines htonll, which conflicts
* with the one in zookeeper.h. As a workaround, define HAVE_HTONLL
* here to prevent util.h from defining htonll again.
*
* All we need from memcached.h is ADMIN_CLIENT_IP...
*/
#define HAVE_HTONLL 1
#include "memcached.h"
/* Kill server if disconnected from zookeeper for too long */
//#define ENABLE_SUICIDE_UPON_DISCONNECT 1
/* Recv. timeout governs ZK heartbeat period, reconnect timeout
* as well as ZK session timeout
* Below sets 30 sec. session timeout, 20 sec Zookeeper ensemble timeout,
* and 10 second heartbeat period
*/
#define DEFAULT_ZK_TO 30000 /* ZK session timeout in msec (server tick time is 2 sec, min is 4 sec) */
#define MAX_ZK_TO 2000 /* Max allowable session timeout in sec */
#define MIN_ZK_TO 10 /* Min 10 seconds, in line with the current heartbeat timeout */
#define ZK_WATCH 1
#define ZK_NOWATCH 0
#define SYSLOGD_PORT 514 /* UDP syslog port # */
#define MAX_SERVICECODE_LENGTH 128
#define MAX_HOSTNAME_LENGTH 128
#ifdef ENABLE_ZK_RECONFIG
/* The maximum config data size per ZK server is 600.
* Therefore, config data of about 26 ZK servers can be stored.
*/
#define MAX_ZK_CONFIG_DATA_LENGTH (16 * 1024)
struct _zk_reconfig {
char data_buffer[MAX_ZK_CONFIG_DATA_LENGTH];
char host_buffer[MAX_ZK_CONFIG_DATA_LENGTH/2]; /* half space is enough */
int64_t version; /* current ZK config version */
bool enabled; /* dynamic reconfig is enabled in ZK ? */
bool needed; /* dynamic reconfig is needed by arcus ? */
} zk_reconfig;
#endif
static const char *zk_root = NULL;
static const char *zk_map_dir = "cache_server_mapping";
static const char *zk_log_dir = "cache_server_log";
static const char *zk_cache_dir = "cache_list";
typedef struct {
char *ensemble_list; /* ZK ensemble IP:port list */
zhandle_t *zh; /* ZK handle */
clientid_t myid;
} zk_info_t;
static zk_info_t zk_info;
static zk_info_t *main_zk=NULL;
static int last_rc=ZOK;
#ifdef ENABLE_SUICIDE_UPON_DISCONNECT
static bool zk_connected = false;
#endif
/* this is to indicate if we get shutdown signal during ZK initialization
* ZK shutdown is done at the end of arcus_zk_init() to simplify synchronization
*/
static volatile sig_atomic_t arcus_zk_shutdown=0;
/* placeholder for zookeeper and memcached settings */
typedef struct {
char *svc; // Service code name
char *mc_ipport; // this memcached ip:port string
char *mc_hostnameport; // this memcached hostname:port string
char *hostip; // localhost server IP
int port; // memcached port number
bool zk_failstop; // memcached automatic failstop on/off
int zk_timeout; // Zookeeper session timeout
bool auto_scrub; // automactic scrub_stale
char *znode_name; // Ephemeral ZK node name for this mc identification
int znode_ver; // Ephemeral ZK node version
bool znode_created; // Ephemeral ZK node is created ?
int verbose; // verbose output
size_t maxbytes; // mc -M option
EXTENSION_LOGGER_DESCRIPTOR *logger; // mc logger
union {
ENGINE_HANDLE *v0;
ENGINE_HANDLE_V1 *v1;
} engine; // mc engine
char *cluster_path; // cluster path for this memcached
#ifdef PROXY_SUPPORT
char *proxy; // proxy server ip:port
#endif
#ifdef ENABLE_CLUSTER_AWARE
struct cluster_config *ch; // cluster configuration handle
#endif
pthread_mutex_t lock;
bool init; // is this structure initialized?
} arcus_zk_config;
arcus_zk_config arcus_conf = {
.svc = NULL,
.mc_ipport = NULL,
.mc_hostnameport = NULL,
.hostip = NULL,
.zk_failstop = true,
.zk_timeout = DEFAULT_ZK_TO,
.auto_scrub = true,
.znode_name = NULL,
.znode_ver = -1,
.znode_created = false,
.verbose = -1,
.port = -1,
.maxbytes = -1,
.logger = NULL,
.cluster_path = NULL,
#ifdef PROXY_SUPPORT
.proxy = NULL,
#endif
#ifdef ENABLE_CLUSTER_AWARE
.ch = NULL,
#endif
.lock = PTHREAD_MUTEX_INITIALIZER,
.init = false
};
/* Arcus ZK stats */
arcus_zk_stats azk_stat;
/* static forward declaration */
static void arcus_zk_watcher(zhandle_t *wzh, int type, int state,
const char *path, void *cxt);
#ifdef ENABLE_ZK_RECONFIG
static int arcus_check_zk_reconfig_enabled(zhandle_t *zh);
static void arcus_zkconfig_watcher(zhandle_t *zh, int type, int state,
const char *path, void *ctx);
#endif
static void arcus_cache_list_watcher(zhandle_t *zh, int type, int state,
const char *path, void *ctx);
static void arcus_zk_sync_cb(int rc, const char *name, const void *data);
static void arcus_zk_log(zhandle_t *zh, const char *);
static void arcus_exit(zhandle_t *zh, int err);
/* State machine thread.
* It performs all blocking ZK operations including cluster_config.
* We don't do blocking operations in the context of watcher callback
* any more.
*/
/* sm request structure */
struct sm_request {
#ifdef ENABLE_ZK_RECONFIG
bool update_zkconfig;
#endif
bool update_cache_list;
};
/* sm structure */
struct sm {
/* sm requests by other threads */
struct sm_request request;
/* Cache of the latest version we pulled from ZK */
struct String_vector sv_cache_list; /* from /cache_list/{svc} */
/* Current # of nodes in cluster */
int cluster_node_count;
/* the time a new node was added to the cluster */
volatile uint64_t node_added_time;
volatile bool mc_pause;
/* Used to wake up the thread */
pthread_mutex_t lock;
pthread_cond_t cond;
bool notification;
volatile bool state_running;
#ifdef ENABLE_SUICIDE_UPON_DISCONNECT
volatile bool timer_running;
#endif
pthread_t state_tid;
#ifdef ENABLE_SUICIDE_UPON_DISCONNECT
/* A timer thread to fail-stop the server
* when it is disconnected from the ZK ensemble.
*/
pthread_t timer_tid;
#endif
} sm_info;
/* sm functions */
static int sm_init(void);
static void sm_lock(void);
static void sm_unlock(void);
static void sm_wakeup(bool locked);
/* async routine synchronization */
static pthread_cond_t azk_cond = PTHREAD_COND_INITIALIZER;
static pthread_mutex_t azk_mtx = PTHREAD_MUTEX_INITIALIZER;
static int azk_count;
/* zookeeper close synchronization */
static pthread_mutex_t zk_lock = PTHREAD_MUTEX_INITIALIZER;
static int
arcus_memcached_scrub_stale(void)
{
ENGINE_ERROR_CODE ret;
ret = arcus_conf.engine.v1->scrub_stale(arcus_conf.engine.v0);
return ret == ENGINE_SUCCESS ? 0 : -1;
}
/* Some znode names use '^' as a delimiter.
* Return pointers to the starting and ending ('^') characters.
*/
static int
breakup_string(char *str, char *start[], char *end[], int vec_len)
{
char *c = str;
int i = 0;
while (i < vec_len) {
start[i] = c;
while (*c != '\0') {
if (*c == '^')
break;
c++;
}
if (*c == '\0') {
end[i] = c;
i++;
break;
}
if (start[i] == c)
break; /* empty */
end[i] = c++;
i++;
}
if (*c != '\0') {
/* There are leftover characters. Ignore them. */
}
return i; /* i <= vec_len */
}
/* mutex for async operations */
static void inc_count(int delta)
{
pthread_mutex_lock(&azk_mtx);
azk_count += delta;
pthread_cond_broadcast(&azk_cond);
pthread_mutex_unlock(&azk_mtx);
}
static void clear_count(void)
{
pthread_mutex_lock(&azk_mtx);
azk_count = 0;
pthread_mutex_unlock(&azk_mtx);
}
static int wait_count(int timeout)
{
struct timeval tv;
struct timespec ts;
int rc = 0;
pthread_mutex_lock(&azk_mtx);
while (azk_count > 0 && rc == 0) {
if (timeout == 0) {
rc = pthread_cond_wait(&azk_cond, &azk_mtx);
} else {
gettimeofday(&tv, NULL);
ts.tv_sec = tv.tv_sec;
ts.tv_nsec = tv.tv_usec*1000;
//clock_gettime(CLOCK_REALTIME, &ts);
ts.tv_sec += timeout/1000; /* timeout: msec */
rc = pthread_cond_timedwait(&azk_cond, &azk_mtx, &ts);
}
}
pthread_mutex_unlock(&azk_mtx);
return rc;
}
static int
arcus_zk_client_init(zk_info_t *zinfo)
{
inc_count(1);
zinfo->zh = zookeeper_init(zinfo->ensemble_list, arcus_zk_watcher,
arcus_conf.zk_timeout, &zinfo->myid, zinfo, 0);
if (!zinfo->zh) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"zookeeper_init() failed: %s\n", strerror(errno));
return EX_PROTOCOL;
}
/* wait until above init callback is called
* We need to wait until ZOO_CONNECTED_STATE
*/
if (wait_count(arcus_conf.zk_timeout) != 0) {
/* zoo_state(zh) != ZOO_CONNECTED_STATE */
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"cannot to be ZOO_CONNECTED_STATE\n");
zookeeper_close(zinfo->zh);
zinfo->zh = NULL;
inc_count(-1);
return EX_PROTOCOL;
}
// "recv" timeout is actually the session timeout
// ZK client ping period is recv_timeout / 3.
if (arcus_conf.zk_timeout != zoo_recv_timeout(zinfo->zh)) {
arcus_conf.zk_timeout = zoo_recv_timeout(zinfo->zh);
}
arcus_conf.logger->log(EXTENSION_LOG_INFO, NULL,
"ZooKeeper client initialized. (ZK session timeout=%d sec)\n",
arcus_conf.zk_timeout/1000);
return 0;
}
// Arcus zookeeper global watch callback routine
static void
arcus_zk_watcher(zhandle_t *wzh, int type, int state, const char *path, void *cxt)
{
if (type != ZOO_SESSION_EVENT) {
return;
}
if (state == ZOO_CONNECTED_STATE) {
const clientid_t *id = zoo_client_id(wzh);
zk_info_t *zinfo = cxt;
arcus_conf.logger->log(EXTENSION_LOG_INFO, NULL,
"ZOO_SESSION_EVENT Connected. server=%s, session_id=%#llx\n",
zoo_get_current_server(wzh),
(long long) id->client_id);
if (zinfo->myid.client_id == 0 || zinfo->myid.client_id != id->client_id) {
if (arcus_conf.verbose > 1)
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"A old session id: 0x%llx\n", (long long) zinfo->myid.client_id);
zinfo->myid = *id;
}
#ifdef ENABLE_ZK_RECONFIG
if (arcus_conf.init && zk_reconfig.needed && !zk_reconfig.enabled) {
/* check if ZK dynamic reconfig is enabled ? */
if (arcus_check_zk_reconfig_enabled(zinfo->zh) < 0) {
/* zoo_getconfig API failed.. (rarely)
* Instead of retry checking, set zk_reconfig to true to make it more safe.
*/
zk_reconfig.enabled = true;
}
if (zk_reconfig.enabled) {
/* Wake up the state machine thread and update zkconfig. */
sm_lock();
sm_info.request.update_zkconfig = true;
sm_wakeup(true);
sm_unlock();
}
}
#endif
// finally connected to one of ZK ensemble. signal go.
inc_count(-1);
#ifdef ENABLE_SUICIDE_UPON_DISCONNECT
zk_connected = true;
#endif
}
else if (state == ZOO_AUTH_FAILED_STATE) {
// authorization failure
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"ZOO_SESSION_EVENT Auth failed. shutting down\n");
arcus_exit(wzh, EX_NOPERM);
}
else if (state == ZOO_EXPIRED_SESSION_STATE) {
if (arcus_conf.zk_failstop) {
// very likely that memcached process exited and restarted within
// session timeout
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"ZOO_SESSION_EVENT Expired. shutting down\n");
// send SMS here??
arcus_exit(wzh, EX_TEMPFAIL);
} else {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"ZOO_SESSION_EVENT Expired. pausing memcached (zk_failstop: off)\n");
sm_lock();
sm_info.mc_pause = true;
sm_wakeup(true);
sm_unlock();
}
}
else if (state == ZOO_ASSOCIATING_STATE || state == ZOO_CONNECTING_STATE) {
/* we get these when connection to Ensemble is dropped and retrying
* this happens emsemble failover as well
* since this is not memcached operation issue, we will allow reconnecting
* but it is possible that app_ping fails and zk server may have disconnected
* and if that's the case, we let heartbeat timeout algorithm decide
* what to do.
*/
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL, "ZOO_SESSION_EVENT Connecting.\n");
#ifdef ENABLE_SUICIDE_UPON_DISCONNECT
/* The server is disconnected from ZK. But we do not know how much
* time has elapsed from the last successful ZK ping. A connection
* timeout (session timeout * 2/3) might have occurred. Or, the
* TCP connection might have reset/closed (immediate).
* See sm_timer_thread. For now, it is being conservative and dies
* in session timeout * 1/3. Perhaps we should do our own ping, not
* rely on ZK session notifications. FIXME
*/
zk_connected = false;
#endif
}
}
#ifdef ENABLE_ZK_RECONFIG
/* config zk watcher */
static void
arcus_zkconfig_watcher(zhandle_t *zh, int type, int state, const char *path, void *ctx)
{
if (type == ZOO_CHANGED_EVENT) {
arcus_conf.logger->log(EXTENSION_LOG_INFO, NULL,
"ZOO_CHANGED_EVENT from ZK config: state=%d, path=%s\n",
state, (path ? path : "null"));
} else if (type == ZOO_SESSION_EVENT) {
/* ZOO_SESSION_EVENT is handled by arcus_zk_watcher.
* Set the update flag when receiving a connected event.
*/
if (state != ZOO_CONNECTED_STATE) return;
} else {
/* Unexpected event(ZOO_DELETED_EVENT or ZOO_NOTWATCHING_EVENT) has occurred */
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Unexpected event(%d) gotten by cache_list_watcher: state=%d path=%s\n",
type, state, (path ? path : "null"));
}
/* In ZK watcher context, don't do anything that may block or fail. */
/* Just wake up the sm thread and update the zk server list.
* This may be a false positive (session event or others).
* But it is harmless or must be treated like changed event.
*/
sm_lock();
sm_info.request.update_zkconfig = true;
sm_wakeup(true);
sm_unlock();
}
#endif
/* cache_list zk watcher */
static void
arcus_cache_list_watcher(zhandle_t *zh, int type, int state, const char *path, void *ctx)
{
if (type == ZOO_CHILD_EVENT) {
arcus_conf.logger->log(EXTENSION_LOG_INFO, NULL,
"ZOO_CHILD_EVENT from ZK cache list: state=%d, path=%s\n",
state, (path ? path : "null"));
} else if (type == ZOO_SESSION_EVENT) {
/* ZOO_SESSION_EVENT is handled by arcus_zk_watcher.
* Set the update flag when receiving a connected event.
*/
if (state != ZOO_CONNECTED_STATE) return;
} else {
/* Unexpected event(ZOO_DELETED_EVENT or ZOO_NOTWATCHING_EVENT) has occurred */
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Unexpected event(%d) gotten by cache_list_watcher: state=%d path=%s\n",
type, state, (path ? path : "null"));
}
/* In ZK watcher context, don't do anything that may block or fail. */
/* Just wake up the sm thread and update the hash ring.
* This may be a false positive (session event or others).
* But it is harmless or must be treated like child event.
*/
sm_lock();
sm_info.request.update_cache_list = true;
sm_wakeup(true);
sm_unlock();
}
static bool
check_my_znode_existence(void)
{
if (cluster_config_get_self_id(arcus_conf.ch) == -1) {
return false;
}
return true;
}
#ifdef ENABLE_CLUSTER_AWARE
/* update cluster config, that is ketama hash ring. */
static int
update_cluster_config(struct String_vector *strv, int *num_added, int *num_removed)
{
arcus_conf.logger->log(EXTENSION_LOG_INFO, NULL,
"update cluster config. (count=%d)\n", (int)strv->count);
if (arcus_conf.verbose > 0) {
for (int i = 0; i < strv->count; i++) {
arcus_conf.logger->log(EXTENSION_LOG_INFO, NULL,
"server[%d] = %s\n", i, strv->data[i]);
}
}
/* reconfigure arcus-memcached cluster */
if (cluster_config_reconfigure(arcus_conf.ch, strv->data, strv->count,
num_added, num_removed) < 0) {
return -1;
}
sm_info.cluster_node_count = strv->count;
return 0;
}
#endif
/* callback for sync command */
static void
arcus_zk_sync_cb(int rc, const char *name, const void *data)
{
if (arcus_conf.verbose > 1) {
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL, "arcus_zk_sync cb\n");
}
// signal cond var
inc_count(-1);
last_rc = rc;
}
/* Log memcached join/leave acvitivity for debugging purpose
* We cannot log in case of memcached crash
*/
static void
arcus_zk_log(zhandle_t *zh, const char *action)
{
int rc;
char zpath[200] = "";
char rcbuf[200] = "";
char sbuf[128] = "";
struct timeval now;
struct tm *ltm;
struct Stat zstat;
if (!zh || zoo_state(zh) != ZOO_CONNECTED_STATE || !arcus_conf.init)
return;
gettimeofday(&now, 0);
ltm = localtime (&now.tv_sec);
strftime(sbuf, sizeof(sbuf), "%Y-%m-%d", ltm);
snprintf(zpath, sizeof(zpath), "%s/%s/%s", zk_root, zk_log_dir, sbuf);
rc = zoo_exists(zh, zpath, ZK_NOWATCH, &zstat);
if (rc == ZNONODE) {
// if this "date" directory does not exist, create one
rc = zoo_create(zh, zpath, NULL, 0, &ZOO_OPEN_ACL_UNSAFE,
0, rcbuf, sizeof(rcbuf));
if (rc == ZOK && arcus_conf.verbose > 1) {
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"znode %s does not exist. created\n", rcbuf);
}
}
if (rc == ZOK || rc == ZNODEEXISTS) {
// if this znode already exist or the creation was successful
snprintf(zpath, sizeof(zpath), "%s/%s/%s/%s-",
zk_root, zk_log_dir, sbuf, arcus_conf.znode_name);
snprintf(sbuf, sizeof(sbuf), "%s", action);
rc = zoo_create(zh, zpath, sbuf, strlen(sbuf), &ZOO_OPEN_ACL_UNSAFE,
ZOO_SEQUENCE, rcbuf, sizeof(rcbuf));
if (arcus_conf.verbose > 1) {
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"znode \"%s\" created\n", rcbuf);
}
}
if (rc) {
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"cannot log this acvitiy. error=%d(%s)\n", rc, zerror(rc));
}
}
static void
arcus_exit(zhandle_t *zh, int err)
{
if (zh)
zookeeper_close(zh);
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL, "shutting down\n");
exit(err);
}
static int arcus_build_znode_name(char *ensemble_list)
{
int sock, rc;
socklen_t socklen=16;
struct in_addr inaddr;
struct sockaddr_in saddr, myaddr;
struct hostent *zkhost, *hp;
char *zip, *hlist;
char *sep1=",";
char *sep2=":";
char myip[50];
char rcbuf[512];
// Need to figure out local IP. first create a dummy udp socket
if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP)) == -1) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"socket() failed: %s\n", strerror(errno));
return EX_OSERR;
}
saddr.sin_family = AF_INET;
saddr.sin_port = htons(SYSLOGD_PORT); // what if this is not open? XXX
// loop through all ensemble IP in case ensemble failure
zip = strtok_r(ensemble_list, sep1, &hlist); // separate IP:PORT tuple
while (zip)
{
zip = strtok(zip, sep2); // extract the first IP
// try to convert IP -> network IP format
if (inet_aton(zip, &inaddr)) {
// just use the IP
saddr.sin_addr = inaddr;
if (arcus_conf.verbose > 1) {
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"Trying ensemble IP: %s\n", zip);
}
} else {
// Must be hostname, not IP. Convert hostname to IP first
zkhost = gethostbyname(zip);
if (!zkhost) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Invalid IP/hostname in arg: %s\n", zip);
// get next token: separate IP:PORT tuple
zip = strtok_r(NULL, sep1, &hlist);
continue;
}
memcpy((char *)&saddr.sin_addr,
zkhost->h_addr_list[0], zkhost->h_length);
inet_ntop(AF_INET, &saddr.sin_addr, rcbuf, sizeof(rcbuf));
if (arcus_conf.verbose > 1) {
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"Trying converted IP of hostname(%s): %s\n", zip, rcbuf);
}
}
// try to connect to ensemble' arcus_conf.logger->logd UDP port
// this is dummy code that simply is used to get local IP address
int flags = fcntl(sock, F_GETFL, 0);
fcntl(sock, F_SETFL, flags | O_NONBLOCK);
rc = connect(sock, (struct sockaddr*) &saddr, sizeof(struct sockaddr_in));
fcntl(sock, F_SETFL, flags);
if (rc == 0) { // connect immediately
if (arcus_conf.verbose > 1) {
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"connected to ensemble \"%s\" syslogd UDP port\n", zip);
}
break;
}
// if cannot connect immediately, try other ensemble
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Cannot connect to ensemble %s: %s\n", zip, strerror(errno));
zip = strtok_r(NULL, sep1, &hlist); // get next token: separate IP:PORT tuple
}
if (!zip) { // failed to connect to all ensemble host. fail
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"not able to connect any Ensemble server\n");
close(sock); sock = -1;
return EX_UNAVAILABLE;
}
// finally, what's my local IP?
if (getsockname(sock, (struct sockaddr *) &myaddr, &socklen)) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"getsockname failed: %s\n", strerror(errno));
close(sock); sock = -1;
return EX_NOHOST;
}
close(sock); sock = -1;
// Finally local IP
inet_ntop(AF_INET, &myaddr.sin_addr, myip, sizeof(myip));
arcus_conf.hostip = strdup(myip);
arcus_conf.logger->log(EXTENSION_LOG_DETAIL, NULL, "local IP: %s\n", myip);
if (getenv("ARCUS_CACHE_PUBLIC_IP") != NULL) {
free(arcus_conf.hostip);
arcus_conf.hostip = strdup(getenv("ARCUS_CACHE_PUBLIC_IP"));
arcus_conf.logger->log(EXTENSION_LOG_DETAIL, NULL, "local public IP: %s\n",
arcus_conf.hostip);
}
#ifdef PROXY_SUPPORT
if (arcus_conf.proxy) {
struct hostent *proxy_host;
char *proxy_ip, *proxy_port;
struct in_addr inaddr;
char buf[50];
proxy_ip = strtok(arcus_conf.proxy, sep2);
proxy_port = strtok(NULL, sep2);
if (inet_aton(proxy_ip, &inaddr)) {
if (arcus_conf.verbose > 1) {
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"Proxy IP: %s\n", proxy_ip);
}
} else {
// Must be hostname, not IP. Convert hostname to IP first
proxy_host = gethostbyname(proxy_ip);
if (!proxy_host) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Invalid proxy IP/hostname in arg: %s\n", proxy_ip);
return EX_UNAVAILABLE;
}
memcpy((char *)&inaddr,
proxy_host->h_addr_list[0], proxy_host->h_length);
inet_ntop(AF_INET, &inaddr, buf, sizeof(buf));
proxy_ip = buf;
}
proxy_host = gethostbyaddr((char*)&inaddr, sizeof(inaddr), AF_INET);
if (!proxy_host) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"cannot get hostname: %s\n", strerror(errno));
return EX_NOHOST;
}
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"proxy hostname: %s\n", proxy_host->h_name);
snprintf(rcbuf, sizeof(rcbuf), "%s:%s", proxy_ip, proxy_port);
arcus_conf.mc_ipport = strdup(rcbuf);
snprintf(rcbuf, sizeof(rcbuf), "%s:%s", proxy_host->h_name, proxy_port);
arcus_conf.mc_hostnameport = strdup(rcbuf);
snprintf(rcbuf, sizeof(rcbuf), "%s-%s", arcus_conf.mc_ipport, proxy_host->h_name);
arcus_conf.znode_name = strdup(rcbuf);
return 0; // EX_OK
}
#endif
if (!arcus_conf.znode_name) {
char *hostp=NULL;
char hostbuf[256];
// Also get local hostname.
// We want IP and hostname to better identify this cache
hp = gethostbyaddr((char*)&myaddr.sin_addr.s_addr,
sizeof(myaddr.sin_addr.s_addr), AF_INET);
if (hp) {
hostp = hp->h_name;
} else {
// if gethostbyaddr() doesn't work, try gethostname
if (gethostname((char *)&hostbuf, sizeof(hostbuf))) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"cannot get hostname: %s\n", strerror(errno));
return EX_NOHOST;
}
hostp = hostbuf;
}
if (strlen(hostp) > MAX_HOSTNAME_LENGTH) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Too long hostname. hostname=%s\n", hostp);
return EX_DATAERR;
}
arcus_conf.logger->log(EXTENSION_LOG_DEBUG, NULL,
"local hostname: %s\n", hostp);
// we need to keep ip:port-hostname tuple for later user (restart)
snprintf(rcbuf, sizeof(rcbuf), "%s:%d", arcus_conf.hostip, arcus_conf.port);
arcus_conf.mc_ipport = strdup(rcbuf);
snprintf(rcbuf, sizeof(rcbuf), "%s:%d", hostp, arcus_conf.port);
arcus_conf.mc_hostnameport = strdup(rcbuf);
snprintf(rcbuf, sizeof(rcbuf), "%s-%s", arcus_conf.mc_ipport, hostp);
arcus_conf.znode_name = strdup(rcbuf);
}
return 0; // EX_OK
}
static int arcus_parse_server_mapping(char *znode)
{
char *start[4], *end[4]; /* enough pointers for future extension */
int max_substrs = 4;
int i, count;
count = breakup_string(znode, start, end, max_substrs);
/* Null-terminate substrings */
for (i = 0; i < count; i++) {
*end[i] = '\0';
}
/* get service code */
arcus_conf.svc = strdup(start[0]);
if (strlen(arcus_conf.svc) > MAX_SERVICECODE_LENGTH) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Too long service code. service_code=%s\n", arcus_conf.svc);
return -1;
}
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Found the valid server mapping. service_code=%s\n",
arcus_conf.svc);
return 0;
}
#ifdef ENABLE_ZK_RECONFIG
static int arcus_check_zk_reconfig_enabled(zhandle_t *zh)
{
int len = 256;
char buf[256];
struct Stat zstat;
int rc = zoo_getconfig(zh, ZK_NOWATCH, buf, &len, &zstat);
if (rc == ZOK && len > 0) {
zk_reconfig.enabled = true;
zk_reconfig.version = -1;
arcus_conf.logger->log(EXTENSION_LOG_INFO, NULL,
"Zookeeper dynamic reconfiguration is enabled.\n");
} else if (rc == ZNONODE) {
zk_reconfig.enabled = false;
arcus_conf.logger->log(EXTENSION_LOG_INFO, NULL,
"Zookeeper dynamic reconfiguration is disabled.\n");
} else {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"zoo_getconfig() failed. error=%d(%s).\n", rc, zerror(rc));
return -1;
}
return 0;
}
#endif
static int arcus_check_server_mapping(zhandle_t *zh, const char *root)
{
struct String_vector strv = {0, NULL};
char zpath[256];
int rc;
/* sync map path */
snprintf(zpath, sizeof(zpath), "%s/%s", root, zk_map_dir);
inc_count(1);
rc = zoo_async(zh, zpath, arcus_zk_sync_cb, NULL);
if (rc != ZOK) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"zoo_async() failed: error=%d(%s)\n", rc, zerror(rc));
return -1;
}
/* wait until above sync callback is called */
wait_count(0);
rc = last_rc;
if (rc != ZOK) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Failed to synchronize zpath=%s: error=%d(%s)\n",
zpath, rc, zerror(rc));
return -1;
}
/* check the cache_server_mapping info. */
do {
/* 1st check: get children of "/cache_server_mapping/ip:port" */
snprintf(zpath, sizeof(zpath), "%s/%s/%s",
root, zk_map_dir, arcus_conf.mc_ipport);
rc = zoo_get_children(zh, zpath, ZK_NOWATCH, &strv);
if (rc != ZNONODE) break;
/* 2nd check: get children of "/cache_server_mapping/hostname:port" */
snprintf(zpath, sizeof(zpath), "%s/%s/%s",
root, zk_map_dir, arcus_conf.mc_hostnameport);
rc = zoo_get_children(zh, zpath, ZK_NOWATCH, &strv);
if (rc != ZNONODE) break;
#ifdef PROXY_SUPPORT
if (arcus_conf.proxy) {
break; /* skip the below third checking */
}
#endif
/* 3rd check: get children of "/cache_server_mapping/ip" */
snprintf(zpath, sizeof(zpath), "%s/%s/%s",
root, zk_map_dir, arcus_conf.hostip);
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Recheck the server mapping without port number. zpath=%s\n",
zpath);
rc = zoo_get_children(zh, zpath, ZK_NOWATCH, &strv);
} while(0);
if (rc != ZOK) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Failed to read the server mapping. zpath=%s error=%d(%s)\n",
zpath, rc, zerror(rc));
return -1;
}
if (strv.count == 1) {
rc = arcus_parse_server_mapping(strv.data[0]);
if (rc < 0) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"Failed to parse server mapping znode.\n");
}
} else {
/* zoo_get_children returns ZOK even if no child exist */
/* We assume only one server mapping znode. We do not care that
* we have more than one (meaning one server participating in
* more than one service in the cluster: not likely though)
*/
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"The server mapping exists but has %d(!= 1) mapping znodes."
" zpath=%s\n", strv.count, zpath);
rc = -1;
}
deallocate_String_vector(&strv);
return rc;
}
static int arcus_create_ephemeral_znode(zhandle_t *zh)
{
int rc;
char zpath[512];
char value[200];
struct Stat zstat;
#ifdef PROXY_SUPPORT
if (arcus_conf.proxy) {
arcus_conf.znode_created = true;
return 0;
}
#endif
snprintf(zpath, sizeof(zpath), "%s/%s",
arcus_conf.cluster_path, arcus_conf.znode_name);
snprintf(value, sizeof(value), "%ldMB", (long)arcus_conf.maxbytes/1024/1024);
rc = zoo_create(zh, zpath, value, strlen(value), &ZOO_OPEN_ACL_UNSAFE,
ZOO_EPHEMERAL, NULL, 0);
if (rc) {
arcus_conf.logger->log(EXTENSION_LOG_WARNING, NULL,
"cannot create znode %s: error=%d(%s)\n", zpath, rc, zerror(rc));
if (rc == ZNODEEXISTS) {
arcus_conf.logger->log( EXTENSION_LOG_DETAIL, NULL,
"old session still exist. Wait a bit\n");
}
return -1;
}