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MaxScale/server/modules/routing/binlogrouter/blr_master.c
MassimilianoPinto 162ae04d20 MXS-867: Binlog server encryption key has same format as MariaDB key file 
Default algorithm is now AES_CBC.
The MariaDB 10.1 key file cannot be read as it might contain more than
1 rows.
2016-12-12 14:01:54 +01:00

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/*lint -e662 */
/*lint -e661 */
/*
* Copyright (c) 2016 MariaDB Corporation Ab
*
* Use of this software is governed by the Business Source License included
* in the LICENSE.TXT file and at www.mariadb.com/bsl.
*
* Change Date: 2019-07-01
*
* On the date above, in accordance with the Business Source License, use
* of this software will be governed by version 2 or later of the General
* Public License.
*/
/**
* @file blr_master.c - contains code for the router to master communication
*
* The binlog router is designed to be used in replication environments to
* increase the replication fanout of a master server. It provides a transparant
* mechanism to read the binlog entries for multiple slaves while requiring
* only a single connection to the actual master to support the slaves.
*
* The current prototype implement is designed to support MySQL 5.6 and has
* a number of limitations. This prototype is merely a proof of concept and
* should not be considered production ready.
*
* @verbatim
* Revision History
*
* Date Who Description
* 02/04/2014 Mark Riddoch Initial implementation
* 07/05/2015 Massimiliano Pinto Added MariaDB 10 Compatibility
* 25/05/2015 Massimiliano Pinto Added BLRM_SLAVE_STOPPED state
* 08/06/2015 Massimiliano Pinto Added m_errno and m_errmsg
* 23/06/2015 Massimiliano Pinto Master communication goes into BLRM_SLAVE_STOPPED state
* when an error is encountered in BLRM_BINLOGDUMP state.
* Server error code and msg are reported via SHOW SLAVE STATUS
* 03/08/2015 Massimiliano Pinto Initial implementation of transaction safety
* 13/08/2015 Massimiliano Pinto Addition of heartbeat check
* 23/08/2015 Massimiliano Pinto Added strerror_r
* 26/08/2015 Massimiliano Pinto Added MariaDB 10 GTID event check with flags = 0
* This is the current supported condition for detecting
* MariaDB 10 transaction start point.
* It's no longer using QUERY_EVENT with BEGIN
* 25/09/2015 Massimiliano Pinto Addition of lastEventReceived for slaves
* 23/10/2015 Markus Makela Added current_safe_event
* 26/04/2016 Massimiliano Pinto Added MariaDB 10.0 and 10.1 GTID event flags detection
* 22/07/2016 Massimiliano Pinto Added semi_sync replication support
* 24/08/2016 Massimiliano Pinto Added slave notification and blr_distribute_binlog_record removed
* 01/09/2016 Massimiliano Pinto Added support for ANNOTATE_ROWS_EVENT in COM_BINLOG_DUMP
* 11/11/2016 Massimiliano Pinto Encryption context is freed and set to null a new binlog file
* is being created due to ROTATE event.
*
* @endverbatim
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <maxscale/service.h>
#include <maxscale/server.h>
#include <maxscale/router.h>
#include <maxscale/atomic.h>
#include <maxscale/session.h>
#include "blr.h"
#include <maxscale/dcb.h>
#include <maxscale/spinlock.h>
#include <maxscale/housekeeper.h>
#include <maxscale/buffer.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <maxscale/log_manager.h>
#include <maxscale/rdtsc.h>
#include <maxscale/thread.h>
/* Temporary requirement for auth data */
#include <maxscale/protocol/mysql.h>
#include <maxscale/alloc.h>
static GWBUF *blr_make_query(DCB *dcb, char *query);
static GWBUF *blr_make_registration(ROUTER_INSTANCE *router);
static GWBUF *blr_make_binlog_dump(ROUTER_INSTANCE *router);
void encode_value(unsigned char *data, unsigned int value, int len);
void blr_handle_binlog_record(ROUTER_INSTANCE *router, GWBUF *pkt);
static int blr_rotate_event(ROUTER_INSTANCE *router, uint8_t *pkt, REP_HEADER *hdr);
static void *CreateMySQLAuthData(char *username, char *password, char *database);
void blr_extract_header(uint8_t *pkt, REP_HEADER *hdr);
static void blr_log_packet(int priority, char *msg, uint8_t *ptr, int len);
void blr_master_close(ROUTER_INSTANCE *);
char *blr_extract_column(GWBUF *buf, int col);
void poll_fake_write_event(DCB *dcb);
GWBUF *blr_read_events_from_pos(ROUTER_INSTANCE *router, unsigned long long pos, REP_HEADER *hdr,
unsigned long long pos_end);
static void blr_check_last_master_event(void *inst);
extern int blr_check_heartbeat(ROUTER_INSTANCE *router);
static void blr_log_identity(ROUTER_INSTANCE *router);
static void blr_extract_header_semisync(uint8_t *pkt, REP_HEADER *hdr);
static int blr_send_semisync_ack (ROUTER_INSTANCE *router, uint64_t pos);
static int blr_get_master_semisync(GWBUF *buf);
static void blr_terminate_master_replication(ROUTER_INSTANCE *router, uint8_t* ptr, int len);
void blr_notify_all_slaves(ROUTER_INSTANCE *router);
extern bool blr_notify_waiting_slave(ROUTER_SLAVE *slave);
static int keepalive = 1;
/** Transaction-Safety feature */
typedef enum
{
BLRM_NO_TRANSACTION, /*< No transaction */
BLRM_TRANSACTION_START, /*< A transaction is open*/
BLRM_COMMIT_SEEN, /*< Received COMMIT event in the current transaction */
BLRM_XID_EVENT_SEEN /*< Received XID event of current transaction */
} master_transaction_t;
/** Master Semi-Sync capability */
typedef enum
{
MASTER_SEMISYNC_NOT_AVAILABLE, /*< Semi-Sync replication not available */
MASTER_SEMISYNC_DISABLED, /*< Semi-Sync is disabled */
MASTER_SEMISYNC_ENABLED /*< Semi-Sync is enabled */
} master_semisync_capability_t;
#define MASTER_BYTES_BEFORE_EVENT 5
#define MASTER_BYTES_BEFORE_EVENT_SEMI_SYNC MASTER_BYTES_BEFORE_EVENT + 2
/* Semi-Sync indicator in network packet (byte 6) */
#define BLR_MASTER_SEMI_SYNC_INDICATOR 0xef
/* Semi-Sync flag ACK_REQ in network packet (byte 7) */
#define BLR_MASTER_SEMI_SYNC_ACK_REQ 0x01
/**
* blr_start_master - controls the connection of the binlog router to the
* master MySQL server and triggers the slave registration process for
* the router.
*
* @param router The router instance
*/
void
blr_start_master(void* data)
{
ROUTER_INSTANCE *router = (ROUTER_INSTANCE*)data;
DCB *client;
router->stats.n_binlogs_ses = 0;
spinlock_acquire(&router->lock);
if (router->master_state != BLRM_UNCONNECTED)
{
if (router->master_state != BLRM_SLAVE_STOPPED)
{
MXS_ERROR("%s: Master Connect: Unexpected master state %s\n",
router->service->name, blrm_states[router->master_state]);
}
else
{
MXS_NOTICE("%s: Master Connect: binlog state is %s\n",
router->service->name, blrm_states[router->master_state]);
}
spinlock_release(&router->lock);
return;
}
router->master_state = BLRM_CONNECTING;
spinlock_release(&router->lock);
if ((client = dcb_alloc(DCB_ROLE_INTERNAL, NULL)) == NULL)
{
MXS_ERROR("Binlog router: failed to create DCB for dummy client");
return;
}
router->client = client;
client->state = DCB_STATE_POLLING; /* Fake the client is reading */
client->data = CreateMySQLAuthData(router->user, router->password, "");
if ((router->session = session_alloc(router->service, client)) == NULL)
{
MXS_ERROR("Binlog router: failed to create session for connection to master");
return;
}
client->session = router->session;
if ((router->master = dcb_connect(router->service->dbref->server, router->session, BLR_PROTOCOL)) == NULL)
{
char *name = MXS_MALLOC(strlen(router->service->name) + strlen(" Master") + 1);
if (name)
{
sprintf(name, "%s Master", router->service->name);
hktask_oneshot(name, blr_start_master, router,
BLR_MASTER_BACKOFF_TIME * router->retry_backoff++);
MXS_FREE(name);
}
if (router->retry_backoff > BLR_MAX_BACKOFF)
{
router->retry_backoff = BLR_MAX_BACKOFF;
}
MXS_ERROR("Binlog router: failed to connect to master server '%s'",
router->service->dbref->server->unique_name);
return;
}
router->master->remote = MXS_STRDUP_A(router->service->dbref->server->name);
MXS_NOTICE("%s: attempting to connect to master server %s:%d, binlog %s, pos %lu",
router->service->name, router->service->dbref->server->name,
router->service->dbref->server->port, router->binlog_name, router->current_pos);
router->connect_time = time(0);
if (setsockopt(router->master->fd, SOL_SOCKET, SO_KEEPALIVE, &keepalive , sizeof(keepalive )))
{
perror("setsockopt");
}
router->master_state = BLRM_AUTHENTICATED;
router->master->func.write(router->master, blr_make_query(router->master, "SELECT UNIX_TIMESTAMP()"));
router->master_state = BLRM_TIMESTAMP;
router->stats.n_masterstarts++;
}
/**
* Reconnect to the master server.
*
* IMPORTANT - must be called with router->active_logs set by the
* thread that set active_logs.
*
* @param router The router instance
*/
static void
blr_restart_master(ROUTER_INSTANCE *router)
{
dcb_close(router->client);
/* Now it is safe to unleash other threads on this router instance */
spinlock_acquire(&router->lock);
router->reconnect_pending = 0;
router->active_logs = 0;
spinlock_release(&router->lock);
if (router->master_state < BLRM_BINLOGDUMP)
{
router->master_state = BLRM_UNCONNECTED;
char *name = (char*)MXS_MALLOC(strlen(router->service->name) + strlen(" Master") + 1);
if (name)
{
sprintf(name, "%s Master", router->service->name);
hktask_oneshot(name, blr_start_master, router,
BLR_MASTER_BACKOFF_TIME * router->retry_backoff++);
MXS_FREE(name);
}
if (router->retry_backoff > BLR_MAX_BACKOFF)
{
router->retry_backoff = BLR_MAX_BACKOFF;
}
}
else
{
router->master_state = BLRM_UNCONNECTED;
blr_start_master(router);
}
}
/**
* Request a reconnect to the master.
*
* If another thread is active processing messages from the master
* then merely set a flag for that thread to do the restart. If no
* threads are active then directly call the restart routine to
* reconnect to the master.
*
* @param router The router instance
*/
void
blr_master_reconnect(ROUTER_INSTANCE *router)
{
int do_reconnect = 0;
if (router->master_state == BLRM_SLAVE_STOPPED)
{
return;
}
spinlock_acquire(&router->lock);
if (router->active_logs)
{
/* Currently processing a response, set a flag
* and get the thread that is process a response
* to deal with the reconnect.
*/
router->reconnect_pending = 1;
router->stats.n_delayedreconnects++;
}
else
{
router->active_logs = 1;
do_reconnect = 1;
}
spinlock_release(&router->lock);
if (do_reconnect)
{
blr_restart_master(router);
spinlock_acquire(&router->lock);
router->active_logs = 0;
spinlock_release(&router->lock);
}
}
/**
* Shutdown a connection to the master
*
* @param router The router instance
*/
void
blr_master_close(ROUTER_INSTANCE *router)
{
dcb_close(router->master);
router->master_state = BLRM_UNCONNECTED;
router->master_event_state = BLR_EVENT_DONE;
gwbuf_free(router->stored_event);
router->stored_event = NULL;
}
/**
* Mark this master connection for a delayed reconnect, used during
* error recovery to cause a reconnect after 60 seconds.
*
* @param router The router instance
*/
void
blr_master_delayed_connect(ROUTER_INSTANCE *router)
{
char *name = (char*)MXS_MALLOC(strlen(router->service->name) + strlen(" Master Recovery") + 1);
if (name)
{
sprintf(name, "%s Master Recovery", router->service->name);
hktask_oneshot(name, blr_start_master, router, 60);
MXS_FREE(name);
}
}
/**
* Binlog router master side state machine event handler.
*
* Handles an incoming response from the master server to the binlog
* router.
*
* @param router The router instance
* @param buf The incoming packet
*/
void
blr_master_response(ROUTER_INSTANCE *router, GWBUF *buf)
{
char query[BLRM_MASTER_REGITRATION_QUERY_LEN + 1];
char task_name[BLRM_TASK_NAME_LEN + 1] = "";
atomic_add(&router->handling_threads, 1);
ss_dassert(router->handling_threads == 1);
spinlock_acquire(&router->lock);
router->active_logs = 1;
spinlock_release(&router->lock);
if (router->master_state > BLRM_MAXSTATE)
{
MXS_ERROR("Invalid master state machine state (%d) for binlog router.",
router->master_state);
gwbuf_free(buf);
spinlock_acquire(&router->lock);
if (router->reconnect_pending)
{
router->active_logs = 0;
spinlock_release(&router->lock);
atomic_add(&router->handling_threads, -1);
MXS_ERROR("%s: Pending reconnect in state %s.",
router->service->name,
blrm_states[router->master_state]);
blr_restart_master(router);
return;
}
router->active_logs = 0;
spinlock_release(&router->lock);
atomic_add(&router->handling_threads, -1);
return;
}
if (router->master_state == BLRM_GTIDMODE && MYSQL_RESPONSE_ERR(buf))
{
/*
* If we get an error response to the GTID Mode then we
* asusme the server does not support GTID modes and
* continue. The error is saved and replayed to slaves if
* they also request the GTID mode.
*/
MXS_ERROR("%s: Master server does not support GTID Mode.",
router->service->name);
}
else if (router->master_state != BLRM_BINLOGDUMP && MYSQL_RESPONSE_ERR(buf))
{
char *msg_err = NULL;
int msg_len = 0;
int len = gwbuf_length(buf);
unsigned long mysql_errno = extract_field(MYSQL_ERROR_CODE(buf), 16);
msg_len = len - 7 - 6; // +7 is where msg starts, 6 is skipped the status message (#42000)
msg_err = (char *)MXS_MALLOC(msg_len + 1);
if (msg_err)
{
// skip status message only as MYSQL_RESPONSE_ERR(buf) points to GWBUF_DATA(buf) +7
memcpy(msg_err, (char *)(MYSQL_ERROR_MSG(buf) + 6), msg_len);
/* NULL terminated error string */
*(msg_err + msg_len) = '\0';
}
MXS_ERROR("%s: Received error: %lu, '%s' from master during '%s' phase "
"of the master state machine.",
router->service->name,
mysql_errno,
msg_err ? msg_err : "(memory failure)",
blrm_states[router->master_state]);
gwbuf_free(buf);
spinlock_acquire(&router->lock);
/* set mysql errno */
router->m_errno = mysql_errno;
/* set mysql error message */
if (router->m_errmsg)
{
MXS_FREE(router->m_errmsg);
}
router->m_errmsg = msg_err ? msg_err : "(memory failure)";
router->active_logs = 0;
if (router->reconnect_pending)
{
spinlock_release(&router->lock);
atomic_add(&router->handling_threads, -1);
blr_restart_master(router);
return;
}
spinlock_release(&router->lock);
atomic_add(&router->handling_threads, -1);
return;
}
switch (router->master_state)
{
case BLRM_TIMESTAMP:
// Response to a timestamp message, no need to save this.
gwbuf_free(buf);
buf = blr_make_query(router->master, "SHOW VARIABLES LIKE 'SERVER_ID'");
router->master_state = BLRM_SERVERID;
router->master->func.write(router->master, buf);
router->retry_backoff = 1;
break;
case BLRM_SERVERID:
{
char *val = blr_extract_column(buf, 2);
// Response to fetch of master's server-id
if (router->saved_master.server_id)
{
GWBUF_CONSUME_ALL(router->saved_master.server_id);
}
router->saved_master.server_id = buf;
blr_cache_response(router, "serverid", buf);
// set router->masterid from master server-id if it's not set by the config option
if (router->masterid == 0)
{
router->masterid = atoi(val);
}
{
char str[BLRM_SET_HEARTBEAT_QUERY_LEN];
sprintf(str, "SET @master_heartbeat_period = %lu000000000", router->heartbeat);
buf = blr_make_query(router->master, str);
}
router->master_state = BLRM_HBPERIOD;
router->master->func.write(router->master, buf);
MXS_FREE(val);
break;
}
case BLRM_HBPERIOD:
// Response to set the heartbeat period
if (router->saved_master.heartbeat)
{
GWBUF_CONSUME_ALL(router->saved_master.heartbeat);
}
router->saved_master.heartbeat = buf;
blr_cache_response(router, "heartbeat", buf);
buf = blr_make_query(router->master, "SET @master_binlog_checksum = @@global.binlog_checksum");
router->master_state = BLRM_CHKSUM1;
router->master->func.write(router->master, buf);
break;
case BLRM_CHKSUM1:
// Response to set the master binlog checksum
if (router->saved_master.chksum1)
{
GWBUF_CONSUME_ALL(router->saved_master.chksum1);
}
router->saved_master.chksum1 = buf;
blr_cache_response(router, "chksum1", buf);
buf = blr_make_query(router->master, "SELECT @master_binlog_checksum");
router->master_state = BLRM_CHKSUM2;
router->master->func.write(router->master, buf);
break;
case BLRM_CHKSUM2:
{
char *val = blr_extract_column(buf, 1);
if (val && strncasecmp(val, "NONE", 4) == 0)
{
router->master_chksum = false;
}
if (val)
{
MXS_FREE(val);
}
// Response to the master_binlog_checksum, should be stored
if (router->saved_master.chksum2)
{
GWBUF_CONSUME_ALL(router->saved_master.chksum2);
}
router->saved_master.chksum2 = buf;
blr_cache_response(router, "chksum2", buf);
if (router->mariadb10_compat)
{
buf = blr_make_query(router->master, "SET @mariadb_slave_capability=4");
router->master_state = BLRM_MARIADB10;
}
else
{
buf = blr_make_query(router->master, "SELECT @@GLOBAL.GTID_MODE");
router->master_state = BLRM_GTIDMODE;
}
router->master->func.write(router->master, buf);
break;
}
case BLRM_MARIADB10:
// Response to the SET @mariadb_slave_capability=4, should be stored
if (router->saved_master.mariadb10)
{
GWBUF_CONSUME_ALL(router->saved_master.mariadb10);
}
router->saved_master.mariadb10 = buf;
blr_cache_response(router, "mariadb10", buf);
buf = blr_make_query(router->master, "SHOW VARIABLES LIKE 'SERVER_UUID'");
router->master_state = BLRM_MUUID;
router->master->func.write(router->master, buf);
break;
case BLRM_GTIDMODE:
// Response to the GTID_MODE, should be stored
if (router->saved_master.gtid_mode)
{
GWBUF_CONSUME_ALL(router->saved_master.gtid_mode);
}
router->saved_master.gtid_mode = buf;
blr_cache_response(router, "gtidmode", buf);
buf = blr_make_query(router->master, "SHOW VARIABLES LIKE 'SERVER_UUID'");
router->master_state = BLRM_MUUID;
router->master->func.write(router->master, buf);
break;
case BLRM_MUUID:
{
char *key;
char *val = NULL;
key = blr_extract_column(buf, 1);
if (key && strlen(key))
{
val = blr_extract_column(buf, 2);
}
if (key)
{
MXS_FREE(key);
}
/* set the master_uuid from master if not set by the option */
if (router->set_master_uuid == NULL)
{
MXS_FREE(router->master_uuid);
router->master_uuid = val;
}
else
{
router->master_uuid = router->set_master_uuid;
}
// Response to the SERVER_UUID, should be stored
if (router->saved_master.uuid)
{
GWBUF_CONSUME_ALL(router->saved_master.uuid);
}
router->saved_master.uuid = buf;
blr_cache_response(router, "uuid", buf);
sprintf(query, "SET @slave_uuid='%s'", router->uuid);
buf = blr_make_query(router->master, query);
router->master_state = BLRM_SUUID;
router->master->func.write(router->master, buf);
break;
}
case BLRM_SUUID:
// Response to the SET @server_uuid, should be stored
if (router->saved_master.setslaveuuid)
{
GWBUF_CONSUME_ALL(router->saved_master.setslaveuuid);
}
router->saved_master.setslaveuuid = buf;
blr_cache_response(router, "ssuuid", buf);
buf = blr_make_query(router->master, "SET NAMES latin1");
router->master_state = BLRM_LATIN1;
router->master->func.write(router->master, buf);
break;
case BLRM_LATIN1:
// Response to the SET NAMES latin1, should be stored
if (router->saved_master.setnames)
{
GWBUF_CONSUME_ALL(router->saved_master.setnames);
}
router->saved_master.setnames = buf;
blr_cache_response(router, "setnames", buf);
buf = blr_make_query(router->master, "SET NAMES utf8");
router->master_state = BLRM_UTF8;
router->master->func.write(router->master, buf);
break;
case BLRM_UTF8:
// Response to the SET NAMES utf8, should be stored
if (router->saved_master.utf8)
{
GWBUF_CONSUME_ALL(router->saved_master.utf8);
}
router->saved_master.utf8 = buf;
blr_cache_response(router, "utf8", buf);
buf = blr_make_query(router->master, "SELECT 1");
router->master_state = BLRM_SELECT1;
router->master->func.write(router->master, buf);
break;
case BLRM_SELECT1:
// Response to the SELECT 1, should be stored
if (router->saved_master.select1)
{
GWBUF_CONSUME_ALL(router->saved_master.select1);
}
router->saved_master.select1 = buf;
blr_cache_response(router, "select1", buf);
buf = blr_make_query(router->master, "SELECT VERSION()");
router->master_state = BLRM_SELECTVER;
router->master->func.write(router->master, buf);
break;
case BLRM_SELECTVER:
// Response to SELECT VERSION should be stored
if (router->saved_master.selectver)
{
GWBUF_CONSUME_ALL(router->saved_master.selectver);
}
router->saved_master.selectver = buf;
blr_cache_response(router, "selectver", buf);
buf = blr_make_query(router->master, "SELECT @@version_comment limit 1");
router->master_state = BLRM_SELECTVERCOM;
router->master->func.write(router->master, buf);
break;
case BLRM_SELECTVERCOM:
// Response to SELECT @@version_comment should be stored
if (router->saved_master.selectvercom)
{
GWBUF_CONSUME_ALL(router->saved_master.selectvercom);
}
router->saved_master.selectvercom = buf;
blr_cache_response(router, "selectvercom", buf);
buf = blr_make_query(router->master, "SELECT @@hostname");
router->master_state = BLRM_SELECTHOSTNAME;
router->master->func.write(router->master, buf);
break;
case BLRM_SELECTHOSTNAME:
// Response to SELECT @@hostname should be stored
if (router->saved_master.selecthostname)
{
GWBUF_CONSUME_ALL(router->saved_master.selecthostname);
}
router->saved_master.selecthostname = buf;
blr_cache_response(router, "selecthostname", buf);
buf = blr_make_query(router->master, "SELECT @@max_allowed_packet");
router->master_state = BLRM_MAP;
router->master->func.write(router->master, buf);
break;
case BLRM_MAP:
// Response to SELECT @@max_allowed_packet should be stored
if (router->saved_master.map)
{
GWBUF_CONSUME_ALL(router->saved_master.map);
}
router->saved_master.map = buf;
blr_cache_response(router, "map", buf);
buf = blr_make_registration(router);
router->master_state = BLRM_REGISTER;
router->master->func.write(router->master, buf);
break;
case BLRM_REGISTER:
/* discard master reply to COM_REGISTER_SLAVE */
gwbuf_free(buf);
/* if semisync option is set, check for master semi-sync availability */
if (router->request_semi_sync)
{
MXS_NOTICE("%s: checking Semi-Sync replication capability for master server %s:%d",
router->service->name,
router->service->dbref->server->name,
router->service->dbref->server->port);
buf = blr_make_query(router->master, "SHOW VARIABLES LIKE 'rpl_semi_sync_master_enabled'");
router->master_state = BLRM_CHECK_SEMISYNC;
router->master->func.write(router->master, buf);
break;
}
else
{
/* Continue */
router->master_state = BLRM_REQUEST_BINLOGDUMP;
}
case BLRM_CHECK_SEMISYNC:
{
/**
* This branch could be reached as fallthrough from BLRM_REGISTER
* if request_semi_sync option is false
*/
if (router->master_state == BLRM_CHECK_SEMISYNC)
{
/* Get master semi-sync installed, enabled, disabled */
router->master_semi_sync = blr_get_master_semisync(buf);
/* Discard buffer */
gwbuf_free(buf);
if (router->master_semi_sync == MASTER_SEMISYNC_NOT_AVAILABLE)
{
/* not installed */
MXS_NOTICE("%s: master server %s:%d doesn't have semi_sync capability",
router->service->name,
router->service->dbref->server->name,
router->service->dbref->server->port);
/* Continue */
router->master_state = BLRM_REQUEST_BINLOGDUMP;
}
else
{
if (router->master_semi_sync == MASTER_SEMISYNC_DISABLED)
{
/* Installed but not enabled, right now */
MXS_NOTICE("%s: master server %s:%d doesn't have semi_sync enabled right now, "
"Requesting Semi-Sync Replication",
router->service->name,
router->service->dbref->server->name,
router->service->dbref->server->port);
}
else
{
/* Installed and enabled */
MXS_NOTICE("%s: master server %s:%d has semi_sync enabled, Requesting Semi-Sync Replication",
router->service->name,
router->service->dbref->server->name,
router->service->dbref->server->port);
}
buf = blr_make_query(router->master, "SET @rpl_semi_sync_slave = 1");
router->master_state = BLRM_REQUEST_SEMISYNC;
router->master->func.write(router->master, buf);
break;
}
}
}
case BLRM_REQUEST_SEMISYNC:
/**
* This branch could be reached as fallthrough from BLRM_REGISTER or BLRM_CHECK_SEMISYNC
* if request_semi_sync option is false or master doesn't support semisync or it's not enabled
*/
if (router->master_state == BLRM_REQUEST_SEMISYNC)
{
/* discard master reply */
gwbuf_free(buf);
/* Continue */
router->master_state = BLRM_REQUEST_BINLOGDUMP;
}
case BLRM_REQUEST_BINLOGDUMP:
/**
* This branch is reached after semi-sync check/request or
* just after sending COM_REGISTER_SLAVE if request_semi_sync option is false
*/
/* Request now a dump of the binlog file */
buf = blr_make_binlog_dump(router);
router->master_state = BLRM_BINLOGDUMP;
router->master->func.write(router->master, buf);
MXS_NOTICE("%s: Request binlog records from %s at "
"position %lu from master server %s:%d",
router->service->name, router->binlog_name,
router->current_pos,
router->service->dbref->server->name,
router->service->dbref->server->port);
/* Log binlog router identity */
blr_log_identity(router);
break;
case BLRM_BINLOGDUMP:
/**
* Main body, we have received a binlog record from the master
*/
blr_handle_binlog_record(router, buf);
/**
* Set heartbeat check task
*/
snprintf(task_name, BLRM_TASK_NAME_LEN, "%s heartbeat", router->service->name);
hktask_add(task_name, blr_check_last_master_event, router, router->heartbeat);
break;
}
if (router->reconnect_pending)
{
blr_restart_master(router);
}
spinlock_acquire(&router->lock);
router->active_logs = 0;
spinlock_release(&router->lock);
atomic_add(&router->handling_threads, -1);
}
/**
* Build a MySQL query into a GWBUF that we can send to the master database
*
* The data is not written to @c dcb but the expected protocol state is fixed.
*
* @param dcb The DCB where this will be written
* @param query The text of the query to send
*/
static GWBUF *
blr_make_query(DCB *dcb, char *query)
{
GWBUF *buf;
unsigned char *data;
int len;
if ((buf = gwbuf_alloc(strlen(query) + 5)) == NULL)
{
return NULL;
}
data = GWBUF_DATA(buf);
len = strlen(query) + 1;
encode_value(&data[0], len, 24); // Payload length
data[3] = 0; // Sequence id
// Payload
data[4] = COM_QUERY; // Command
memcpy(&data[5], query, strlen(query));
// This is hack to get the result set processing in order for binlogrouter
MySQLProtocol *proto = (MySQLProtocol*)dcb->protocol;
proto->current_command = MYSQL_COM_QUERY;
return buf;
}
/**
* Build a MySQL slave registration into a GWBUF that we can send to the
* master database
*
* @param router The router instance
* @return A MySQL Replication registration message in a GWBUF structure
*/
static GWBUF *
blr_make_registration(ROUTER_INSTANCE *router)
{
GWBUF *buf;
unsigned char *data;
int len = 18;
int port = 3306;
if ((buf = gwbuf_alloc(len + 4)) == NULL)
{
return NULL;
}
data = GWBUF_DATA(buf);
encode_value(&data[0], len, 24); // Payload length
data[3] = 0; // Sequence ID
data[4] = COM_REGISTER_SLAVE; // Command
encode_value(&data[5], router->serverid, 32); // Slave Server ID
data[9] = 0; // Slave hostname length
data[10] = 0; // Slave username length
data[11] = 0; // Slave password length
if (router->service->ports)
{
port = router->service->ports->port;
}
encode_value(&data[12], port, 16); // Slave master port
encode_value(&data[14], 0, 32); // Replication rank
encode_value(&data[18], router->masterid, 32); // Master server-id
// This is hack to get the result set processing in order for binlogrouter
MySQLProtocol *proto = (MySQLProtocol*)router->master->protocol;
proto->current_command = MYSQL_COM_REGISTER_SLAVE;
return buf;
}
/**
* Build a Binlog dump command into a GWBUF that we can send to the
* master database
*
* @param router The router instance
* @return A MySQL Replication COM_BINLOG_DUMP message in a GWBUF structure
*/
static GWBUF *
blr_make_binlog_dump(ROUTER_INSTANCE *router)
{
GWBUF *buf;
unsigned char *data;
int binlog_file_len = strlen(router->binlog_name);
/* COM_BINLOG_DUMP needs 11 bytes + binlogname (terminating NULL is not required) */
int len = 11 + binlog_file_len;
if ((buf = gwbuf_alloc(len + 4)) == NULL)
{
return NULL;
}
data = GWBUF_DATA(buf);
encode_value(&data[0], len, 24); // Payload length
data[3] = 0; // Sequence ID
data[4] = COM_BINLOG_DUMP; // Command
encode_value(&data[5],
router->current_pos, 32); // binlog position
/* With mariadb10 always ask for annotate rows events */
if (router->mariadb10_compat)
{
/* set flag for annotate rows event request */
encode_value(&data[9], BLR_REQUEST_ANNOTATE_ROWS_EVENT, 16);
}
else
{
encode_value(&data[9], 0, 16); // No flag set
}
encode_value(&data[11],
router->serverid, 32); // Server-id of MaxScale
memcpy((char *)&data[15], router->binlog_name,
binlog_file_len); // binlog filename
// This is hack to get the result set processing in order for binlogrouter
MySQLProtocol *proto = (MySQLProtocol*)router->master->protocol;
proto->current_command = MYSQL_COM_BINLOG_DUMP;
return buf;
}
/**
* Encode a value into a number of bits in a MySQL packet
*
* @param data Point to location in target packet
* @param value The value to pack
* @param len Number of bits to encode value into
*/
void
encode_value(unsigned char *data, unsigned int value, int len)
{
while (len > 0)
{
*data++ = value & 0xff;
value >>= 8;
len -= 8;
}
}
/**
* Check that the stored event checksum matches the calculated checksum
*/
static bool verify_checksum(ROUTER_INSTANCE *router, size_t len, uint8_t *ptr)
{
bool rval = true;
uint32_t offset = MYSQL_HEADER_LEN + 1;
uint32_t size = len - (offset + MYSQL_CHECKSUM_LEN);
uint32_t checksum = crc32(0L, ptr + offset, size);
uint32_t pktsum = EXTRACT32(ptr + offset + size);
if (pktsum != checksum)
{
rval = false;
MXS_ERROR("%s: Checksum error in event from master, "
"binlog %s @ %lu. Closing master connection.",
router->service->name, router->binlog_name,
router->current_pos);
router->stats.n_badcrc++;
}
return rval;
}
/**
* @brief Reset router errors
*
* @param router Router instance
* @param hdr Replication header
*/
static void reset_errors(ROUTER_INSTANCE *router, REP_HEADER *hdr)
{
spinlock_acquire(&router->lock);
/* set mysql errno to 0 */
router->m_errno = 0;
/* Remove error message */
if (router->m_errmsg)
{
MXS_FREE(router->m_errmsg);
}
router->m_errmsg = NULL;
spinlock_release(&router->lock);
#ifdef SHOW_EVENTS
printf("blr: len %lu, event type 0x%02x, flags 0x%04x, "
"event size %d, event timestamp %lu\n",
(unsigned long)len - 4,
hdr->event_type,
hdr->flags,
hdr->event_size,
(unsigned long)hdr->timestamp);
#endif
}
/**
* blr_handle_binlog_record - we have received binlog records from
* the master and we must now work out what to do with them.
*
* @param router The router instance
* @param pkt The binlog records
*/
void
blr_handle_binlog_record(ROUTER_INSTANCE *router, GWBUF *pkt)
{
uint8_t *msg = NULL, *ptr;
REP_HEADER hdr;
unsigned int len = 0;
int prev_length = -1;
int n_bufs = -1, pn_bufs = -1;
int check_packet_len;
int semisync_bytes;
int semi_sync_send_ack = 0;
/*
* Loop over all the packets while we still have some data
* and the packet length is enough to hold a replication event
* header.
*/
while (pkt)
{
ptr = GWBUF_DATA(pkt);
len = gw_mysql_get_byte3(ptr);
semisync_bytes = 0;
/*
* ptr now points at the current message in a contiguous buffer,
* this buffer is either within the GWBUF or in a malloc'd
* copy if the message straddles GWBUF's.
*/
if (len < BINLOG_EVENT_HDR_LEN && router->master_event_state != BLR_EVENT_ONGOING)
{
char *event_msg = "unknown";
/* Packet is too small to be a binlog event */
if (ptr[4] == 0xfe) /* EOF Packet */
{
event_msg = "end of file";
}
else if (ptr[4] == 0xff) /* EOF Packet */
{
event_msg = "error";
}
MXS_NOTICE("Non-event message (%s) from master.", event_msg);
gwbuf_free(pkt);
break;
}
else
{
if (router->master_event_state == BLR_EVENT_DONE)
{
/** This is the start of a new event */
spinlock_acquire(&router->lock);
router->stats.n_binlogs++;
router->stats.n_binlogs_ses++;
spinlock_release(&router->lock);
/* Check for semi-sync in event with OK byte[4]:
* move pointer 2 bytes ahead and set check_packet_len accordingly
*/
if (ptr[4] == 0 && router->master_semi_sync != MASTER_SEMISYNC_NOT_AVAILABLE &&
ptr[5] == BLR_MASTER_SEMI_SYNC_INDICATOR)
{
check_packet_len = MASTER_BYTES_BEFORE_EVENT_SEMI_SYNC;
semi_sync_send_ack = ptr[6];
/* Extract header from the semi-sync event */
blr_extract_header_semisync(ptr, &hdr);
/** Remove the semi-sync bytes */
memmove(ptr, ptr + 2, 5);
ptr += 2;
semisync_bytes = 2;
}
else
{
semi_sync_send_ack = 0;
check_packet_len = MASTER_BYTES_BEFORE_EVENT;
/* Extract header from thr event */
blr_extract_header(ptr, &hdr);
}
/* Sanity check */
if (hdr.ok == 0)
{
if (hdr.event_size != len - (check_packet_len - MYSQL_HEADER_LEN) &&
(hdr.event_size + (check_packet_len - MYSQL_HEADER_LEN)) < MYSQL_PACKET_LENGTH_MAX)
{
MXS_ERROR("Packet length is %d, but event size is %d, "
"binlog file %s position %lu, "
"length of previous event %d.",
len, hdr.event_size,
router->binlog_name,
router->current_pos,
prev_length);
blr_log_packet(LOG_ERR, "Packet:", ptr, len);
MXS_ERROR("This event (0x%x) was contained in %d GWBUFs, "
"the previous events was contained in %d GWBUFs",
router->lastEventReceived, n_bufs, pn_bufs);
if (msg)
{
MXS_FREE(msg);
/* msg = NULL; Not needed unless msg will be referred to again */
}
break;
}
/**
* This is the first (and possibly last) packet of a replication
* event. We store the header in case the event is large and
* it is transmitted over multiple network packets.
*/
router->master_event_state = BLR_EVENT_STARTED;
memcpy(&router->stored_header, &hdr, sizeof(hdr));
reset_errors(router, &hdr);
}
else
{
/* Terminate replication and exit from main loop */
blr_terminate_master_replication(router, ptr, len);
gwbuf_free(pkt);
pkt = NULL;
break;
}
}
else
{
/** We're processing a multi-packet replication event */
ss_dassert(router->master_event_state == BLR_EVENT_ONGOING);
}
/** Gather the event into one big buffer */
GWBUF *part = gwbuf_split(&pkt, len + MYSQL_HEADER_LEN);
if (semisync_bytes)
{
/** Consume the two semi-sync bytes */
part = gwbuf_consume(part, semisync_bytes);
}
ss_dassert(router->master_event_state == BLR_EVENT_STARTED ||
router->master_event_state == BLR_EVENT_ONGOING);
if (router->master_event_state == BLR_EVENT_ONGOING)
{
/**
* Consume the network header so that we can append the raw
* event data to the original buffer. This allows both checksum
* calculations and encryption to process it as a contiguous event
*/
part = gwbuf_consume(part, MYSQL_HEADER_LEN);
}
router->stored_event = gwbuf_append(router->stored_event, part);
if (len < MYSQL_PACKET_LENGTH_MAX)
{
/**
* This is either the only packet for the event or the last
* packet in a series for this event. The buffer now contains
* the network header of the first packet (4 bytes) and one OK byte.
* The semi-sync bytes are always consumed at an earlier stage.
*/
ss_dassert(router->master_event_state != BLR_EVENT_DONE);
if (router->master_event_state != BLR_EVENT_STARTED)
{
/**
* This is not the first packet for this event. We must use
* the stored header.
*/
memcpy(&hdr, &router->stored_header, sizeof(hdr));
}
/** The event is now complete */
router->master_event_state = BLR_EVENT_DONE;
}
else
{
/**
* This packet is a part of a series of packets that contain an
* event larger than MYSQL_PACKET_LENGTH_MAX bytes.
*
* For each partial event chunk, we remove the network header and
* append it to router->stored_event. The first event is an
* exception to this and it is appended as-is with the network
* header and the extra OK byte.
*/
ss_dassert(len == MYSQL_PACKET_LENGTH_MAX);
router->master_event_state = BLR_EVENT_ONGOING;
continue;
}
/**
* We now have the complete event in one contiguous buffer:
* router->master_event_state is BLR_EVENT_DONE
*/
router->stored_event = gwbuf_make_contiguous(router->stored_event);
MXS_ABORT_IF_NULL(router->stored_event);
ptr = GWBUF_DATA(router->stored_event);
/**
* len is now the length of the complete event plus 4 bytes of network
* header and one OK byte. Semi-sync bytes are never stored.
*/
len = gwbuf_length(router->stored_event);
/**
* If checksums are enabled, verify that the stored checksum
* matches the one we calculated
*/
if (router->master_chksum && !verify_checksum(router, len, ptr))
{
MXS_FREE(msg);
blr_master_close(router);
blr_master_delayed_connect(router);
return;
}
if (hdr.ok == 0)
{
router->lastEventReceived = hdr.event_type;
router->lastEventTimestamp = hdr.timestamp;
/**
* Check for an open transaction, if the option is set
* Only complete transactions should be sent to sleves
*
* If a trasaction is pending router->binlog_position
* won't be updated to router->current_pos
*/
spinlock_acquire(&router->binlog_lock);
if (router->trx_safe == 0 || (router->trx_safe && router->pending_transaction == BLRM_NO_TRANSACTION))
{
/* no pending transaction: set current_pos to binlog_position */
router->binlog_position = router->current_pos;
router->current_safe_event = router->current_pos;
}
spinlock_release(&router->binlog_lock);
/**
* Detect transactions in events
* Only complete transactions should be sent to sleves
*/
/**
* If MariaDB 10 compatibility:
* check for MARIADB10_GTID_EVENT with flags = 0
* This marks the transaction starts instead of
* QUERY_EVENT with "BEGIN"
*/
if (router->trx_safe)
{
if (router->mariadb10_compat)
{
if (hdr.event_type == MARIADB10_GTID_EVENT)
{
uint64_t n_sequence;
uint32_t domainid;
unsigned int flags;
n_sequence = extract_field(ptr + MYSQL_HEADER_LEN + 1 + BINLOG_EVENT_HDR_LEN, 64);
domainid = extract_field(ptr + MYSQL_HEADER_LEN + 1 + BINLOG_EVENT_HDR_LEN + 8, 32);
flags = *(ptr + MYSQL_HEADER_LEN + 1 + BINLOG_EVENT_HDR_LEN + 8 + 4);
if ((flags & (MARIADB_FL_DDL | MARIADB_FL_STANDALONE)) == 0)
{
spinlock_acquire(&router->binlog_lock);
if (router->pending_transaction > 0)
{
MXS_ERROR("A MariaDB 10 transaction "
"is already open "
"@ %lu (GTID %u-%u-%lu) and "
"a new one starts @ %lu",
router->binlog_position,
domainid, hdr.serverid,
n_sequence,
router->current_pos);
// An action should be taken here
}
router->pending_transaction = BLRM_TRANSACTION_START;
spinlock_release(&router->binlog_lock);
}
}
}
/**
* look for QUERY_EVENT [BEGIN / COMMIT] and XID_EVENT
*/
if (hdr.event_type == QUERY_EVENT)
{
char *statement_sql;
int db_name_len, var_block_len, statement_len;
db_name_len = ptr[MYSQL_HEADER_LEN + 1 + BINLOG_EVENT_HDR_LEN + 4 + 4];
var_block_len = ptr[MYSQL_HEADER_LEN + 1 + BINLOG_EVENT_HDR_LEN + 4 + 4 + 1 + 2];
statement_len = len - (MYSQL_HEADER_LEN + 1 + BINLOG_EVENT_HDR_LEN + 4 + 4 + 1 + 2 + 2 \
+ var_block_len + 1 + db_name_len);
statement_sql = MXS_CALLOC(1, statement_len + 1);
MXS_ABORT_IF_NULL(statement_sql);
memcpy(statement_sql,
(char *)ptr + MYSQL_HEADER_LEN + 1 + BINLOG_EVENT_HDR_LEN + 4 + 4 + 1 + 2 + 2 \
+ var_block_len + 1 + db_name_len,
statement_len);
spinlock_acquire(&router->binlog_lock);
/* Check for BEGIN (it comes for START TRANSACTION too) */
if (strncmp(statement_sql, "BEGIN", 5) == 0)
{
if (router->pending_transaction > BLRM_NO_TRANSACTION)
{
MXS_ERROR("A transaction is already open "
"@ %lu and a new one starts @ %lu",
router->binlog_position,
router->current_pos);
// An action should be taken here
}
router->pending_transaction = BLRM_TRANSACTION_START;
}
/* Check for COMMIT in non transactional store engines */
if (strncmp(statement_sql, "COMMIT", 6) == 0)
{
router->pending_transaction = BLRM_COMMIT_SEEN;
}
spinlock_release(&router->binlog_lock);
MXS_FREE(statement_sql);
}
/* Check for COMMIT in Transactional engines, i.e InnoDB */
if (hdr.event_type == XID_EVENT)
{
spinlock_acquire(&router->binlog_lock);
if (router->pending_transaction)
{
router->pending_transaction = BLRM_XID_EVENT_SEEN;
}
spinlock_release(&router->binlog_lock);
}
}
/** Gather statistics about the replication event types */
int event_limit = router->mariadb10_compat ?
MAX_EVENT_TYPE_MARIADB10 : MAX_EVENT_TYPE;
if (hdr.event_type <= event_limit)
{
router->stats.events[hdr.event_type]++;
}
if (hdr.event_type == FORMAT_DESCRIPTION_EVENT && hdr.next_pos == 0)
{
// Fake format description message
MXS_DEBUG("Replication fake event. "
"Binlog %s @ %lu.",
router->binlog_name,
router->current_pos);
router->stats.n_fakeevents++;
if (hdr.event_type == FORMAT_DESCRIPTION_EVENT)
{
uint8_t *new_fde;
unsigned int new_fde_len;
/*
* We need to save this to replay to new
* slaves that attach later.
*/
new_fde_len = hdr.event_size;
new_fde = MXS_MALLOC(hdr.event_size);
if (new_fde)
{
memcpy(new_fde, ptr + MYSQL_HEADER_LEN + 1, hdr.event_size);
if (router->saved_master.fde_event)
{
MXS_FREE(router->saved_master.fde_event);
}
router->saved_master.fde_event = new_fde;
router->saved_master.fde_len = new_fde_len;
}
}
}
else
{
if (hdr.event_type == HEARTBEAT_EVENT)
{
#ifdef SHOW_EVENTS
printf("Replication heartbeat\n");
#endif
MXS_DEBUG("Replication heartbeat. "
"Binlog %s @ %lu.",
router->binlog_name,
router->current_pos);
router->stats.n_heartbeats++;
if (router->pending_transaction)
{
router->stats.lastReply = time(0);
}
}
else if (hdr.flags != LOG_EVENT_ARTIFICIAL_F)
{
if (hdr.event_type == ROTATE_EVENT)
{
spinlock_acquire(&router->binlog_lock);
router->rotating = 1;
spinlock_release(&router->binlog_lock);
}
uint32_t offset = MYSQL_HEADER_LEN + 1; // Skip header and OK byte
/**
* Write the raw event data to disk without the network
* header or the OK byte
*/
if (blr_write_binlog_record(router, &hdr, len - offset, ptr + offset) == 0)
{
gwbuf_free(pkt);
blr_master_close(router);
blr_master_delayed_connect(router);
return;
}
/* Check for rotate event */
if (hdr.event_type == ROTATE_EVENT)
{
if (!blr_rotate_event(router, ptr + offset, &hdr))
{
gwbuf_free(pkt);
blr_master_close(router);
blr_master_delayed_connect(router);
return;
}
}
/* Handle semi-sync request from master */
if (router->master_semi_sync != MASTER_SEMISYNC_NOT_AVAILABLE &&
semi_sync_send_ack == BLR_MASTER_SEMI_SYNC_ACK_REQ)
{
MXS_DEBUG("%s: binlog record in file %s, pos %lu has "
"SEMI_SYNC_ACK_REQ and needs a Semi-Sync ACK packet to "
"be sent to the master server %s:%d",
router->service->name, router->binlog_name,
router->current_pos,
router->service->dbref->server->name,
router->service->dbref->server->port);
/* Send Semi-Sync ACK packet to master server */
blr_send_semisync_ack(router, hdr.next_pos);
/* Reset ACK sending */
semi_sync_send_ack = 0;
}
/**
* Distributing binlog events to slaves
* may depend on pending transaction
*/
spinlock_acquire(&router->binlog_lock);
if (router->trx_safe == 0 || (router->trx_safe && router->pending_transaction == BLRM_NO_TRANSACTION))
{
router->binlog_position = router->current_pos;
router->current_safe_event = router->last_event_pos;
spinlock_release(&router->binlog_lock);
/* Notify clients events can be read */
blr_notify_all_slaves(router);
}
else
{
/**
* If transaction is closed:
*
* 1) Notify clients events can be read
* from router->binlog_position
* 2) set router->binlog_position to
* router->current_pos
*/
if (router->pending_transaction > BLRM_TRANSACTION_START)
{
spinlock_release(&router->binlog_lock);
/* Notify clients events can be read */
blr_notify_all_slaves(router);
/* update binlog_position and set pending to 0 */
spinlock_acquire(&router->binlog_lock);
router->binlog_position = router->current_pos;
router->pending_transaction = BLRM_NO_TRANSACTION;
spinlock_release(&router->binlog_lock);
}
else
{
spinlock_release(&router->binlog_lock);
}
}
}
else
{
router->stats.n_artificial++;
MXS_DEBUG("Artificial event not written "
"to disk or distributed. "
"Type 0x%x, Length %d, Binlog "
"%s @ %lu.",
hdr.event_type,
hdr.event_size,
router->binlog_name,
router->current_pos);
ptr += MYSQL_HEADER_LEN + 1;
if (hdr.event_type == ROTATE_EVENT)
{
spinlock_acquire(&router->binlog_lock);
router->rotating = 1;
spinlock_release(&router->binlog_lock);
if (!blr_rotate_event(router, ptr, &hdr))
{
gwbuf_free(pkt);
blr_master_close(router);
blr_master_delayed_connect(router);
return;
}
}
}
}
}
else
{
blr_terminate_master_replication(router, ptr, len);
}
/** Finished processing the event */
gwbuf_free(router->stored_event);
router->stored_event = NULL;
}
if (msg)
{
MXS_FREE(msg);
msg = NULL;
}
}
blr_file_flush(router);
}
/**
* Populate a header structure for a replication message from a GWBUF structure.
*
* @param pkt The incoming packet in a GWBUF chain
* @param hdr The packet header to populate
*/
void
blr_extract_header(register uint8_t *ptr, register REP_HEADER *hdr)
{
hdr->payload_len = EXTRACT24(ptr);
hdr->seqno = ptr[3];
hdr->ok = ptr[4];
hdr->timestamp = EXTRACT32(&ptr[5]);
hdr->event_type = ptr[9];
hdr->serverid = EXTRACT32(&ptr[10]);
hdr->event_size = EXTRACT32(&ptr[14]);
hdr->next_pos = EXTRACT32(&ptr[18]);
hdr->flags = EXTRACT16(&ptr[22]);
}
/**
* Process a binlog rotate event.
*
* @param router The instance of the router
* @param ptr The packet containing the rotate event
* @param hdr The replication message header
* @return 1 if the file could be rotated, 0 otherwise.
*/
static int
blr_rotate_event(ROUTER_INSTANCE *router, uint8_t *ptr, REP_HEADER *hdr)
{
int len, slen;
uint64_t pos;
char file[BINLOG_FNAMELEN + 1];
ptr += 19; // Skip event header
len = hdr->event_size - 19; // Event size minus header
pos = extract_field(ptr + 4, 32);
pos <<= 32;
pos |= extract_field(ptr, 32);
slen = len - (8 + 4); // Allow for position and CRC
if (router->master_chksum == 0)
{
slen += 4;
}
if (slen > BINLOG_FNAMELEN)
{
slen = BINLOG_FNAMELEN;
}
memcpy(file, ptr + 8, slen);
file[slen] = 0;
#ifdef VERBOSE_ROTATE
printf("binlog rotate: ");
while (len--)
{
printf("0x%02x ", *ptr++);
}
printf("\n");
printf("New file: %s @ %ld\n", file, pos);
#endif
strcpy(router->prevbinlog, router->binlog_name);
int rotated = 1;
int remove_encrytion_ctx = 0;
if (strncmp(router->binlog_name, file, slen) != 0)
{
remove_encrytion_ctx = 1;
router->stats.n_rotates++;
if (blr_file_rotate(router, file, pos) == 0)
{
rotated = 0;
}
}
spinlock_acquire(&router->binlog_lock);
router->rotating = 0;
/* remove current binlog encryption context */
if (remove_encrytion_ctx == 1)
{
MXS_FREE(router->encryption_ctx);
router->encryption_ctx = NULL;
}
spinlock_release(&router->binlog_lock);
return rotated;
}
/**
* Create the auth data needed to be able to call dcb_connect.
*
* This doesn't really belong here and should be moved at some stage.
*/
static void *
CreateMySQLAuthData(char *username, char *password, char *database)
{
MYSQL_session *auth_info;
if (username == NULL || password == NULL)
{
MXS_ERROR("You must specify both username and password for the binlog router.");
return NULL;
}
if (strlen(username) > MYSQL_USER_MAXLEN)
{
MXS_ERROR("Provided user name %s is longer than maximum length %d.",
username, MYSQL_USER_MAXLEN);
return NULL;
}
if (strlen(database) > MYSQL_DATABASE_MAXLEN)
{
MXS_ERROR("Provided database %s is longer than maximum length %d.",
database, MYSQL_DATABASE_MAXLEN);
return NULL;
}
if ((auth_info = MXS_CALLOC(1, sizeof(MYSQL_session))) == NULL)
{
return NULL;
}
strcpy(auth_info->user, username);
strcpy(auth_info->db, database);
gw_sha1_str((const uint8_t *)password, strlen(password), auth_info->client_sha1);
return auth_info;
}
/** Actions that can be taken when an event is being distributed to the slaves*/
typedef enum
{
SLAVE_SEND_EVENT, /*< Send the event to the slave */
SLAVE_FORCE_CATCHUP, /*< Force the slave into catchup mode */
SLAVE_EVENT_ALREADY_SENT /*< The slave already has the event, don't send it */
} slave_event_action_t;
/**
* Write a raw event (the first 40 bytes at most) to a log file
*
* @param priority The syslog priority of the message (LOG_ERR, LOG_WARNING, etc.)
* @param msg A textual message to write before the packet
* @param ptr Pointer to the message buffer
* @param len Length of message packet
*/
static void
blr_log_packet(int priority, char *msg, uint8_t *ptr, int len)
{
char buf[400] = "";
char *bufp;
int i;
bufp = buf;
bufp += sprintf(bufp, "%s length = %d: ", msg, len);
for (i = 0; i < len && i < 40; i++)
{
bufp += sprintf(bufp, "0x%02x ", ptr[i]);
}
if (i < len)
{
MXS_LOG_MESSAGE(priority, "%s...", buf);
}
else
{
MXS_LOG_MESSAGE(priority, "%s", buf);
}
}
/**
* Check if the master connection is in place and we
* are downlaoding binlogs
*
* @param router The router instance
* @return non-zero if we are recivign binlog records
*/
int
blr_master_connected(ROUTER_INSTANCE *router)
{
return router->master_state == BLRM_BINLOGDUMP;
}
/**
* Extract a result value from the set of messages that make up a
* MySQL response packet.
*
* @param buf The GWBUF containing the response
* @param col The column number to return
* @return The result form the column or NULL. The caller must free the result
*/
char *
blr_extract_column(GWBUF *buf, int col)
{
uint8_t *ptr;
int len, ncol, collen;
char *rval;
if (buf == NULL)
{
return NULL;
}
ptr = (uint8_t *)GWBUF_DATA(buf);
/* First packet should be the column count */
len = EXTRACT24(ptr);
ptr += 3;
if (*ptr != 1) // Check sequence number is 1
{
return NULL;
}
ptr++;
ncol = *ptr++;
if (ncol < col) // Not that many column in result
{
return NULL;
}
// Now ptr points at the column definition
while (ncol-- > 0)
{
len = EXTRACT24(ptr);
ptr += 4; // Skip to payload
ptr += len; // Skip over payload
}
// Now we should have an EOF packet
len = EXTRACT24(ptr);
ptr += 4; // Skip to payload
if (*ptr != 0xfe)
{
return NULL;
}
ptr += len;
// Finally we have reached the row
len = EXTRACT24(ptr);
ptr += 4;
/** The first EOF packet signals the start of the resultset rows and the second
EOF packet signals the end of the result set. If the resultset
contains a second EOF packet right after the first one, the result set is empty and
contains no rows. */
if (len == 5 && *ptr == 0xfe)
{
return NULL;
}
while (--col > 0)
{
collen = *ptr++;
ptr += collen;
}
collen = *ptr++;
if ((rval = MXS_MALLOC(collen + 1)) == NULL)
{
return NULL;
}
memcpy(rval, ptr, collen);
rval[collen] = 0; // NULL terminate
return rval;
}
/**
* Read a replication event form current opened binlog into a GWBUF structure.
*
* @param router The router instance
* @param pos Position of binlog record to read
* @param hdr Binlog header to populate
* @return The binlog record wrapped in a GWBUF structure
*/
GWBUF
*blr_read_events_from_pos(ROUTER_INSTANCE *router,
unsigned long long pos,
REP_HEADER *hdr,
unsigned long long pos_end)
{
unsigned long long end_pos = 0;
uint8_t hdbuf[19];
uint8_t *data;
GWBUF *result;
int n;
int event_limit;
/* Get current binnlog position */
end_pos = pos_end;
/* end of file reached, we're done */
if (pos == end_pos)
{
return NULL;
}
/* error */
if (pos > end_pos)
{
MXS_ERROR("Reading saved events, the specified pos %llu "
"is ahead of current pos %lu for file %s",
pos, router->current_pos, router->binlog_name);
return NULL;
}
/* Read the event header information from the file */
if ((n = pread(router->binlog_fd, hdbuf, 19, pos)) != 19)
{
switch (n)
{
case 0:
MXS_DEBUG("Reading saved events: reached end of binlog file at %llu.", pos);
break;
case -1:
{
char err_msg[MXS_STRERROR_BUFLEN];
MXS_ERROR("Reading saved events: failed to read binlog "
"file %s at position %llu"
" (%s).", router->binlog_name,
pos, strerror_r(errno, err_msg, sizeof(err_msg)));
if (errno == EBADF)
{
MXS_ERROR("Reading saved events: bad file descriptor for file %s"
", descriptor %d.",
router->binlog_name, router->binlog_fd);
}
}
break;
default:
MXS_ERROR("Reading saved events: short read when reading the header. "
"Expected 19 bytes but got %d bytes. "
"Binlog file is %s, position %llu",
n, router->binlog_name, pos);
break;
}
return NULL;
}
hdr->timestamp = EXTRACT32(hdbuf);
hdr->event_type = hdbuf[4];
hdr->serverid = EXTRACT32(&hdbuf[5]);
hdr->event_size = extract_field(&hdbuf[9], 32);
hdr->next_pos = EXTRACT32(&hdbuf[13]);
hdr->flags = EXTRACT16(&hdbuf[17]);
event_limit = router->mariadb10_compat ? MAX_EVENT_TYPE_MARIADB10 : MAX_EVENT_TYPE;
if (hdr->event_type > event_limit)
{
MXS_ERROR("Reading saved events: invalid event type 0x%x. "
"Binlog file is %s, position %llu",
hdr->event_type,
router->binlog_name, pos);
return NULL;
}
if ((result = gwbuf_alloc(hdr->event_size)) == NULL)
{
MXS_ERROR("Reading saved events: failed to allocate memory for binlog entry, "
"size %d at %llu.",
hdr->event_size, pos);
return NULL;
}
/* Copy event header*/
data = GWBUF_DATA(result);
memcpy(data, hdbuf, 19);
/* Read event data and put int into buffer after header */
if ((n = pread(router->binlog_fd, &data[19], hdr->event_size - 19, pos + 19)) != hdr->event_size - 19)
{
if (n == -1)
{
char err_msg[MXS_STRERROR_BUFLEN];
MXS_ERROR("Reading saved events: the event at %llu in %s. "
"%s, expected %d bytes.",
pos, router->binlog_name,
strerror_r(errno, err_msg, sizeof(err_msg)), hdr->event_size - 19);
}
else
{
MXS_ERROR("Reading saved events: short read when reading "
"the event at %llu in %s. "
"Expected %d bytes got %d bytes.",
pos, router->binlog_name, hdr->event_size - 19, n);
if (end_pos - pos < hdr->event_size)
{
MXS_ERROR("Reading saved events: binlog event "
"is close to the end of the binlog file, "
"current file size is %llu.", end_pos);
}
}
/* free buffer */
gwbuf_free(result);
return NULL;
}
return result;
}
/**
* Stop and start the master connection
*
* @param router The router instance
*/
void
blr_stop_start_master(ROUTER_INSTANCE *router)
{
if (router->master)
{
if (router->master->fd != -1 && router->master->state == DCB_STATE_POLLING)
{
blr_master_close(router);
}
}
spinlock_acquire(&router->lock);
router->master_state = BLRM_SLAVE_STOPPED;
/* set last_safe_pos */
router->last_safe_pos = router->binlog_position;
/**
* Set router->prevbinlog to router->binlog_name
* The FDE event with current filename may arrive after STOP SLAVE is received
*/
if (strcmp(router->binlog_name, router->prevbinlog) != 0)
{
strcpy(router->prevbinlog, router->binlog_name); // Same size
}
if (router->client)
{
if (router->client->fd != -1 && router->client->state == DCB_STATE_POLLING)
{
dcb_close(router->client);
router->client = NULL;
}
}
router->master_state = BLRM_UNCONNECTED;
spinlock_release(&router->lock);
blr_master_reconnect(router);
}
/**
* The heartbeat check function called from the housekeeper.
* We can try a new master connection if current one is seen out of date
*
* @param router Current router instance
*/
static void
blr_check_last_master_event(void *inst)
{
ROUTER_INSTANCE *router = (ROUTER_INSTANCE *)inst;
int master_check = 1;
int master_state = BLRM_UNCONNECTED;
char task_name[BLRM_TASK_NAME_LEN + 1] = "";
spinlock_acquire(&router->lock);
master_check = blr_check_heartbeat(router);
master_state = router->master_state;
spinlock_release(&router->lock);
if (!master_check)
{
/*
* stop current master connection
* and try a new connection
*/
blr_stop_start_master(router);
}
if ( (!master_check) || (master_state != BLRM_BINLOGDUMP) )
{
/*
* Remove the task, it will be added again
* when master state is back to BLRM_BINLOGDUMP
* by blr_master_response()
*/
snprintf(task_name, BLRM_TASK_NAME_LEN, "%s heartbeat", router->service->name);
hktask_remove(task_name);
}
}
/**
* Check last heartbeat or last received event against router->heartbeat time interval
*
* checked interval is againts (router->heartbeat + BLR_NET_LATENCY_WAIT_TIME)
* that is currently set to 1
*
* @param router Current router instance
* @return 0 if master connection must be closed and opened again, 1 otherwise
*/
int
blr_check_heartbeat(ROUTER_INSTANCE *router)
{
time_t t_now = time(0);
char *event_desc = NULL;
if (router->master_state != BLRM_BINLOGDUMP)
{
return 1;
}
event_desc = blr_last_event_description(router);
if (router->master_state == BLRM_BINLOGDUMP && router->lastEventReceived > 0)
{
if ((t_now - router->stats.lastReply) > (router->heartbeat + BLR_NET_LATENCY_WAIT_TIME))
{
MXS_ERROR("No event received from master %s:%d in heartbeat period (%lu seconds), "
"last event (%s %d) received %lu seconds ago. Assuming connection is dead "
"and reconnecting.",
router->service->dbref->server->name,
router->service->dbref->server->port,
router->heartbeat,
event_desc != NULL ? event_desc : "unknown",
router->lastEventReceived,
t_now - router->stats.lastReply);
return 0;
}
}
return 1;
}
/**
* Log binlog router identy after master registration, state is BLRM_BINLOG_DUMP
*
* @param router The router instance
*/
static void blr_log_identity(ROUTER_INSTANCE *router)
{
char *master_uuid;
char *master_hostname;
char *master_version;
if (router->set_master_version)
{
master_version = router->set_master_version;
}
else
{
master_version = blr_extract_column(router->saved_master.selectver, 1);
}
if (router->set_master_hostname)
{
master_hostname = router->set_master_hostname;
}
else
{
master_hostname = blr_extract_column(router->saved_master.selecthostname, 1);
}
if (router->set_master_uuid)
{
master_uuid = router->master_uuid;
}
else
{
master_uuid = blr_extract_column(router->saved_master.uuid, 2);
}
/* Seen by the master */
MXS_NOTICE("%s: identity seen by the master: "
"server_id: %d, uuid: %s",
router->service->name,
router->serverid, (router->uuid == NULL ? "not available" : router->uuid));
/* Seen by the slaves */
/* MariaDB 5.5 and MariaDB don't have the MASTER_UUID var */
if (master_uuid == NULL)
{
MXS_NOTICE("%s: identity seen by the slaves: "
"server_id: %d, hostname: %s, MySQL version: %s",
router->service->name,
router->masterid, (master_hostname == NULL ? "not available" : master_hostname),
(master_version == NULL ? "not available" : master_version));
}
else
{
MXS_NOTICE("%s: identity seen by the slaves: "
"server_id: %d, uuid: %s, hostname: %s, MySQL version: %s",
router->service->name,
router->masterid, master_uuid,
(master_hostname == NULL ? "not available" : master_hostname),
(master_version == NULL ? "not available" : master_version));
}
}
/**
* @brief Write data into binlogs (incomplete event)
*
* Writes @c data_len bytes of data from @c buf into the current binlog being processed.
*
* @param router Router instance
* @param data_len Number of bytes to write
* @param buf Pointer where the data is read
* @return Number of bytes written or 0 on error
*/
int
blr_write_data_into_binlog(ROUTER_INSTANCE *router, uint32_t data_len, uint8_t *buf)
{
int n;
if ((n = pwrite(router->binlog_fd, buf, data_len,
router->last_written)) != data_len)
{
char err_msg[MXS_STRERROR_BUFLEN];
MXS_ERROR("%s: Failed to write binlog record at %lu of %s, %s. "
"Truncating to previous record.",
router->service->name, router->binlog_position,
router->binlog_name,
strerror_r(errno, err_msg, sizeof(err_msg)));
/* Remove any partial event that was written */
if (ftruncate(router->binlog_fd, router->binlog_position))
{
MXS_ERROR("%s: Failed to truncate binlog record at %lu of %s, %s. ",
router->service->name, router->last_written,
router->binlog_name,
strerror_r(errno, err_msg, sizeof(err_msg)));
}
return 0;
}
router->last_written += data_len;
return n;
}
/**
* Send a replication event packet to a slave
*
* The first replication event packet contains one byte set to either
* 0x0, 0xfe or 0xff which signals what the state of the replication stream is.
* If the data pointed by @c buf is not the start of the replication header
* and part of the replication event is already sent, @c first must be set to
* false so that the first status byte is not sent again.
*
* @param slave Slave where the packet is sent to
* @param buf Buffer containing the data
* @param len Length of the data
* @param first If this is the first packet of a multi-packet event
* @return True on success, false when memory allocation fails
*/
bool blr_send_packet(ROUTER_SLAVE *slave, uint8_t *buf, uint32_t len, bool first)
{
bool rval = true;
unsigned int datalen = len + (first ? 1 : 0);
GWBUF *buffer = gwbuf_alloc(datalen + MYSQL_HEADER_LEN);
if (buffer)
{
uint8_t *data = GWBUF_DATA(buffer);
encode_value(data, datalen, 24);
data += 3;
*data++ = slave->seqno++;
if (first)
{
*data++ = 0; // OK byte
}
if (len > 0)
{
memcpy(data, buf, len);
}
slave->stats.n_bytes += GWBUF_LENGTH(buffer);
slave->dcb->func.write(slave->dcb, buffer);
}
else
{
MXS_ERROR("failed to allocate %ld bytes of memory when writing an"
" event.", datalen + MYSQL_HEADER_LEN);
rval = false;
}
return rval;
}
/**
* Send a single replication event to a slave
*
* This sends the complete replication event to a slave. If the event size exceeds
* the maximum size of a MySQL packet, it will be sent in multiple packets.
*
* @param role What is the role of the caller, slave or master.
* @param binlog_name The name of the binlogfile.
* @param binlog_pos The position in the binlogfile.
* @param slave Slave where the event is sent to
* @param hdr Replication header
* @param buf Pointer to the replication event as it was read from the disk
* @return True on success, false if memory allocation failed
*/
bool blr_send_event(blr_thread_role_t role,
const char* binlog_name,
uint32_t binlog_pos,
ROUTER_SLAVE *slave,
REP_HEADER *hdr,
uint8_t *buf)
{
bool rval = true;
if ((strcmp(slave->lsi_binlog_name, binlog_name) == 0) &&
(slave->lsi_binlog_pos == binlog_pos))
{
MXS_ERROR("Slave %s:%i, server-id %d, binlog '%s', position %u: "
"thread %lu in the role of %s could not send the event, "
"the event has already been sent by thread %lu in the role of %s. "
"%u bytes buffered for writing in DCB %p. %lu events received from master.",
slave->dcb->remote,
ntohs((slave->dcb->ipv4).sin_port),
slave->serverid,
binlog_name,
binlog_pos,
thread_self(),
ROLETOSTR(role),
slave->lsi_sender_tid,
ROLETOSTR(slave->lsi_sender_role),
gwbuf_length(slave->dcb->writeq), slave->dcb,
slave->router->stats.n_binlogs);
return false;
}
/** Check if the event and the OK byte fit into a single packet */
if (hdr->event_size + 1 < MYSQL_PACKET_LENGTH_MAX)
{
rval = blr_send_packet(slave, buf, hdr->event_size, true);
}
else
{
/** Total size of all the payloads in all the packets */
int64_t len = hdr->event_size + 1;
bool first = true;
while (rval && len > 0)
{
uint64_t payload_len = first ? MYSQL_PACKET_LENGTH_MAX - 1 :
MXS_MIN(MYSQL_PACKET_LENGTH_MAX, len);
if (blr_send_packet(slave, buf, payload_len, first))
{
/** The check for exactly 0x00ffffff bytes needs to be done
* here as well */
if (len == MYSQL_PACKET_LENGTH_MAX)
{
blr_send_packet(slave, buf, 0, false);
}
/** Add the extra byte written by blr_send_packet */
len -= first ? payload_len + 1 : payload_len;
buf += payload_len;
first = false;
}
else
{
rval = false;
}
}
}
slave->stats.n_events++;
if (rval)
{
strcpy(slave->lsi_binlog_name, binlog_name);
slave->lsi_binlog_pos = binlog_pos;
slave->lsi_sender_role = role;
slave->lsi_sender_tid = thread_self();
}
else
{
MXS_ERROR("Failed to send an event of %u bytes to slave at %s:%d.",
hdr->event_size, slave->dcb->remote,
ntohs(slave->dcb->ipv4.sin_port));
}
return rval;
}
/**
* Stop the slave connection and log errors
*
* @param router Router instance
* @param ptr Pointer to the start of the packet
* @param len Length of the packet
*/
static void blr_terminate_master_replication(ROUTER_INSTANCE* router, uint8_t* ptr, int len)
{
unsigned long mysql_errno = extract_field(ptr + 5, 16);
int msg_len = len - 7 - 6; // msg len is decreased by 7 and 6
char *msg_err = (char *)MXS_MALLOC(msg_len + 1);
MXS_ABORT_IF_NULL(msg_err);
memcpy(msg_err, (char *)ptr + 7 + 6, msg_len);
*(msg_err + msg_len) = '\0';
spinlock_acquire(&router->lock);
char* old_errmsg = router->m_errmsg;
router->m_errmsg = msg_err;
router->m_errno = mysql_errno;
router->master_state = BLRM_SLAVE_STOPPED;
router->stats.n_binlog_errors++;
spinlock_release(&router->lock);
MXS_FREE(old_errmsg);
MXS_ERROR("Error packet in binlog stream.%s @ %lu.",
router->binlog_name, router->current_pos);
}
/**
* Populate a header structure for a replication message from a GWBUF structure with semi-sync enabled.
*
* @param pkt The incoming packet in a GWBUF chain
* @param hdr The packet header to populate
*/
static void
blr_extract_header_semisync(register uint8_t *ptr, register REP_HEADER *hdr)
{
hdr->payload_len = EXTRACT24(ptr);
hdr->seqno = ptr[3];
hdr->ok = ptr[4];
/* Data available after 2 bytes (the 2 semisync bytes) */
hdr->timestamp = EXTRACT32(&ptr[5 + 2]);
hdr->event_type = ptr[9 + 2];
hdr->serverid = EXTRACT32(&ptr[10 + 2]);
hdr->event_size = EXTRACT32(&ptr[14 + 2]);
hdr->next_pos = EXTRACT32(&ptr[18 + 2]);
hdr->flags = EXTRACT16(&ptr[22 + 2]);
}
/**
* Send a MySQL Replication Semi-Sync ACK to the master server.
*
* @param router The router instance.
* @param pos The binlog position for the ACK reply.
* @return 1 if the packect is sent, 0 on errors
*/
static int
blr_send_semisync_ack(ROUTER_INSTANCE *router, uint64_t pos)
{
int seqno = 0;
int semi_sync_flag = BLR_MASTER_SEMI_SYNC_INDICATOR;
GWBUF *buf;
int len;
uint8_t *data;
int binlog_file_len = strlen(router->binlog_name);
/* payload is: 1 byte semi-sync indicator + 8 bytes position + binlog name len */
len = 1 + 8 + binlog_file_len;
/* add network header to size */
if ((buf = gwbuf_alloc(len + 4)) == NULL)
{
return 0;
}
data = GWBUF_DATA(buf);
encode_value(&data[0], len, 24); // Payload length
data[3] = 0; // Sequence ID
data[4] = semi_sync_flag; // Semi-sync indicator
/**
* Next Bytes are: 8 bytes log position + len bin_log filename
*/
/* Position */
encode_value(&data[5], pos, 64);
/* Binlog filename */
memcpy((char *)&data[13], router->binlog_name, binlog_file_len);
router->master->func.write(router->master, buf);
return 1;
}
/**
* Check the master semisync capability.
*
* @param buf The GWBUF data with master reply.
* @return Semisync value: non available, enabled, disabled
*/
static int
blr_get_master_semisync(GWBUF *buf)
{
char *key;
char *val = NULL;
int master_semisync = MASTER_SEMISYNC_NOT_AVAILABLE;
key = blr_extract_column(buf, 1);
if (key && strlen(key))
{
val = blr_extract_column(buf, 2);
}
free(key);
if (val) {
if (strncasecmp(val, "ON", 4) == 0)
master_semisync = MASTER_SEMISYNC_ENABLED;
else
master_semisync = MASTER_SEMISYNC_DISABLED;
}
free(val);
return master_semisync;
}
/**
* Notify all the registered slaves to read from binlog file
* the new events just received
*
* @param router The router instance
*/
void blr_notify_all_slaves(ROUTER_INSTANCE *router)
{
ROUTER_SLAVE *slave;
int notified = 0;
spinlock_acquire(&router->lock);
slave = router->slaves;
while (slave)
{
/* Notify a slave that has CS_WAIT_DATA bit set */
if (slave->state == BLRS_DUMPING &&
blr_notify_waiting_slave(slave))
{
notified++;
}
slave = slave->next;
}
spinlock_release(&router->lock);
if (notified > 0)
{
MXS_DEBUG("Notified %d slaves about new data.", notified);
}
}
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