Markus Mäkelä cbc1e864d9 Use RFC 3986 compliant addresses in log messages
When log messages are written with both address and port information, IPv6
addresses can cause confusion if the normal address:port formatting is
used. The RFC 3986 suggests that all IPv6 addresses are expressed as a
bracket enclosed address optionally followed by the port that is separate
from the address by a colon.

In practice, the "all interfaces" address and port number 3306 can be
written in IPv4 numbers-and-dots notation as 0.0.0.0:3306 and in IPv6
notation as [::]:3306. Using the latter format in log messages keeps the
output consistent with all types of addresses.

The details of the standard can be found at the following addresses:

     https://www.ietf.org/rfc/rfc3986.txt

     https://www.rfc-editor.org/std/std66.txt
2017-03-31 14:12:58 +03:00

2589 lines
86 KiB
C

/*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/bsl11.
*
* 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 "blr.h"
#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 <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/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("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("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("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)
{
MXS_FREE(router->master_uuid);
router->master_uuid = val;
}
// 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 %u 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,
dcb_get_port(slave->dcb),
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,
dcb_get_port(slave->dcb));
}
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);
}
}