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MaxScale/server/modules/routing/binlog/blr_master.c
MassimilianoPinto f60254f626 Added MariaDB 10 transaction detection 
Added MariaDB 10 transaction detection
2015-08-26 17:32:45 +02:00

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/*
* This file is distributed as part of MaxScale. It is free
* software: you can redistribute it and/or modify it under the terms of the
* GNU General Public License as published by the Free Software Foundation,
* version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Copyright MariaDB Corporation Ab 2014-2015
*/
/**
* @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
*
* @endverbatim
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <service.h>
#include <server.h>
#include <router.h>
#include <atomic.h>
#include <session.h>
#include <blr.h>
#include <dcb.h>
#include <spinlock.h>
#include <housekeeper.h>
#include <buffer.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <skygw_types.h>
#include <skygw_utils.h>
#include <log_manager.h>
#include <rdtsc.h>
/* Temporary requirement for auth data */
#include <mysql_client_server_protocol.h>
extern int lm_enabled_logfiles_bitmask;
extern size_t log_ses_count[];
extern __thread log_info_t tls_log_info;
static GWBUF *blr_make_query(char *statement);
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);
void blr_distribute_binlog_record(ROUTER_INSTANCE *router, REP_HEADER *hdr, uint8_t *ptr);
static void *CreateMySQLAuthData(char *username, char *password, char *database);
void blr_extract_header(uint8_t *pkt, REP_HEADER *hdr);
static void blr_log_packet(logfile_id_t file, char *msg, uint8_t *ptr, int len);
void blr_master_close(ROUTER_INSTANCE *);
char *blr_extract_column(GWBUF *buf, int col);
void blr_cache_response(ROUTER_INSTANCE *router, char *response, GWBUF *buf);
void poll_fake_write_event(DCB *dcb);
GWBUF *blr_read_events_from_pos(ROUTER_INSTANCE *router, unsigned long long pos, REP_HEADER *hdr);
static void blr_check_last_master_event(void *inst);
extern int blr_check_heartbeat(ROUTER_INSTANCE *router);
extern char * blr_last_event_description(ROUTER_INSTANCE *router);
static int keepalive = 1;
/**
* 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) {
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"%s: Master Connect: Unexpected master state %s\n",
router->service->name, blrm_states[router->master_state])));
} else {
LOGIF(LM, (skygw_log_write_flush(LOGFILE_MESSAGE,
"%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;
/* Discard the queued residual data */
while (router->residual)
{
router->residual = gwbuf_consume(router->residual, GWBUF_LENGTH(router->residual));
}
router->residual = NULL;
spinlock_release(&router->lock);
if ((client = dcb_alloc(DCB_ROLE_INTERNAL)) == NULL)
{
LOGIF(LE, (skygw_log_write_flush(LOGFILE_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)
{
LOGIF(LE, (skygw_log_write_flush(LOGFILE_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;
if ((name = malloc(strlen(router->service->name)
+ strlen(" Master") + 1)) != NULL)
{
sprintf(name, "%s Master", router->service->name);
hktask_oneshot(name, blr_start_master, router,
BLR_MASTER_BACKOFF_TIME * router->retry_backoff++);
free(name);
}
if (router->retry_backoff > BLR_MAX_BACKOFF)
router->retry_backoff = BLR_MAX_BACKOFF;
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"Binlog router: failed to connect to master server '%s'",
router->service->dbref->server->unique_name)));
return;
}
router->master->remote = strdup(router->service->dbref->server->name);
LOGIF(LM,(skygw_log_write(
LOGFILE_MESSAGE,
"%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("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);
/* Discard the queued residual data */
while (router->residual)
{
router->residual = gwbuf_consume(router->residual, GWBUF_LENGTH(router->residual));
}
router->residual = NULL;
/* 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)
{
char *name;
router->master_state = BLRM_UNCONNECTED;
if ((name = malloc(strlen(router->service->name)
+ strlen(" Master")+1)) != NULL)
{
sprintf(name, "%s Master", router->service->name);
hktask_oneshot(name, blr_start_master, router,
BLR_MASTER_BACKOFF_TIME * router->retry_backoff++);
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;
}
/**
* 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;
if ((name = malloc(strlen(router->service->name)
+ strlen(" Master Recovery")+1)) != NULL)
{
sprintf(name, "%s Master Recovery", router->service->name);
hktask_oneshot(name, blr_start_master, router, 60);
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 < 0 || router->master_state > BLRM_MAXSTATE)
{
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"Invalid master state machine state (%d) for binlog router.",
router->master_state)));
gwbuf_consume(buf, gwbuf_length(buf));
spinlock_acquire(&router->lock);
if (router->reconnect_pending)
{
router->active_logs = 0;
spinlock_release(&router->lock);
atomic_add(&router->handling_threads, -1);
LOGIF(LE, (skygw_log_write(
LOGFILE_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.
*/
LOGIF(LE, (skygw_log_write(
LOGFILE_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 *)malloc(msg_len + 1);
// skip status message only as MYSQL_RESPONSE_ERR(buf) points to GWBUF_DATA(buf) +7
strncpy(msg_err, (char *)(MYSQL_ERROR_MSG(buf) + 6), msg_len);
/* NULL terminated error string */
*(msg_err+msg_len)='\0';
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"%s: Received error: %u, '%s' from master during '%s' phase "
"of the master state machine.",
router->service->name,
mysql_errno, msg_err,
blrm_states[router->master_state]
)));
gwbuf_consume(buf, gwbuf_length(buf));
spinlock_acquire(&router->lock);
/* set mysql errno */
router->m_errno = mysql_errno;
/* set mysql error message */
if (router->m_errmsg)
free(router->m_errmsg);
router->m_errmsg = msg_err;
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_consume(buf, GWBUF_LENGTH(buf));
buf = blr_make_query("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(str);
}
router->master_state = BLRM_HBPERIOD;
router->master->func.write(router->master, buf);
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("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("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)
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("SET @mariadb_slave_capability=4");
router->master_state = BLRM_MARIADB10;
} else {
buf = blr_make_query("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("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("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)
free(key);
/* set the master_uuid from master if not set by the option */
if (router->set_master_uuid == NULL)
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(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("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("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("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("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("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("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("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:
// Request a dump of the binlog file
buf = blr_make_binlog_dump(router);
router->master_state = BLRM_BINLOGDUMP;
router->master->func.write(router->master, buf);
LOGIF(LM,(skygw_log_write(
LOGFILE_MESSAGE,
"%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)));
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
*
* @param query The text of the query to send
*/
static GWBUF *
blr_make_query(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));
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;
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
encode_value(&data[12],
router->service->ports->port, 16); // Slave master port
encode_value(&data[14], 0, 32); // Replication rank
encode_value(&data[18], router->masterid, 32); // Master server-id
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 len = 0x1b;
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
encode_value(&data[9], 0, 16); // Flags
encode_value(&data[11],
router->serverid, 32); // Server-id of MaxScale
strncpy((char *)&data[15], router->binlog_name,
BINLOG_FNAMELEN); // binlog filename
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;
}
}
/**
* 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, *pdata;
REP_HEADER hdr;
unsigned int len = 0, reslen;
unsigned int pkt_length;
int no_residual = 1;
int preslen = -1;
int prev_length = -1;
int n_bufs = -1, pn_bufs = -1;
/*
* Prepend any residual buffer to the buffer chain we have
* been called with.
*/
if (router->residual)
{
pkt = gwbuf_append(router->residual, pkt);
router->residual = NULL;
no_residual = 0;
}
pkt_length = gwbuf_length(pkt);
/*
* 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 && pkt_length > 24)
{
reslen = GWBUF_LENGTH(pkt);
pdata = GWBUF_DATA(pkt);
if (reslen < 3) // Payload length straddles buffers
{
/* Get the length of the packet from the residual and new packet */
if (reslen >= 3)
{
len = EXTRACT24(pdata);
}
else if (reslen == 2)
{
len = EXTRACT16(pdata);
len |= (*(uint8_t *)GWBUF_DATA(pkt->next) << 16);
}
else if (reslen == 1)
{
len = *pdata;
len |= (EXTRACT16(GWBUF_DATA(pkt->next)) << 8);
}
len += 4; // Allow space for the header
}
else
{
len = EXTRACT24(pdata) + 4;
}
/* len is now the payload length for the packet we are working on */
if (reslen < len && pkt_length >= len)
{
/*
* The message is contained in more than the current
* buffer, however we have the complete messasge in
* this buffer and the chain of remaining buffers.
*
* Allocate a contiguous buffer for the binlog message
* and copy the complete message into this buffer.
*/
int remainder = len;
GWBUF *p = pkt;
if ((msg = malloc(len)) == NULL)
{
LOGIF(LE,(skygw_log_write(
LOGFILE_ERROR,
"Insufficient memory to buffer event "
"of %d bytes. Binlog %s @ %d.",
len, router->binlog_name,
router->current_pos)));
break;
}
n_bufs = 0;
ptr = msg;
while (p && remainder > 0)
{
int plen = GWBUF_LENGTH(p);
int n = (remainder > plen ? plen : remainder);
memcpy(ptr, GWBUF_DATA(p), n);
remainder -= n;
ptr += n;
if (remainder > 0)
p = p->next;
n_bufs++;
}
if (remainder)
{
LOGIF(LE,(skygw_log_write(
LOGFILE_ERROR,
"Expected entire message in buffer "
"chain, but failed to create complete "
"message as expected. %s @ %d",
router->binlog_name,
router->current_pos)));
free(msg);
msg = NULL;
break;
}
ptr = msg;
}
else if (reslen < len)
{
/*
* The message is not fully contained in the current
* and we do not have the complete message in the
* buffer chain. Therefore we must stop processing
* until we receive the next buffer.
*/
router->stats.n_residuals++;
LOGIF(LD,(skygw_log_write(
LOGFILE_DEBUG,
"Residual data left after %d records. %s @ %d",
router->stats.n_binlogs,
router->binlog_name, router->current_pos)));
break;
}
else
{
/*
* The message is fully contained in the current buffer
*/
ptr = pdata;
n_bufs = 1;
}
/*
* 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)
{
char *msg = "";
/* Packet is too small to be a binlog event */
if (ptr[4] == 0xfe) /* EOF Packet */
{
msg = "end of file";
}
else if (ptr[4] == 0xff) /* EOF Packet */
{
msg = "error";
}
LOGIF(LM,(skygw_log_write(
LOGFILE_MESSAGE,
"Non-event message (%s) from master.",
msg)));
}
else
{
router->stats.n_binlogs++;
router->stats.n_binlogs_ses++;
blr_extract_header(ptr, &hdr);
/* Sanity check */
if (hdr.ok == 0 && hdr.event_size != len - 5)
{
LOGIF(LE,(skygw_log_write(
LOGFILE_ERROR,
"Packet length is %d, but event size is %d, "
"binlog file %s position %d "
"reslen is %d and preslen is %d, "
"length of previous event %d. %s",
len, hdr.event_size,
router->binlog_name,
router->current_pos,
reslen, preslen, prev_length,
(prev_length == -1 ?
(no_residual ? "No residual data from previous call" : "Residual data from previous call") : "")
)));
blr_log_packet(LOGFILE_ERROR, "Packet:", ptr, len);
LOGIF(LE,(skygw_log_write(
LOGFILE_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)
{
free(msg);
msg = NULL;
}
break;
}
if (hdr.ok == 0)
{
int event_limit;
spinlock_acquire(&router->lock);
/* set mysql errno to 0 */
router->m_errno = 0;
/* Remove error message */
if (router->m_errmsg)
free(router->m_errmsg);
router->m_errmsg = NULL;
spinlock_release(&router->lock);
#ifdef SHOW_EVENTS
printf("blr: event type 0x%02x, flags 0x%04x, event size %d, event timestamp %lu\n", hdr.event_type, hdr.flags, hdr.event_size, hdr.timestamp);
#endif
/*
* First check that the checksum we calculate matches the
* checksum in the packet we received.
*/
if (router->master_chksum)
{
uint32_t chksum, pktsum;
chksum = crc32(0L, NULL, 0);
chksum = crc32(chksum, ptr + 5, hdr.event_size - 4);
pktsum = EXTRACT32(ptr + hdr.event_size + 1);
if (pktsum != chksum)
{
router->stats.n_badcrc++;
if (msg)
{
free(msg);
msg = NULL;
}
LOGIF(LE,(skygw_log_write(LOGFILE_ERROR,
"%s: Checksum error in event "
"from master, "
"binlog %s @ %d. "
"Closing master connection.",
router->service->name,
router->binlog_name,
router->current_pos)));
blr_master_close(router);
blr_master_delayed_connect(router);
return;
}
}
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
*/
if (router->trx_safe == 0 || (router->trx_safe && router->pending_transaction == 0)) {
/* no pending transaction: set current_pos to binlog_position */
spinlock_acquire(&router->binlog_lock);
router->binlog_position = 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+4+20, 64);
domainid = extract_field(ptr+4+20 + 8, 32);
flags = *(ptr+4+20 + 8 + 4);
if (flags == 0) {
if (router->pending_transaction > 0) {
LOGIF(LE,(skygw_log_write_flush(LOGFILE_ERROR,
"Error: a MariaDB 10 transaction "
"is already open "
"@ %lu (GTID %lu-%lu-%llu) and "
"a new one starts @ %lu",
router->binlog_position,
domainid, hdr.serverid, n_sequence,
router->current_pos)));
// An action should be taken here
}
spinlock_acquire(&router->lock);
router->pending_transaction = 1;
spinlock_release(&router->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[4+20+ 4 + 4];
var_block_len = ptr[4+20+ 4 + 4 + 1 + 2];
statement_len = len - (4+20+4+4+1+2+2+var_block_len+1+db_name_len);
statement_sql = calloc(1, statement_len+1);
strncpy(statement_sql, (char *)ptr+4+20+4+4+1+2+2+var_block_len+1+db_name_len, statement_len);
/* Check for BEGIN (it comes for START TRANSACTION too) */
if (strncmp(statement_sql, "BEGIN", 5) == 0) {
if (router->pending_transaction > 0) {
LOGIF(LE,(skygw_log_write_flush(LOGFILE_ERROR,
"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
}
spinlock_acquire(&router->lock);
router->pending_transaction = 1;
spinlock_release(&router->lock);
}
/* Check for COMMIT in non transactional store engines */
if (strncmp(statement_sql, "COMMIT", 6) == 0) {
spinlock_acquire(&router->lock);
router->pending_transaction = 2;
spinlock_release(&router->lock);
}
free(statement_sql);
}
/* Check for COMMIT in Transactional engines, i.e InnoDB */
if(hdr.event_type == XID_EVENT) {
if (router->pending_transaction) {
spinlock_acquire(&router->lock);
router->pending_transaction = 3;
spinlock_release(&router->lock);
}
}
}
event_limit = router->mariadb10_compat ? MAX_EVENT_TYPE_MARIADB10 : MAX_EVENT_TYPE;
if (hdr.event_type >= 0 && 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
LOGIF(LD,(skygw_log_write(LOGFILE_DEBUG,
"Replication fake event. "
"Binlog %s @ %d.",
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 = malloc(hdr.event_size);
if (new_fde)
{
memcpy(new_fde, ptr + 5, hdr.event_size);
if (router->saved_master.fde_event)
free(router->saved_master.fde_event);
router->saved_master.fde_event = new_fde;
router->saved_master.fde_len = new_fde_len;
}
else
{
LOGIF(LE,(skygw_log_write(LOGFILE_ERROR,
"%s: Received a format description "
"event that MaxScale was unable to "
"record. Event length is %d.",
router->service->name,
hdr.event_size)));
blr_log_packet(LOGFILE_ERROR,
"Format Description Event:", ptr, len);
}
}
}
else
{
if (hdr.event_type == HEARTBEAT_EVENT)
{
#ifdef SHOW_EVENTS
printf("Replication heartbeat\n");
#endif
LOGIF(LD,(skygw_log_write(
LOGFILE_DEBUG,
"Replication heartbeat. "
"Binlog %s @ %d.",
router->binlog_name,
router->current_pos)));
router->stats.n_heartbeats++;
}
else if (hdr.flags != LOG_EVENT_ARTIFICIAL_F)
{
ptr = ptr + 5; // We don't put the first byte of the payload
// into the binlog file
if (hdr.event_type == ROTATE_EVENT)
router->rotating = 1;
/* current event is being written to disk file */
if (blr_write_binlog_record(router, &hdr, ptr) == 0)
{
/*
* Failed to write to the
* binlog file, destroy the
* buffer chain and close the
* connection with the master
*/
while ((pkt = gwbuf_consume(pkt,
GWBUF_LENGTH(pkt))) != NULL);
blr_master_close(router);
blr_master_delayed_connect(router);
return;
}
/* Check for rotete event */
if (hdr.event_type == ROTATE_EVENT)
{
if (!blr_rotate_event(router, ptr, &hdr))
{
/*
* Failed to write to the
* binlog file, destroy the
* buffer chain and close the
* connection with the master
*/
while ((pkt = gwbuf_consume(pkt,
GWBUF_LENGTH(pkt))) != NULL);
blr_master_close(router);
blr_master_delayed_connect(router);
return;
}
}
/**
* Distributing binlog events to slaves
* may depend on pending transaction
*/
if (router->trx_safe == 0 || (router->trx_safe && router->pending_transaction == 0)) {
spinlock_acquire(&router->binlog_lock);
router->binlog_position = router->current_pos;
spinlock_release(&router->binlog_lock);
/* Now distribute events */
blr_distribute_binlog_record(router, &hdr, ptr);
} else {
/**
* If transaction is closed:
*
* 1) read current binlog starting
* from router->binlog_position
*
* 2) distribute read event
*
* 3) set router->binlog_position to
* router->current_pos
*
*/
if (router->pending_transaction > 1) {
unsigned long long pos;
GWBUF *record;
uint8_t *raw_data;
REP_HEADER new_hdr;
int i=0;
spinlock_acquire(&router->binlog_lock);
pos = router->binlog_position;
spinlock_release(&router->binlog_lock);
while ((record = blr_read_events_from_pos(router, pos, &new_hdr)) != NULL) {
i++;
raw_data = GWBUF_DATA(record);
/* distribute event */
blr_distribute_binlog_record(router, &new_hdr, raw_data);
spinlock_acquire(&router->binlog_lock);
pos = new_hdr.next_pos;
spinlock_release(&router->binlog_lock);
gwbuf_free(record);
}
spinlock_acquire(&router->lock);
router->binlog_position = router->current_pos;
router->pending_transaction = 0;
spinlock_release(&router->lock);
}
}
}
else
{
router->stats.n_artificial++;
LOGIF(LD,(skygw_log_write(
LOGFILE_DEBUG,
"Artificial event not written "
"to disk or distributed. "
"Type 0x%x, Length %d, Binlog "
"%s @ %d.",
hdr.event_type,
hdr.event_size,
router->binlog_name,
router->current_pos)));
ptr += 5;
if (hdr.event_type == ROTATE_EVENT)
{
router->rotating = 1;
if (!blr_rotate_event(router, ptr, &hdr))
{
/*
* Failed to write to the
* binlog file, destroy the
* buffer chain and close the
* connection with the master
*/
while ((pkt = gwbuf_consume(pkt,
GWBUF_LENGTH(pkt))) != NULL);
blr_master_close(router);
blr_master_delayed_connect(router);
return;
}
}
}
}
}
else
{
unsigned long mysql_errno = extract_field(ptr+5, 16);
char *msg_err = NULL;
int msg_len=0;
msg_err = (char *)ptr+7+6; // err msg starts after 7 bytes + 6 of status message
msg_len = len-7-6; // msg len is decreased by 7 and 6
msg_err = (char *)malloc(msg_len + 1);
strncpy(msg_err, (char *)ptr+7+6, msg_len);
/* NULL terminate error string */
*(msg_err+msg_len)='\0';
spinlock_acquire(&router->lock);
/* set mysql_errno */
router->m_errno = mysql_errno;
/* set io error message */
if (router->m_errmsg)
free(router->m_errmsg);
router->m_errmsg = msg_err;
/* Force stopped state */
router->master_state = BLRM_SLAVE_STOPPED;
spinlock_release(&router->lock);
LOGIF(LE,(skygw_log_write(LOGFILE_ERROR,
"Error packet in binlog stream.%s @ %d.",
router->binlog_name,
router->current_pos)));
router->stats.n_binlog_errors++;
}
}
if (msg)
{
free(msg);
msg = NULL;
}
prev_length = len;
while (len > 0)
{
int n, plen;
plen = GWBUF_LENGTH(pkt);
n = (plen < len ? plen : len);
pkt = gwbuf_consume(pkt, n);
len -= n;
pkt_length -= n;
}
preslen = reslen;
pn_bufs = n_bufs;
}
/*
* Check if we have a residual, part binlog message to deal with.
* Just simply store the GWBUF for next time
*/
if (pkt)
{
router->residual = pkt;
ss_dassert(pkt_length != 0);
}
else
{
ss_dassert(pkt_length == 0);
}
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
*/
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);
if (strncmp(router->binlog_name, file, slen) != 0)
{
router->stats.n_rotates++;
if (blr_file_rotate(router, file, pos) == 0)
{
router->rotating = 0;
return 0;
}
}
router->rotating = 0;
return 1;
}
/**
* 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)
{
LOGIF(LE,(skygw_log_write(
LOGFILE_ERROR,
"You must specify both username and password for the binlog router.\n")));
return NULL;
}
if ((auth_info = calloc(1, sizeof(MYSQL_session))) == NULL)
return NULL;
strncpy(auth_info->user, username,MYSQL_USER_MAXLEN);
strncpy(auth_info->db, database,MYSQL_DATABASE_MAXLEN);
gw_sha1_str((const uint8_t *)password, strlen(password), auth_info->client_sha1);
return auth_info;
}
/**
* Distribute the binlog record we have just received to all the registered slaves.
*
* @param router The router instance
* @param hdr The replication event header
* @param ptr The raw replication event data
*/
void
blr_distribute_binlog_record(ROUTER_INSTANCE *router, REP_HEADER *hdr, uint8_t *ptr)
{
GWBUF *pkt;
uint8_t *buf;
ROUTER_SLAVE *slave, *nextslave;
int action;
spinlock_acquire(&router->lock);
slave = router->slaves;
while (slave)
{
if (slave->state != BLRS_DUMPING)
{
slave = slave->next;
continue;
}
spinlock_acquire(&slave->catch_lock);
if ((slave->cstate & (CS_UPTODATE|CS_BUSY)) == CS_UPTODATE)
{
/*
* This slave is reporting it is to date with the binlog of the
* master running on this slave.
* It has no thread running currently that is sending binlog
* events.
*/
action = 1;
slave->cstate |= CS_BUSY;
}
else if ((slave->cstate & (CS_UPTODATE|CS_BUSY)) == (CS_UPTODATE|CS_BUSY))
{
/*
* The slave is up to date with the binlog and a process is
* running on this slave to send binlog events.
*/
slave->overrun = 1;
action = 2;
}
else if ((slave->cstate & CS_UPTODATE) == 0)
{
/* Slave is in catchup mode */
action = 3;
}
slave->stats.n_actions[action-1]++;
spinlock_release(&slave->catch_lock);
if (action == 1)
{
if (slave->binlog_pos <= router->last_written &&
(strcmp(slave->binlogfile, router->binlog_name) == 0 ||
(hdr->event_type == ROTATE_EVENT &&
strcmp(slave->binlogfile, router->prevbinlog))))
{
/*
* The slave should be up to date, check that the binlog
* position matches the event we have to distribute or
* this is a rotate event. Send the event directly from
* memory to the slave.
*/
slave->lastEventTimestamp = hdr->timestamp;
pkt = gwbuf_alloc(hdr->event_size + 5);
buf = GWBUF_DATA(pkt);
encode_value(buf, hdr->event_size + 1, 24);
buf += 3;
*buf++ = slave->seqno++;
*buf++ = 0; // OK
memcpy(buf, ptr, hdr->event_size);
if (hdr->event_type == ROTATE_EVENT)
{
blr_slave_rotate(router, slave, ptr);
}
slave->stats.n_bytes += gwbuf_length(pkt);
slave->stats.n_events++;
slave->dcb->func.write(slave->dcb, pkt);
if (hdr->event_type != ROTATE_EVENT)
{
slave->binlog_pos = hdr->next_pos;
}
spinlock_acquire(&slave->catch_lock);
if (slave->overrun)
{
slave->stats.n_overrun++;
slave->overrun = 0;
poll_fake_write_event(slave->dcb);
}
else
{
slave->cstate &= ~CS_BUSY;
}
spinlock_release(&slave->catch_lock);
}
else if (slave->binlog_pos == hdr->next_pos
&& strcmp(slave->binlogfile, router->binlog_name) == 0)
{
/*
* Slave has already read record from file, no
* need to distrbute this event
*/
spinlock_acquire(&slave->catch_lock);
slave->cstate &= ~CS_BUSY;
spinlock_release(&slave->catch_lock);
}
else if ((slave->binlog_pos > hdr->next_pos - hdr->event_size)
&& strcmp(slave->binlogfile, router->binlog_name) == 0)
{
/*
* The slave is ahead of the master, this should never
* happen. Force the slave to catchup mode in order to
* try to resolve the issue.
*/
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"Slave %d is ahead of expected position %s@%d. "
"Expected position %d",
slave->serverid, slave->binlogfile,
(unsigned long)slave->binlog_pos,
hdr->next_pos - hdr->event_size)));
spinlock_acquire(&slave->catch_lock);
slave->cstate &= ~(CS_UPTODATE|CS_BUSY);
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
else
{
/*
* The slave is not at the position it should be. Force it into
* catchup mode rather than send this event.
*/
spinlock_acquire(&slave->catch_lock);
slave->cstate &= ~(CS_UPTODATE|CS_BUSY);
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
}
else if (action == 3)
{
/* Slave is not up to date
* Check if it is either expecting a callback or
* is busy processing a callback
*/
spinlock_acquire(&slave->catch_lock);
if ((slave->cstate & (CS_EXPECTCB|CS_BUSY)) == 0)
{
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
else
spinlock_release(&slave->catch_lock);
}
slave = slave->next;
}
spinlock_release(&router->lock);
}
/**
* Write a raw event (the first 40 bytes at most) to a log file
*
* @param file The logfile to write to
* @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(logfile_id_t file, 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)
skygw_log_write_flush(file, "%s...", buf);
else
skygw_log_write_flush(file, "%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;
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;
while (--col > 0)
{
collen = *ptr++;
ptr += collen;
}
collen = *ptr++;
if ((rval = 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 end_pos = 0;
struct stat statb;
uint8_t hdbuf[19];
uint8_t *data;
GWBUF *result;
int n;
/* Get current binnlog position */
end_pos = router->current_pos;
/* end of file reached, we're done */
if (pos == end_pos) {
return NULL;
}
/* error */
if (pos > end_pos)
{
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"Error: Reading saved events, the specified pos %lu "
"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:
LOGIF(LD, (skygw_log_write(LOGFILE_DEBUG,
"Reading saved events: reached end of binlog file at %d.", pos)));
break;
case -1:
{
char err_msg[BLRM_STRERROR_R_MSG_SIZE+1] = "";
strerror_r(errno, err_msg, BLRM_STRERROR_R_MSG_SIZE);
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: failed to read binlog "
"file %s at position %d"
" (%s).", router->binlog_name,
pos, err_msg)));
if (errno == EBADF)
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: bad file descriptor for file %s"
", descriptor %d.",
router->binlog_name, router->binlog_fd)));
break;
}
default:
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: short read when reading the header. "
"Expected 19 bytes but got %d bytes. "
"Binlog file is %s, position %d",
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]);
/* Add MariaDB 10 checks */
if (hdr->event_type > MAX_EVENT_TYPE)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: invalid event type 0x%x. "
"Binlog file is %s, position %d",
hdr->event_type,
router->binlog_name, pos)));
return NULL;
}
if ((result = gwbuf_alloc(hdr->event_size)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: failed to allocate memory for binlog entry, "
"size %d at %d.",
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[BLRM_STRERROR_R_MSG_SIZE+1] = "";
strerror_r(errno, err_msg, BLRM_STRERROR_R_MSG_SIZE);
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: the event at %ld in %s. "
"%s, expected %d bytes.",
pos, router->binlog_name,
err_msg, hdr->event_size - 19)));
} else {
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: short read when reading "
"the event at %ld in %s. "
"Expected %d bytes got %d bytes.",
pos, router->binlog_name, hdr->event_size - 19, n)));
if (end_pos - pos < hdr->event_size)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Error: Reading saved events: binlog event "
"is close to the end of the binlog file, "
"current file size is %u.", 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)
strncpy(router->prevbinlog, router->binlog_name, BINLOG_FNAMELEN);
if (router->client) {
if (router->client->fd != -1 && router->client->state == DCB_STATE_POLLING) {
dcb_close(router->client);
router->client = NULL;
}
}
/* Discard the queued residual data */
while (router->residual)
{
router->residual = gwbuf_consume(router->residual, GWBUF_LENGTH(router->residual));
}
router->residual = NULL;
/* Now it is safe to unleash other threads on this router instance */
router->reconnect_pending = 0;
router->active_logs = 0;
router->master_state = BLRM_UNCONNECTED;
spinlock_release(&router->lock);
blr_start_master(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)) {
LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
"ERROR: No event received from master %s:%d in heartbeat period (%d 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;
}
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