MassimilianoPinto 895989446d MXS-224: Added SQL commands to the log message at slave disconnect time
MXS-224: Added SQL commands to the log message at slave disconnect time
2015-08-19 12:04:15 +02:00

2125 lines
64 KiB
C

/*
* 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
*/
/**
* @file blr_slave.c - contains code for the router to slave 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
* 14/04/2014 Mark Riddoch Initial implementation
* 18/02/2015 Massimiliano Pinto Addition of DISCONNECT ALL and DISCONNECT SERVER server_id
* 18/03/2015 Markus Makela Better detection of CRC32 | NONE checksum
* 19/03/2015 Massimiliano Pinto Addition of basic MariaDB 10 compatibility support
* 07/05/2015 Massimiliano Pinto Added MariaDB 10 Compatibility
* 11/05/2015 Massimiliano Pinto Only MariaDB 10 Slaves can register to binlog router with a MariaDB 10 Master
*
* @endverbatim
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <service.h>
#include <server.h>
#include <router.h>
#include <atomic.h>
#include <spinlock.h>
#include <blr.h>
#include <dcb.h>
#include <spinlock.h>
#include <housekeeper.h>
#include <skygw_types.h>
#include <skygw_utils.h>
#include <log_manager.h>
#include <version.h>
static void encode_value(unsigned char *data, unsigned int value, int len);
static int blr_slave_query(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *queue);
static int blr_slave_replay(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *master);
static void blr_slave_send_error(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, char *msg);
static int blr_slave_send_timestamp(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_register(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *queue);
static int blr_slave_binlog_dump(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *queue);
int blr_slave_catchup(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, bool large);
uint8_t *blr_build_header(GWBUF *pkt, REP_HEADER *hdr);
int blr_slave_callback(DCB *dcb, DCB_REASON reason, void *data);
static int blr_slave_fake_rotate(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static void blr_slave_send_fde(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_send_maxscale_version(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_send_server_id(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_send_maxscale_variables(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_send_master_status(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_send_slave_status(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_send_slave_hosts(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_send_fieldcount(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, int count);
static int blr_slave_send_columndef(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, char *name, int type, int len, uint8_t seqno);
static int blr_slave_send_eof(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, int seqno);
static int blr_slave_send_disconnected_server(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, int server_id, int found);
static int blr_slave_disconnect_all(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave);
static int blr_slave_disconnect_server(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, int server_id);
static int blr_slave_send_ok(ROUTER_INSTANCE* router, ROUTER_SLAVE* slave);
void poll_fake_write_event(DCB *dcb);
extern int lm_enabled_logfiles_bitmask;
extern size_t log_ses_count[];
extern __thread log_info_t tls_log_info;
/**
* Process a request packet from the slave server.
*
* The router can handle a limited subset of requests from the slave, these
* include a subset of general SQL queries, a slave registeration command and
* the binlog dump command.
*
* The strategy for responding to these commands is to use caches responses
* for the the same commands that have previously been made to the real master
* if this is possible, if it is not then the router itself will synthesize a
* response.
*
* @param router The router instance this defines the master for this replication chain
* @param slave The slave specific data
* @param queue The incoming request packet
*/
int
blr_slave_request(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *queue)
{
if (slave->state < 0 || slave->state > BLRS_MAXSTATE)
{
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "Invalid slave state machine state (%d) for binlog router.",
slave->state)));
gwbuf_consume(queue, gwbuf_length(queue));
return 0;
}
slave->stats.n_requests++;
switch (MYSQL_COMMAND(queue))
{
case COM_QUERY:
slave->stats.n_queries++;
return blr_slave_query(router, slave, queue);
break;
case COM_REGISTER_SLAVE:
/*
* If Master is MariaDB10 don't allow registration from
* MariaDB/Mysql 5 Slaves
*/
if (router->mariadb10_compat && !slave->mariadb10_compat) {
slave->state = BLRS_ERRORED;
blr_send_custom_error(slave->dcb, 1, 0,
"MariaDB 10 Slave is required for Slave registration");
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"%s: Slave %s: a MariaDB 10 Slave is required for Slave registration",
router->service->name,
slave->dcb->remote)));
dcb_close(slave->dcb);
return 1;
} else {
/* Master and Slave version OK: continue with slave registration */
return blr_slave_register(router, slave, queue);
}
break;
case COM_BINLOG_DUMP:
return blr_slave_binlog_dump(router, slave, queue);
break;
case COM_STATISTICS:
return blr_statistics(router, slave, queue);
break;
case COM_PING:
return blr_ping(router, slave, queue);
break;
case COM_QUIT:
LOGIF(LD, (skygw_log_write(LOGFILE_DEBUG,
"COM_QUIT received from slave with server_id %d",
slave->serverid)));
break;
default:
blr_send_custom_error(slave->dcb, 1, 0,
"MySQL command not supported by the binlog router.");
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"Unexpected MySQL Command (%d) received from slave",
MYSQL_COMMAND(queue))));
break;
}
return 0;
}
/**
* Handle a query from the slave. This is expected to be one of the "standard"
* queries we expect as part of the registraton process. Most of these can
* be dealt with by replying the stored responses we got from the master
* when MaxScale registered as a slave. The exception to the rule is the
* request to obtain the current timestamp value of the server.
*
* The original set added for the registration process has been enhanced in
* order to support some commands that are useful for monitoring the binlog
* router.
*
* Eight select statements are currently supported:
* SELECT UNIX_TIMESTAMP();
* SELECT @master_binlog_checksum
* SELECT @@GLOBAL.GTID_MODE
* SELECT VERSION()
* SELECT 1
* SELECT @@version_comment limit 1
* SELECT @@hostname
* SELECT @@max_allowed_packet
* SELECT @@maxscale_version
* SELECT @@server_id
*
* Five show commands are supported:
* SHOW VARIABLES LIKE 'SERVER_ID'
* SHOW VARIABLES LIKE 'SERVER_UUID'
* SHOW VARIABLES LIKE 'MAXSCALE%
* SHOW MASTER STATUS
* SHOW SLAVE HOSTS
*
* Five set commands are supported:
* SET @master_binlog_checksum = @@global.binlog_checksum
* SET @master_heartbeat_period=...
* SET @slave_slave_uuid=...
* SET NAMES latin1
* SET NAMES utf8
*
* @param router The router instance this defines the master for this replication chain
* @param slave The slave specific data
* @param queue The incoming request packet
* @return Non-zero if data has been sent
*/
static int
blr_slave_query(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *queue)
{
char *qtext, *query_text;
char *sep = " ,=";
char *word, *brkb;
int query_len;
qtext = GWBUF_DATA(queue);
query_len = extract_field((uint8_t *)qtext, 24) - 1;
qtext += 5; // Skip header and first byte of the payload
query_text = strndup(qtext, query_len);
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE, "Execute statement from the slave '%s'", query_text)));
/*
* Implement a very rudimental "parsing" of the query text by extarcting the
* words from the statement and matchng them against the subset of queries we
* are expecting from the slave. We already have responses to these commands,
* except for the select of UNIX_TIMESTAMP(), that we have saved from MaxScale's
* own interaction with the real master. We simply replay these saved responses
* to the slave.
*/
if ((word = strtok_r(query_text, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR, "%s: Incomplete query.",
router->service->name)));
}
else if (strcasecmp(word, "SELECT") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR, "%s: Incomplete select query.",
router->service->name)));
}
else if (strcasecmp(word, "UNIX_TIMESTAMP()") == 0)
{
free(query_text);
return blr_slave_send_timestamp(router, slave);
}
else if (strcasecmp(word, "@master_binlog_checksum") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.chksum2);
}
else if (strcasecmp(word, "@@GLOBAL.GTID_MODE") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.gtid_mode);
}
else if (strcasecmp(word, "1") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.select1);
}
else if (strcasecmp(word, "VERSION()") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.selectver);
}
else if (strcasecmp(word, "@@version_comment") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.selectvercom);
}
else if (strcasecmp(word, "@@hostname") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.selecthostname);
}
else if (strcasecmp(word, "@@max_allowed_packet") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.map);
}
else if (strcasecmp(word, "@@maxscale_version") == 0)
{
free(query_text);
return blr_slave_send_maxscale_version(router, slave);
}
else if (strcasecmp(word, "@@server_id") == 0)
{
free(query_text);
return blr_slave_send_server_id(router, slave);
}
}
else if (strcasecmp(word, "SHOW") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR, "%s: Incomplete show query.",
router->service->name)));
}
else if (strcasecmp(word, "VARIABLES") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"%s: Expected LIKE clause in SHOW VARIABLES.",
router->service->name)));
}
else if (strcasecmp(word, "LIKE") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"%s: Missing LIKE clause in SHOW VARIABLES.",
router->service->name)));
}
else if (strcasecmp(word, "'SERVER_ID'") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.server_id);
}
else if (strcasecmp(word, "'SERVER_UUID'") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.uuid);
}
else if (strcasecmp(word, "'MAXSCALE%'") == 0)
{
free(query_text);
return blr_slave_send_maxscale_variables(router, slave);
}
}
}
else if (strcasecmp(word, "MASTER") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"%s: Expected SHOW MASTER STATUS command",
router->service->name)));
}
else if (strcasecmp(word, "STATUS") == 0)
{
free(query_text);
return blr_slave_send_master_status(router, slave);
}
}
else if (strcasecmp(word, "SLAVE") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"%s: Expected SHOW MASTER STATUS command",
router->service->name)));
}
else if (strcasecmp(word, "STATUS") == 0)
{
free(query_text);
return blr_slave_send_slave_status(router, slave);
}
else if (strcasecmp(word, "HOSTS") == 0)
{
free(query_text);
return blr_slave_send_slave_hosts(router, slave);
}
}
}
else if (strcasecmp(query_text, "SET") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR, "%s: Incomplete set command.",
router->service->name)));
}
else if (strcasecmp(word, "@master_heartbeat_period") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.heartbeat);
}
else if (strcasecmp(word, "@mariadb_slave_capability") == 0)
{
/* mariadb10 compatibility is set for the slave */
slave->mariadb10_compat=true;
free(query_text);
if (router->mariadb10_compat) {
return blr_slave_replay(router, slave, router->saved_master.mariadb10);
} else {
return blr_slave_send_ok(router, slave);
}
}
else if (strcasecmp(word, "@master_binlog_checksum") == 0)
{
word = strtok_r(NULL, sep, &brkb);
if (word && (strcasecmp(word, "'none'") == 0))
slave->nocrc = 1;
else if (word && (strcasecmp(word, "@@global.binlog_checksum") == 0))
slave->nocrc = !router->master_chksum;
else
slave->nocrc = 0;
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.chksum1);
}
else if (strcasecmp(word, "@slave_uuid") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) != NULL)
slave->uuid = strdup(word);
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.setslaveuuid);
}
else if (strcasecmp(word, "NAMES") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR, "%s: Truncated SET NAMES command.",
router->service->name)));
}
else if (strcasecmp(word, "latin1") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.setnames);
}
else if (strcasecmp(word, "utf8") == 0)
{
free(query_text);
return blr_slave_replay(router, slave, router->saved_master.utf8);
}
}
}
else if (strcasecmp(query_text, "DISCONNECT") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR, "%s: Incomplete DISCONNECT command.",
router->service->name)));
}
else if (strcasecmp(word, "ALL") == 0)
{
free(query_text);
return blr_slave_disconnect_all(router, slave);
}
else if (strcasecmp(word, "SERVER") == 0)
{
if ((word = strtok_r(NULL, sep, &brkb)) == NULL)
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"%s: Expected DISCONNECT SERVER $server_id",
router->service->name)));
} else {
free(query_text);
return blr_slave_disconnect_server(router, slave, atoi(word));
}
}
}
free(query_text);
query_text = strndup(qtext, query_len);
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "Unexpected query from slave %s: %s", slave->dcb->remote, query_text)));
free(query_text);
blr_slave_send_error(router, slave, "Unexpected SQL query received from slave.");
return 1;
}
/**
* Send a reply to a command we have received from the slave. The reply itself
* is merely a copy of a previous message we received from the master when we
* registered as a slave. Hence we just replay this saved reply.
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @param master The saved master response
* @return Non-zero if data was sent
*/
static int
blr_slave_replay(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *master)
{
GWBUF *clone;
if (!master)
return 0;
if ((clone = gwbuf_clone(master)) != NULL)
{
return slave->dcb->func.write(slave->dcb, clone);
}
else
{
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Failed to clone server response to send to slave.")));
return 0;
}
}
/**
* Construct an error response
*
* @param router The router instance
* @param slave The slave server instance
* @param msg The error message to send
*/
static void
blr_slave_send_error(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, char *msg)
{
GWBUF *pkt;
unsigned char *data;
int len;
if ((pkt = gwbuf_alloc(strlen(msg) + 13)) == NULL)
return;
data = GWBUF_DATA(pkt);
len = strlen(msg) + 9;
encode_value(&data[0], len, 24); // Payload length
data[3] = 1; // Sequence id
// Payload
data[4] = 0xff; // Error indicator
data[5] = 0; // Error Code
data[6] = 0; // Error Code
strncpy((char *)&data[7], "#00000", 6);
memcpy(&data[13], msg, strlen(msg)); // Error Message
slave->dcb->func.write(slave->dcb, pkt);
}
/*
* Some standard packets that have been captured from a network trace of server
* interactions. These packets are the schema definition sent in response to
* a SELECT UNIX_TIMESTAMP() statement and the EOF packet that marks the end
* of transmission of the result set.
*/
static uint8_t timestamp_def[] = {
0x01, 0x00, 0x00, 0x01, 0x01, 0x26, 0x00, 0x00, 0x02, 0x03, 0x64, 0x65, 0x66, 0x00, 0x00, 0x00,
0x10, 0x55, 0x4e, 0x49, 0x58, 0x5f, 0x54, 0x49, 0x4d, 0x45, 0x53, 0x54, 0x41, 0x4d, 0x50, 0x28,
0x29, 0x00, 0x0c, 0x3f, 0x00, 0x0b, 0x00, 0x00, 0x00, 0x08, 0x81, 0x00, 0x00, 0x00, 0x00, 0x05,
0x00, 0x00, 0x03, 0xfe, 0x00, 0x00, 0x02, 0x00
};
static uint8_t timestamp_eof[] = { 0x05, 0x00, 0x00, 0x05, 0xfe, 0x00, 0x00, 0x02, 0x00 };
/**
* Send a response to a "SELECT UNIX_TIMESTAMP()" request. This differs from the other
* requests since we do not save a copy of the original interaction with the master
* and simply replay it. We want to always send the current time. We have stored a typcial
* response, which gives us the schema information normally returned. This is sent to the
* client and then we add a dynamic part that will insert the current timestamp data.
* Finally we send a preprepaed EOF packet to end the response stream.
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent
*/
static int
blr_slave_send_timestamp(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
GWBUF *pkt;
char timestamp[20];
uint8_t *ptr;
int len, ts_len;
sprintf(timestamp, "%ld", time(0));
ts_len = strlen(timestamp);
len = sizeof(timestamp_def) + sizeof(timestamp_eof) + 5 + ts_len;
if ((pkt = gwbuf_alloc(len)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
memcpy(ptr, timestamp_def, sizeof(timestamp_def)); // Fixed preamble
ptr += sizeof(timestamp_def);
encode_value(ptr, ts_len + 1, 24); // Add length of data packet
ptr += 3;
*ptr++ = 0x04; // Sequence number in response
*ptr++ = ts_len; // Length of result string
strncpy((char *)ptr, timestamp, ts_len); // Result string
ptr += ts_len;
memcpy(ptr, timestamp_eof, sizeof(timestamp_eof)); // EOF packet to terminate result
return slave->dcb->func.write(slave->dcb, pkt);
}
/**
* Send a response the the SQL command SELECT @@MAXSCALE_VERSION
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent
*/
static int
blr_slave_send_maxscale_version(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
GWBUF *pkt;
char version[40];
uint8_t *ptr;
int len, vers_len;
sprintf(version, "%s", MAXSCALE_VERSION);
vers_len = strlen(version);
blr_slave_send_fieldcount(router, slave, 1);
blr_slave_send_columndef(router, slave, "MAXSCALE_VERSION", 0xf, vers_len, 2);
blr_slave_send_eof(router, slave, 3);
len = 5 + vers_len;
if ((pkt = gwbuf_alloc(len)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, vers_len + 1, 24); // Add length of data packet
ptr += 3;
*ptr++ = 0x04; // Sequence number in response
*ptr++ = vers_len; // Length of result string
strncpy((char *)ptr, version, vers_len); // Result string
ptr += vers_len;
slave->dcb->func.write(slave->dcb, pkt);
return blr_slave_send_eof(router, slave, 5);
}
/**
* Send a response the the SQL command SELECT @@server_id
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent
*/
static int
blr_slave_send_server_id(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
GWBUF *pkt;
char server_id[40];
uint8_t *ptr;
int len, id_len;
sprintf(server_id, "%d", router->masterid);
id_len = strlen(server_id);
blr_slave_send_fieldcount(router, slave, 1);
blr_slave_send_columndef(router, slave, "SERVER_ID", 0xf, id_len, 2);
blr_slave_send_eof(router, slave, 3);
len = 5 + id_len;
if ((pkt = gwbuf_alloc(len)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, id_len + 1, 24); // Add length of data packet
ptr += 3;
*ptr++ = 0x04; // Sequence number in response
*ptr++ = id_len; // Length of result string
strncpy((char *)ptr, server_id, id_len); // Result string
ptr += id_len;
slave->dcb->func.write(slave->dcb, pkt);
return blr_slave_send_eof(router, slave, 5);
}
/**
* Send the response to the SQL command "SHOW VARIABLES LIKE 'MAXSCALE%'
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent
*/
static int
blr_slave_send_maxscale_variables(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
GWBUF *pkt;
char name[40];
char version[40];
uint8_t *ptr;
int len, vers_len, seqno = 2;
blr_slave_send_fieldcount(router, slave, 2);
blr_slave_send_columndef(router, slave, "Variable_name", 0xf, 40, seqno++);
blr_slave_send_columndef(router, slave, "value", 0xf, 40, seqno++);
blr_slave_send_eof(router, slave, seqno++);
sprintf(version, "%s", MAXSCALE_VERSION);
vers_len = strlen(version);
strcpy(name, "MAXSCALE_VERSION");
len = 5 + vers_len + strlen(name) + 1;
if ((pkt = gwbuf_alloc(len)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, vers_len + 2 + strlen(name), 24); // Add length of data packet
ptr += 3;
*ptr++ = seqno++; // Sequence number in response
*ptr++ = strlen(name); // Length of result string
strncpy((char *)ptr, name, strlen(name)); // Result string
ptr += strlen(name);
*ptr++ = vers_len; // Length of result string
strncpy((char *)ptr, version, vers_len); // Result string
ptr += vers_len;
slave->dcb->func.write(slave->dcb, pkt);
return blr_slave_send_eof(router, slave, seqno++);
}
/**
* Send the response to the SQL command "SHOW MASTER STATUS"
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent
*/
static int
blr_slave_send_master_status(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
GWBUF *pkt;
char file[40];
char position[40];
uint8_t *ptr;
int len, file_len;
blr_slave_send_fieldcount(router, slave, 5);
blr_slave_send_columndef(router, slave, "File", 0xf, 40, 2);
blr_slave_send_columndef(router, slave, "Position", 0xf, 40, 3);
blr_slave_send_columndef(router, slave, "Binlog_Do_DB", 0xf, 40, 4);
blr_slave_send_columndef(router, slave, "Binlog_Ignore_DB", 0xf, 40, 5);
blr_slave_send_columndef(router, slave, "Execute_Gtid_Set", 0xf, 40, 6);
blr_slave_send_eof(router, slave, 7);
sprintf(file, "%s", router->binlog_name);
file_len = strlen(file);
sprintf(position, "%ld", router->binlog_position);
len = 5 + file_len + strlen(position) + 1 + 3;
if ((pkt = gwbuf_alloc(len)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, len - 4, 24); // Add length of data packet
ptr += 3;
*ptr++ = 0x08; // Sequence number in response
*ptr++ = strlen(file); // Length of result string
strncpy((char *)ptr, file, strlen(file)); // Result string
ptr += strlen(file);
*ptr++ = strlen(position); // Length of result string
strncpy((char *)ptr, position, strlen(position)); // Result string
ptr += strlen(position);
*ptr++ = 0; // Send 3 empty values
*ptr++ = 0;
*ptr++ = 0;
slave->dcb->func.write(slave->dcb, pkt);
return blr_slave_send_eof(router, slave, 9);
}
/*
* Columns to send for a "SHOW SLAVE STATUS" command
*/
static char *slave_status_columns[] = {
"Slave_IO_State", "Master_Host", "Master_User", "Master_Port", "Connect_Retry",
"Master_Log_File", "Read_Master_Log_Pos", "Relay_Log_File", "Relay_Log_Pos",
"Relay_Master_Log_File", "Slave_IO_Running", "Slave_SQL_Running", "Replicate_Do_DB",
"Replicate_Ignore_DB", "Replicate_Do_Table",
"Replicate_Ignore_Table", "Replicate_Wild_Do_Table", "Replicate_Wild_Ignore_Table",
"Last_Errno", "Last_Error", "Skip_Counter", "Exec_Master_Log_Pos", "Relay_Log_Space",
"Until_Condition", "Until_Log_File", "Until_Log_Pos", "Master_SSL_Allowed",
"Master_SSL_CA_File", "Master_SSL_CA_Path", "Master_SSL_Cert", "Master_SSL_Cipher",
"Master_SSL_Key", "Seconds_Behind_Master",
"Master_SSL_Verify_Server_Cert", "Last_IO_Errno", "Last_IO_Error", "Last_SQL_Errno",
"Last_SQL_Error", "Replicate_Ignore_Server_Ids", "Master_Server_Id", "Master_UUID",
"Master_Info_File", "SQL_Delay", "SQL_Remaining_Delay", "Slave_SQL_Running_State",
"Master_Retry_Count", "Master_Bind", "Last_IO_Error_TimeStamp",
"Last_SQL_Error_Timestamp", "Master_SSL_Crl", "Master_SSL_Crlpath",
"Retrieved_Gtid_Set", "Executed_Gtid_Set", "Auto_Position", NULL
};
/**
* Send the response to the SQL command "SHOW SLAVE STATUS"
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent
*/
static int
blr_slave_send_slave_status(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
GWBUF *pkt;
char column[42];
uint8_t *ptr;
int len, actual_len, col_len, seqno, ncols, i;
/* Count the columns */
for (ncols = 0; slave_status_columns[ncols]; ncols++);
blr_slave_send_fieldcount(router, slave, ncols);
seqno = 2;
for (i = 0; slave_status_columns[i]; i++)
blr_slave_send_columndef(router, slave, slave_status_columns[i], 0xf, 40, seqno++);
blr_slave_send_eof(router, slave, seqno++);
len = 5 + (ncols * 41); // Max length
if ((pkt = gwbuf_alloc(len)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, len - 4, 24); // Add length of data packet
ptr += 3;
*ptr++ = seqno++; // Sequence number in response
sprintf(column, "%s", blrm_states[router->master_state]);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%s", router->service->dbref->server->name ? router->service->dbref->server->name : "");
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%s", router->user ? router->user : "");
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%d", router->service->dbref->server->port);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%d", 60); // Connect retry
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%s", router->binlog_name);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%ld", router->binlog_position);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
/* We have no relay log, we relay the binlog, so we will send the same data */
sprintf(column, "%s", router->binlog_name);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%ld", router->binlog_position);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
/* We have no relay log, we relay the binlog, so we will send the same data */
sprintf(column, "%s", router->binlog_name);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
strcpy(column, "Yes");
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
strcpy(column, "Yes");
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0; // Send 6 empty values
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
/* Last error information */
sprintf(column, "%d", 0);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0;
/* Skip_Counter */
sprintf(column, "%d", 0);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%ld", router->binlog_position);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%ld", router->binlog_position);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
strcpy(column, "None");
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0;
/* Until_Log_Pos */
sprintf(column, "%d", 0);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
/* Master_SSL_Allowed */
strcpy(column, "No");
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0; // Empty SSL columns
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
/* Seconds_Behind_Master */
sprintf(column, "%d", 0);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
/* Master_SSL_Verify_Server_Cert */
strcpy(column, "No");
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
/* Last_IO_Error */
sprintf(column, "%d", 0);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0;
/* Last_SQL_Error */
sprintf(column, "%d", 0);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0;
*ptr++ = 0;
/* Master_Server_Id */
sprintf(column, "%d", router->masterid);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
sprintf(column, "%s", router->master_uuid ?
router->master_uuid : router->uuid);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0;
/* SQL_Delay*/
sprintf(column, "%d", 0);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0xfb; // NULL value
/* Slave_Running_State */
strcpy(column, "Slave running");
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
/* Master_Retry_Count */
sprintf(column, "%d", 1000);
col_len = strlen(column);
*ptr++ = col_len; // Length of result string
strncpy((char *)ptr, column, col_len); // Result string
ptr += col_len;
*ptr++ = 0; // Send 5 empty values
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
// No GTID support send empty values
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
actual_len = ptr - (uint8_t *)GWBUF_DATA(pkt);
ptr = GWBUF_DATA(pkt);
encode_value(ptr, actual_len - 4, 24); // Add length of data packet
pkt = gwbuf_rtrim(pkt, len - actual_len); // Trim the buffer to the actual size
slave->dcb->func.write(slave->dcb, pkt);
return blr_slave_send_eof(router, slave, seqno++);
}
/**
* Send the response to the SQL command "SHOW SLAVE HOSTS"
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent
*/
static int
blr_slave_send_slave_hosts(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
GWBUF *pkt;
char server_id[40];
char host[40];
char port[40];
char master_id[40];
char slave_uuid[40];
uint8_t *ptr;
int len, seqno;
ROUTER_SLAVE *sptr;
blr_slave_send_fieldcount(router, slave, 5);
blr_slave_send_columndef(router, slave, "Server_id", 0xf, 40, 2);
blr_slave_send_columndef(router, slave, "Host", 0xf, 40, 3);
blr_slave_send_columndef(router, slave, "Port", 0xf, 40, 4);
blr_slave_send_columndef(router, slave, "Master_id", 0xf, 40, 5);
blr_slave_send_columndef(router, slave, "Slave_UUID", 0xf, 40, 6);
blr_slave_send_eof(router, slave, 7);
seqno = 8;
spinlock_acquire(&router->lock);
sptr = router->slaves;
while (sptr)
{
if (sptr->state != 0)
{
sprintf(server_id, "%d", sptr->serverid);
sprintf(host, "%s", sptr->hostname ? sptr->hostname : "");
sprintf(port, "%d", sptr->port);
sprintf(master_id, "%d", router->serverid);
sprintf(slave_uuid, "%s", sptr->uuid ? sptr->uuid : "");
len = 5 + strlen(server_id) + strlen(host) + strlen(port)
+ strlen(master_id) + strlen(slave_uuid) + 5;
if ((pkt = gwbuf_alloc(len)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, len - 4, 24); // Add length of data packet
ptr += 3;
*ptr++ = seqno++; // Sequence number in response
*ptr++ = strlen(server_id); // Length of result string
strncpy((char *)ptr, server_id, strlen(server_id)); // Result string
ptr += strlen(server_id);
*ptr++ = strlen(host); // Length of result string
strncpy((char *)ptr, host, strlen(host)); // Result string
ptr += strlen(host);
*ptr++ = strlen(port); // Length of result string
strncpy((char *)ptr, port, strlen(port)); // Result string
ptr += strlen(port);
*ptr++ = strlen(master_id); // Length of result string
strncpy((char *)ptr, master_id, strlen(master_id)); // Result string
ptr += strlen(master_id);
*ptr++ = strlen(slave_uuid); // Length of result string
strncpy((char *)ptr, slave_uuid, strlen(slave_uuid)); // Result string
ptr += strlen(slave_uuid);
slave->dcb->func.write(slave->dcb, pkt);
}
sptr = sptr->next;
}
spinlock_release(&router->lock);
return blr_slave_send_eof(router, slave, seqno);
}
/**
* Process a slave replication registration message.
*
* We store the various bits of information the slave gives us and generate
* a reply message.
*
* @param router The router instance
* @param slave The slave server
* @param queue The BINLOG_DUMP packet
* @return Non-zero if data was sent
*/
static int
blr_slave_register(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *queue)
{
GWBUF *resp;
uint8_t *ptr;
int slen;
ptr = GWBUF_DATA(queue);
ptr += 4; // Skip length and sequence number
if (*ptr++ != COM_REGISTER_SLAVE)
return 0;
slave->serverid = extract_field(ptr, 32);
ptr += 4;
slen = *ptr++;
if (slen != 0)
{
slave->hostname = strndup((char *)ptr, slen);
ptr += slen;
}
else
slave->hostname = NULL;
slen = *ptr++;
if (slen != 0)
{
ptr += slen;
slave->user = strndup((char *)ptr, slen);
}
else
slave->user = NULL;
slen = *ptr++;
if (slen != 0)
{
slave->passwd = strndup((char *)ptr, slen);
ptr += slen;
}
else
slave->passwd = NULL;
slave->port = extract_field(ptr, 16);
ptr += 2;
slave->rank = extract_field(ptr, 32);
/*
* Now construct a response
*/
if ((resp = gwbuf_alloc(11)) == NULL)
return 0;
ptr = GWBUF_DATA(resp);
encode_value(ptr, 7, 24); // Payload length
ptr += 3;
*ptr++ = 1; // Sequence number
encode_value(ptr, 0, 24);
ptr += 3;
encode_value(ptr, slave->serverid, 32);
slave->state = BLRS_REGISTERED;
return slave->dcb->func.write(slave->dcb, resp);
}
/**
* Process a COM_BINLOG_DUMP message from the slave. This is the
* final step in the process of registration. The new master, MaxScale
* must send a response packet and generate a fake BINLOG_ROTATE event
* with the binlog file requested by the slave. And then send a
* FORMAT_DESCRIPTION_EVENT that has been saved from the real master.
*
* Once send MaxScale must continue to send binlog events to the slave.
*
* @param router The router instance
* @param slave The slave server
* @param queue The BINLOG_DUMP packet
* @return The number of bytes written to the slave
*/
static int
blr_slave_binlog_dump(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, GWBUF *queue)
{
GWBUF *resp;
uint8_t *ptr;
int len, rval, binlognamelen;
REP_HEADER hdr;
uint32_t chksum;
ptr = GWBUF_DATA(queue);
len = extract_field(ptr, 24);
binlognamelen = len - 11;
if (binlognamelen > BINLOG_FNAMELEN)
{
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"blr_slave_binlog_dump truncating binlog filename "
"from %d to %d",
binlognamelen, BINLOG_FNAMELEN)));
binlognamelen = BINLOG_FNAMELEN;
}
ptr += 4; // Skip length and sequence number
if (*ptr++ != COM_BINLOG_DUMP)
{
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"blr_slave_binlog_dump expected a COM_BINLOG_DUMP but received %d",
*(ptr-1))));
return 0;
}
slave->binlog_pos = extract_field(ptr, 32);
ptr += 4;
ptr += 2;
ptr += 4;
strncpy(slave->binlogfile, (char *)ptr, binlognamelen);
slave->binlogfile[binlognamelen] = 0;
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%s: COM_BINLOG_DUMP: binlog name '%s', length %d, "
"from position %lu.", router->service->name,
slave->binlogfile, binlognamelen,
(unsigned long)slave->binlog_pos)));
slave->seqno = 1;
if (slave->nocrc)
len = 19 + 8 + binlognamelen;
else
len = 19 + 8 + 4 + binlognamelen;
// Build a fake rotate event
resp = gwbuf_alloc(len + 5);
hdr.payload_len = len + 1;
hdr.seqno = slave->seqno++;
hdr.ok = 0;
hdr.timestamp = 0L;
hdr.event_type = ROTATE_EVENT;
hdr.serverid = router->masterid;
hdr.event_size = len;
hdr.next_pos = 0;
hdr.flags = 0x20;
ptr = blr_build_header(resp, &hdr);
encode_value(ptr, slave->binlog_pos, 64);
ptr += 8;
memcpy(ptr, slave->binlogfile, binlognamelen);
ptr += binlognamelen;
if (!slave->nocrc)
{
/*
* Now add the CRC to the fake binlog rotate event.
*
* The algorithm is first to compute the checksum of an empty buffer
* and then the checksum of the event portion of the message, ie we do not
* include the length, sequence number and ok byte that makes up the first
* 5 bytes of the message. We also do not include the 4 byte checksum itself.
*/
chksum = crc32(0L, NULL, 0);
chksum = crc32(chksum, GWBUF_DATA(resp) + 5, hdr.event_size - 4);
encode_value(ptr, chksum, 32);
}
rval = slave->dcb->func.write(slave->dcb, resp);
/* Send the FORMAT_DESCRIPTION_EVENT */
if (slave->binlog_pos != 4)
blr_slave_send_fde(router, slave);
slave->dcb->low_water = router->low_water;
slave->dcb->high_water = router->high_water;
dcb_add_callback(slave->dcb, DCB_REASON_DRAINED, blr_slave_callback, slave);
slave->state = BLRS_DUMPING;
LOGIF(LM, (skygw_log_write(
LOGFILE_MESSAGE,
"%s: New slave %s, server id %d, requested binlog file %s from position %lu",
router->service->name, slave->dcb->remote,
slave->serverid,
slave->binlogfile, (unsigned long)slave->binlog_pos)));
if (slave->binlog_pos != router->binlog_position ||
strcmp(slave->binlogfile, router->binlog_name) != 0)
{
spinlock_acquire(&slave->catch_lock);
slave->cstate &= ~CS_UPTODATE;
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
return rval;
}
/**
* Encode a value into a number of bits in a MySQL packet
*
* @param data Pointer to location in target packet
* @param value The value to encode into the buffer
* @param len Number of bits to encode value into
*/
static void
encode_value(unsigned char *data, unsigned int value, int len)
{
while (len > 0)
{
*data++ = value & 0xff;
value >>= 8;
len -= 8;
}
}
/**
* 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
* @return A pointer to the first byte following the event header
*/
uint8_t *
blr_build_header(GWBUF *pkt, REP_HEADER *hdr)
{
uint8_t *ptr;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, hdr->payload_len, 24);
ptr += 3;
*ptr++ = hdr->seqno;
*ptr++ = hdr->ok;
encode_value(ptr, hdr->timestamp, 32);
ptr += 4;
*ptr++ = hdr->event_type;
encode_value(ptr, hdr->serverid, 32);
ptr += 4;
encode_value(ptr, hdr->event_size, 32);
ptr += 4;
encode_value(ptr, hdr->next_pos, 32);
ptr += 4;
encode_value(ptr, hdr->flags, 16);
ptr += 2;
return ptr;
}
/**
* We have a registered slave that is behind the current leading edge of the
* binlog. We must replay the log entries to bring this node up to speed.
*
* There may be a large number of records to send to the slave, the process
* is triggered by the slave COM_BINLOG_DUMP message and all the events must
* be sent without receiving any new event. This measn there is no trigger into
* MaxScale other than this initial message. However, if we simply send all the
* events we end up with an extremely long write queue on the DCB and risk
* running the server out of resources.
*
* The slave catchup routine will send a burst of replication events per single
* call. The paramter "long" control the number of events in the burst. The
* short burst is intended to be used when the master receive an event and
* needs to put the slave into catchup mode. This prevents the slave taking
* too much time away from the thread that is processing the master events.
*
* At the end of the burst a fake EPOLLOUT event is added to the poll event
* queue. This ensures that the slave callback for processing DCB write drain
* will be called and future catchup requests will be handled on another thread.
*
* @param router The binlog router
* @param slave The slave that is behind
* @param large Send a long or short burst of events
* @return The number of bytes written
*/
int
blr_slave_catchup(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, bool large)
{
GWBUF *head, *record;
REP_HEADER hdr;
int written, rval = 1, burst;
int rotating = 0;
unsigned long burst_size;
uint8_t *ptr;
if (large)
burst = router->long_burst;
else
burst = router->short_burst;
burst_size = router->burst_size;
spinlock_acquire(&slave->catch_lock);
if (slave->cstate & CS_BUSY)
{
spinlock_release(&slave->catch_lock);
return 0;
}
slave->cstate |= CS_BUSY;
spinlock_release(&slave->catch_lock);
if (slave->file == NULL)
{
rotating = router->rotating;
if ((slave->file = blr_open_binlog(router, slave->binlogfile)) == NULL)
{
if (rotating)
{
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
slave->cstate &= ~CS_BUSY;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
return rval;
}
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"blr_slave_catchup failed to open binlog file %s",
slave->binlogfile)));
slave->cstate &= ~CS_BUSY;
slave->state = BLRS_ERRORED;
dcb_close(slave->dcb);
return 0;
}
}
slave->stats.n_bursts++;
while (burst-- && burst_size > 0 &&
(record = blr_read_binlog(router, slave->file, slave->binlog_pos, &hdr)) != NULL)
{
head = gwbuf_alloc(5);
ptr = GWBUF_DATA(head);
encode_value(ptr, hdr.event_size + 1, 24);
ptr += 3;
*ptr++ = slave->seqno++;
*ptr++ = 0; // OK
head = gwbuf_append(head, record);
slave->lastEventTimestamp = hdr.timestamp;
if (hdr.event_type == ROTATE_EVENT)
{
unsigned long beat1 = hkheartbeat;
blr_close_binlog(router, slave->file);
if (hkheartbeat - beat1 > 1) LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "blr_close_binlog took %d beats",
hkheartbeat - beat1)));
blr_slave_rotate(router, slave, GWBUF_DATA(record));
beat1 = hkheartbeat;
if ((slave->file = blr_open_binlog(router, slave->binlogfile)) == NULL)
{
if (rotating)
{
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
slave->cstate &= ~CS_BUSY;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
return rval;
}
LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR,
"blr_slave_catchup failed to open binlog file %s",
slave->binlogfile)));
slave->state = BLRS_ERRORED;
dcb_close(slave->dcb);
break;
}
if (hkheartbeat - beat1 > 1) LOGIF(LE, (skygw_log_write(
LOGFILE_ERROR, "blr_open_binlog took %d beats",
hkheartbeat - beat1)));
}
slave->stats.n_bytes += gwbuf_length(head);
written = slave->dcb->func.write(slave->dcb, head);
if (written && hdr.event_type != ROTATE_EVENT)
{
slave->binlog_pos = hdr.next_pos;
}
rval = written;
slave->stats.n_events++;
burst_size -= hdr.event_size;
}
if (record == NULL)
slave->stats.n_failed_read++;
spinlock_acquire(&slave->catch_lock);
slave->cstate &= ~CS_BUSY;
spinlock_release(&slave->catch_lock);
if (record)
{
slave->stats.n_flows++;
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
else if (slave->binlog_pos == router->binlog_position &&
strcmp(slave->binlogfile, router->binlog_name) == 0)
{
int state_change = 0;
spinlock_acquire(&router->binlog_lock);
spinlock_acquire(&slave->catch_lock);
/*
* Now check again since we hold the router->binlog_lock
* and slave->catch_lock.
*/
if (slave->binlog_pos != router->binlog_position ||
strcmp(slave->binlogfile, router->binlog_name) != 0)
{
slave->cstate &= ~CS_UPTODATE;
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
spinlock_release(&router->binlog_lock);
poll_fake_write_event(slave->dcb);
}
else
{
if ((slave->cstate & CS_UPTODATE) == 0)
{
slave->stats.n_upd++;
slave->cstate |= CS_UPTODATE;
spinlock_release(&slave->catch_lock);
spinlock_release(&router->binlog_lock);
state_change = 1;
}
}
if (state_change)
{
slave->stats.n_caughtup++;
if (slave->stats.n_caughtup == 1)
{
LOGIF(LM, (skygw_log_write(LOGFILE_MESSAGE,
"%s: Slave %s is up to date %s, %lu.",
router->service->name,
slave->dcb->remote,
slave->binlogfile, (unsigned long)slave->binlog_pos)));
}
else if ((slave->stats.n_caughtup % 50) == 0)
{
LOGIF(LM, (skygw_log_write(LOGFILE_MESSAGE,
"%s: Slave %s is up to date %s, %lu.",
router->service->name,
slave->dcb->remote,
slave->binlogfile, (unsigned long)slave->binlog_pos)));
}
}
}
else
{
if (slave->binlog_pos >= blr_file_size(slave->file)
&& router->rotating == 0
&& strcmp(router->binlog_name, slave->binlogfile) != 0
&& (blr_master_connected(router)
|| blr_file_next_exists(router, slave)))
{
/* We may have reached the end of file of a non-current
* binlog file.
*
* Note if the master is rotating there is a window during
* which the rotate event has been written to the old binlog
* but the new binlog file has not yet been created. Therefore
* we ignore these issues during the rotate processing.
*/
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR,
"Slave reached end of file for binlog file %s at %lu "
"which is not the file currently being downloaded. "
"Master binlog is %s, %lu. This may be caused by a "
"previous failure of the master.",
slave->binlogfile, (unsigned long)slave->binlog_pos,
router->binlog_name, router->binlog_position)));
if (blr_slave_fake_rotate(router, slave))
{
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
else
{
slave->state = BLRS_ERRORED;
dcb_close(slave->dcb);
}
}
else if (blr_master_connected(router))
{
spinlock_acquire(&slave->catch_lock);
slave->cstate |= CS_EXPECTCB;
spinlock_release(&slave->catch_lock);
poll_fake_write_event(slave->dcb);
}
}
return rval;
}
/**
* The DCB callback used by the slave to obtain DCB_REASON_LOW_WATER callbacks
* when the server sends all the the queue data for a DCB. This is the mechanism
* that is used to implement the flow control mechanism for the sending of
* large quantities of binlog records during the catchup process.
*
* @param dcb The DCB of the slave connection
* @param reason The reason the callback was called
* @param data The user data, in this case the server structure
*/
int
blr_slave_callback(DCB *dcb, DCB_REASON reason, void *data)
{
ROUTER_SLAVE *slave = (ROUTER_SLAVE *)data;
ROUTER_INSTANCE *router = slave->router;
if (reason == DCB_REASON_DRAINED)
{
if (slave->state == BLRS_DUMPING)
{
spinlock_acquire(&slave->catch_lock);
slave->cstate &= ~(CS_UPTODATE|CS_EXPECTCB);
spinlock_release(&slave->catch_lock);
slave->stats.n_dcb++;
blr_slave_catchup(router, slave, true);
}
else
{
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG, "Ignored callback due to slave state %s",
blrs_states[slave->state])));
}
}
if (reason == DCB_REASON_LOW_WATER)
{
if (slave->state == BLRS_DUMPING)
{
slave->stats.n_cb++;
blr_slave_catchup(router, slave, true);
}
else
{
slave->stats.n_cbna++;
}
}
return 0;
}
/**
* Rotate the slave to the new binlog file
*
* @param slave The slave instance
* @param ptr The rotate event (minus header and OK byte)
*/
void
blr_slave_rotate(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, uint8_t *ptr)
{
int len = EXTRACT24(ptr + 9); // Extract the event length
len = len - (19 + 8); // Remove length of header and position
if (router->master_chksum)
len -= 4;
if (len > BINLOG_FNAMELEN)
len = BINLOG_FNAMELEN;
ptr += 19; // Skip header
slave->binlog_pos = extract_field(ptr, 32);
slave->binlog_pos += (((uint64_t)extract_field(ptr+4, 32)) << 32);
memcpy(slave->binlogfile, ptr + 8, len);
slave->binlogfile[len] = 0;
}
/**
* Generate an internal rotate event that we can use to cause the slave to move beyond
* a binlog file that is misisng the rotate eent at the end.
*
* @param router The router instance
* @param slave The slave to rotate
* @return Non-zero if the rotate took place
*/
static int
blr_slave_fake_rotate(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
char *sptr;
int filenum;
GWBUF *resp;
uint8_t *ptr;
int len, binlognamelen;
REP_HEADER hdr;
uint32_t chksum;
if ((sptr = strrchr(slave->binlogfile, '.')) == NULL)
return 0;
blr_close_binlog(router, slave->file);
filenum = atoi(sptr + 1);
sprintf(slave->binlogfile, BINLOG_NAMEFMT, router->fileroot, filenum + 1);
slave->binlog_pos = 4;
if ((slave->file = blr_open_binlog(router, slave->binlogfile)) == NULL)
return 0;
binlognamelen = strlen(slave->binlogfile);
len = 19 + 8 + 4 + binlognamelen;
/* no slave crc, remove 4 bytes */
if (slave->nocrc)
len -= 4;
// Build a fake rotate event
resp = gwbuf_alloc(len + 5);
hdr.payload_len = len + 1;
hdr.seqno = slave->seqno++;
hdr.ok = 0;
hdr.timestamp = 0L;
hdr.event_type = ROTATE_EVENT;
hdr.serverid = router->masterid;
hdr.event_size = len;
hdr.next_pos = 0;
hdr.flags = 0x20;
ptr = blr_build_header(resp, &hdr);
encode_value(ptr, slave->binlog_pos, 64);
ptr += 8;
memcpy(ptr, slave->binlogfile, binlognamelen);
ptr += binlognamelen;
if (!slave->nocrc) {
/*
* Now add the CRC to the fake binlog rotate event.
*
* The algorithm is first to compute the checksum of an empty buffer
* and then the checksum of the event portion of the message, ie we do not
* include the length, sequence number and ok byte that makes up the first
* 5 bytes of the message. We also do not include the 4 byte checksum itself.
*/
chksum = crc32(0L, NULL, 0);
chksum = crc32(chksum, GWBUF_DATA(resp) + 5, hdr.event_size - 4);
encode_value(ptr, chksum, 32);
}
slave->dcb->func.write(slave->dcb, resp);
return 1;
}
/**
* Send a "fake" format description event to the newly connected slave
*
* @param router The router instance
* @param slave The slave to send the event to
*/
static void
blr_slave_send_fde(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
BLFILE *file;
REP_HEADER hdr;
GWBUF *record, *head;
uint8_t *ptr;
uint32_t chksum;
if ((file = blr_open_binlog(router, slave->binlogfile)) == NULL)
return;
if ((record = blr_read_binlog(router, file, 4, &hdr)) == NULL)
{
blr_close_binlog(router, file);
return;
}
blr_close_binlog(router, file);
head = gwbuf_alloc(5);
ptr = GWBUF_DATA(head);
encode_value(ptr, hdr.event_size + 1, 24); // Payload length
ptr += 3;
*ptr++ = slave->seqno++;
*ptr++ = 0; // OK
head = gwbuf_append(head, record);
ptr = GWBUF_DATA(record);
encode_value(ptr, time(0), 32); // Overwrite timestamp
ptr += 13;
encode_value(ptr, 0, 32); // Set next position to 0
/*
* Since we have changed the timestamp we must recalculate the CRC
*
* Position ptr to the start of the event header,
* calculate a new checksum
* and write it into the header
*/
ptr = GWBUF_DATA(record) + hdr.event_size - 4;
chksum = crc32(0L, NULL, 0);
chksum = crc32(chksum, GWBUF_DATA(record), hdr.event_size - 4);
encode_value(ptr, chksum, 32);
slave->dcb->func.write(slave->dcb, head);
}
/**
* Send the field count packet in a response packet sequence.
*
* @param router The router
* @param slave The slave connection
* @param count Number of columns in the result set
* @return Non-zero on success
*/
static int
blr_slave_send_fieldcount(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, int count)
{
GWBUF *pkt;
uint8_t *ptr;
if ((pkt = gwbuf_alloc(5)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, 1, 24); // Add length of data packet
ptr += 3;
*ptr++ = 0x01; // Sequence number in response
*ptr++ = count; // Length of result string
return slave->dcb->func.write(slave->dcb, pkt);
}
/**
* Send the column definition packet in a response packet sequence.
*
* @param router The router
* @param slave The slave connection
* @param name Name of the column
* @param type Column type
* @param len Column length
* @param seqno Packet sequence number
* @return Non-zero on success
*/
static int
blr_slave_send_columndef(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, char *name, int type, int len, uint8_t seqno)
{
GWBUF *pkt;
uint8_t *ptr;
if ((pkt = gwbuf_alloc(26 + strlen(name))) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, 22 + strlen(name), 24); // Add length of data packet
ptr += 3;
*ptr++ = seqno; // Sequence number in response
*ptr++ = 3; // Catalog is always def
*ptr++ = 'd';
*ptr++ = 'e';
*ptr++ = 'f';
*ptr++ = 0; // Schema name length
*ptr++ = 0; // virtual table name length
*ptr++ = 0; // Table name length
*ptr++ = strlen(name); // Column name length;
while (*name)
*ptr++ = *name++; // Copy the column name
*ptr++ = 0; // Orginal column name
*ptr++ = 0x0c; // Length of next fields always 12
*ptr++ = 0x3f; // Character set
*ptr++ = 0;
encode_value(ptr, len, 32); // Add length of column
ptr += 4;
*ptr++ = type;
*ptr++ = 0x81; // Two bytes of flags
if (type == 0xfd)
*ptr++ = 0x1f;
else
*ptr++ = 0x00;
*ptr++= 0;
*ptr++= 0;
*ptr++= 0;
return slave->dcb->func.write(slave->dcb, pkt);
}
/**
* Send an EOF packet in a response packet sequence.
*
* @param router The router
* @param slave The slave connection
* @param seqno The sequence number of the EOF packet
* @return Non-zero on success
*/
static int
blr_slave_send_eof(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, int seqno)
{
GWBUF *pkt;
uint8_t *ptr;
if ((pkt = gwbuf_alloc(9)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
encode_value(ptr, 5, 24); // Add length of data packet
ptr += 3;
*ptr++ = seqno; // Sequence number in response
*ptr++ = 0xfe; // Length of result string
encode_value(ptr, 0, 16); // No errors
ptr += 2;
encode_value(ptr, 2, 16); // Autocommit enabled
return slave->dcb->func.write(slave->dcb, pkt);
}
/**
* Send the reply only to the SQL command "DISCONNECT SERVER $server_id'
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent
*/
static int
blr_slave_send_disconnected_server(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, int server_id, int found)
{
GWBUF *pkt;
char state[40];
char serverid[40];
uint8_t *ptr;
int len, id_len, seqno = 2;
sprintf(serverid, "%d", server_id);
if (found)
strcpy(state, "disconnected");
else
strcpy(state, "not found");
id_len = strlen(serverid);
len = 5 + id_len + strlen(state) + 1;
if ((pkt = gwbuf_alloc(len)) == NULL)
return 0;
blr_slave_send_fieldcount(router, slave, 2);
blr_slave_send_columndef(router, slave, "server_id", 0x03, 40, seqno++);
blr_slave_send_columndef(router, slave, "state", 0xf, 40, seqno++);
blr_slave_send_eof(router, slave, seqno++);
ptr = GWBUF_DATA(pkt);
encode_value(ptr, id_len + 2 + strlen(state), 24); // Add length of data packet
ptr += 3;
*ptr++ = seqno++; // Sequence number in response
*ptr++ = id_len; // Length of result string
strncpy((char *)ptr, serverid, id_len); // Result string
ptr += id_len;
*ptr++ = strlen(state); // Length of result string
strncpy((char *)ptr, state, strlen(state)); // Result string
ptr += strlen(state);
slave->dcb->func.write(slave->dcb, pkt);
return blr_slave_send_eof(router, slave, seqno++);
}
/**
* Send the response to the SQL command "DISCONNECT SERVER $server_id'
* and close the connection to that server
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @param server_id The slave server_id to disconnect
* @return Non-zero if data was sent to the client
*/
static int
blr_slave_disconnect_server(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave, int server_id)
{
ROUTER_OBJECT *router_obj= router->service->router;
ROUTER_SLAVE *sptr;
int n;
int server_found = 0;
spinlock_acquire(&router->lock);
sptr = router->slaves;
/* look for server_id among all registered slaves */
while (sptr)
{
/* don't examine slaves with state = 0 */
if (sptr->state != 0 && sptr->serverid == server_id)
{
/* server_id found */
server_found = 1;
LOGIF(LM, (skygw_log_write(LOGFILE_MESSAGE, "%s: Slave %s, server id %d, disconnected by %s@%s",
router->service->name,
sptr->dcb->remote,
server_id,
slave->dcb->user,
slave->dcb->remote)));
/* send server_id with disconnect state to client */
n = blr_slave_send_disconnected_server(router, slave, server_id, 1);
/* force session close for matched slave */
router_obj->closeSession(router->service->router_instance, sptr);
break;
} else {
sptr = sptr->next;
}
}
spinlock_release(&router->lock);
/** server id was not found
* send server_id with not found state to the client
*/
if (!server_found)
{
n = blr_slave_send_disconnected_server(router, slave, server_id, 0);
}
if (n == 0) {
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR, "Error: gwbuf memory allocation in "
"DISCONNECT SERVER server_id [%d]",
sptr->serverid)));
blr_slave_send_error(router, slave, "Memory allocation error for DISCONNECT SERVER");
}
return 1;
}
/**
* Send the response to the SQL command "DISCONNECT ALL'
* and close the connection to all slave servers
*
* @param router The binlog router instance
* @param slave The slave server to which we are sending the response
* @return Non-zero if data was sent to the client
*/
static int
blr_slave_disconnect_all(ROUTER_INSTANCE *router, ROUTER_SLAVE *slave)
{
ROUTER_OBJECT *router_obj= router->service->router;
ROUTER_SLAVE *sptr;
char server_id[40];
char state[40];
uint8_t *ptr;
int len, seqno;
GWBUF *pkt;
/* preparing output result */
blr_slave_send_fieldcount(router, slave, 2);
blr_slave_send_columndef(router, slave, "server_id", 0x03, 40, 2);
blr_slave_send_columndef(router, slave, "state", 0xf, 40, 3);
blr_slave_send_eof(router, slave, 4);
seqno = 5;
spinlock_acquire(&router->lock);
sptr = router->slaves;
while (sptr)
{
/* skip servers with state = 0 */
if (sptr->state != 0)
{
sprintf(server_id, "%d", sptr->serverid);
sprintf(state, "disconnected");
len = 5 + strlen(server_id) + strlen(state) + 1;
if ((pkt = gwbuf_alloc(len)) == NULL) {
LOGIF(LE, (skygw_log_write(LOGFILE_ERROR, "Error: gwbuf memory allocation in "
"DISCONNECT ALL for [%s], server_id [%d]",
sptr->dcb->remote, sptr->serverid)));
spinlock_release(&router->lock);
blr_slave_send_error(router, slave, "Memory allocation error for DISCONNECT ALL");
return 1;
}
LOGIF(LM, (skygw_log_write(LOGFILE_MESSAGE, "%s: Slave %s, server id %d, disconnected by %s@%s",
router->service->name,
sptr->dcb->remote, sptr->serverid, slave->dcb->user, slave->dcb->remote)));
ptr = GWBUF_DATA(pkt);
encode_value(ptr, len - 4, 24); // Add length of data packet
ptr += 3;
*ptr++ = seqno++; // Sequence number in response
*ptr++ = strlen(server_id); // Length of result string
strncpy((char *)ptr, server_id, strlen(server_id)); // Result string
ptr += strlen(server_id);
*ptr++ = strlen(state); // Length of result string
strncpy((char *)ptr, state, strlen(state)); // Result string
ptr += strlen(state);
slave->dcb->func.write(slave->dcb, pkt);
/* force session close*/
router_obj->closeSession(router->service->router_instance, sptr);
}
sptr = sptr->next;
}
spinlock_release(&router->lock);
blr_slave_send_eof(router, slave, seqno);
return 1;
}
/**
* Send a MySQL OK packet to the DCB
*
* @param dcb The DCB to send the OK packet to
* @return result of a write call, non-zero if write was successful
*/
static int
blr_slave_send_ok(ROUTER_INSTANCE* router, ROUTER_SLAVE* slave)
{
GWBUF *pkt;
uint8_t *ptr;
if ((pkt = gwbuf_alloc(11)) == NULL)
return 0;
ptr = GWBUF_DATA(pkt);
*ptr++ = 7; // Payload length
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 1; // Seqno
*ptr++ = 0; // ok
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 2;
*ptr++ = 0;
*ptr++ = 0;
*ptr++ = 0;
return slave->dcb->func.write(slave->dcb, pkt);
}