mirror of
https://github.com/MariaDB/server.git
synced 2025-02-02 03:51:50 +01:00
55842061e7
Semi-sync uses an extra connection from slave to master to send replies, this is a normal client connection, and used a normal SET query to set the reply information on master, which is visible to user and may cause some confusion and complaining. This problem is fixed by using the method of sending reply by using the same connection that is used by master dump thread to send binlog to slave. Since now the semi-sync plugins are integrated with the server code, it is not a problem to use the internal net interfaces to do this. The master dump thread will mark the event requires a reply and wait for the reply when the event just sent is the last event of a transaction and semi-sync status is ON; And the slave will send a reply to master when it received such an event that requires a reply.
1305 lines
37 KiB
C++
1305 lines
37 KiB
C++
/* Copyright (C) 2007 Google Inc.
|
|
Copyright (C) 2008 MySQL AB
|
|
|
|
This program 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 of the License.
|
|
|
|
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 St, Fifth Floor, Boston, MA 02110-1301 USA */
|
|
|
|
|
|
#include "semisync_master.h"
|
|
|
|
#define TIME_THOUSAND 1000
|
|
#define TIME_MILLION 1000000
|
|
#define TIME_BILLION 1000000000
|
|
|
|
/* This indicates whether semi-synchronous replication is enabled. */
|
|
char rpl_semi_sync_master_enabled;
|
|
unsigned long rpl_semi_sync_master_timeout;
|
|
unsigned long rpl_semi_sync_master_trace_level;
|
|
char rpl_semi_sync_master_status = 0;
|
|
unsigned long rpl_semi_sync_master_yes_transactions = 0;
|
|
unsigned long rpl_semi_sync_master_no_transactions = 0;
|
|
unsigned long rpl_semi_sync_master_off_times = 0;
|
|
unsigned long rpl_semi_sync_master_timefunc_fails = 0;
|
|
unsigned long rpl_semi_sync_master_num_timeouts = 0;
|
|
unsigned long rpl_semi_sync_master_wait_sessions = 0;
|
|
unsigned long rpl_semi_sync_master_back_wait_pos = 0;
|
|
unsigned long rpl_semi_sync_master_trx_wait_time = 0;
|
|
unsigned long long rpl_semi_sync_master_trx_wait_num = 0;
|
|
unsigned long rpl_semi_sync_master_net_wait_time = 0;
|
|
unsigned long long rpl_semi_sync_master_net_wait_num = 0;
|
|
unsigned long rpl_semi_sync_master_clients = 0;
|
|
unsigned long long rpl_semi_sync_master_net_wait_total_time = 0;
|
|
unsigned long long rpl_semi_sync_master_trx_wait_total_time = 0;
|
|
|
|
|
|
static int getWaitTime(const struct timeval& start_tv);
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* <ActiveTranx> class : manage all active transaction nodes
|
|
*
|
|
******************************************************************************/
|
|
|
|
ActiveTranx::ActiveTranx(int max_connections,
|
|
pthread_mutex_t *lock,
|
|
unsigned long trace_level)
|
|
: Trace(trace_level), num_transactions_(max_connections),
|
|
num_entries_(max_connections << 1),
|
|
lock_(lock)
|
|
{
|
|
/* Allocate the memory for the array */
|
|
node_array_ = new TranxNode[num_transactions_];
|
|
for (int idx = 0; idx < num_transactions_; ++idx)
|
|
{
|
|
node_array_[idx].log_pos_ = 0;
|
|
node_array_[idx].hash_next_ = NULL;
|
|
node_array_[idx].next_ = node_array_ + idx + 1;
|
|
|
|
node_array_[idx].log_name_ = new char[FN_REFLEN];
|
|
node_array_[idx].log_name_[0] = '\x0';
|
|
}
|
|
node_array_[num_transactions_-1].next_ = NULL;
|
|
|
|
/* All nodes in the array go to the pool initially. */
|
|
free_pool_ = node_array_;
|
|
|
|
/* No transactions are in the list initially. */
|
|
trx_front_ = NULL;
|
|
trx_rear_ = NULL;
|
|
|
|
/* Create the hash table to find a transaction's ending event. */
|
|
trx_htb_ = new TranxNode *[num_entries_];
|
|
for (int idx = 0; idx < num_entries_; ++idx)
|
|
trx_htb_[idx] = NULL;
|
|
|
|
sql_print_information("Semi-sync replication initialized for %d "
|
|
"transactions.", num_transactions_);
|
|
}
|
|
|
|
ActiveTranx::~ActiveTranx()
|
|
{
|
|
for (int idx = 0; idx < num_transactions_; ++idx)
|
|
{
|
|
delete [] node_array_[idx].log_name_;
|
|
node_array_[idx].log_name_ = NULL;
|
|
}
|
|
|
|
delete [] node_array_;
|
|
delete [] trx_htb_;
|
|
|
|
node_array_ = NULL;
|
|
trx_htb_ = NULL;
|
|
num_transactions_ = 0;
|
|
num_entries_ = 0;
|
|
}
|
|
|
|
unsigned int ActiveTranx::calc_hash(const unsigned char *key,
|
|
unsigned int length)
|
|
{
|
|
unsigned int nr = 1, nr2 = 4;
|
|
|
|
/* The hash implementation comes from calc_hashnr() in mysys/hash.c. */
|
|
while (length--)
|
|
{
|
|
nr ^= (((nr & 63)+nr2)*((unsigned int) (unsigned char) *key++))+ (nr << 8);
|
|
nr2 += 3;
|
|
}
|
|
return((unsigned int) nr);
|
|
}
|
|
|
|
unsigned int ActiveTranx::get_hash_value(const char *log_file_name,
|
|
my_off_t log_file_pos)
|
|
{
|
|
unsigned int hash1 = calc_hash((const unsigned char *)log_file_name,
|
|
strlen(log_file_name));
|
|
unsigned int hash2 = calc_hash((const unsigned char *)(&log_file_pos),
|
|
sizeof(log_file_pos));
|
|
|
|
return (hash1 + hash2) % num_entries_;
|
|
}
|
|
|
|
ActiveTranx::TranxNode* ActiveTranx::alloc_tranx_node()
|
|
{
|
|
TranxNode *ptr = free_pool_;
|
|
|
|
if (free_pool_)
|
|
{
|
|
free_pool_ = free_pool_->next_;
|
|
ptr->next_ = NULL;
|
|
ptr->hash_next_ = NULL;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
free_pool should never be NULL here, because we have
|
|
max_connections number of pre-allocated nodes.
|
|
*/
|
|
sql_print_error("You have encountered a semi-sync bug (free_pool == NULL), "
|
|
"please report to http://bugs.mysql.com");
|
|
assert(free_pool_);
|
|
}
|
|
|
|
return ptr;
|
|
}
|
|
|
|
int ActiveTranx::compare(const char *log_file_name1, my_off_t log_file_pos1,
|
|
const char *log_file_name2, my_off_t log_file_pos2)
|
|
{
|
|
int cmp = strcmp(log_file_name1, log_file_name2);
|
|
|
|
if (cmp != 0)
|
|
return cmp;
|
|
|
|
if (log_file_pos1 > log_file_pos2)
|
|
return 1;
|
|
else if (log_file_pos1 < log_file_pos2)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
int ActiveTranx::insert_tranx_node(const char *log_file_name,
|
|
my_off_t log_file_pos)
|
|
{
|
|
const char *kWho = "ActiveTranx:insert_tranx_node";
|
|
TranxNode *ins_node;
|
|
int result = 0;
|
|
unsigned int hash_val;
|
|
|
|
function_enter(kWho);
|
|
|
|
ins_node = alloc_tranx_node();
|
|
if (!ins_node)
|
|
{
|
|
sql_print_error("%s: transaction node allocation failed for: (%s, %lu)",
|
|
kWho, log_file_name, (unsigned long)log_file_pos);
|
|
result = -1;
|
|
goto l_end;
|
|
}
|
|
|
|
/* insert the binlog position in the active transaction list. */
|
|
strcpy(ins_node->log_name_, log_file_name);
|
|
ins_node->log_pos_ = log_file_pos;
|
|
|
|
if (!trx_front_)
|
|
{
|
|
/* The list is empty. */
|
|
trx_front_ = trx_rear_ = ins_node;
|
|
}
|
|
else
|
|
{
|
|
int cmp = compare(ins_node, trx_rear_);
|
|
if (cmp > 0)
|
|
{
|
|
/* Compare with the tail first. If the transaction happens later in
|
|
* binlog, then make it the new tail.
|
|
*/
|
|
trx_rear_->next_ = ins_node;
|
|
trx_rear_ = ins_node;
|
|
}
|
|
else
|
|
{
|
|
/* Otherwise, it is an error because the transaction should hold the
|
|
* mysql_bin_log.LOCK_log when appending events.
|
|
*/
|
|
sql_print_error("%s: binlog write out-of-order, tail (%s, %lu), "
|
|
"new node (%s, %lu)", kWho,
|
|
trx_rear_->log_name_, (unsigned long)trx_rear_->log_pos_,
|
|
ins_node->log_name_, (unsigned long)ins_node->log_pos_);
|
|
result = -1;
|
|
goto l_end;
|
|
}
|
|
}
|
|
|
|
hash_val = get_hash_value(ins_node->log_name_, ins_node->log_pos_);
|
|
ins_node->hash_next_ = trx_htb_[hash_val];
|
|
trx_htb_[hash_val] = ins_node;
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: insert (%s, %lu) in entry(%u)", kWho,
|
|
ins_node->log_name_, (unsigned long)ins_node->log_pos_,
|
|
hash_val);
|
|
|
|
l_end:
|
|
return function_exit(kWho, result);
|
|
}
|
|
|
|
bool ActiveTranx::is_tranx_end_pos(const char *log_file_name,
|
|
my_off_t log_file_pos)
|
|
{
|
|
const char *kWho = "ActiveTranx::is_tranx_end_pos";
|
|
function_enter(kWho);
|
|
|
|
unsigned int hash_val = get_hash_value(log_file_name, log_file_pos);
|
|
TranxNode *entry = trx_htb_[hash_val];
|
|
|
|
while (entry != NULL)
|
|
{
|
|
if (compare(entry, log_file_name, log_file_pos) == 0)
|
|
break;
|
|
|
|
entry = entry->hash_next_;
|
|
}
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: probe (%s, %lu) in entry(%u)", kWho,
|
|
log_file_name, (unsigned long)log_file_pos, hash_val);
|
|
|
|
function_exit(kWho, (entry != NULL));
|
|
return (entry != NULL);
|
|
}
|
|
|
|
int ActiveTranx::clear_active_tranx_nodes(const char *log_file_name,
|
|
my_off_t log_file_pos)
|
|
{
|
|
const char *kWho = "ActiveTranx::::clear_active_tranx_nodes";
|
|
TranxNode *new_front;
|
|
|
|
function_enter(kWho);
|
|
|
|
if (log_file_name != NULL)
|
|
{
|
|
new_front = trx_front_;
|
|
|
|
while (new_front)
|
|
{
|
|
if (compare(new_front, log_file_name, log_file_pos) > 0)
|
|
break;
|
|
new_front = new_front->next_;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* If log_file_name is NULL, clear everything. */
|
|
new_front = NULL;
|
|
}
|
|
|
|
if (new_front == NULL)
|
|
{
|
|
/* No active transaction nodes after the call. */
|
|
|
|
/* Clear the hash table. */
|
|
memset(trx_htb_, 0, num_entries_ * sizeof(TranxNode *));
|
|
|
|
/* Clear the active transaction list. */
|
|
if (trx_front_ != NULL)
|
|
{
|
|
trx_rear_->next_ = free_pool_;
|
|
free_pool_ = trx_front_;
|
|
trx_front_ = NULL;
|
|
trx_rear_ = NULL;
|
|
}
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: free all nodes back to free list", kWho);
|
|
}
|
|
else if (new_front != trx_front_)
|
|
{
|
|
TranxNode *curr_node, *next_node;
|
|
|
|
/* Delete all transaction nodes before the confirmation point. */
|
|
int n_frees = 0;
|
|
curr_node = trx_front_;
|
|
while (curr_node != new_front)
|
|
{
|
|
next_node = curr_node->next_;
|
|
|
|
/* Put the node in the memory pool. */
|
|
curr_node->next_ = free_pool_;
|
|
free_pool_ = curr_node;
|
|
n_frees++;
|
|
|
|
/* Remove the node from the hash table. */
|
|
unsigned int hash_val = get_hash_value(curr_node->log_name_, curr_node->log_pos_);
|
|
TranxNode **hash_ptr = &(trx_htb_[hash_val]);
|
|
while ((*hash_ptr) != NULL)
|
|
{
|
|
if ((*hash_ptr) == curr_node)
|
|
{
|
|
(*hash_ptr) = curr_node->hash_next_;
|
|
break;
|
|
}
|
|
hash_ptr = &((*hash_ptr)->hash_next_);
|
|
}
|
|
|
|
curr_node = next_node;
|
|
}
|
|
|
|
trx_front_ = new_front;
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: free %d nodes back until pos (%s, %lu)",
|
|
kWho, n_frees,
|
|
trx_front_->log_name_, (unsigned long)trx_front_->log_pos_);
|
|
}
|
|
|
|
return function_exit(kWho, 0);
|
|
}
|
|
|
|
|
|
/*******************************************************************************
|
|
*
|
|
* <ReplSemiSyncMaster> class: the basic code layer for sync-replication master.
|
|
* <ReplSemiSyncSlave> class: the basic code layer for sync-replication slave.
|
|
*
|
|
* The most important functions during semi-syn replication listed:
|
|
*
|
|
* Master:
|
|
* . reportReplyBinlog(): called by the binlog dump thread when it receives
|
|
* the slave's status information.
|
|
* . updateSyncHeader(): based on transaction waiting information, decide
|
|
* whether to request the slave to reply.
|
|
* . writeTraxInBinlog(): called by the transaction thread when it finishes
|
|
* writing all transaction events in binlog.
|
|
* . commitTrx(): transaction thread wait for the slave reply.
|
|
*
|
|
* Slave:
|
|
* . slaveReadSyncHeader(): read the semi-sync header from the master, get the
|
|
* sync status and get the payload for events.
|
|
* . slaveReply(): reply to the master about the replication progress.
|
|
*
|
|
******************************************************************************/
|
|
|
|
ReplSemiSyncMaster::ReplSemiSyncMaster()
|
|
: active_tranxs_(NULL),
|
|
init_done_(false),
|
|
reply_file_name_inited_(false),
|
|
reply_file_pos_(0L),
|
|
wait_file_name_inited_(false),
|
|
wait_file_pos_(0),
|
|
master_enabled_(false),
|
|
wait_timeout_(0L),
|
|
state_(0),
|
|
enabled_transactions_(0),
|
|
disabled_transactions_(0),
|
|
switched_off_times_(0),
|
|
timefunc_fails_(0),
|
|
wait_sessions_(0),
|
|
wait_backtraverse_(0),
|
|
total_trx_wait_num_(0),
|
|
total_trx_wait_time_(0),
|
|
total_net_wait_num_(0),
|
|
total_net_wait_time_(0),
|
|
max_transactions_(0L)
|
|
{
|
|
strcpy(reply_file_name_, "");
|
|
strcpy(wait_file_name_, "");
|
|
}
|
|
|
|
int ReplSemiSyncMaster::initObject()
|
|
{
|
|
int result;
|
|
const char *kWho = "ReplSemiSyncMaster::initObject";
|
|
|
|
if (init_done_)
|
|
{
|
|
fprintf(stderr, "%s called twice\n", kWho);
|
|
return 1;
|
|
}
|
|
init_done_ = true;
|
|
|
|
/* References to the parameter works after set_options(). */
|
|
setWaitTimeout(rpl_semi_sync_master_timeout);
|
|
setTraceLevel(rpl_semi_sync_master_trace_level);
|
|
max_transactions_ = (int)max_connections;
|
|
|
|
/* Mutex initialization can only be done after MY_INIT(). */
|
|
pthread_mutex_init(&LOCK_binlog_, MY_MUTEX_INIT_FAST);
|
|
pthread_cond_init(&COND_binlog_send_, NULL);
|
|
|
|
if (rpl_semi_sync_master_enabled)
|
|
result = enableMaster();
|
|
else
|
|
result = disableMaster();
|
|
|
|
return result;
|
|
}
|
|
|
|
int ReplSemiSyncMaster::enableMaster()
|
|
{
|
|
int result = 0;
|
|
|
|
/* Must have the lock when we do enable of disable. */
|
|
lock();
|
|
|
|
if (!getMasterEnabled())
|
|
{
|
|
active_tranxs_ = new ActiveTranx(max_connections,
|
|
&LOCK_binlog_,
|
|
trace_level_);
|
|
if (active_tranxs_ != NULL)
|
|
{
|
|
commit_file_name_inited_ = false;
|
|
reply_file_name_inited_ = false;
|
|
wait_file_name_inited_ = false;
|
|
|
|
set_master_enabled(true);
|
|
state_ = true;
|
|
sql_print_information("Semi-sync replication enabled on the master.");
|
|
}
|
|
else
|
|
{
|
|
sql_print_error("Cannot allocate memory to enable semi-sync on the master.");
|
|
result = -1;
|
|
}
|
|
}
|
|
|
|
unlock();
|
|
|
|
return result;
|
|
}
|
|
|
|
int ReplSemiSyncMaster::disableMaster()
|
|
{
|
|
/* Must have the lock when we do enable of disable. */
|
|
lock();
|
|
|
|
if (getMasterEnabled())
|
|
{
|
|
/* Switch off the semi-sync first so that waiting transaction will be
|
|
* waken up.
|
|
*/
|
|
switch_off();
|
|
|
|
assert(active_tranxs_ != NULL);
|
|
delete active_tranxs_;
|
|
active_tranxs_ = NULL;
|
|
|
|
reply_file_name_inited_ = false;
|
|
wait_file_name_inited_ = false;
|
|
commit_file_name_inited_ = false;
|
|
|
|
set_master_enabled(false);
|
|
sql_print_information("Semi-sync replication disabled on the master.");
|
|
}
|
|
|
|
unlock();
|
|
|
|
return 0;
|
|
}
|
|
|
|
ReplSemiSyncMaster::~ReplSemiSyncMaster()
|
|
{
|
|
if (init_done_)
|
|
{
|
|
pthread_mutex_destroy(&LOCK_binlog_);
|
|
pthread_cond_destroy(&COND_binlog_send_);
|
|
}
|
|
|
|
delete active_tranxs_;
|
|
}
|
|
|
|
void ReplSemiSyncMaster::lock()
|
|
{
|
|
pthread_mutex_lock(&LOCK_binlog_);
|
|
}
|
|
|
|
void ReplSemiSyncMaster::unlock()
|
|
{
|
|
pthread_mutex_unlock(&LOCK_binlog_);
|
|
}
|
|
|
|
void ReplSemiSyncMaster::cond_broadcast()
|
|
{
|
|
pthread_cond_broadcast(&COND_binlog_send_);
|
|
}
|
|
|
|
int ReplSemiSyncMaster::cond_timewait(struct timespec *wait_time)
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::cond_timewait()";
|
|
int wait_res;
|
|
|
|
function_enter(kWho);
|
|
wait_res = pthread_cond_timedwait(&COND_binlog_send_,
|
|
&LOCK_binlog_, wait_time);
|
|
return function_exit(kWho, wait_res);
|
|
}
|
|
|
|
void ReplSemiSyncMaster::add_slave()
|
|
{
|
|
lock();
|
|
rpl_semi_sync_master_clients++;
|
|
unlock();
|
|
}
|
|
|
|
void ReplSemiSyncMaster::remove_slave()
|
|
{
|
|
lock();
|
|
rpl_semi_sync_master_clients--;
|
|
unlock();
|
|
}
|
|
|
|
bool ReplSemiSyncMaster::is_semi_sync_slave()
|
|
{
|
|
int null_value;
|
|
long long val= 0;
|
|
get_user_var_int("rpl_semi_sync_slave", &val, &null_value);
|
|
return val;
|
|
}
|
|
|
|
int ReplSemiSyncMaster::reportReplyBinlog(uint32 server_id,
|
|
const char *log_file_name,
|
|
my_off_t log_file_pos)
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::reportReplyBinlog";
|
|
int cmp;
|
|
bool can_release_threads = false;
|
|
bool need_copy_send_pos = true;
|
|
|
|
if (!(getMasterEnabled()))
|
|
return 0;
|
|
|
|
function_enter(kWho);
|
|
|
|
lock();
|
|
|
|
/* This is the real check inside the mutex. */
|
|
if (!getMasterEnabled())
|
|
goto l_end;
|
|
|
|
if (!is_on())
|
|
/* We check to see whether we can switch semi-sync ON. */
|
|
try_switch_on(server_id, log_file_name, log_file_pos);
|
|
|
|
/* The position should increase monotonically, if there is only one
|
|
* thread sending the binlog to the slave.
|
|
* In reality, to improve the transaction availability, we allow multiple
|
|
* sync replication slaves. So, if any one of them get the transaction,
|
|
* the transaction session in the primary can move forward.
|
|
*/
|
|
if (reply_file_name_inited_)
|
|
{
|
|
cmp = ActiveTranx::compare(log_file_name, log_file_pos,
|
|
reply_file_name_, reply_file_pos_);
|
|
|
|
/* If the requested position is behind the sending binlog position,
|
|
* would not adjust sending binlog position.
|
|
* We based on the assumption that there are multiple semi-sync slave,
|
|
* and at least one of them shou/ld be up to date.
|
|
* If all semi-sync slaves are behind, at least initially, the primary
|
|
* can find the situation after the waiting timeout. After that, some
|
|
* slaves should catch up quickly.
|
|
*/
|
|
if (cmp < 0)
|
|
{
|
|
/* If the position is behind, do not copy it. */
|
|
need_copy_send_pos = false;
|
|
}
|
|
}
|
|
|
|
if (need_copy_send_pos)
|
|
{
|
|
strcpy(reply_file_name_, log_file_name);
|
|
reply_file_pos_ = log_file_pos;
|
|
reply_file_name_inited_ = true;
|
|
|
|
/* Remove all active transaction nodes before this point. */
|
|
assert(active_tranxs_ != NULL);
|
|
active_tranxs_->clear_active_tranx_nodes(log_file_name, log_file_pos);
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: Got reply at (%s, %lu)", kWho,
|
|
log_file_name, (unsigned long)log_file_pos);
|
|
}
|
|
|
|
if (wait_sessions_ > 0)
|
|
{
|
|
/* Let us check if some of the waiting threads doing a trx
|
|
* commit can now proceed.
|
|
*/
|
|
cmp = ActiveTranx::compare(reply_file_name_, reply_file_pos_,
|
|
wait_file_name_, wait_file_pos_);
|
|
if (cmp >= 0)
|
|
{
|
|
/* Yes, at least one waiting thread can now proceed:
|
|
* let us release all waiting threads with a broadcast
|
|
*/
|
|
can_release_threads = true;
|
|
wait_file_name_inited_ = false;
|
|
}
|
|
}
|
|
|
|
l_end:
|
|
unlock();
|
|
|
|
if (can_release_threads)
|
|
{
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: signal all waiting threads.", kWho);
|
|
|
|
cond_broadcast();
|
|
}
|
|
|
|
return function_exit(kWho, 0);
|
|
}
|
|
|
|
int ReplSemiSyncMaster::commitTrx(const char* trx_wait_binlog_name,
|
|
my_off_t trx_wait_binlog_pos)
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::commitTrx";
|
|
|
|
function_enter(kWho);
|
|
|
|
if (getMasterEnabled() && trx_wait_binlog_name)
|
|
{
|
|
struct timeval start_tv;
|
|
struct timespec abstime;
|
|
int wait_result, start_time_err;
|
|
const char *old_msg= 0;
|
|
|
|
start_time_err = gettimeofday(&start_tv, 0);
|
|
|
|
/* Acquire the mutex. */
|
|
lock();
|
|
|
|
/* This must be called after acquired the lock */
|
|
old_msg= thd_enter_cond(NULL, &COND_binlog_send_, &LOCK_binlog_,
|
|
"Waiting for semi-sync ACK from slave");
|
|
|
|
/* This is the real check inside the mutex. */
|
|
if (!getMasterEnabled() || !is_on())
|
|
goto l_end;
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
{
|
|
sql_print_information("%s: wait pos (%s, %lu), repl(%d)\n", kWho,
|
|
trx_wait_binlog_name, (unsigned long)trx_wait_binlog_pos,
|
|
(int)is_on());
|
|
}
|
|
|
|
while (is_on())
|
|
{
|
|
if (reply_file_name_inited_)
|
|
{
|
|
int cmp = ActiveTranx::compare(reply_file_name_, reply_file_pos_,
|
|
trx_wait_binlog_name, trx_wait_binlog_pos);
|
|
if (cmp >= 0)
|
|
{
|
|
/* We have already sent the relevant binlog to the slave: no need to
|
|
* wait here.
|
|
*/
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: Binlog reply is ahead (%s, %lu),",
|
|
kWho, reply_file_name_, (unsigned long)reply_file_pos_);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Let us update the info about the minimum binlog position of waiting
|
|
* threads.
|
|
*/
|
|
if (wait_file_name_inited_)
|
|
{
|
|
int cmp = ActiveTranx::compare(trx_wait_binlog_name, trx_wait_binlog_pos,
|
|
wait_file_name_, wait_file_pos_);
|
|
if (cmp <= 0)
|
|
{
|
|
/* This thd has a lower position, let's update the minimum info. */
|
|
strcpy(wait_file_name_, trx_wait_binlog_name);
|
|
wait_file_pos_ = trx_wait_binlog_pos;
|
|
|
|
wait_backtraverse_++;
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: move back wait position (%s, %lu),",
|
|
kWho, wait_file_name_, (unsigned long)wait_file_pos_);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
strcpy(wait_file_name_, trx_wait_binlog_name);
|
|
wait_file_pos_ = trx_wait_binlog_pos;
|
|
wait_file_name_inited_ = true;
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: init wait position (%s, %lu),",
|
|
kWho, wait_file_name_, (unsigned long)wait_file_pos_);
|
|
}
|
|
|
|
if (start_time_err == 0)
|
|
{
|
|
int diff_usecs = start_tv.tv_usec + wait_timeout_ * TIME_THOUSAND;
|
|
|
|
/* Calcuate the waiting period. */
|
|
abstime.tv_sec = start_tv.tv_sec;
|
|
if (diff_usecs < TIME_MILLION)
|
|
{
|
|
abstime.tv_nsec = diff_usecs * TIME_THOUSAND;
|
|
}
|
|
else
|
|
{
|
|
while (diff_usecs >= TIME_MILLION)
|
|
{
|
|
abstime.tv_sec++;
|
|
diff_usecs -= TIME_MILLION;
|
|
}
|
|
abstime.tv_nsec = diff_usecs * TIME_THOUSAND;
|
|
}
|
|
|
|
/* In semi-synchronous replication, we wait until the binlog-dump
|
|
* thread has received the reply on the relevant binlog segment from the
|
|
* replication slave.
|
|
*
|
|
* Let us suspend this thread to wait on the condition;
|
|
* when replication has progressed far enough, we will release
|
|
* these waiting threads.
|
|
*/
|
|
wait_sessions_++;
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: wait %lu ms for binlog sent (%s, %lu)",
|
|
kWho, wait_timeout_,
|
|
wait_file_name_, (unsigned long)wait_file_pos_);
|
|
|
|
wait_result = cond_timewait(&abstime);
|
|
wait_sessions_--;
|
|
|
|
if (wait_result != 0)
|
|
{
|
|
/* This is a real wait timeout. */
|
|
sql_print_warning("Timeout waiting for reply of binlog (file: %s, pos: %lu), "
|
|
"semi-sync up to file %s, position %lu.",
|
|
trx_wait_binlog_name, (unsigned long)trx_wait_binlog_pos,
|
|
reply_file_name_, (unsigned long)reply_file_pos_);
|
|
total_wait_timeouts_++;
|
|
|
|
/* switch semi-sync off */
|
|
switch_off();
|
|
}
|
|
else
|
|
{
|
|
int wait_time;
|
|
|
|
wait_time = getWaitTime(start_tv);
|
|
if (wait_time < 0)
|
|
{
|
|
if (trace_level_ & kTraceGeneral)
|
|
{
|
|
/* This is a time/gettimeofday function call error. */
|
|
sql_print_error("Replication semi-sync gettimeofday fail1 at "
|
|
"wait position (%s, %lu)",
|
|
trx_wait_binlog_name, (unsigned long)trx_wait_binlog_pos);
|
|
}
|
|
timefunc_fails_++;
|
|
}
|
|
else
|
|
{
|
|
total_trx_wait_num_++;
|
|
total_trx_wait_time_ += wait_time;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (trace_level_ & kTraceGeneral)
|
|
{
|
|
/* This is a gettimeofday function call error. */
|
|
sql_print_error("Replication semi-sync gettimeofday fail2 at "
|
|
"wait position (%s, %lu)",
|
|
trx_wait_binlog_name, (unsigned long)trx_wait_binlog_pos);
|
|
}
|
|
timefunc_fails_++;
|
|
|
|
/* switch semi-sync off */
|
|
switch_off();
|
|
}
|
|
}
|
|
|
|
l_end:
|
|
/*
|
|
At this point, the binlog file and position of this transaction
|
|
must have been removed from ActiveTranx.
|
|
*/
|
|
assert(!active_tranxs_->is_tranx_end_pos(trx_wait_binlog_name,
|
|
trx_wait_binlog_pos));
|
|
|
|
/* Update the status counter. */
|
|
if (is_on() && rpl_semi_sync_master_clients)
|
|
enabled_transactions_++;
|
|
else
|
|
disabled_transactions_++;
|
|
|
|
/* The lock held will be released by thd_exit_cond, so no need to
|
|
call unlock() here */
|
|
thd_exit_cond(NULL, old_msg);
|
|
}
|
|
|
|
return function_exit(kWho, 0);
|
|
}
|
|
|
|
/* Indicate that semi-sync replication is OFF now.
|
|
*
|
|
* What should we do when it is disabled? The problem is that we want
|
|
* the semi-sync replication enabled again when the slave catches up
|
|
* later. But, it is not that easy to detect that the slave has caught
|
|
* up. This is caused by the fact that MySQL's replication protocol is
|
|
* asynchronous, meaning that if the master does not use the semi-sync
|
|
* protocol, the slave would not send anything to the master.
|
|
* Still, if the master is sending (N+1)-th event, we assume that it is
|
|
* an indicator that the slave has received N-th event and earlier ones.
|
|
*
|
|
* If semi-sync is disabled, all transactions still update the wait
|
|
* position with the last position in binlog. But no transactions will
|
|
* wait for confirmations and the active transaction list would not be
|
|
* maintained. In binlog dump thread, updateSyncHeader() checks whether
|
|
* the current sending event catches up with last wait position. If it
|
|
* does match, semi-sync will be switched on again.
|
|
*/
|
|
int ReplSemiSyncMaster::switch_off()
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::switch_off";
|
|
int result;
|
|
|
|
function_enter(kWho);
|
|
state_ = false;
|
|
|
|
/* Clear the active transaction list. */
|
|
assert(active_tranxs_ != NULL);
|
|
result = active_tranxs_->clear_active_tranx_nodes(NULL, 0);
|
|
|
|
switched_off_times_++;
|
|
wait_file_name_inited_ = false;
|
|
reply_file_name_inited_ = false;
|
|
sql_print_information("Semi-sync replication switched OFF.");
|
|
cond_broadcast(); /* wake up all waiting threads */
|
|
|
|
return function_exit(kWho, result);
|
|
}
|
|
|
|
int ReplSemiSyncMaster::try_switch_on(int server_id,
|
|
const char *log_file_name,
|
|
my_off_t log_file_pos)
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::try_switch_on";
|
|
bool semi_sync_on = false;
|
|
|
|
function_enter(kWho);
|
|
|
|
/* If the current sending event's position is larger than or equal to the
|
|
* 'largest' commit transaction binlog position, the slave is already
|
|
* catching up now and we can switch semi-sync on here.
|
|
* If commit_file_name_inited_ indicates there are no recent transactions,
|
|
* we can enable semi-sync immediately.
|
|
*/
|
|
if (commit_file_name_inited_)
|
|
{
|
|
int cmp = ActiveTranx::compare(log_file_name, log_file_pos,
|
|
commit_file_name_, commit_file_pos_);
|
|
semi_sync_on = (cmp >= 0);
|
|
}
|
|
else
|
|
{
|
|
semi_sync_on = true;
|
|
}
|
|
|
|
if (semi_sync_on)
|
|
{
|
|
/* Switch semi-sync replication on. */
|
|
state_ = true;
|
|
|
|
sql_print_information("Semi-sync replication switched ON with slave (server_id: %d) "
|
|
"at (%s, %lu)",
|
|
server_id, log_file_name,
|
|
(unsigned long)log_file_pos);
|
|
}
|
|
|
|
return function_exit(kWho, 0);
|
|
}
|
|
|
|
int ReplSemiSyncMaster::reserveSyncHeader(unsigned char *header,
|
|
unsigned long size)
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::reserveSyncHeader";
|
|
function_enter(kWho);
|
|
|
|
int hlen=0;
|
|
if (!is_semi_sync_slave())
|
|
{
|
|
hlen= 0;
|
|
}
|
|
else
|
|
{
|
|
/* No enough space for the extra header, disable semi-sync master */
|
|
if (sizeof(kSyncHeader) > size)
|
|
{
|
|
sql_print_warning("No enough space in the packet "
|
|
"for semi-sync extra header, "
|
|
"semi-sync replication disabled");
|
|
disableMaster();
|
|
return 0;
|
|
}
|
|
|
|
/* Set the magic number and the sync status. By default, no sync
|
|
* is required.
|
|
*/
|
|
memcpy(header, kSyncHeader, sizeof(kSyncHeader));
|
|
hlen= sizeof(kSyncHeader);
|
|
}
|
|
return function_exit(kWho, hlen);
|
|
}
|
|
|
|
int ReplSemiSyncMaster::updateSyncHeader(unsigned char *packet,
|
|
const char *log_file_name,
|
|
my_off_t log_file_pos,
|
|
uint32 server_id)
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::updateSyncHeader";
|
|
int cmp = 0;
|
|
bool sync = false;
|
|
|
|
/* If the semi-sync master is not enabled, or the slave is not a semi-sync
|
|
* target, do not request replies from the slave.
|
|
*/
|
|
if (!getMasterEnabled() || !is_semi_sync_slave())
|
|
{
|
|
sync = false;
|
|
return 0;
|
|
}
|
|
|
|
function_enter(kWho);
|
|
|
|
lock();
|
|
|
|
/* This is the real check inside the mutex. */
|
|
if (!getMasterEnabled())
|
|
{
|
|
sync = false;
|
|
goto l_end;
|
|
}
|
|
|
|
if (is_on())
|
|
{
|
|
/* semi-sync is ON */
|
|
sync = false; /* No sync unless a transaction is involved. */
|
|
|
|
if (reply_file_name_inited_)
|
|
{
|
|
cmp = ActiveTranx::compare(log_file_name, log_file_pos,
|
|
reply_file_name_, reply_file_pos_);
|
|
if (cmp <= 0)
|
|
{
|
|
/* If we have already got the reply for the event, then we do
|
|
* not need to sync the transaction again.
|
|
*/
|
|
goto l_end;
|
|
}
|
|
}
|
|
|
|
if (wait_file_name_inited_)
|
|
{
|
|
cmp = ActiveTranx::compare(log_file_name, log_file_pos,
|
|
wait_file_name_, wait_file_pos_);
|
|
}
|
|
else
|
|
{
|
|
cmp = 1;
|
|
}
|
|
|
|
/* If we are already waiting for some transaction replies which
|
|
* are later in binlog, do not wait for this one event.
|
|
*/
|
|
if (cmp >= 0)
|
|
{
|
|
/*
|
|
* We only wait if the event is a transaction's ending event.
|
|
*/
|
|
assert(active_tranxs_ != NULL);
|
|
sync = active_tranxs_->is_tranx_end_pos(log_file_name,
|
|
log_file_pos);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (commit_file_name_inited_)
|
|
{
|
|
int cmp = ActiveTranx::compare(log_file_name, log_file_pos,
|
|
commit_file_name_, commit_file_pos_);
|
|
sync = (cmp >= 0);
|
|
}
|
|
else
|
|
{
|
|
sync = true;
|
|
}
|
|
}
|
|
|
|
if (trace_level_ & kTraceDetail)
|
|
sql_print_information("%s: server(%d), (%s, %lu) sync(%d), repl(%d)",
|
|
kWho, server_id, log_file_name,
|
|
(unsigned long)log_file_pos, sync, (int)is_on());
|
|
|
|
l_end:
|
|
unlock();
|
|
|
|
/* We do not need to clear sync flag because we set it to 0 when we
|
|
* reserve the packet header.
|
|
*/
|
|
if (sync)
|
|
{
|
|
(packet)[2] = kPacketFlagSync;
|
|
}
|
|
|
|
return function_exit(kWho, 0);
|
|
}
|
|
|
|
int ReplSemiSyncMaster::writeTranxInBinlog(const char* log_file_name,
|
|
my_off_t log_file_pos)
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::writeTranxInBinlog";
|
|
int result = 0;
|
|
|
|
function_enter(kWho);
|
|
|
|
lock();
|
|
|
|
/* This is the real check inside the mutex. */
|
|
if (!getMasterEnabled())
|
|
goto l_end;
|
|
|
|
/* Update the 'largest' transaction commit position seen so far even
|
|
* though semi-sync is switched off.
|
|
* It is much better that we update commit_file_* here, instead of
|
|
* inside commitTrx(). This is mostly because updateSyncHeader()
|
|
* will watch for commit_file_* to decide whether to switch semi-sync
|
|
* on. The detailed reason is explained in function updateSyncHeader().
|
|
*/
|
|
if (commit_file_name_inited_)
|
|
{
|
|
int cmp = ActiveTranx::compare(log_file_name, log_file_pos,
|
|
commit_file_name_, commit_file_pos_);
|
|
if (cmp > 0)
|
|
{
|
|
/* This is a larger position, let's update the maximum info. */
|
|
strcpy(commit_file_name_, log_file_name);
|
|
commit_file_pos_ = log_file_pos;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
strcpy(commit_file_name_, log_file_name);
|
|
commit_file_pos_ = log_file_pos;
|
|
commit_file_name_inited_ = true;
|
|
}
|
|
|
|
if (is_on() && rpl_semi_sync_master_clients)
|
|
{
|
|
assert(active_tranxs_ != NULL);
|
|
if(active_tranxs_->insert_tranx_node(log_file_name, log_file_pos))
|
|
{
|
|
/*
|
|
if insert tranx_node failed, print a warning message
|
|
and turn off semi-sync
|
|
*/
|
|
sql_print_warning("Semi-sync failed to insert tranx_node for binlog file: %s, position: %lu",
|
|
log_file_name, (ulong)log_file_pos);
|
|
switch_off();
|
|
}
|
|
}
|
|
|
|
l_end:
|
|
unlock();
|
|
|
|
return function_exit(kWho, result);
|
|
}
|
|
|
|
int ReplSemiSyncMaster::readSlaveReply(NET *net, uint32 server_id,
|
|
const char *event_buf)
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::readSlaveReply";
|
|
const unsigned char *packet;
|
|
char log_file_name[FN_REFLEN];
|
|
my_off_t log_file_pos;
|
|
ulong packet_len;
|
|
int result = -1;
|
|
|
|
struct timeval start_tv;
|
|
int start_time_err= 0;
|
|
ulong trc_level = trace_level_;
|
|
|
|
function_enter(kWho);
|
|
|
|
assert((unsigned char)event_buf[1] == kPacketMagicNum);
|
|
if ((unsigned char)event_buf[2] != kPacketFlagSync)
|
|
{
|
|
/* current event does not require reply */
|
|
result = 0;
|
|
goto l_end;
|
|
}
|
|
|
|
if (trc_level & kTraceNetWait)
|
|
start_time_err = gettimeofday(&start_tv, 0);
|
|
|
|
/* We flush to make sure that the current event is sent to the network,
|
|
* instead of being buffered in the TCP/IP stack.
|
|
*/
|
|
if (net_flush(net))
|
|
{
|
|
sql_print_error("Semi-sync master failed on net_flush() "
|
|
"before waiting for slave reply");
|
|
goto l_end;
|
|
}
|
|
|
|
net_clear(net, 0);
|
|
if (trc_level & kTraceDetail)
|
|
sql_print_information("%s: Wait for replica's reply", kWho);
|
|
|
|
/* Wait for the network here. Though binlog dump thread can indefinitely wait
|
|
* here, transactions would not wait indefintely.
|
|
* Transactions wait on binlog replies detected by binlog dump threads. If
|
|
* binlog dump threads wait too long, transactions will timeout and continue.
|
|
*/
|
|
packet_len = my_net_read(net);
|
|
|
|
if (trc_level & kTraceNetWait)
|
|
{
|
|
if (start_time_err != 0)
|
|
{
|
|
sql_print_error("Semi-sync master wait for reply "
|
|
"gettimeofday fail to get start time");
|
|
timefunc_fails_++;
|
|
}
|
|
else
|
|
{
|
|
int wait_time;
|
|
|
|
wait_time = getWaitTime(start_tv);
|
|
if (wait_time < 0)
|
|
{
|
|
sql_print_error("Semi-sync master wait for reply "
|
|
"gettimeofday fail to get wait time.");
|
|
timefunc_fails_++;
|
|
}
|
|
else
|
|
{
|
|
total_net_wait_num_++;
|
|
total_net_wait_time_ += wait_time;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (packet_len == packet_error || packet_len < REPLY_BINLOG_NAME_OFFSET)
|
|
{
|
|
if (packet_len == packet_error)
|
|
sql_print_error("Read semi-sync reply network error: %s (errno: %d)",
|
|
net->last_error, net->last_errno);
|
|
else
|
|
sql_print_error("Read semi-sync reply length error: %s (errno: %d)",
|
|
net->last_error, net->last_errno);
|
|
goto l_end;
|
|
}
|
|
|
|
packet = net->read_pos;
|
|
if (packet[REPLY_MAGIC_NUM_OFFSET] != ReplSemiSyncMaster::kPacketMagicNum)
|
|
{
|
|
sql_print_error("Read semi-sync reply magic number error");
|
|
goto l_end;
|
|
}
|
|
|
|
log_file_pos = uint8korr(packet + REPLY_BINLOG_POS_OFFSET);
|
|
strcpy(log_file_name, (const char*)packet + REPLY_BINLOG_NAME_OFFSET);
|
|
|
|
if (trc_level & kTraceDetail)
|
|
sql_print_information("%s: Got reply (%s, %lu)",
|
|
kWho, log_file_name, (ulong)log_file_pos);
|
|
|
|
result = reportReplyBinlog(server_id, log_file_name, log_file_pos);
|
|
|
|
l_end:
|
|
return function_exit(kWho, result);
|
|
}
|
|
|
|
|
|
int ReplSemiSyncMaster::resetMaster()
|
|
{
|
|
const char *kWho = "ReplSemiSyncMaster::resetMaster";
|
|
int result = 0;
|
|
|
|
function_enter(kWho);
|
|
|
|
|
|
lock();
|
|
|
|
state_ = getMasterEnabled()? 1 : 0;
|
|
|
|
wait_file_name_inited_ = false;
|
|
reply_file_name_inited_ = false;
|
|
commit_file_name_inited_ = false;
|
|
|
|
enabled_transactions_ = 0;
|
|
disabled_transactions_ = 0;
|
|
switched_off_times_ = 0;
|
|
timefunc_fails_ = 0;
|
|
wait_sessions_ = 0;
|
|
wait_backtraverse_ = 0;
|
|
total_trx_wait_num_ = 0;
|
|
total_trx_wait_time_ = 0;
|
|
total_net_wait_num_ = 0;
|
|
total_net_wait_time_ = 0;
|
|
|
|
unlock();
|
|
|
|
return function_exit(kWho, result);
|
|
}
|
|
|
|
void ReplSemiSyncMaster::setExportStats()
|
|
{
|
|
lock();
|
|
|
|
rpl_semi_sync_master_status = state_ && rpl_semi_sync_master_clients;
|
|
rpl_semi_sync_master_yes_transactions = enabled_transactions_;
|
|
rpl_semi_sync_master_no_transactions = disabled_transactions_;
|
|
rpl_semi_sync_master_off_times = switched_off_times_;
|
|
rpl_semi_sync_master_timefunc_fails = timefunc_fails_;
|
|
rpl_semi_sync_master_num_timeouts = total_wait_timeouts_;
|
|
rpl_semi_sync_master_wait_sessions = wait_sessions_;
|
|
rpl_semi_sync_master_back_wait_pos = wait_backtraverse_;
|
|
rpl_semi_sync_master_trx_wait_num = total_trx_wait_num_;
|
|
rpl_semi_sync_master_trx_wait_time =
|
|
((total_trx_wait_num_) ?
|
|
(unsigned long)((double)total_trx_wait_time_ /
|
|
((double)total_trx_wait_num_)) : 0);
|
|
rpl_semi_sync_master_net_wait_num = total_net_wait_num_;
|
|
rpl_semi_sync_master_net_wait_time =
|
|
((total_net_wait_num_) ?
|
|
(unsigned long)((double)total_net_wait_time_ /
|
|
((double)total_net_wait_num_)) : 0);
|
|
|
|
rpl_semi_sync_master_net_wait_total_time = total_net_wait_time_;
|
|
rpl_semi_sync_master_trx_wait_total_time = total_trx_wait_time_;
|
|
|
|
unlock();
|
|
}
|
|
|
|
/* Get the waiting time given the wait's staring time.
|
|
*
|
|
* Return:
|
|
* >= 0: the waiting time in microsecons(us)
|
|
* < 0: error in gettimeofday or time back traverse
|
|
*/
|
|
static int getWaitTime(const struct timeval& start_tv)
|
|
{
|
|
unsigned long long start_usecs, end_usecs;
|
|
struct timeval end_tv;
|
|
int end_time_err;
|
|
|
|
/* Starting time in microseconds(us). */
|
|
start_usecs = start_tv.tv_sec * TIME_MILLION + start_tv.tv_usec;
|
|
|
|
/* Get the wait time interval. */
|
|
end_time_err = gettimeofday(&end_tv, 0);
|
|
|
|
/* Ending time in microseconds(us). */
|
|
end_usecs = end_tv.tv_sec * TIME_MILLION + end_tv.tv_usec;
|
|
|
|
if (end_time_err != 0 || end_usecs < start_usecs)
|
|
return -1;
|
|
|
|
return (int)(end_usecs - start_usecs);
|
|
}
|