Moved semisync from a plugin to normal server

Part of MDEV-13073 AliSQL Optimize performance of semisync

Did the following renames to match other similar variables
key_ss_mutex_LOCK_binlog_       > key_LOCK_bing
key_ss_cond_COND_binlog_send_  -> key_COND_binlog_send
COND_binlog_send_              -> COND_binlog_send
LOCK_binlog_                   -> LOCK_binlog

debian/mariadb-server-10.2.install does not install semisync libs.

1 files changed, 288 insertions, 0 deletions

diff --git a/sql/semisync_slave.cc b/sql/semisync_slave.cc
new file mode 100644
index 00000000000..63bf9dca0e8
--- /dev/null
+++ b/sql/semisync_slave.cc
@@ -0,0 +1,288 @@
+/* Copyright (c) 2008 MySQL AB, 2009 Sun Microsystems, Inc.
+   Use is subject to license terms.
+
+   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 <my_global.h>
+#include "semisync_slave.h"
+
+my_bool rpl_semi_sync_slave_enabled;
+my_bool rpl_semi_sync_slave_status= 0;
+ulong rpl_semi_sync_slave_trace_level;
+ReplSemiSyncSlave repl_semisync_slave;
+
+/*
+  indicate whether or not the slave should send a reply to the master.
+
+  This is set to true in repl_semi_slave_read_event if the current
+  event read is the last event of a transaction. And the value is
+  checked in repl_semi_slave_queue_event.
+*/
+bool semi_sync_need_reply= false;
+
+
+int ReplSemiSyncSlave::initObject()
+{
+  int result= 0;
+  const char *kWho = "ReplSemiSyncSlave::initObject";
+
+  if (init_done_)
+  {
+    fprintf(stderr, "%s called twice\n", kWho);
+    return 1;
+  }
+  init_done_ = true;
+
+  /* References to the parameter works after set_options(). */
+  setSlaveEnabled(rpl_semi_sync_slave_enabled);
+  setTraceLevel(rpl_semi_sync_slave_trace_level);
+
+  return result;
+}
+
+int ReplSemiSyncSlave::slaveReadSyncHeader(const char *header,
+                                      unsigned long total_len,
+                                      bool  *need_reply,
+                                      const char **payload,
+                                      unsigned long *payload_len)
+{
+  const char *kWho = "ReplSemiSyncSlave::slaveReadSyncHeader";
+  int read_res = 0;
+  function_enter(kWho);
+
+  if ((unsigned char)(header[0]) == kPacketMagicNum)
+  {
+    *need_reply  = (header[1] & kPacketFlagSync);
+    *payload_len = total_len - 2;
+    *payload     = header + 2;
+
+    if (trace_level_ & kTraceDetail)
+      sql_print_information("%s: reply - %d", kWho, *need_reply);
+  }
+  else
+  {
+    sql_print_error("Missing magic number for semi-sync packet, packet "
+                    "len: %lu", total_len);
+    read_res = -1;
+  }
+
+  return function_exit(kWho, read_res);
+}
+
+int ReplSemiSyncSlave::slaveStart(Binlog_relay_IO_param *param)
+{
+  bool semi_sync= getSlaveEnabled();
+
+  sql_print_information("Slave I/O thread: Start %s replication to\
+ master '%s@%s:%d' in log '%s' at position %lu",
+			semi_sync ? "semi-sync" : "asynchronous",
+			param->user, param->host, param->port,
+			param->master_log_name[0] ? param->master_log_name : "FIRST",
+			(unsigned long)param->master_log_pos);
+
+  if (semi_sync && !rpl_semi_sync_slave_status)
+    rpl_semi_sync_slave_status= 1;
+  return 0;
+}
+
+int ReplSemiSyncSlave::slaveStop(Binlog_relay_IO_param *param)
+{
+  if (rpl_semi_sync_slave_status)
+    rpl_semi_sync_slave_status= 0;
+  if (mysql_reply)
+    mysql_close(mysql_reply);
+  mysql_reply= 0;
+  return 0;
+}
+
+int ReplSemiSyncSlave::slaveReply(MYSQL *mysql,
+                                 const char *binlog_filename,
+                                 my_off_t binlog_filepos)
+{
+  const char *kWho = "ReplSemiSyncSlave::slaveReply";
+  NET *net= &mysql->net;
+  uchar reply_buffer[REPLY_MAGIC_NUM_LEN
+                     + REPLY_BINLOG_POS_LEN
+                     + REPLY_BINLOG_NAME_LEN];
+  int  reply_res, name_len = strlen(binlog_filename);
+
+  function_enter(kWho);
+
+  /* Prepare the buffer of the reply. */
+  reply_buffer[REPLY_MAGIC_NUM_OFFSET] = kPacketMagicNum;
+  int8store(reply_buffer + REPLY_BINLOG_POS_OFFSET, binlog_filepos);
+  memcpy(reply_buffer + REPLY_BINLOG_NAME_OFFSET,
+         binlog_filename,
+         name_len + 1 /* including trailing '\0' */);
+
+  if (trace_level_ & kTraceDetail)
+    sql_print_information("%s: reply (%s, %lu)", kWho,
+                          binlog_filename, (ulong)binlog_filepos);
+
+  net_clear(net, 0);
+  /* Send the reply. */
+  reply_res = my_net_write(net, reply_buffer,
+                           name_len + REPLY_BINLOG_NAME_OFFSET);
+  if (!reply_res)
+  {
+    reply_res = net_flush(net);
+    if (reply_res)
+      sql_print_error("Semi-sync slave net_flush() reply failed");
+  }
+  else
+  {
+    sql_print_error("Semi-sync slave send reply failed: %s (%d)",
+                    net->last_error, net->last_errno);
+  }
+
+  return function_exit(kWho, reply_res);
+}
+
+/***************************************************************************
+ Semisync slave interface setup and deinit
+***************************************************************************/
+
+C_MODE_START
+
+int repl_semi_reset_slave(Binlog_relay_IO_param *param)
+{
+  // TODO: reset semi-sync slave status here
+  return 0;
+}
+
+int repl_semi_slave_request_dump(Binlog_relay_IO_param *param,
+				 uint32 flags)
+{
+  MYSQL *mysql= param->mysql;
+  MYSQL_RES *res= 0;
+  MYSQL_ROW row;
+  const char *query;
+
+  if (!repl_semisync_slave.getSlaveEnabled())
+    return 0;
+
+  /* Check if master server has semi-sync plugin installed */
+  query= "SHOW VARIABLES LIKE 'rpl_semi_sync_master_enabled'";
+  if (mysql_real_query(mysql, query, strlen(query)) ||
+      !(res= mysql_store_result(mysql)))
+  {
+    sql_print_error("Execution failed on master: %s", query);
+    return 1;
+  }
+
+  row= mysql_fetch_row(res);
+  if (!row)
+  {
+    /* Master does not support semi-sync */
+    sql_print_warning("Master server does not support semi-sync, "
+                      "fallback to asynchronous replication");
+    rpl_semi_sync_slave_status= 0;
+    mysql_free_result(res);
+    return 0;
+  }
+  mysql_free_result(res);
+
+  /*
+    Tell master dump thread that we want to do semi-sync
+    replication
+  */
+  query= "SET @rpl_semi_sync_slave= 1";
+  if (mysql_real_query(mysql, query, strlen(query)))
+  {
+    sql_print_error("Set 'rpl_semi_sync_slave=1' on master failed");
+    return 1;
+  }
+  mysql_free_result(mysql_store_result(mysql));
+  rpl_semi_sync_slave_status= 1;
+  return 0;
+}
+
+int repl_semi_slave_read_event(Binlog_relay_IO_param *param,
+			       const char *packet, unsigned long len,
+			       const char **event_buf, unsigned long *event_len)
+{
+  if (rpl_semi_sync_slave_status)
+    return repl_semisync_slave.slaveReadSyncHeader(packet, len,
+                                                   &semi_sync_need_reply,
+                                                   event_buf, event_len);
+  *event_buf= packet;
+  *event_len= len;
+  return 0;
+}
+
+int repl_semi_slave_queue_event(Binlog_relay_IO_param *param,
+				const char *event_buf,
+				unsigned long event_len,
+				uint32 flags)
+{
+  if (rpl_semi_sync_slave_status && semi_sync_need_reply)
+  {
+    /*
+      We deliberately ignore the error in slaveReply, such error
+      should not cause the slave IO thread to stop, and the error
+      messages are already reported.
+    */
+    (void) repl_semisync_slave.slaveReply(param->mysql,
+                                    param->master_log_name,
+                                    param->master_log_pos);
+  }
+  return 0;
+}
+
+int repl_semi_slave_io_start(Binlog_relay_IO_param *param)
+{
+  return repl_semisync_slave.slaveStart(param);
+}
+
+int repl_semi_slave_io_end(Binlog_relay_IO_param *param)
+{
+  return repl_semisync_slave.slaveStop(param);
+}
+
+C_MODE_END
+
+Binlog_relay_IO_observer relay_io_observer=
+{
+  sizeof(Binlog_relay_IO_observer), // len
+
+  repl_semi_slave_io_start,	// start
+  repl_semi_slave_io_end,	// stop
+  repl_semi_slave_request_dump,	// request_transmit
+  repl_semi_slave_read_event,	// after_read_event
+  repl_semi_slave_queue_event,	// after_queue_event
+  repl_semi_reset_slave,	// reset
+};
+
+static bool semi_sync_slave_inited= 0;
+
+int semi_sync_slave_init()
+{
+  void *p= 0;
+  if (repl_semisync_slave.initObject())
+    return 1;
+  if (register_binlog_relay_io_observer(&relay_io_observer, p))
+    return 1;
+  semi_sync_slave_inited= 1;
+  return 0;
+}
+
+void semi_sync_slave_deinit()
+{
+  void *p= 0;
+  if (!semi_sync_slave_inited)
+    return;
+  unregister_binlog_relay_io_observer(&relay_io_observer, p);
+  semi_sync_slave_inited= 0;
+}