Add global variable mysql-kill_backend_connection_when_disconnect

include/MySQL_Thread.h

@@ -415,6 +415,7 @@ class MySQL_Threads_Handler
  int query_cache_size_MB;
  bool stats_time_backend_query;
  bool stats_time_query_processor;
+ bool kill_backend_connection_when_disconnect;
  } variables;
  struct {
  unsigned int mirror_sessions_current;

include/proxysql_structs.h

@@ -643,6 +643,7 @@ __thread bool mysql_thread___default_reconnect;
 __thread bool mysql_thread___session_idle_show_processlist;
 __thread bool mysql_thread___sessions_sort;
 __thread bool mysql_thread___session_idle_ms;
+__thread bool mysql_thread___kill_backend_connection_when_disconnect;
 
 /* variables used for Query Cache */
 __thread int mysql_thread___query_cache_size_MB;
@@ -750,6 +751,7 @@ extern __thread bool mysql_thread___default_reconnect;
 extern __thread bool mysql_thread___session_idle_show_processlist;
 extern __thread bool mysql_thread___sessions_sort;
 extern __thread bool mysql_thread___session_idle_ms;
+extern __thread bool mysql_thread___kill_backend_connection_when_disconnect;
 
 /* variables used for Query Cache */
 extern __thread int mysql_thread___query_cache_size_MB;

lib/MySQL_HostGroups_Manager.cpp

@@ -1531,22 +1531,24 @@ void MySQL_HostGroups_Manager::destroy_MyConn_from_pool(MySQL_Connection *c, boo
  // the connection seems health, but we are trying to destroy it
  // probably because there is a long running query
  // therefore we will try to kill the connection
- MySQL_Connection_userinfo *ui=c->userinfo;
- char *auth_password=NULL;
- if (ui->password) {
- if (ui->password[0]=='*') { // we don't have the real password, let's pass sha1
- auth_password=ui->sha1_pass;
- } else {
- auth_password=ui->password;
+ if (mysql_thread___kill_backend_connection_when_disconnect) {
+ MySQL_Connection_userinfo *ui=c->userinfo;
+ char *auth_password=NULL;
+ if (ui->password) {
+ if (ui->password[0]=='*') { // we don't have the real password, let's pass sha1
+ auth_password=ui->sha1_pass;
+ } else {
+ auth_password=ui->password;
+ }
  }
+ KillArgs *ka = new KillArgs(ui->username, auth_password, c->parent->address, c->parent->port, c->mysql->thread_id, KILL_CONNECTION);
+ pthread_attr_t attr;
+ pthread_attr_init(&attr);
+ pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+ pthread_attr_setstacksize (&attr, 256*1024);
+ pthread_t pt;
+ pthread_create(&pt, &attr, &kill_query_thread, ka);
  }
- KillArgs *ka = new KillArgs(ui->username, auth_password, c->parent->address, c->parent->port, c->mysql->thread_id, KILL_CONNECTION);
- pthread_attr_t attr;
- pthread_attr_init(&attr);
- pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
- pthread_attr_setstacksize (&attr, 256*1024);
- pthread_t pt;
- pthread_create(&pt, &attr, &kill_query_thread, ka);
  }
  }
  if (to_del) {

lib/MySQL_Thread.cpp

@@ -286,6 +286,7 @@ static char * mysql_thread_variables_names[]= {
  (char *)"poll_timeout_on_failure",
  (char *)"server_capabilities",
  (char *)"server_version",
+ (char *)"kill_backend_connection_when_disconnect",
  (char *)"sessions_sort",
 #ifdef IDLE_THREADS
  (char *)"session_idle_show_processlist",
@@ -419,6 +420,7 @@ MySQL_Threads_Handler::MySQL_Threads_Handler() {
  variables.connpoll_reset_queue_length = 50;
  variables.stats_time_backend_query=false;
  variables.stats_time_query_processor=false;
+ variables.kill_backend_connection_when_disconnect=true;
  variables.sessions_sort=true;
 #ifdef IDLE_THREADS
  variables.session_idle_ms=1000;
@@ -672,6 +674,7 @@ int MySQL_Threads_Handler::get_variable_int(char *name) {
  if (!strcasecmp(name,"connpoll_reset_queue_length")) return (int)variables.connpoll_reset_queue_length;
  if (!strcasecmp(name,"stats_time_backend_query")) return (int)variables.stats_time_backend_query;
  if (!strcasecmp(name,"stats_time_query_processor")) return (int)variables.stats_time_query_processor;
+ if (!strcasecmp(name,"kill_backend_connection_when_disconnect")) return (int)variables.kill_backend_connection_when_disconnect;
  if (!strcasecmp(name,"sessions_sort")) return (int)variables.sessions_sort;
 #ifdef IDLE_THREADS
  if (!strcasecmp(name,"session_idle_show_processlist")) return (int)variables.session_idle_show_processlist;
@@ -1052,6 +1055,9 @@ char * MySQL_Threads_Handler::get_variable(char *name) { // this is the public f
  if (!strcasecmp(name,"stats_time_query_processor")) {
  return strdup((variables.stats_time_query_processor ? "true" : "false"));
  }
+ if (!strcasecmp(name,"kill_backend_connection_when_disconnect")) {
+ return strdup((variables.kill_backend_connection_when_disconnect ? "true" : "false"));
+ }
  if (!strcasecmp(name,"sessions_sort")) {
  return strdup((variables.sessions_sort ? "true" : "false"));
  }
@@ -2033,6 +2039,17 @@ bool MySQL_Threads_Handler::set_variable(char *name, char *value) { // this is t
  }
  return false;
  }
+ if (!strcasecmp(name,"kill_backend_connection_when_disconnect")) {
+ if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
+ variables.kill_backend_connection_when_disconnect=true;
+ return true;
+ }
+ if (strcasecmp(value,"false")==0 || strcasecmp(value,"0")==0) {
+ variables.kill_backend_connection_when_disconnect=false;
+ return true;
+ }
+ return false;
+ }
  if (!strcasecmp(name,"servers_stats")) {
  if (strcasecmp(value,"true")==0 || strcasecmp(value,"1")==0) {
  variables.servers_stats=true;
@@ -3389,6 +3406,7 @@ void MySQL_Thread::refresh_variables() {
  mysql_thread___query_digests_lowercase=(bool)GloMTH->get_variable_int((char *)"query_digests_lowercase");
  variables.stats_time_backend_query=(bool)GloMTH->get_variable_int((char *)"stats_time_backend_query");
  variables.stats_time_query_processor=(bool)GloMTH->get_variable_int((char *)"stats_time_query_processor");
+ mysql_thread___kill_backend_connection_when_disconnect=(bool)GloMTH->get_variable_int((char *)"kill_backend_connection_when_disconnect");
  mysql_thread___sessions_sort=(bool)GloMTH->get_variable_int((char *)"sessions_sort");
 #ifdef IDLE_THREADS
  mysql_thread___session_idle_show_processlist=(bool)GloMTH->get_variable_int((char *)"session_idle_show_processlist");