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proxysql/lib/MySrvConnList.cpp

257 lines
11 KiB

#include "MySQL_HostGroups_Manager.h"
#include "MySQL_Data_Stream.h"
extern ProxySQL_Admin *GloAdmin;
extern MySQL_Threads_Handler *GloMTH;
extern MySQL_Monitor *GloMyMon;
class MySrvConnList;
class MySrvC;
class MySrvList;
class MyHGC;
MySQL_Connection *MySrvConnList::index(unsigned int _k) {
return (MySQL_Connection *)conns->index(_k);
}
MySQL_Connection * MySrvConnList::remove(int _k) {
return (MySQL_Connection *)conns->remove_index_fast(_k);
}
MySrvConnList::MySrvConnList(MySrvC *_mysrvc) {
mysrvc=_mysrvc;
conns=new PtrArray();
}
void MySrvConnList::add(MySQL_Connection *c) {
conns->add(c);
}
MySrvConnList::~MySrvConnList() {
mysrvc=NULL;
while (conns_length()) {
MySQL_Connection *conn=(MySQL_Connection *)conns->remove_index_fast(0);
delete conn;
}
delete conns;
}
void MySrvConnList::drop_all_connections() {
proxy_debug(PROXY_DEBUG_MYSQL_CONNPOOL, 7, "Dropping all connections (%u total) on MySrvConnList %p for server %s:%d , hostgroup=%d , status=%d\n", conns_length(), this, mysrvc->address, mysrvc->port, mysrvc->myhgc->hid, (int)mysrvc->get_status());
while (conns_length()) {
MySQL_Connection *conn=(MySQL_Connection *)conns->remove_index_fast(0);
delete conn;
}
}
void MySrvConnList::get_random_MyConn_inner_search(unsigned int start, unsigned int end, unsigned int& conn_found_idx, unsigned int& connection_quality_level, unsigned int& number_of_matching_session_variables, const MySQL_Connection * client_conn) {
char *schema = client_conn->userinfo->schemaname;
MySQL_Connection * conn=NULL;
unsigned int k;
for (k = start; k < end; k++) {
conn = (MySQL_Connection *)conns->index(k);
if (conn->match_tracked_options(client_conn)) {
if (connection_quality_level == 0) {
// this is our best candidate so far
connection_quality_level = 1;
conn_found_idx = k;
}
if (conn->requires_CHANGE_USER(client_conn)==false) {
if (connection_quality_level == 1) {
// this is our best candidate so far
connection_quality_level = 2;
conn_found_idx = k;
}
unsigned int cnt_match = 0; // number of matching session variables
unsigned int not_match = 0; // number of not matching session variables
cnt_match = conn->number_of_matching_session_variables(client_conn, not_match);
if (strcmp(conn->userinfo->schemaname,schema)==0) {
cnt_match++;
} else {
not_match++;
}
if (not_match==0) {
// it seems we found the perfect connection
number_of_matching_session_variables = cnt_match;
connection_quality_level = 3;
conn_found_idx = k;
return; // exit immediately, we found the perfect connection
} else {
// we didn't find the perfect connection
// but maybe is better than what we have so far?
if (cnt_match > number_of_matching_session_variables) {
// this is our best candidate so far
number_of_matching_session_variables = cnt_match;
conn_found_idx = k;
}
}
} else {
if (connection_quality_level == 1) {
int rca = mysql_thread___reset_connection_algorithm;
if (rca==1) {
int ql = GloMTH->variables.connpoll_reset_queue_length;
if (ql==0) {
// if:
// mysql-reset_connection_algorithm=1 and
// mysql-connpoll_reset_queue_length=0
// we will not return a connection with connection_quality_level == 1
// because we want to run COM_CHANGE_USER
// This change was introduced to work around Galera bug
// https://github.com/codership/galera/issues/613
connection_quality_level = 0;
}
}
}
}
}
}
}
MySQL_Connection * MySrvConnList::get_random_MyConn(MySQL_Session *sess, bool ff) {
MySQL_Connection * conn=NULL;
unsigned int i;
unsigned int conn_found_idx;
unsigned int l=conns_length();
unsigned int connection_quality_level = 0;
bool needs_warming = false;
// connection_quality_level:
// 0 : not found any good connection, tracked options are not OK
// 1 : tracked options are OK , but CHANGE USER is required
// 2 : tracked options are OK , CHANGE USER is not required, but some SET statement or INIT_DB needs to be executed
// 3 : tracked options are OK , CHANGE USER is not required, and it seems that SET statements or INIT_DB ARE not required
unsigned int number_of_matching_session_variables = 0; // this includes session variables AND schema
bool connection_warming = mysql_thread___connection_warming;
int free_connections_pct = mysql_thread___free_connections_pct;
if (mysrvc->myhgc->attributes.configured == true) {
// mysql_hostgroup_attributes takes priority
connection_warming = mysrvc->myhgc->attributes.connection_warming;
free_connections_pct = mysrvc->myhgc->attributes.free_connections_pct;
}
if (connection_warming == true) {
unsigned int total_connections = mysrvc->ConnectionsFree->conns_length()+mysrvc->ConnectionsUsed->conns_length();
unsigned int expected_warm_connections = free_connections_pct*mysrvc->max_connections/100;
if (total_connections < expected_warm_connections) {
needs_warming = true;
}
}
if (l && ff==false && needs_warming==false) {
if (l>32768) {
i=rand()%l;
} else {
i=fastrand()%l;
}
if (sess && sess->client_myds && sess->client_myds->myconn && sess->client_myds->myconn->userinfo) {
MySQL_Connection * client_conn = sess->client_myds->myconn;
get_random_MyConn_inner_search(i, l, conn_found_idx, connection_quality_level, number_of_matching_session_variables, client_conn);
if (connection_quality_level !=3 ) { // we didn't find the perfect connection
get_random_MyConn_inner_search(0, i, conn_found_idx, connection_quality_level, number_of_matching_session_variables, client_conn);
}
// connection_quality_level:
// 1 : tracked options are OK , but CHANGE USER is required
// 2 : tracked options are OK , CHANGE USER is not required, but some SET statement or INIT_DB needs to be executed
switch (connection_quality_level) {
case 0: // not found any good connection, tracked options are not OK
// we must check if connections need to be freed before
// creating a new connection
{
unsigned int conns_free = mysrvc->ConnectionsFree->conns_length();
unsigned int conns_used = mysrvc->ConnectionsUsed->conns_length();
unsigned int pct_max_connections = (3 * mysrvc->max_connections) / 4;
unsigned int connections_to_free = 0;
if (conns_free >= 1) {
// connection cleanup is triggered when connections exceed 3/4 of the total
// allowed max connections, this cleanup ensures that at least *one connection*
// will be freed.
if (pct_max_connections <= (conns_free + conns_used)) {
connections_to_free = (conns_free + conns_used) - pct_max_connections;
if (connections_to_free == 0) connections_to_free = 1;
}
while (conns_free && connections_to_free) {
MySQL_Connection* conn = mysrvc->ConnectionsFree->remove(0);
delete conn;
conns_free = mysrvc->ConnectionsFree->conns_length();
connections_to_free -= 1;
}
}
// we must create a new connection
conn = new MySQL_Connection();
conn->parent=mysrvc;
// if attributes.multiplex == true , STATUS_MYSQL_CONNECTION_NO_MULTIPLEX_HG is set to false. And vice-versa
conn->set_status(!conn->parent->myhgc->attributes.multiplex, STATUS_MYSQL_CONNECTION_NO_MULTIPLEX_HG);
__sync_fetch_and_add(&MyHGM->status.server_connections_created, 1);
proxy_debug(PROXY_DEBUG_MYSQL_CONNPOOL, 7, "Returning MySQL Connection %p, server %s:%d\n", conn, conn->parent->address, conn->parent->port);
}
break;
case 1: //tracked options are OK , but CHANGE USER is required
// we may consider creating a new connection
{
unsigned int conns_free = mysrvc->ConnectionsFree->conns_length();
unsigned int conns_used = mysrvc->ConnectionsUsed->conns_length();
if ((conns_used > conns_free) && (mysrvc->max_connections > (conns_free/2 + conns_used/2)) ) {
conn = new MySQL_Connection();
conn->parent=mysrvc;
// if attributes.multiplex == true , STATUS_MYSQL_CONNECTION_NO_MULTIPLEX_HG is set to false. And vice-versa
conn->set_status(!conn->parent->myhgc->attributes.multiplex, STATUS_MYSQL_CONNECTION_NO_MULTIPLEX_HG);
__sync_fetch_and_add(&MyHGM->status.server_connections_created, 1);
proxy_debug(PROXY_DEBUG_MYSQL_CONNPOOL, 7, "Returning MySQL Connection %p, server %s:%d\n", conn, conn->parent->address, conn->parent->port);
} else {
conn=(MySQL_Connection *)conns->remove_index_fast(conn_found_idx);
}
}
break;
case 2: // tracked options are OK , CHANGE USER is not required, but some SET statement or INIT_DB needs to be executed
case 3: // tracked options are OK , CHANGE USER is not required, and it seems that SET statements or INIT_DB ARE not required
// here we return the best connection we have, no matter if connection_quality_level is 2 or 3
conn=(MySQL_Connection *)conns->remove_index_fast(conn_found_idx);
break;
default: // this should never happen
// LCOV_EXCL_START
assert(0);
break;
// LCOV_EXCL_STOP
}
} else {
conn=(MySQL_Connection *)conns->remove_index_fast(i);
}
proxy_debug(PROXY_DEBUG_MYSQL_CONNPOOL, 7, "Returning MySQL Connection %p, server %s:%d\n", conn, conn->parent->address, conn->parent->port);
return conn;
} else {
unsigned long long curtime = monotonic_time();
curtime = curtime / 1000 / 1000; // convert to second
MyHGC *_myhgc = mysrvc->myhgc;
if (curtime > _myhgc->current_time_now) {
_myhgc->current_time_now = curtime;
_myhgc->new_connections_now = 0;
}
_myhgc->new_connections_now++;
unsigned int throttle_connections_per_sec_to_hostgroup = (unsigned int) mysql_thread___throttle_connections_per_sec_to_hostgroup;
if (_myhgc->attributes.configured == true) {
// mysql_hostgroup_attributes takes priority
throttle_connections_per_sec_to_hostgroup = _myhgc->attributes.throttle_connections_per_sec;
}
if (_myhgc->new_connections_now > (unsigned int) throttle_connections_per_sec_to_hostgroup) {
__sync_fetch_and_add(&MyHGM->status.server_connections_delayed, 1);
return NULL;
} else {
conn = new MySQL_Connection();
conn->parent=mysrvc;
// if attributes.multiplex == true , STATUS_MYSQL_CONNECTION_NO_MULTIPLEX_HG is set to false. And vice-versa
conn->set_status(!conn->parent->myhgc->attributes.multiplex, STATUS_MYSQL_CONNECTION_NO_MULTIPLEX_HG);
__sync_fetch_and_add(&MyHGM->status.server_connections_created, 1);
proxy_debug(PROXY_DEBUG_MYSQL_CONNPOOL, 7, "Returning MySQL Connection %p, server %s:%d\n", conn, conn->parent->address, conn->parent->port);
return conn;
}
}
return NULL; // never reach here
}