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Added mechanism for choosing slave for a query based on the current load in all connected slaves. Counting operations is not correctly done here. Reading values and choosing accordingly is done.

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Fixed several things in session command reply processing.
This commit is contained in:
VilhoRaatikka
2014-06-29 22:21:30 +03:00
parent 20637ee224
commit fcf67716fd
10 changed files with 593 additions and 297 deletions
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196
server/modules/routing/readwritesplit/readwritesplit.c
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@ -115,12 +115,18 @@ int bref_cmp_behind_master(
const void* bref1,
const void* bref2);
int bref_cmp_current_load(
const void* bref1,
const void* bref2);
int (*criteria_cmpfun[LAST_CRITERIA])(const void*, const void*)=
{
NULL,
bref_cmp_global_conn,
bref_cmp_router_conn,
bref_cmp_behind_master
bref_cmp_behind_master,
bref_cmp_current_load
};
static bool select_connect_backend_servers(
@ -460,7 +466,6 @@ static void* newSession(
int max_nslaves; /*< max # of slaves used in this session */
int i;
const int min_nservers = 1; /*< hard-coded for now */
static uint64_t router_client_ses_seq; /*< ID for client session */
client_rses = (ROUTER_CLIENT_SES *)calloc(1, sizeof(ROUTER_CLIENT_SES));
@ -1105,11 +1110,11 @@ static int routeQuery(
{
atomic_add(&inst->stats.n_slave, 1);
/**
* This backend_ref waits resultset, flag it.
* Add one waiter to backend reference
*/
bref_set_state(get_bref_from_dcb(router_cli_ses,
slave_dcb),
BREF_WAITING_RESULT);
BREF_WAITING_RESULT);
}
else
{
@ -1154,15 +1159,14 @@ static int routeQuery(
{
succp = get_dcb(&master_dcb, router_cli_ses, BE_MASTER);
}
if (succp)
{
if ((ret = master_dcb->func.write(master_dcb, querybuf)) == 1)
{
atomic_add(&inst->stats.n_master, 1);
/**
* This backend_ref waits reply to write stmt,
* flag it.
* Add one waiter to backend reference.
*/
bref_set_state(get_bref_from_dcb(router_cli_ses, master_dcb),
BREF_WAITING_RESULT);
@ -1368,8 +1372,7 @@ static void clientReply (
scur = &bref->bref_sescmd_cur;
/**
* Active cursor means that reply is from session command
* execution. Majority of the time there are no session commands
* being executed.
* execution.
*/
if (sescmd_cursor_is_active(scur))
{
@ -1380,8 +1383,7 @@ static void clientReply (
(uint8_t *)GWBUF_DATA((scur->scmd_cur_cmd->my_sescmd_buf));
size_t len = MYSQL_GET_PACKET_LEN(buf);
char* cmdstr = (char *)malloc(len+1);
ROUTER_INSTANCE* inst = (ROUTER_INSTANCE *)instance;
snprintf(cmdstr, len+1, "%s", &buf[5]);
LOGIF(LE, (skygw_log_write_flush(
@ -1393,13 +1395,13 @@ static void clientReply (
free(cmdstr);
/** Inform the client */
handle_error_reply_client(ses,writebuf);
handle_error_reply_client(ses, writebuf);
/** Unlock router session */
rses_end_locked_router_action(router_cli_ses);
goto lock_failed;
}
else
else if (GWBUF_IS_TYPE_SESCMD_RESPONSE(writebuf))
{
/**
* Discard all those responses that have already been sent to
@ -1407,8 +1409,12 @@ static void clientReply (
* needs to be sent to client or NULL.
*/
writebuf = sescmd_cursor_process_replies(client_dcb,
writebuf,
bref);
writebuf,
bref);
}
else
{
ss_dassert(false);
}
}
@ -1416,7 +1422,9 @@ static void clientReply (
{
/** Write reply to client DCB */
SESSION_ROUTE_REPLY(backend_dcb->session, writebuf);
#if 0
bref_clear_state(bref, BREF_WAITING_RESULT);
#endif
}
/** Unlock router session */
rses_end_locked_router_action(router_cli_ses);
@ -1427,7 +1435,7 @@ static void clientReply (
/** Log to debug that router was closed */
goto lock_failed;
}
/** There is one pending session command to be xexecuted. */
/** There is one pending session command to be executed. */
if (sescmd_cursor_is_active(scur))
{
bool succp;
@ -1479,21 +1487,78 @@ int bref_cmp_behind_master(
return 1;
}
int bref_cmp_current_load(
const void* bref1,
const void* bref2)
{
SERVER* s1 = ((backend_ref_t *)bref1)->bref_backend->backend_server;
SERVER* s2 = ((backend_ref_t *)bref2)->bref_backend->backend_server;
return ((s1->stats.n_current_ops < s2->stats.n_current_ops) ? -1 :
((s1->stats.n_current_ops > s2->stats.n_current_ops) ? 1 : 0));
}
static void bref_clear_state(
backend_ref_t* bref,
bref_state_t state)
{
bref->bref_state &= ~state;
if (state != BREF_WAITING_RESULT)
{
bref->bref_state &= ~state;
}
else
{
int prev1;
int prev2;
prev1 = atomic_add(&bref->bref_num_result_wait, -1);
ss_dassert(prev1 >= 0);
prev2 = atomic_add(
&bref->bref_backend->backend_server->stats.n_current_ops, -1);
ss_dassert(prev2 >= 0);
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Current waiters %d and ops %d after in %s:%d",
prev1-1,
prev2-1,
bref->bref_backend->backend_server->name,
bref->bref_backend->backend_server->port)));
}
}
static void bref_set_state(
backend_ref_t* bref,
bref_state_t state)
{
bref->bref_state |= state;
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Set state %d for %s:%d fd %d",
if (state != BREF_WAITING_RESULT)
{
bref->bref_state |= state;
}
else
{
int prev1;
int prev2;
prev1 = atomic_add(&bref->bref_num_result_wait, 1);
ss_dassert(prev1 >= 0);
prev2 = atomic_add(
&bref->bref_backend->backend_server->stats.n_current_ops, 1);
ss_dassert(prev2 >= 0);
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Current waiters %d and ops %d before in %s:%d",
prev1,
prev2,
bref->bref_backend->backend_server->name,
bref->bref_backend->backend_server->port)));
}
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [bref_set_state] Set state %d for %s:%d fd %d",
pthread_self(),
bref->bref_state,
bref->bref_backend->backend_server->name,
bref->bref_backend->backend_server->port,
@ -1662,6 +1727,13 @@ static bool select_connect_backend_servers(
b->backend_conn_count)));
break;
case LEAST_CURRENT_OPERATIONS:
LOGIF(LT, (skygw_log_write_flush(LOGFILE_TRACE,
"%s %d:%d",
b->backend_server->name,
b->backend_server->port,
b->backend_server->stats.n_current_ops)));
break;
default:
break;
}
@ -1681,13 +1753,11 @@ static bool select_connect_backend_servers(
LOGIF(LT, (skygw_log_write_flush(
LOGFILE_TRACE,
"Examine server "
"%s:%d %s with %d connections. "
"router->bitvalue is %d",
"%s:%d %s with %d active operations.",
b->backend_server->name,
b->backend_server->port,
STRSRVSTATUS(b->backend_server),
b->backend_conn_count,
router->bitmask)));
b->backend_server->stats.n_current_ops)));
if (SERVER_IS_RUNNING(b->backend_server) &&
((b->backend_server->status & router->bitmask) ==
@ -2195,35 +2265,27 @@ static GWBUF* sescmd_cursor_process_replies(
/** Faster backend has already responded to client : discard */
if (scmd->my_sescmd_is_replied)
{
bool last_packet = false;
CHK_GWBUF(replybuf);
packet = (uint8_t *)GWBUF_DATA(replybuf);
/**
* If it is response to MYSQL_COM_STMT_PREPARE, then buffer
* only includes the response.
*/
if (scmd->my_sescmd_prop->rses_prop_data.sescmd.my_sescmd_packet_type ==
MYSQL_COM_STMT_PREPARE)
while (!last_packet)
{
while (replybuf != NULL)
{
#if defined(SS_DEBUG)
int buflen;
buflen = GWBUF_LENGTH(replybuf);
replybuf = gwbuf_consume(replybuf, buflen);
#else
replybuf = gwbuf_consume(
replybuf,
GWBUF_LENGTH(replybuf));
int buflen;
buflen = GWBUF_LENGTH(replybuf);
ss_debug(GWBUF_IS_TYPE_SESCMD_RESPONSE(replybuf) ==
(scmd->my_sescmd_packet_type == MYSQL_COM_STMT_PREPARE));
last_packet = GWBUF_IS_TYPE_RESPONSE_END(replybuf);
/** discard packet */
replybuf = gwbuf_consume(replybuf, buflen);
}
#if 0
bref_clear_state(bref, BREF_WAITING_RESULT);
#endif
}
}
/** Only consume the leading packet */
else
{
packetlen = packet[0]+packet[1]*256+packet[2]*256*256;
replybuf = gwbuf_consume(replybuf, packetlen+headerlen);
}
}
/** Response is in the buffer and it will be sent to client. */
else if (replybuf != NULL)
@ -2408,7 +2470,7 @@ static bool execute_sescmd_in_backend(
goto return_succp;
}
if (!sescmd_cursor_is_active(scur))
{
/** Cursor is left active when function returns. */
@ -2425,9 +2487,11 @@ static bool execute_sescmd_in_backend(
uint8_t* ptr = GWBUF_DATA(tmpbuf);
unsigned char cmd = MYSQL_GET_COMMAND(ptr);
LOGIF(LT, (skygw_log_write(
LOGFILE_TRACE,
"Just before write, fd %d : cmd %s.",
LOGIF(LD, (skygw_log_write(
LOGFILE_DEBUG,
"%lu [execute_sescmd_in_backend] Just before write, fd "
"%d : cmd %s.",
pthread_self(),
dcb->fd,
STRPACKETTYPE(cmd))));
}
@ -2444,6 +2508,11 @@ static bool execute_sescmd_in_backend(
case MYSQL_COM_QUERY:
case MYSQL_COM_INIT_DB:
default:
/**
* Mark session command buffer, it triggers writing
* MySQL command to protocol
*/
gwbuf_set_type(scur->scmd_cur_cmd->my_sescmd_buf, GWBUF_TYPE_SESCMD);
rc = dcb->func.write(
dcb,
sescmd_cursor_clone_querybuf(scur));
@ -2723,14 +2792,13 @@ static bool route_session_write(
rses_property_done(prop);
succp = false;
goto return_succp;
}
prop = rses_property_init(RSES_PROP_TYPE_SESCMD);
}
/**
* Additional reference is created to querybuf to
* prevent it from being released before properties
* are cleaned up as a part of router sessionclean-up.
*/
prop = rses_property_init(RSES_PROP_TYPE_SESCMD);
mysql_sescmd_init(prop, querybuf, packet_type, router_cli_ses);
/** Add sescmd property to router client session */
@ -2745,12 +2813,11 @@ static bool route_session_write(
scur = backend_ref_get_sescmd_cursor(&backend_ref[i]);
/**
* This backend_ref waits reply, flag it.
* Add one waiter to backend reference.
*/
bref_set_state(get_bref_from_dcb(router_cli_ses,
backend_ref[i].bref_dcb),
BREF_WAITING_RESULT);
BREF_WAITING_RESULT);
/**
* Start execution if cursor is not already executing.
* Otherwise, cursor will execute pending commands
@ -2820,6 +2887,7 @@ static void rwsplit_process_options(
c == LEAST_GLOBAL_CONNECTIONS ||
c == LEAST_ROUTER_CONNECTIONS ||
c == LEAST_BEHIND_MASTER ||
c == LEAST_CURRENT_OPERATIONS ||
c == UNDEFINED_CRITERIA);
if (c == UNDEFINED_CRITERIA)
@ -2829,7 +2897,7 @@ static void rwsplit_process_options(
"slave selection criteria \"%s\". "
"Allowed values are \"LEAST_GLOBAL_CONNECTIONS\", "
"LEAST_ROUTER_CONNECTIONS, "
"and \"LEAST_ROUTER_CONNECTIONS\".",
"and \"LEAST_CURRENT_OPERATIONS\".",
STRCRITERIA(router->rwsplit_config.rw_slave_select_criteria))));
}
else
@ -2957,7 +3025,6 @@ static bool handle_error_new_connection(
/** failed DCB has already been replaced */
if (bref == NULL)
{
rses_end_locked_router_action(rses);
succp = true;
goto return_succp;
}
@ -2968,7 +3035,6 @@ static bool handle_error_new_connection(
*/
if (backend_dcb->state != DCB_STATE_POLLING)
{
rses_end_locked_router_action(rses);
succp = true;
goto return_succp;
}
@ -2980,7 +3046,9 @@ static bool handle_error_new_connection(
DCB* client_dcb;
client_dcb = ses->client;
client_dcb->func.write(client_dcb, errmsg);
bref_clear_state(bref, BREF_WAITING_RESULT);
#if 0
bref_clear_state(bref, BREF_WAITING_RESULT);
#endif
}
bref_clear_state(bref, BREF_IN_USE);
bref_set_state(bref, BREF_CLOSED);