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Added new rules for Master selection

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Added new rules for Master selection using replication tree
This commit is contained in:
MassimilianoPinto 2014-06-25 18:38:33 +02:00
parent 5a65bc2aaa
commit dbf12f6183
1 changed files with 74 additions and 12 deletions
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86
server/modules/routing/readwritesplit/readwritesplit.c
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@ -232,6 +232,10 @@ static void bref_set_state(backend_ref_t* bref, bref_state_t state);
static int router_handle_state_switch(DCB* dcb, DCB_REASON reason, void* data);
static BACKEND *get_root_master(
backend_ref_t *servers,
int router_nservers);
static SPINLOCK instlock;
static ROUTER_INSTANCE* instances;
@ -610,7 +614,8 @@ static void* newSession(
}
/** Copy backend pointers to router session. */
client_rses->rses_master_ref = master_ref;
ss_dassert(SERVER_IS_MASTER(master_ref->bref_backend->backend_server));
/* assert with master_host */
ss_dassert(master_host && ((*p_master_ref)->bref_backend->backend_server == master_host->backend_server) && SERVER_MASTER);
client_rses->rses_backend_ref = backend_ref;
client_rses->rses_nbackends = router_nservers; /*< # of backend servers */
client_rses->rses_capabilities = RCAP_TYPE_STMT_INPUT;
@ -791,6 +796,7 @@ static bool get_dcb(
int smallest_nconn = -1;
int i;
bool succp = false;
BACKEND *master_host = NULL;
CHK_CLIENT_RSES(rses);
ss_dassert(p_dcb != NULL && *(p_dcb) == NULL);
@ -801,13 +807,18 @@ static bool get_dcb(
}
backend_ref = rses->rses_backend_ref;
/* get root master from availbal servers */
master_host = get_root_master(backend_ref, rses->rses_nbackends);
if (btype == BE_SLAVE)
{
for (i=0; i<rses->rses_nbackends; i++)
{
BACKEND* b = backend_ref[i].bref_backend;
/* check slave bit, also for relay servers (Master & Servers) */
if (BREF_IS_IN_USE((&backend_ref[i])) &&
SERVER_IS_SLAVE(b->backend_server) &&
(SERVER_IS_SLAVE(b->backend_server) || SERVER_IS_RELAY_SERVER(b->backend_server)) &&
(master_host != NULL && b->backend_server != master_host->backend_server) &&
(smallest_nconn == -1 ||
b->backend_conn_count < smallest_nconn))
{
@ -825,9 +836,10 @@ static bool get_dcb(
{
*p_dcb = backend_ref->bref_dcb;
succp = true;
/* this was changed */
ss_dassert(
SERVER_IS_MASTER(backend_ref->bref_backend->backend_server) &&
(master_host && (b->backend_server == master_host->backend_server)) &&
smallest_nconn == -1);
LOGIF(LE, (skygw_log_write_flush(
@ -847,8 +859,9 @@ static bool get_dcb(
{
BACKEND* b = backend_ref[i].bref_backend;
/* removed SERVER_IS_MASTER and use master_host */
if (BREF_IS_IN_USE((&backend_ref[i])) &&
(SERVER_IS_MASTER(b->backend_server)))
(master_host && (b->backend_server == master_host->backend_server)))
{
*p_dcb = backend_ref[i].bref_dcb;
succp = true;
@ -1475,6 +1488,7 @@ static bool select_connect_backend_servers(
const int min_nslaves = 0; /*< not configurable at the time */
bool is_synced_master;
int (*p)(const void *, const void *);
BACKEND *master_host = NULL;
if (p_master_ref == NULL || backend_ref == NULL)
{
@ -1482,7 +1496,10 @@ static bool select_connect_backend_servers(
succp = false;
goto return_succp;
}
/* get the root Master */
master_host = get_root_master(backend_ref, router_nservers);
/** Master is already chosen and connected. This is slave failure case */
if (*p_master_ref != NULL &&
BREF_IS_IN_USE((*p_master_ref)))
@ -1496,7 +1513,8 @@ static bool select_connect_backend_servers(
master_found = true;
master_connected = true;
ss_dassert(SERVER_IS_MASTER((*p_master_ref)->bref_backend->backend_server));
/* assert with master_host */
ss_dassert(master_host && ((*p_master_ref)->bref_backend->backend_server == master_host->backend_server) && SERVER_MASTER);
}
/** New session or master failure case */
else
@ -1547,8 +1565,9 @@ static bool select_connect_backend_servers(
b->backend_conn_count)));
}
#endif
/* assert with master_host */
ss_dassert(!master_connected ||
SERVER_IS_MASTER((*p_master_ref)->bref_backend->backend_server));
(master_host && ((*p_master_ref)->bref_backend->backend_server == master_host->backend_server) && SERVER_MASTER));
/**
* Sort the pointer list to servers according to connection counts. As
* a consequence those backends having least connections are in the
@ -1613,13 +1632,15 @@ static bool select_connect_backend_servers(
STRSRVSTATUS(b->backend_server),
b->backend_conn_count,
router->bitmask)));
if (SERVER_IS_RUNNING(b->backend_server) &&
((b->backend_server->status & router->bitmask) ==
router->bitvalue))
{
/* check also for relay servers and don't take the master_host */
if (slaves_found < max_nslaves &&
SERVER_IS_SLAVE(b->backend_server))
(SERVER_IS_SLAVE(b->backend_server) || SERVER_IS_RELAY_SERVER(b->backend_server)) &&
(master_host != NULL && (b->backend_server != master_host->backend_server)))
{
slaves_found += 1;
@ -1680,7 +1701,8 @@ static bool select_connect_backend_servers(
}
}
}
else if (SERVER_IS_MASTER(b->backend_server))
/* take the master_host for master */
else if (master_host && (b->backend_server == master_host->backend_server))
{
*p_master_ref = &backend_ref[i];
@ -1747,8 +1769,9 @@ static bool select_connect_backend_servers(
b->backend_server->port,
b->backend_conn_count)));
}
/* assert with master_host */
ss_dassert(!master_connected ||
SERVER_IS_MASTER((*p_master_ref)->bref_backend->backend_server));
(master_host && ((*p_master_ref)->bref_backend->backend_server == master_host->backend_server) && SERVER_MASTER));
#endif
/**
@ -2977,3 +3000,42 @@ static int router_handle_state_switch(
return_rc:
return rc;
}
static BACKEND *get_root_master(backend_ref_t *servers, int router_nservers) {
int i = 0;
BACKEND * master_host = NULL;
/* (1) find root server(s) with lowest replication depth level */
for (i = 0; i< router_nservers; i++) {
BACKEND* b = NULL;
b = servers[i].bref_backend;
if (b && SERVER_IS_RUNNING(b->backend_server)) {
if (master_host && b->backend_server->depth < master_host->backend_server->depth) {
master_host = b;
} else {
if (master_host == NULL) {
master_host = b;
}
}
}
}
/* (2) get the status of server(s) with lowest replication level and check it against SERVER_MASTER bitvalue */
if (master_host) {
int found = 0;
for (i = 0; i<router_nservers; i++) {
BACKEND* b = NULL;
b = servers[i].bref_backend;
if (b && SERVER_IS_RUNNING(b->backend_server) && (b->backend_server->depth == master_host->backend_server->depth)) {
if (b->backend_server->status & SERVER_MASTER) {
master_host = b;
found = 1;
}
}
}
if (!found)
master_host = NULL;
}
return master_host;
}