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MXS-1777 Changing server weights to match 2.2 behavior.

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Match 2.2, changed the weights back to non-inverse because 0-weight
is a special case. Renamed to server_weight for greppability.
This commit is contained in:
Niclas Antti 2018-09-24 12:05:47 +03:00
parent d0c5b2ff61
commit 7d231e5328
5 changed files with 30 additions and 29 deletions
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2
include/maxscale/service.h
View File

@ -63,7 +63,7 @@ typedef struct server_ref_t
{
struct server_ref_t* next; /**< Next server reference */
SERVER* server; /**< The actual server */
double inv_weight; /**< Inverse of weight in the range [0..1], 0 is best. */
double server_weight; /**< Weight in the range [0..1]. 0 is worst, and a special case. */
int connections; /**< Number of connections created through this reference */
bool active; /**< Whether this reference is valid and in use*/
} SERVER_REF;

24
server/core/service.cc
View File

@ -947,7 +947,7 @@ static SERVER_REF* server_ref_create(SERVER* server)
sref->next = NULL;
sref->server = server;
// all servers have weight 1.0, when weights are not configured.
sref->inv_weight = 1.0;
sref->server_weight = 1.0;
sref->connections = 0;
sref->active = true;
}
@ -1699,22 +1699,24 @@ static void service_calculate_weights(SERVICE* service)
char buf[50]; // Enough to hold most numbers
/** Service has a weighting parameter and at least one server */
double total {0};
bool weights_are_in_use = false;
/** Calculate total weight */
for (SERVER_REF* server = service->dbref; server; server = server->next)
{
if (server_get_parameter(server->server, weightby, buf, sizeof(buf)))
{
total += atoi(buf);
weights_are_in_use = true;
long w = atol(buf);
if (w > 0)
{
total += w;
}
}
}
if (!weights_are_in_use)
if (total == 0)
{
MXS_WARNING("Weighting Parameter for service '%s' will be ignored as "
"no servers have values for the parameter '%s'.",
MXS_WARNING("Weighting parameters for service '%s' will be ignored as "
"no servers have (positive) values for the parameter '%s'.",
service->name,
weightby);
}
@ -1725,10 +1727,10 @@ static void service_calculate_weights(SERVICE* service)
{
if (server_get_parameter(server->server, weightby, buf, sizeof(buf)))
{
int config_weight = atoi(buf);
long config_weight = atol(buf);
if (config_weight <= 0)
{
MXS_WARNING("Weighting parameter '%s' is set to %d for server '%s'."
MXS_WARNING("Weighting parameter '%s' is set to %ld for server '%s'."
" The runtime weight will be set to 0, and the server"
" will only be used if no other servers are available.",
weightby,
@ -1736,7 +1738,7 @@ static void service_calculate_weights(SERVICE* service)
server->server->name);
config_weight = 0;
}
server->inv_weight = 1.0 - config_weight / total;
server->server_weight = config_weight / total;
}
else
{
@ -1745,7 +1747,7 @@ static void service_calculate_weights(SERVICE* service)
" will only be used if no other servers are available.",
weightby,
server->server->name);
server->inv_weight = 1.0;
server->server_weight = 0;
}
}
}

23
server/modules/routing/readconnroute/readconnroute.cc
View File

@ -364,22 +364,21 @@ static MXS_ROUTER_SESSION* newSession(MXS_ROUTER* instance, MXS_SESSION* session
{
candidate = ref;
}
else if (candidate->connections == 0)
else if (ref->server_weight == 0 || candidate->server_weight == 0)
{
/* The candidate is already as good as it gets. */
if (ref->server_weight) // anything with a weight is better
{
candidate = ref;
}
}
else if (ref->connections == 0)
{
candidate = ref;
}
else if (ref->inv_weight * ref->connections
< candidate->inv_weight * candidate->connections)
else if (ref->connections / ref->server_weight
< candidate->connections / candidate->server_weight)
{
/* ref has a better score. */
candidate = ref;
}
else if (mxs::almost_equal_server_scores(ref->inv_weight * ref->connections,
candidate->inv_weight * candidate->connections)
else if (mxs::almost_equal_server_scores(ref->server_weight * ref->connections,
candidate->server_weight * candidate->connections)
&& ref->server->stats.n_connections < candidate->server->stats.n_connections)
{
/* The servers are about equally good, but ref has had fewer connections over time.
@ -712,7 +711,7 @@ static void diagnostics(MXS_ROUTER* router, DCB* dcb)
dcb_printf(dcb,
"\t\t%-20s %3.1f%% %d\n",
ref->server->name,
(1.0 - ref->inv_weight) * 100,
ref->server_weight * 100,
ref->connections);
}
}
@ -887,7 +886,7 @@ static SERVER_REF* get_root_master(SERVER_REF* servers)
if (ref->active && server_is_master(ref->server))
{
// No master found yet or this one has better weight.
if (master_host == NULL || ref->inv_weight < master_host->inv_weight)
if (master_host == NULL || ref->server_weight > master_host->server_weight)
{
master_host = ref;
}

2
server/modules/routing/readwritesplit/readwritesplit.cc
View File

@ -372,7 +372,7 @@ void RWSplit::diagnostics(DCB* dcb)
dcb_printf(dcb,
"\t\t%-20s %3.1f%% %-6d %-6d %d\n",
ref->server->name,
(1.0 - ref->inv_weight) * 100,
ref->server_weight * 100,
ref->server->stats.n_current,
ref->connections,
ref->server->stats.n_current_ops);

8
server/modules/routing/readwritesplit/rwsplit_select_backends.cc
View File

@ -79,7 +79,7 @@ SRWBackendVector::iterator best_score(SRWBackendVector& sBackends,
SRWBackendVector::iterator backend_cmp_router_conn(SRWBackendVector& sBackends)
{
static auto server_score = [](SERVER_REF* server) {
return server->inv_weight * server->connections;
return server->server_weight ? server->connections / server->server_weight : 0;
};
return best_score(sBackends, server_score);
@ -89,7 +89,7 @@ SRWBackendVector::iterator backend_cmp_router_conn(SRWBackendVector& sBackends)
SRWBackendVector::iterator backend_cmp_global_conn(SRWBackendVector& sBackends)
{
static auto server_score = [](SERVER_REF* server) {
return server->inv_weight * server->server->stats.n_current;
return server->server_weight ? server->server->stats.n_current / server->server_weight : 0;
};
return best_score(sBackends, server_score);
@ -99,7 +99,7 @@ SRWBackendVector::iterator backend_cmp_global_conn(SRWBackendVector& sBackends)
SRWBackendVector::iterator backend_cmp_behind_master(SRWBackendVector& sBackends)
{
static auto server_score = [](SERVER_REF* server) {
return server->inv_weight * server->server->rlag;
return server->server_weight ? server->server->rlag / server->server_weight : 0;
};
return best_score(sBackends, server_score);
@ -109,7 +109,7 @@ SRWBackendVector::iterator backend_cmp_behind_master(SRWBackendVector& sBackends
SRWBackendVector::iterator backend_cmp_current_load(SRWBackendVector& sBackends)
{
static auto server_score = [](SERVER_REF* server) {
return server->inv_weight * server->server->stats.n_current_ops;
return server->server_weight ? server->server->stats.n_current_ops / server->server_weight : 0;
};
return best_score(sBackends, server_score);