mcon_collection* mongo_find_candidate_servers(mongo_con_manager *manager, mongo_read_preference *rp, mongo_servers *servers)
{
int i;
mcon_collection *all, *filtered;
mongo_manager_log(manager, MLOG_RS, MLOG_FINE, "finding candidate servers");
all = mongo_find_all_candidate_servers(manager, rp);
if (servers->options.con_type == MONGO_CON_TYPE_REPLSET) {
filtered = mongo_filter_candidates_by_replicaset_name(manager, all, servers);
} else {
filtered = mongo_filter_candidates_by_seed(manager, all, servers);
}
mcon_collection_free(all);
all = filtered;
filtered = mongo_filter_candidates_by_credentials(manager, all, servers);
mcon_collection_free(all);
all = filtered;
if (rp->tagset_count != 0) {
mongo_manager_log(manager, MLOG_RS, MLOG_FINE, "limiting by tagsets");
/* If we have tagsets configured for the replicaset then we need to do
* some more filtering */
for (i = 0; i < rp->tagset_count; i++) {
char *tmp_ts = mongo_read_preference_squash_tagset(rp->tagsets[i]);
mongo_manager_log(manager, MLOG_RS, MLOG_FINE, "checking tagset: %s", tmp_ts);
filtered = mongo_filter_candidates_by_tagset(manager, all, rp->tagsets[i]);
mongo_manager_log(manager, MLOG_RS, MLOG_FINE, "tagset %s matched %d candidates", tmp_ts, filtered->count);
free(tmp_ts);
if (filtered->count > 0) {
mcon_collection_free(all);
return filtered;
}
}
mcon_collection_free(filtered);
mcon_collection_free(all);
return NULL;
} else {
return all;
}
}
mcon_collection *mongo_select_nearest_servers(mongo_con_manager *manager, mcon_collection *col, mongo_read_preference *rp)
{
mcon_collection *filtered;
int i, nearest_ping;
filtered = mcon_init_collection(sizeof(mongo_connection*));
mongo_manager_log(manager, MLOG_RS, MLOG_FINE, "selecting near servers");
switch (rp->type) {
case MONGO_RP_PRIMARY:
case MONGO_RP_PRIMARY_PREFERRED:
case MONGO_RP_SECONDARY:
case MONGO_RP_SECONDARY_PREFERRED:
case MONGO_RP_NEAREST:
/* The nearest ping time is in the first element */
nearest_ping = ((mongo_connection*)col->data[0])->ping_ms;
mongo_manager_log(manager, MLOG_RS, MLOG_FINE, "selecting near servers: nearest is %dms", nearest_ping);
/* FIXME: Change to iterator later */
for (i = 0; i < col->count; i++) {
if (((mongo_connection*)col->data[i])->ping_ms <= nearest_ping + MONGO_RP_CUTOFF) {
mcon_collection_add(filtered, col->data[i]);
}
}
break;
default:
return NULL;
}
/* Clean up the old collection that we no longer need */
mcon_collection_free(col);
mcon_collection_iterate(manager, filtered, mongo_print_connection_iterate_wrapper);
mongo_manager_log(manager, MLOG_RS, MLOG_FINE, "selecting near server: done");
return filtered;
}
static mongo_connection *mongo_get_connection_multiple(mongo_con_manager *manager, mongo_servers *servers, int connection_flags, char **error_message)
{
mongo_connection *con = NULL;
mongo_connection *tmp;
mcon_collection *collection = NULL;
mongo_read_preference tmp_rp; /* We only support NEAREST for MULTIPLE right now */
int i;
int found_connected_server = 0;
mcon_str *messages;
int found_supported_wire_version = 1;
mcon_str_ptr_init(messages);
/* Create a connection to every of the servers in the seed list */
for (i = 0; i < servers->count; i++) {
int ismaster_error = 0;
char *con_error_message = NULL;
tmp = mongo_get_connection_single(manager, servers->server[i], &servers->options, connection_flags, (char **) &con_error_message);
if (tmp) {
found_connected_server++;
/* Run ismaster, if needed, to extract server flags */
ismaster_error = mongo_connection_ismaster(manager, tmp, &servers->options, NULL, NULL, NULL, &con_error_message, NULL);
switch (ismaster_error) {
case 1: /* Run just fine */
case 2: /* ismaster() skipped due to interval */
break;
case 0: /* Some error */
case 3: /* Run just fine, but hostname didn't match what we expected */
case 4: /* Danger danger, reported wire version does not overlap what we support */
default:
mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "server_flags: error while getting the server configuration %s:%d: %s", servers->server[i]->host, servers->server[i]->port, con_error_message);
/* If it failed because of wire version, we have to bail out completely
* later on, but we should continue to aggregate the errors in case more
* servers are unsupported */
if (ismaster_error == 4) {
mongo_manager_connection_deregister(manager, tmp);
found_supported_wire_version = 0;
} else {
mongo_connection_destroy(manager, tmp, MONGO_CLOSE_BROKEN);
}
tmp = NULL;
found_connected_server--;
}
}
if (!tmp) {
if (!(connection_flags & MONGO_CON_FLAG_DONT_CONNECT)) {
mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "Couldn't connect to '%s:%d': %s", servers->server[i]->host, servers->server[i]->port, con_error_message);
if (messages->l) {
mcon_str_addl(messages, "; ", 2, 0);
}
mcon_str_add(messages, "Failed to connect to: ", 0);
mcon_str_add(messages, servers->server[i]->host, 0);
mcon_str_addl(messages, ":", 1, 0);
mcon_str_add_int(messages, servers->server[i]->port);
mcon_str_addl(messages, ": ", 2, 0);
mcon_str_add(messages, con_error_message, 1); /* Also frees con_error_message */
} else {
free(con_error_message);
}
}
}
if (!found_supported_wire_version) {
*error_message = strdup("Found a server running unsupported wire version. Please upgrade the driver, or take the server out of rotation");
mcon_str_ptr_dtor(messages);
return NULL;
}
/* If we don't have a connected server then there is no point in continueing */
if (!found_connected_server && (connection_flags & MONGO_CON_FLAG_DONT_CONNECT)) {
mcon_str_ptr_dtor(messages);
return NULL;
}
/* When selecting a *mongos* node, readPreferences make no sense as we
* don't have a "primary" or "secondary" mongos. The mongos nodes aren't
* tagged either. To pick a mongos we therefore simply pick the "nearest"
* mongos node. */
tmp_rp.type = MONGO_RP_NEAREST;
tmp_rp.tagsets = NULL;
tmp_rp.tagset_count = 0;
collection = mongo_find_candidate_servers(manager, &tmp_rp, servers);
if (!collection || collection->count == 0) {
if (messages->l) {
*error_message = strdup(messages->d);
} else {
*error_message = strdup("No candidate servers found");
}
goto bailout;
}
collection = mongo_sort_servers(manager, collection, &servers->read_pref);
collection = mongo_select_nearest_servers(manager, collection, &servers->options, &servers->read_pref);
if (!collection) {
*error_message = strdup("No server near us");
goto bailout;
}
con = mongo_pick_server_from_set(manager, collection, &servers->read_pref);
bailout:
/* Cleaning up */
mcon_str_ptr_dtor(messages);
if (collection) {
mcon_collection_free(collection);
}
return con;
}
static mongo_connection *mongo_get_read_write_connection_replicaset(mongo_con_manager *manager, mongo_servers *servers, int connection_flags, char **error_message)
{
mongo_connection *con = NULL;
mongo_connection *tmp;
mcon_collection *collection;
char *con_error_message = NULL;
int i;
int found_connected_server = 0;
/* Create a connection to all of the servers in the seed list */
for (i = 0; i < servers->count; i++) {
tmp = mongo_get_connection_single(manager, servers->server[i], &servers->options, connection_flags, (char **) &con_error_message);
if (tmp) {
found_connected_server++;
} else if (!(connection_flags & MONGO_CON_FLAG_DONT_CONNECT)) {
mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "Couldn't connect to '%s:%d': %s", servers->server[i]->host, servers->server[i]->port, con_error_message);
free(con_error_message);
}
}
if (!found_connected_server && (connection_flags & MONGO_CON_FLAG_DONT_CONNECT)) {
return NULL;
}
/* Discover more nodes. This also adds a connection to "servers" for each
* new node */
if (!mongo_discover_topology(manager, servers)) {
/* Total failure, we cannot proceed */
*error_message = strdup("Incompatible server detected. This driver release is not compatible with one of the connected servers");
return NULL;
}
/* Depending on whether we want a read or a write connection, run the correct algorithms */
if (connection_flags & MONGO_CON_FLAG_WRITE) {
mongo_read_preference tmp_rp;
tmp_rp.type = MONGO_RP_PRIMARY;
tmp_rp.tagsets = NULL;
tmp_rp.tagset_count = 0;
collection = mongo_find_candidate_servers(manager, &tmp_rp, servers);
mongo_read_preference_dtor(&tmp_rp);
} else if (connection_flags & MONGO_CON_FLAG_DONT_FILTER) {
/* We just want to know if we have something to talk to, irregardless of RP */
mongo_read_preference tmp_rp;
tmp_rp.type = MONGO_RP_NEAREST;
tmp_rp.tagsets = NULL;
tmp_rp.tagset_count = 0;
collection = mongo_find_candidate_servers(manager, &tmp_rp, servers);
mongo_read_preference_dtor(&tmp_rp);
} else {
collection = mongo_find_candidate_servers(manager, &servers->read_pref, servers);
}
if (!collection) {
*error_message = strdup("No candidate servers found");
return NULL;
}
if (collection->count == 0) {
*error_message = strdup("No candidate servers found");
mcon_collection_free(collection);
return NULL;
}
collection = mongo_sort_servers(manager, collection, &servers->read_pref);
collection = mongo_select_nearest_servers(manager, collection, &servers->options, &servers->read_pref);
con = mongo_pick_server_from_set(manager, collection, &servers->read_pref);
/* Cleaning up */
mcon_collection_free(collection);
return con;
}
static mongo_connection *mongo_get_connection_multiple(mongo_con_manager *manager, mongo_servers *servers, int connection_flags, char **error_message)
{
mongo_connection *con = NULL;
mongo_connection *tmp;
mcon_collection *collection = NULL;
char *con_error_message = NULL;
mongo_read_preference tmp_rp; /* We only support NEAREST for MULTIPLE right now */
int i;
int found_connected_server = 0;
mcon_str *messages;
mcon_str_ptr_init(messages);
/* Create a connection to every of the servers in the seed list */
for (i = 0; i < servers->count; i++) {
tmp = mongo_get_connection_single(manager, servers->server[i], &servers->options, connection_flags, (char **) &con_error_message);
if (tmp) {
found_connected_server = 1;
} else if (!(connection_flags & MONGO_CON_FLAG_DONT_CONNECT)) {
mongo_manager_log(manager, MLOG_CON, MLOG_WARN, "Couldn't connect to '%s:%d': %s", servers->server[i]->host, servers->server[i]->port, con_error_message);
if (messages->l) {
mcon_str_addl(messages, "; ", 2, 0);
}
mcon_str_add(messages, "Failed to connect to: ", 0);
mcon_str_add(messages, servers->server[i]->host, 0);
mcon_str_addl(messages, ":", 1, 0);
mcon_str_add_int(messages, servers->server[i]->port);
mcon_str_addl(messages, ": ", 2, 0);
mcon_str_add(messages, con_error_message, 1); /* Also frees con_error_message */
}
}
/* If we don't have a connected server then there is no point in continueing */
if (!found_connected_server && (connection_flags & MONGO_CON_FLAG_DONT_CONNECT)) {
return NULL;
}
/* When selecting a *mongos* node, readPreferences make no sense as we
* don't have a "primary" or "secondary" mongos. The mongos nodes aren't
* tagged either. To pick a mongos we therefore simply pick the "nearest"
* mongos node. */
tmp_rp.type = MONGO_RP_NEAREST;
tmp_rp.tagsets = NULL;
tmp_rp.tagset_count = 0;
collection = mongo_find_candidate_servers(manager, &tmp_rp, servers);
if (!collection || collection->count == 0) {
if (messages->l) {
*error_message = strdup(messages->d);
} else {
*error_message = strdup("No candidate servers found");
}
goto bailout;
}
collection = mongo_sort_servers(manager, collection, &servers->read_pref);
collection = mongo_select_nearest_servers(manager, collection, &servers->read_pref);
if (!collection) {
*error_message = strdup("No server near us");
goto bailout;
}
con = mongo_pick_server_from_set(manager, collection, &servers->read_pref);
bailout:
/* Cleaning up */
mcon_str_ptr_dtor(messages);
if (collection) {
mcon_collection_free(collection);
}
return con;
}
