const std::string& resolved_ip, void** client_key) {

*client_key = nullptr;

std::lock_guard<std::mutex> lock(_lock);

//VLOG_RPC << "get_client(" << hostport << ")";

auto cache_entry = _client_cache.find(hostport);

if (cache_entry == _client_cache.end()) {

cache_entry =

_client_cache.insert(std::make_pair(hostport, std::list<CachedClient>())).first;

DCHECK(cache_entry != _client_cache.end());

}

std::list<CachedClient>& info_list = cache_entry->second;

// Find a cached client with matching resolved IP

for (auto it = info_list.begin(); it != info_list.end(); ++it) {

if (it->resolved_ip == resolved_ip) {

*client_key = it->client_key;

VLOG_RPC << "get_client(): cached client for " << hostport << " with ip "

<< resolved_ip;

info_list.erase(it);

return;

}

}

// No matching client found. Clear all cached clients with stale IPs for this hostport.

// These clients were created with old resolved IPs and should be closed.

for (auto& cached_client : info_list) {

auto client_map_entry = _client_map.find(cached_client.client_key);

if (client_map_entry != _client_map.end()) {

ThriftClientImpl* client_to_close = client_map_entry->second;

client_to_close->close();

delete client_to_close;

_client_map.erase(client_map_entry);

_client_hostport_map.erase(cached_client.client_key);

if (_metrics_enabled) {

thrift_opened_clients->increment(-1);

}

}

}

info_list.clear();

void** client_key, int timeout_ms) {

// Resolve hostname to IP address via DNS cache.

// If the hostname is already an IP address, DNS cache will return it directly.

std::string resolved_ip;

Status dns_status = ExecEnv::GetInstance()->dns_cache()->get(hostport.hostname, &resolved_ip);

if (!dns_status.ok() || resolved_ip.empty()) {

return Status::InternalError("Failed to resolve hostname {} to IP address: {}",

hostport.hostname, dns_status.to_string());

}

// Try to get a cached client with matching resolved IP

_get_client_from_cache(hostport, resolved_ip, client_key);

if (*client_key == nullptr) {

// No cached client with matching IP, create a new one using the resolved IP

RETURN_IF_ERROR(

_create_client(hostport, resolved_ip, factory_method, client_key, timeout_ms));

}

if (_metrics_enabled) {

thrift_used_clients->increment(1);

}

return Status::OK();

int timeout_ms) {

DCHECK(*client_key != nullptr) << "Trying to reopen nullptr client";

ThriftClientImpl* client_to_close = nullptr;

TNetworkAddress hostport;

{

std::lock_guard<std::mutex> lock(_lock);

auto client_map_entry = _client_map.find(*client_key);

DCHECK(client_map_entry != _client_map.end());

client_to_close = client_map_entry->second;

// Get the original hostport (with hostname) for this client

auto hostport_entry = _client_hostport_map.find(*client_key);

DCHECK(hostport_entry != _client_hostport_map.end());

hostport = hostport_entry->second;

}

client_to_close->close();

// TODO: Thrift TBufferedTransport cannot be re-opened after Close() because it does

// not clean up internal buffers it reopens. To work around this issue, create a new

// client instead.

{

std::lock_guard<std::mutex> lock(_lock);

_client_map.erase(*client_key);

_client_hostport_map.erase(*client_key);

}

delete client_to_close;

*client_key = nullptr;

if (_metrics_enabled) {

thrift_opened_clients->increment(-1);

}

// Re-resolve hostname to IP address

std::string resolved_ip;

Status dns_status = ExecEnv::GetInstance()->dns_cache()->get(hostport.hostname, &resolved_ip);

if (!dns_status.ok() || resolved_ip.empty()) {

return Status::InternalError("Failed to resolve hostname {} to IP address: {}",

hostport.hostname, dns_status.to_string());

}

RETURN_IF_ERROR(_create_client(hostport, resolved_ip, factory_method, client_key, timeout_ms));

return Status::OK();

const std::string& resolved_ip,

ClientFactory& factory_method, void** client_key,

int timeout_ms) {

// Create a new TNetworkAddress with the resolved IP instead of hostname.

// This ensures that all client connections are made using IP addresses.

TNetworkAddress addr_with_ip;

addr_with_ip.hostname = resolved_ip;

addr_with_ip.port = hostport.port;

std::unique_ptr<ThriftClientImpl> client_impl(factory_method(addr_with_ip, client_key));

//VLOG_CONNECTION << "create_client(): adding new client for "

// << client_impl->ipaddress() << ":" << client_impl->port();

client_impl->set_conn_timeout(config::thrift_connect_timeout_seconds * 1000);

Status status = client_impl->open_with_retry(config::thrift_client_open_num_tries, 100);

if (!status.ok()) {

*client_key = nullptr;

return status;

}

DCHECK(*client_key != nullptr);

// In thrift, timeout == 0, means wait infinitely, so that it should not happen.

// See https://github.com/apache/thrift/blob/master/lib/cpp/src/thrift/transport/TSocket.cpp.

// There is some code like this: int ret = THRIFT_POLL(fds, 2, (recvTimeout_ == 0) ? -1 : recvTimeout_);

// If the developer missed to set the timeout, we should use default timeout, not infinitely.

// See https://linux.die.net/man/2/poll. Specifying a negative value in timeout means an infinite timeout.

client_impl->set_send_timeout(timeout_ms == 0 ? config::thrift_rpc_timeout_ms : timeout_ms);

client_impl->set_recv_timeout(timeout_ms == 0 ? config::thrift_rpc_timeout_ms : timeout_ms);

{

std::lock_guard<std::mutex> lock(_lock);

// Because the client starts life 'checked out', we don't add it to the cache map

DCHECK(_client_map.count(*client_key) == 0);

_client_map[*client_key] = client_impl.release();

// Store the original hostport (with hostname) for this client

_client_hostport_map[*client_key] = hostport;

}

if (_metrics_enabled) {

thrift_opened_clients->increment(1);

}

return Status::OK();

DCHECK(*client_key != nullptr) << "Trying to release nullptr client";

ThriftClientImpl* client_to_close = nullptr;

{

std::lock_guard<std::mutex> lock(_lock);

auto client_map_entry = _client_map.find(*client_key);

DCHECK(client_map_entry != _client_map.end());

ThriftClientImpl* client = client_map_entry->second;

// Get the original hostport (with hostname) for this client

auto hostport_entry = _client_hostport_map.find(*client_key);

DCHECK(hostport_entry != _client_hostport_map.end());

const TNetworkAddress& hostport = hostport_entry->second;

auto cache_list = _client_cache.find(hostport);

DCHECK(cache_list != _client_cache.end());

if (_max_cache_size_per_host >= 0 &&

cache_list->second.size() >= _max_cache_size_per_host) {

// cache of this host is full, close this client connection and remove from maps

_client_map.erase(*client_key);

_client_hostport_map.erase(*client_key);

client_to_close = client;

} else {

// Store the client with its resolved IP address

CachedClient cached_client;

cached_client.client_key = *client_key;

cached_client.resolved_ip = client->ipaddress();

cache_list->second.push_back(cached_client);

// There is no need to close client if we put it to cache list.

client_to_close = nullptr;

}

}

if (client_to_close != nullptr) {

client_to_close->close();

delete client_to_close;

if (_metrics_enabled) {

thrift_opened_clients->increment(-1);

}

}

if (_metrics_enabled) {

thrift_used_clients->increment(-1);

}

*client_key = nullptr;

std::stringstream out;

out << "ClientCacheHelper(#hosts=" << _client_cache.size() << " [";

bool isfirst = true;

for (const auto& [endpoint, client_keys] : _client_cache) {

if (!isfirst) {

out << " ";

isfirst = false;

}

out << endpoint << ":" << client_keys.size();

}

out << "])";

return out.str();

// Not strictly needed if init_metrics is called before any cache

// usage, but ensures that _metrics_enabled is published.

std::lock_guard<std::mutex> lock(_lock);

_thrift_client_metric_entity = DorisMetrics::instance()->metric_registry()->register_entity(

std::string("thrift_client.") + name, {{"name", name}});

INT_GAUGE_METRIC_REGISTER(_thrift_client_metric_entity, thrift_used_clients);

INT_GAUGE_METRIC_REGISTER(_thrift_client_metric_entity, thrift_opened_clients);

_metrics_enabled = true;