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#include <IO/Resource/DynamicResourceManager.h>
#include <IO/SchedulerNodeFactory.h>
#include <IO/ResourceManagerFactory.h>
#include <IO/ISchedulerQueue.h>
#include <Common/Exception.h>
#include <Common/StringUtils/StringUtils.h>
#include <map>
#include <tuple>
namespace DB
{
namespace ErrorCodes
{
extern const int RESOURCE_ACCESS_DENIED;
extern const int RESOURCE_NOT_FOUND;
extern const int INVALID_SCHEDULER_NODE;
}
DynamicResourceManager::State::State(EventQueue * event_queue, const Poco::Util::AbstractConfiguration & config)
: classifiers(config)
{
Poco::Util::AbstractConfiguration::Keys keys;
const String config_prefix = "resources";
config.keys(config_prefix, keys);
// Create resource for every element under <resources> tag
for (const auto & key : keys)
{
resources.emplace(key, std::make_shared<Resource>(key, event_queue, config, config_prefix + "." + key));
}
}
DynamicResourceManager::State::Resource::Resource(
const String & name,
EventQueue * event_queue,
const Poco::Util::AbstractConfiguration & config,
const std::string & config_prefix)
{
Poco::Util::AbstractConfiguration::Keys keys;
config.keys(config_prefix, keys);
// Sort nodes by path to create parents before children
std::map<String, String> path2key;
for (const auto & key : keys)
{
if (!startsWith(key, "node"))
continue;
String path = config.getString(config_prefix + "." + key + "[@path]", "");
if (path.empty())
throw Exception(ErrorCodes::INVALID_SCHEDULER_NODE, "Attribute 'path' must be specified in all nodes for resource '{}'", name);
if (path[0] != '/')
throw Exception(ErrorCodes::INVALID_SCHEDULER_NODE, "Path must start with '/' for resource '{}'", name);
if (auto [_, inserted] = path2key.emplace(path, key); !inserted)
throw Exception(ErrorCodes::INVALID_SCHEDULER_NODE, "Duplicate path '{}' for resource '{}'", path, name);
}
// Create nodes
bool has_root = false;
for (auto [path, key] : path2key)
{
// Validate path
size_t slash = path.rfind('/');
if (slash == String::npos)
throw Exception(ErrorCodes::INVALID_SCHEDULER_NODE, "Invalid scheduler node path '{}' for resource '{}'", path, name);
// Create node
String basename = path.substr(slash + 1); // root name is empty string
auto [iter, _] = nodes.emplace(path, Node(basename, event_queue, config, config_prefix + "." + key));
if (path == "/")
{
has_root = true;
continue;
}
// Attach created node to parent (if not root)
// NOTE: resource root is attached to the scheduler using event queue for thread-safety
String parent_path = path.substr(0, slash);
if (parent_path.empty())
parent_path = "/";
if (auto parent = nodes.find(parent_path); parent != nodes.end())
parent->second.ptr->attachChild(iter->second.ptr);
else
throw Exception(ErrorCodes::INVALID_SCHEDULER_NODE, "Parent node doesn't exist for path '{}' for resource '{}'", path, name);
}
if (!has_root)
throw Exception(ErrorCodes::INVALID_SCHEDULER_NODE, "undefined root node path '/' for resource '{}'", name);
}
DynamicResourceManager::State::Resource::~Resource()
{
// NOTE: we should rely on `attached_to` and cannot use `parent`,
// NOTE: because `parent` can be `nullptr` in case attachment is still in event queue
if (attached_to != nullptr)
{
ISchedulerNode * root = nodes.find("/")->second.ptr.get();
attached_to->event_queue->enqueue([my_scheduler = attached_to, root]
{
my_scheduler->removeChild(root);
});
}
}
DynamicResourceManager::State::Node::Node(const String & name, EventQueue * event_queue, const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix)
: type(config.getString(config_prefix + ".type", "fifo"))
, ptr(SchedulerNodeFactory::instance().get(type, event_queue, config, config_prefix))
{
ptr->basename = name;
}
bool DynamicResourceManager::State::Resource::equals(const DynamicResourceManager::State::Resource & o) const
{
if (nodes.size() != o.nodes.size())
return false;
for (const auto & [path, o_node] : o.nodes)
{
auto iter = nodes.find(path);
if (iter == nodes.end())
return false;
if (!iter->second.equals(o_node))
return false;
}
return true;
}
bool DynamicResourceManager::State::Node::equals(const DynamicResourceManager::State::Node & o) const
{
if (type != o.type)
return false;
return ptr->equals(o.ptr.get());
}
DynamicResourceManager::Classifier::Classifier(const DynamicResourceManager::StatePtr & state_, const String & classifier_name)
: state(state_)
{
// State is immutable, but nodes are mutable and thread-safe
// So it's safe to obtain node pointers w/o lock
for (auto [resource_name, path] : state->classifiers.get(classifier_name))
{
if (auto resource_iter = state->resources.find(resource_name); resource_iter != state->resources.end())
{
const auto & resource = resource_iter->second;
if (auto node_iter = resource->nodes.find(path); node_iter != resource->nodes.end())
{
if (auto * queue = dynamic_cast<ISchedulerQueue *>(node_iter->second.ptr.get()))
resources.emplace(resource_name, ResourceLink{.queue = queue});
else
throw Exception(ErrorCodes::RESOURCE_NOT_FOUND, "Unable to access non-queue node at path '{}' for resource '{}'", path, resource_name);
}
else
throw Exception(ErrorCodes::RESOURCE_NOT_FOUND, "Path '{}' for resource '{}' does not exist", path, resource_name);
}
else
resources.emplace(resource_name, ResourceLink{}); // resource not configured yet - use unlimited resource
}
}
ResourceLink DynamicResourceManager::Classifier::get(const String & resource_name)
{
if (auto iter = resources.find(resource_name); iter != resources.end())
return iter->second;
else
throw Exception(ErrorCodes::RESOURCE_ACCESS_DENIED, "Access denied to resource '{}'", resource_name);
}
DynamicResourceManager::DynamicResourceManager()
: state(new State())
{
scheduler.start();
}
void DynamicResourceManager::updateConfiguration(const Poco::Util::AbstractConfiguration & config)
{
StatePtr new_state = std::make_shared<State>(scheduler.event_queue, config);
std::lock_guard lock{mutex};
// Resource update leads to loss of runtime data of nodes and may lead to temporary violation of constraints (e.g. limits)
// Try to minimise this by reusing "equal" resources (initialized with the same configuration).
for (auto & [name, new_resource] : new_state->resources)
{
if (auto iter = state->resources.find(name); iter != state->resources.end()) // Resource update
{
State::ResourcePtr old_resource = iter->second;
if (old_resource->equals(*new_resource))
new_resource = old_resource; // Rewrite with older version to avoid loss of runtime data
}
}
// Commit new state
// NOTE: dtor will detach from scheduler old resources that are not in use currently
state = new_state;
// Attach new and updated resources to the scheduler
for (auto & [name, resource] : new_state->resources)
{
const SchedulerNodePtr & root = resource->nodes.find("/")->second.ptr;
if (root->parent == nullptr)
{
resource->attached_to = &scheduler;
scheduler.event_queue->enqueue([this, root]
{
scheduler.attachChild(root);
});
}
}
// NOTE: after mutex unlock `state` became available for Classifier(s) and must be immutable
}
ClassifierPtr DynamicResourceManager::acquire(const String & classifier_name)
{
// Acquire a reference to the current state
StatePtr state_;
{
std::lock_guard lock{mutex};
state_ = state;
}
return std::make_shared<Classifier>(state_, classifier_name);
}
void registerDynamicResourceManager(ResourceManagerFactory & factory)
{
factory.registerMethod<DynamicResourceManager>("dynamic");
}
}
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