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#include <Storages/MergeTree/EphemeralLockInZooKeeper.h>
#include <Common/ZooKeeper/KeeperException.h>
#include <Common/logger_useful.h>
#include <base/types.h>
#include <Common/ZooKeeper/ZooKeeperWithFaultInjection.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
}
EphemeralLockInZooKeeper::EphemeralLockInZooKeeper(const String & path_prefix_, const ZooKeeperWithFaultInjectionPtr & zookeeper_, const String & path_, const String & conflict_path_)
: zookeeper(zookeeper_), path_prefix(path_prefix_), path(path_), conflict_path(conflict_path_)
{
if (conflict_path.empty() && path.size() <= path_prefix.size())
throw Exception(ErrorCodes::LOGICAL_ERROR, "Logical error: name of the main node is shorter than prefix.");
}
template <typename T>
std::optional<EphemeralLockInZooKeeper> createEphemeralLockInZooKeeper(
const String & path_prefix_, const String & temp_path, const ZooKeeperWithFaultInjectionPtr & zookeeper_, const T & deduplication_path)
{
static constexpr bool async_insert = std::is_same_v<T, std::vector<String>>;
String path;
if (deduplication_path.empty())
{
String holder_path = temp_path + "/" + EphemeralLockInZooKeeper::LEGACY_LOCK_OTHER;
path = zookeeper_->create(path_prefix_, holder_path, zkutil::CreateMode::EphemeralSequential);
}
else
{
String holder_path = temp_path + "/" + EphemeralLockInZooKeeper::LEGACY_LOCK_INSERT;
/// Check for duplicates in advance, to avoid superfluous block numbers allocation
Coordination::Requests ops;
if constexpr (async_insert)
{
for (const auto & single_dedup_path : deduplication_path)
zkutil::addCheckNotExistsRequest(ops, *zookeeper_, single_dedup_path);
}
else
{
zkutil::addCheckNotExistsRequest(ops, *zookeeper_, deduplication_path);
}
auto deduplication_path_ops_size = ops.size();
ops.emplace_back(zkutil::makeCreateRequest(path_prefix_, holder_path, zkutil::CreateMode::EphemeralSequential));
Coordination::Responses responses;
Coordination::Error e = zookeeper_->tryMulti(ops, responses);
if (e == Coordination::Error::ZNODEEXISTS)
{
if constexpr (async_insert)
{
auto failed_idx = zkutil::getFailedOpIndex(Coordination::Error::ZNODEEXISTS, responses);
if (failed_idx < deduplication_path_ops_size)
{
const String & failed_op_path = ops[failed_idx]->getPath();
LOG_DEBUG(
&Poco::Logger::get("createEphemeralLockInZooKeeper"),
"Deduplication path already exists: deduplication_path={}",
failed_op_path);
return EphemeralLockInZooKeeper{"", nullptr, "", failed_op_path};
}
}
else if (responses[0]->error == Coordination::Error::ZNODEEXISTS)
{
LOG_DEBUG(
&Poco::Logger::get("createEphemeralLockInZooKeeper"),
"Deduplication path already exists: deduplication_path={}",
deduplication_path);
return {};
}
}
if (e != Coordination::Error::ZOK)
{
zkutil::KeeperMultiException::check(e, ops, responses); // This should always throw the proper exception
throw Exception(ErrorCodes::LOGICAL_ERROR, "Unable to handle error {} when acquiring ephemeral lock in ZK", toString(e));
}
path = dynamic_cast<const Coordination::CreateResponse *>(responses.back().get())->path_created;
}
return EphemeralLockInZooKeeper{path_prefix_, zookeeper_, path};
}
void EphemeralLockInZooKeeper::unlock()
{
Coordination::Requests ops;
getUnlockOp(ops);
zookeeper->multi(ops);
zookeeper = nullptr;
}
void EphemeralLockInZooKeeper::getUnlockOp(Coordination::Requests & ops)
{
checkCreated();
ops.emplace_back(zkutil::makeRemoveRequest(path, -1));
}
EphemeralLockInZooKeeper::~EphemeralLockInZooKeeper()
{
if (!isLocked())
return;
try
{
unlock();
}
catch (const zkutil::KeeperException & e)
{
if (Coordination::isHardwareError(e.code))
LOG_DEBUG(
&Poco::Logger::get("EphemeralLockInZooKeeper"),
"ZooKeeper communication error during unlock: code={} message='{}'",
e.code,
e.message());
else if (e.code == Coordination::Error::ZNONODE)
/// To avoid additional round-trip for unlocking,
/// ephemeral node can be deleted explicitly as part of another multi op request to ZK
/// and marked as such via assumeUnlocked() if we got successful response.
/// But it's possible that the multi op request can be executed on server side, and client will not get response due to network issue.
/// In such case, assumeUnlocked() will not be called, so we'll get ZNONODE error here since the noded is already deleted
LOG_DEBUG(
&Poco::Logger::get("EphemeralLockInZooKeeper"),
"ZooKeeper node was already deleted: code={} message={}",
e.code,
e.message());
else
tryLogCurrentException("EphemeralLockInZooKeeper");
}
catch (...)
{
tryLogCurrentException("EphemeralLockInZooKeeper");
}
}
EphemeralLocksInAllPartitions::EphemeralLocksInAllPartitions(
const String & block_numbers_path, const String & path_prefix, const String & temp_path,
zkutil::ZooKeeper & zookeeper_)
: zookeeper(&zookeeper_)
{
String holder_path = temp_path + "/" + EphemeralLockInZooKeeper::LEGACY_LOCK_OTHER;
while (true)
{
Coordination::Stat partitions_stat;
Strings partitions = zookeeper->getChildren(block_numbers_path, &partitions_stat);
Coordination::Requests lock_ops;
for (const auto & partition : partitions)
{
String partition_path_prefix = block_numbers_path + "/" + partition + "/" + path_prefix;
lock_ops.push_back(zkutil::makeCreateRequest(
partition_path_prefix, holder_path, zkutil::CreateMode::EphemeralSequential));
}
lock_ops.push_back(zkutil::makeCheckRequest(block_numbers_path, partitions_stat.version));
Coordination::Responses lock_responses;
Coordination::Error rc = zookeeper->tryMulti(lock_ops, lock_responses);
if (rc == Coordination::Error::ZBADVERSION)
{
LOG_TRACE(&Poco::Logger::get("EphemeralLocksInAllPartitions"), "Someone has inserted a block in a new partition while we were creating locks. Retry.");
continue;
}
else if (rc != Coordination::Error::ZOK)
throw Coordination::Exception(rc);
for (size_t i = 0; i < partitions.size(); ++i)
{
size_t prefix_size = block_numbers_path.size() + 1 + partitions[i].size() + 1 + path_prefix.size();
const String & path = dynamic_cast<const Coordination::CreateResponse &>(*lock_responses[i]).path_created;
if (path.size() <= prefix_size)
throw Exception(ErrorCodes::LOGICAL_ERROR, "Logical error: name of the sequential node is shorter than prefix.");
UInt64 number = parse<UInt64>(path.c_str() + prefix_size, path.size() - prefix_size);
locks.push_back(LockInfo{path, partitions[i], number});
}
return;
}
}
void EphemeralLocksInAllPartitions::unlock()
{
if (!zookeeper)
return;
std::vector<zkutil::ZooKeeper::FutureRemove> futures;
futures.reserve(locks.size());
for (const auto & lock : locks)
{
futures.push_back(zookeeper->asyncRemove(lock.path));
}
for (auto & future : futures)
future.get();
locks.clear();
zookeeper = nullptr;
}
EphemeralLocksInAllPartitions::~EphemeralLocksInAllPartitions()
{
try
{
unlock();
}
catch (...)
{
tryLogCurrentException("~EphemeralLocksInAllPartitions");
}
}
template std::optional<EphemeralLockInZooKeeper> createEphemeralLockInZooKeeper<String>(
const String & path_prefix_, const String & temp_path, const ZooKeeperWithFaultInjectionPtr & zookeeper_, const String & deduplication_path);
template std::optional<EphemeralLockInZooKeeper> createEphemeralLockInZooKeeper<std::vector<String>>(
const String & path_prefix_, const String & temp_path, const ZooKeeperWithFaultInjectionPtr & zookeeper_, const std::vector<String> & deduplication_path);
}
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