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/**
* Copyright (C) 2019-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <mutex>
#include "mongo/db/repl/repl_sync_shared_data.h"
#include "mongo/db/server_options.h"
namespace mongo {
namespace repl {
class InitialSyncSharedData final : public ReplSyncSharedData {
private:
class RetryingOperation;
public:
typedef boost::optional<RetryingOperation> RetryableOperation;
InitialSyncSharedData(int rollBackId, Milliseconds allowedOutageDuration, ClockSource* clock)
: ReplSyncSharedData(clock),
_rollBackId(rollBackId),
_allowedOutageDuration(allowedOutageDuration) {}
int getRollBackId() const {
return _rollBackId;
}
int getRetryingOperationsCount(WithLock lk) {
return _retryingOperationsCount;
}
int getTotalRetries(WithLock lk) {
return _totalRetries;
}
/**
* Sets the wire version of the sync source.
*/
void setSyncSourceWireVersion(WithLock, WireVersion wireVersion) {
_syncSourceWireVersion = wireVersion;
}
/**
* Returns the wire version of the sync source, if previously set.
*/
boost::optional<WireVersion> getSyncSourceWireVersion(WithLock) {
return _syncSourceWireVersion;
}
/**
* Sets the initial sync ID of the sync source.
*/
void setInitialSyncSourceId(WithLock, boost::optional<UUID> syncSourceId) {
_initialSyncSourceId = syncSourceId;
}
/**
* Gets the previously-set initial sync ID of the sync source.
*/
boost::optional<UUID> getInitialSyncSourceId(WithLock) {
return _initialSyncSourceId;
}
/**
* Returns the total time the sync source has been unreachable, including any current outage.
*/
Milliseconds getTotalTimeUnreachable(WithLock lk);
/**
* Returns the total time the sync source has been unreachable in the current outage.
* Returns Milliseconds::min() if there is no current outage.
*/
Milliseconds getCurrentOutageDuration(WithLock lk);
/**
* Returns the time the current outage (if any) began. Returns Date_t() if no outage in
* progress.
*/
Date_t getSyncSourceUnreachableSince(WithLock lk) {
return _syncSourceUnreachableSince;
}
/**
* shouldRetryOperation() is the interface for retries. For each retryable operation, declare a
* RetryableOperation which is passed to this method. When the operation succeeds, destroy the
* RetryableOperation (outside the lock) or assign boost::none to it.
*
* Returns true if the operation should be retried, false if it has timed out.
*/
bool shouldRetryOperation(WithLock lk, RetryableOperation* retryableOp);
/**
* Returns the total time the sync source may be unreachable in a single outage before
* shouldRetryOperation() returns false.
*/
Milliseconds getAllowedOutageDuration(WithLock lk) {
return _allowedOutageDuration;
}
void setAllowedOutageDuration_forTest(WithLock, Milliseconds allowedOutageDuration) {
_allowedOutageDuration = allowedOutageDuration;
}
private:
class RetryingOperation {
public:
RetryingOperation(InitialSyncSharedData* sharedData) : _sharedData(sharedData) {}
// This class is a non-copyable RAII class.
RetryingOperation(const RetryingOperation&) = delete;
RetryingOperation(RetryingOperation&&) = delete;
~RetryingOperation() {
if (_sharedData) {
stdx::lock_guard<InitialSyncSharedData> lk(*_sharedData);
release(lk);
}
}
RetryingOperation& operator=(const RetryingOperation&) = delete;
RetryingOperation& operator=(RetryingOperation&&) = default;
/**
* release() is used by shouldRetryOperation to allow destroying a RetryingOperation
* while holding the lock.
*/
void release(WithLock lk) {
_sharedData->decrementRetryingOperations(lk);
_sharedData = nullptr;
}
InitialSyncSharedData* getSharedData() {
return _sharedData;
}
private:
InitialSyncSharedData* _sharedData;
};
/**
* Increment the number of retrying operations, set syncSourceUnreachableSince if this is the
* only retrying operation. This is used when an operation starts retrying.
*
* Returns the new number of retrying operations.
*/
int incrementRetryingOperations(WithLock lk);
/**
* Decrements the number of retrying operations. If now zero, clear syncSourceUnreachableSince
* and update _totalTimeUnreachable.
* Returns the new number of retrying operations.
*/
int decrementRetryingOperations(WithLock lk);
void incrementTotalRetries(WithLock lk) {
_totalRetries++;
}
// Rollback ID at start of initial sync.
const int _rollBackId;
/**
* This object must be locked when accessing the members below.
*/
// Number of operations currently being retried due to a transient error.
int _retryingOperationsCount = 0;
// Number of total retry attempts for all operations. Does not include initial attempts,
// so should normally be 0.
int _totalRetries = 0;
// If any operation is currently retrying, the earliest time at which any operation detected
// a transient network error. Otherwise is Date_t().
Date_t _syncSourceUnreachableSince;
// The total time across all outages in this initial sync attempt, but excluding any current
// outage, that we were retrying because we were unable to reach the sync source.
Milliseconds _totalTimeUnreachable;
// Time allowed for an outage before "shouldRetryOperation" returns false.
Milliseconds _allowedOutageDuration;
// Operation that may currently be retrying.
RetryableOperation _retryableOp;
// The sync source wire version at the start of data cloning.
boost::optional<WireVersion> _syncSourceWireVersion;
// The initial sync ID on the source at the start of data cloning.
boost::optional<UUID> _initialSyncSourceId;
};
} // namespace repl
} // namespace mongo
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