org.apache.hadoop.hdds.scm.block.DeletedBlockLog Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hdds.scm.block;
import org.apache.hadoop.hdds.protocol.proto
.StorageContainerDatanodeProtocolProtos.ContainerBlocksDeletionACKProto
.DeleteBlockTransactionResult;
import org.apache.hadoop.hdds.protocol.proto
.StorageContainerDatanodeProtocolProtos.DeletedBlocksTransaction;
import java.io.Closeable;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.UUID;
/**
* The DeletedBlockLog is a persisted log in SCM to keep tracking
* container blocks which are under deletion. It maintains info
* about under-deletion container blocks that notified by OM,
* and the state how it is processed.
*/
public interface DeletedBlockLog extends Closeable {
/**
* Scan entire log once and returns TXs to DatanodeDeletedBlockTransactions.
* Once DatanodeDeletedBlockTransactions is full, the scan behavior will
* stop.
* @param transactions a list of TXs will be set into.
* @return Mapping from containerId to latest transactionId for the container.
* @throws IOException
*/
Map getTransactions(DatanodeDeletedBlockTransactions transactions)
throws IOException;
/**
* Return all failed transactions in the log. A transaction is considered
* to be failed if it has been sent more than MAX_RETRY limit and its
* count is reset to -1.
*
* @return a list of failed deleted block transactions.
* @throws IOException
*/
List getFailedTransactions()
throws IOException;
/**
* Increments count for given list of transactions by 1.
* The log maintains a valid range of counts for each transaction
* [0, MAX_RETRY]. If exceed this range, resets it to -1 to indicate
* the transaction is no longer valid.
*
* @param txIDs - transaction ID.
*/
void incrementCount(List txIDs)
throws IOException;
/**
* Commits a transaction means to delete all footprints of a transaction
* from the log. This method doesn't guarantee all transactions can be
* successfully deleted, it tolerate failures and tries best efforts to.
* @param transactionResults - delete block transaction results.
* @param dnID - ID of datanode which acknowledges the delete block command.
*/
void commitTransactions(List transactionResults,
UUID dnID);
/**
* Creates a block deletion transaction and adds that into the log.
*
* @param containerID - container ID.
* @param blocks - blocks that belong to the same container.
*
* @throws IOException
*/
void addTransaction(long containerID, List blocks)
throws IOException;
/**
* Creates block deletion transactions for a set of containers,
* add into the log and persist them atomically. An object key
* might be stored in multiple containers and multiple blocks,
* this API ensures that these updates are done in atomic manner
* so if any of them fails, the entire operation fails without
* any updates to the log. Note, this doesn't mean to create only
* one transaction, it creates multiple transactions (depends on the
* number of containers) together (on success) or non (on failure).
*
* @param containerBlocksMap a map of containerBlocks.
* @throws IOException
*/
void addTransactions(Map> containerBlocksMap)
throws IOException;
/**
* Returns the total number of valid transactions. A transaction is
* considered to be valid as long as its count is in range [0, MAX_RETRY].
*
* @return number of a valid transactions.
* @throws IOException
*/
int getNumOfValidTransactions() throws IOException;
}