/*
* Copyright © 2012-2014 Cask Data, Inc.
*
* Licensed 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 co.cask.tephra;
import co.cask.tephra.snapshot.DefaultSnapshotCodec;
import co.cask.tephra.snapshot.SnapshotCodecV2;
import co.cask.tephra.snapshot.SnapshotCodecV3;
import co.cask.tephra.snapshot.SnapshotCodecV4;
import java.util.concurrent.TimeUnit;
/**
* Transaction system constants
*/
public class TxConstants {
/**
* Defines what level of conflict detection should be used for transactions. {@code ROW} means that only the
* table name and row key for each change will be used to determine if the transaction change sets conflict.
* {@code COLUMN} means that the table name, row key, column family, and column qualifier will all be used to
* identify write conflicts. {@code NONE} means that no conflict detection will be performed, but transaction
* clients will still track the current transaction's change set to rollback any persisted changes in the event of
* a failure. This should only be used where writes to the same coordinate should never conflict, such as
* append-only data. The default value used by {@code TransactionAwareHTable} implementations is {@code COLUMN}.
*
* <p>
* <strong>Note: for a given table, all clients must use the same conflict detection setting!</strong>
* Otherwise conflicts will not be flagged correctly.
* </p>
*/
public enum ConflictDetection {
ROW,
COLUMN,
NONE
}
/**
* Property set for {@code org.apache.hadoop.hbase.HColumnDescriptor} to configure time-to-live on data within
* the column family. The value given is in milliseconds. Once a cell's data has surpassed the given value in age,
* the cell's data will no longer be visible and may be garbage collected.
*/
public static final String PROPERTY_TTL = "dataset.table.ttl";
/**
* This is how many tx we allow per millisecond, if you care about the system for 100 years:
* Long.MAX_VALUE / (System.currentTimeMillis() + TimeUnit.DAYS.toMillis(365 * 100)) =
* (as of Feb 20, 2014) 2,028,653. It is safe and convenient to use 1,000,000 as multiplier:
* <ul>
* <li>
* we hardly can do more than 1 billion txs per second
* </li>
* <li>
* long value will not overflow for 200 years
* </li>
* <li>
* makes reading & debugging easier if multiplier is 10^n
* </li>
* </ul>
*/
public static final long MAX_TX_PER_MS = 1000000;
/**
* Since HBase {@code Delete} operations cannot be undone at the same timestamp, "deleted" data is instead
* overwritten with an empty {@code byte[]} to flag it as removed. Cells with empty values will be filtered out
* of the results for read operations. If cells with empty values should be included in results (meaning data
* cannot be transactionally deleted), then set this configuration property to true.
*/
public static final String ALLOW_EMPTY_VALUES_KEY = "data.tx.allow.empty.values";
public static final boolean ALLOW_EMPTY_VALUES_DEFAULT = false;
/**
* Key used to set the serialized transaction as an attribute on Get and Scan operations.
*/
public static final String TX_OPERATION_ATTRIBUTE_KEY = "cask.tx";
/**
* Key used to flag a delete operation as part of a transaction rollback. This is used so that the
* {@code TransactionProcessor} coprocessor loaded on a table can differentiate between deletes issued
* as part of a normal client operation versus those performed when rolling back a transaction.
*/
public static final String TX_ROLLBACK_ATTRIBUTE_KEY = "cask.tx.rollback";
/**
* Column qualifier used for a special delete marker tombstone, which identifies an entire column family as deleted.
*/
public static final byte[] FAMILY_DELETE_QUALIFIER = new byte[0];
// Constants for monitoring status
public static final String STATUS_OK = "OK";
public static final String STATUS_NOTOK = "NOTOK";
/**
* Indicates whether data written before Tephra was enabled on a table should be readable. Reading non-transactional
* data can lead to slight performance penalty. Hence it is disabled by default.
* @see <a href="https://issues.cask.co/browse/TEPHRA-89">TEPHRA-89</a>
*/
public static final String READ_NON_TX_DATA = "data.tx.read.pre.existing";
public static final boolean DEFAULT_READ_NON_TX_DATA = false;
/**
* TransactionManager configuration.
*/
public static final class Manager {
// TransactionManager configuration
public static final String CFG_DO_PERSIST = "tx.persist";
/** Directory in HDFS used for transaction snapshot and log storage. */
public static final String CFG_TX_SNAPSHOT_DIR = "data.tx.snapshot.dir";
/** Directory on the local filesystem used for transaction snapshot and log storage. */
public static final String CFG_TX_SNAPSHOT_LOCAL_DIR = "data.tx.snapshot.local.dir";
/** How often to clean up timed out transactions, in seconds, or 0 for no cleanup. */
public static final String CFG_TX_CLEANUP_INTERVAL = "data.tx.cleanup.interval";
/** The user id to access HDFS if not running in secure HDFS. */
public static final String CFG_TX_HDFS_USER = "data.tx.hdfs.user";
/** Default value for how often to check in-progress transactions for expiration, in seconds. */
public static final int DEFAULT_TX_CLEANUP_INTERVAL = 10;
/**
* The timeout for a transaction, in seconds. If the transaction is not finished in that time,
* it is marked invalid.
*/
public static final String CFG_TX_TIMEOUT = "data.tx.timeout";
/** Default value for transaction timeout, in seconds. */
public static final int DEFAULT_TX_TIMEOUT = 30;
/**
* The timeout for a long running transaction, in seconds. If the transaction is not finished in that time,
* it is marked invalid.
*/
public static final String CFG_TX_LONG_TIMEOUT = "data.tx.long.timeout";
/** Default value for long running transaction timeout, in seconds. */
public static final int DEFAULT_TX_LONG_TIMEOUT = (int) TimeUnit.DAYS.toSeconds(1);
/** The frequency (in seconds) to perform periodic snapshots, or 0 for no periodic snapshots. */
public static final String CFG_TX_SNAPSHOT_INTERVAL = "data.tx.snapshot.interval";
/** Default value for frequency of periodic snapshots of transaction state. */
public static final long DEFAULT_TX_SNAPSHOT_INTERVAL = 300;
/** Number of most recent transaction snapshots to retain. */
public static final String CFG_TX_SNAPSHOT_RETAIN = "data.tx.snapshot.retain";
/** Default value for number of most recent snapshots to retain. */
public static final int DEFAULT_TX_SNAPSHOT_RETAIN = 10;
}
/**
* TransactionService configuration.
*/
public static final class Service {
/** for the zookeeper quorum string for leader election for tx server. */
public static final String CFG_DATA_TX_ZOOKEEPER_QUORUM
= "data.tx.zookeeper.quorum";
/** for the name used to announce service availability to discovery service */
public static final String CFG_DATA_TX_DISCOVERY_SERVICE_NAME
= "data.tx.discovery.service.name";
/** for the port of the tx server. */
public static final String CFG_DATA_TX_BIND_PORT
= "data.tx.bind.port";
/** for the address (hostname) of the tx server. */
public static final String CFG_DATA_TX_BIND_ADDRESS
= "data.tx.bind.address";
/** the number of IO threads in the tx service. */
public static final String CFG_DATA_TX_SERVER_IO_THREADS
= "data.tx.server.io.threads";
/** the number of handler threads in the tx service. */
public static final String CFG_DATA_TX_SERVER_THREADS
= "data.tx.server.threads";
public static final String CFG_DATA_TX_THRIFT_MAX_READ_BUFFER
= "data.tx.thrift.max.read.buffer";
public static final String DEFAULT_DATA_TX_DISCOVERY_SERVICE_NAME
= "transaction";
/** default tx service port. */
public static final int DEFAULT_DATA_TX_BIND_PORT
= 15165;
/** default tx service address. */
public static final String DEFAULT_DATA_TX_BIND_ADDRESS
= "0.0.0.0";
/** default number of handler IO threads in tx service. */
public static final int DEFAULT_DATA_TX_SERVER_IO_THREADS
= 2;
/** default number of handler threads in tx service. */
public static final int DEFAULT_DATA_TX_SERVER_THREADS
= 20;
/** default thrift max read buffer size */
public static final int DEFAULT_DATA_TX_THRIFT_MAX_READ_BUFFER
= 16 * 1024 * 1024;
// Configuration key names and defaults used by tx client.
/** to specify the tx client socket timeout in ms. */
public static final String CFG_DATA_TX_CLIENT_TIMEOUT
= "data.tx.client.timeout";
/** to specify the tx client provider strategy. */
public static final String CFG_DATA_TX_CLIENT_PROVIDER
= "data.tx.client.provider";
/** to specify the number of threads for client provider "pool". */
public static final String CFG_DATA_TX_CLIENT_COUNT
= "data.tx.client.count";
/** timeout (in milliseconds) for obtaining client from client provider "pool". */
public static final String CFG_DATA_TX_CLIENT_OBTAIN_TIMEOUT_MS
= "data.tx.client.obtain.timeout";
/** to specify the retry strategy for a failed thrift call. */
public static final String CFG_DATA_TX_CLIENT_RETRY_STRATEGY
= "data.tx.client.retry.strategy";
/** to specify the number of times to retry a failed thrift call. */
public static final String CFG_DATA_TX_CLIENT_ATTEMPTS
= "data.tx.client.retry.attempts";
/** to specify the initial sleep time for retry strategy backoff. */
public static final String CFG_DATA_TX_CLIENT_BACKOFF_INITIAL
= "data.tx.client.retry.backoff.initial";
/** to specify the backoff factor for retry strategy backoff. */
public static final String CFG_DATA_TX_CLIENT_BACKOFF_FACTOR
= "data.tx.client.retry.backoff.factor";
/** to specify the sleep time limit for retry strategy backoff. */
public static final String CFG_DATA_TX_CLIENT_BACKOFF_LIMIT
= "data.tx.client.retry.backoff.limit";
/** the default tx client socket timeout in milli seconds. */
public static final int DEFAULT_DATA_TX_CLIENT_TIMEOUT_MS
= 30 * 1000;
/** default number of tx clients for client provider "pool". */
public static final int DEFAULT_DATA_TX_CLIENT_COUNT
= 50;
/** default timeout (in milliseconds) for obtaining client from client provider "pool". */
public static final long DEFAULT_DATA_TX_CLIENT_OBTAIN_TIMEOUT_MS
= TimeUnit.SECONDS.toMillis(3);
/** default tx client provider strategy. */
public static final String DEFAULT_DATA_TX_CLIENT_PROVIDER
= "pool";
/** retry strategy for thrift clients, e.g. backoff, or n-times. */
public static final String DEFAULT_DATA_TX_CLIENT_RETRY_STRATEGY
= "backoff";
/** default number of attempts for strategy n-times. */
public static final int DEFAULT_DATA_TX_CLIENT_ATTEMPTS
= 2;
/** default initial sleep is 100ms. */
public static final int DEFAULT_DATA_TX_CLIENT_BACKOFF_INITIAL
= 100;
/** default backoff factor is 4. */
public static final int DEFAULT_DATA_TX_CLIENT_BACKOFF_FACTOR
= 4;
/** default sleep limit is 30 sec. */
public static final int DEFAULT_DATA_TX_CLIENT_BACKOFF_LIMIT
= 30 * 1000;
}
/**
* Configuration properties for metrics reporting
*/
public static final class Metrics {
/**
* Frequency at which metrics should be reported, in seconds.
*/
public static final String REPORT_PERIOD_KEY = "data.tx.metrics.period";
/**
* Default report period for metrics, in seconds.
*/
public static final int REPORT_PERIOD_DEFAULT = 60;
}
/**
* Configuration properties used by HBase
*/
public static final class HBase {
public static final String ZOOKEEPER_QUORUM = "hbase.zookeeper.quorum";
public static final String ZK_SESSION_TIMEOUT = "zookeeper.session.timeout";
public static final int DEFAULT_ZK_SESSION_TIMEOUT = 180 * 1000;
}
/**
* Configuration for the TransactionDataJanitor coprocessor.
*/
public static final class DataJanitor {
/**
* Whether or not the TransactionDataJanitor coprocessor should be enabled on tables.
* Disable for testing.
*/
public static final String CFG_TX_JANITOR_ENABLE = "data.tx.janitor.enable";
public static final boolean DEFAULT_TX_JANITOR_ENABLE = true;
}
/**
* Configuration for the transaction snapshot persistence.
*/
public static final class Persist {
/**
* The class names of all known transaction snapshot codecs.
*/
public static final String CFG_TX_SNAPHOT_CODEC_CLASSES = "data.tx.snapshot.codecs";
public static final Class[] DEFAULT_TX_SNAPHOT_CODEC_CLASSES =
{ DefaultSnapshotCodec.class, SnapshotCodecV2.class, SnapshotCodecV3.class, SnapshotCodecV4.class };
}
/**
* Configuration for transaction log edit entries
*/
public static final class TransactionLog {
/**
* Key used to denote the number of entries appended.
*/
public static final String NUM_ENTRIES_APPENDED = "count";
public static final String VERSION_KEY = "version";
public static final byte CURRENT_VERSION = 2;
}
}