Examples with UpgradeInProgressException org.apache.phoenix.exception.UpgradeInProgressException used on opensource projects

Example 1 with UpgradeInProgressException

use of org.apache.phoenix.exception.UpgradeInProgressException in project phoenix by apache.

the class UpgradeIT method testAcquiringAndReleasingUpgradeMutex.

@Test
public void testAcquiringAndReleasingUpgradeMutex() throws Exception {
    ConnectionQueryServices services = null;
    byte[] mutexRowKey = SchemaUtil.getTableKey(null, PhoenixDatabaseMetaData.SYSTEM_CATALOG_SCHEMA, generateUniqueName());
    try (Connection conn = getConnection(false, null)) {
        services = conn.unwrap(PhoenixConnection.class).getQueryServices();
        putUnlockKVInSysMutex(mutexRowKey);
        assertTrue(((ConnectionQueryServicesImpl) services).acquireUpgradeMutex(MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0, mutexRowKey));
        try {
            ((ConnectionQueryServicesImpl) services).acquireUpgradeMutex(MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0, mutexRowKey);
            fail();
        } catch (UpgradeInProgressException expected) {
        }
        assertTrue(((ConnectionQueryServicesImpl) services).releaseUpgradeMutex(mutexRowKey));
        assertFalse(((ConnectionQueryServicesImpl) services).releaseUpgradeMutex(mutexRowKey));
    }
}

Example 2 with UpgradeInProgressException

use of org.apache.phoenix.exception.UpgradeInProgressException in project phoenix by apache.

the class ConnectionQueryServicesImpl method upgradeSystemTables.

/**
 * There is no other locking needed here since only one connection (on the same or different JVM) will be able to
 * acquire the upgrade mutex via {@link #acquireUpgradeMutex(long, byte[])}.
 */
@Override
public void upgradeSystemTables(final String url, final Properties props) throws SQLException {
    PhoenixConnection metaConnection = null;
    boolean success = false;
    String snapshotName = null;
    String sysCatalogTableName = null;
    SQLException toThrow = null;
    boolean acquiredMutexLock = false;
    byte[] mutexRowKey = SchemaUtil.getTableKey(null, PhoenixDatabaseMetaData.SYSTEM_CATALOG_SCHEMA, PhoenixDatabaseMetaData.SYSTEM_CATALOG_TABLE);
    boolean snapshotCreated = false;
    try {
        if (!isUpgradeRequired()) {
            throw new UpgradeNotRequiredException();
        }
        Properties scnProps = PropertiesUtil.deepCopy(props);
        scnProps.setProperty(PhoenixRuntime.CURRENT_SCN_ATTRIB, Long.toString(MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP));
        scnProps.remove(PhoenixRuntime.TENANT_ID_ATTRIB);
        String globalUrl = JDBCUtil.removeProperty(url, PhoenixRuntime.TENANT_ID_ATTRIB);
        metaConnection = new PhoenixConnection(ConnectionQueryServicesImpl.this, globalUrl, scnProps, newEmptyMetaData());
        metaConnection.setRunningUpgrade(true);
        try {
            metaConnection.createStatement().executeUpdate(QueryConstants.CREATE_TABLE_METADATA);
        } catch (NewerTableAlreadyExistsException ignore) {
        // Ignore, as this will happen if the SYSTEM.CATALOG already exists at this fixed
        // timestamp. A TableAlreadyExistsException is not thrown, since the table only exists
        // *after* this fixed timestamp.
        } catch (TableAlreadyExistsException e) {
            long currentServerSideTableTimeStamp = e.getTable().getTimeStamp();
            sysCatalogTableName = e.getTable().getPhysicalName().getString();
            if (currentServerSideTableTimeStamp < MIN_SYSTEM_TABLE_TIMESTAMP) {
                // upgrade, so no need for a bunch of wasted RPCs.
                if (currentServerSideTableTimeStamp <= MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_10_0 && !SchemaUtil.isNamespaceMappingEnabled(PTableType.SYSTEM, ConnectionQueryServicesImpl.this.getProps())) {
                    try (HBaseAdmin admin = getAdmin()) {
                        createSysMutexTableIfNotExists(admin, this.getProps());
                    }
                }
                if (acquiredMutexLock = acquireUpgradeMutex(currentServerSideTableTimeStamp, mutexRowKey)) {
                    snapshotName = getSysCatalogSnapshotName(currentServerSideTableTimeStamp);
                    createSnapshot(snapshotName, sysCatalogTableName);
                    snapshotCreated = true;
                }
            }
            String columnsToAdd = "";
            // include any new columns we've added.
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_3_0) {
                // We know that we always need to add the STORE_NULLS column for 4.3 release
                columnsToAdd = addColumn(columnsToAdd, PhoenixDatabaseMetaData.STORE_NULLS + " " + PBoolean.INSTANCE.getSqlTypeName());
                try (HBaseAdmin admin = getAdmin()) {
                    HTableDescriptor[] localIndexTables = admin.listTables(MetaDataUtil.LOCAL_INDEX_TABLE_PREFIX + ".*");
                    for (HTableDescriptor table : localIndexTables) {
                        if (table.getValue(MetaDataUtil.PARENT_TABLE_KEY) == null && table.getValue(MetaDataUtil.IS_LOCAL_INDEX_TABLE_PROP_NAME) != null) {
                            table.setValue(MetaDataUtil.PARENT_TABLE_KEY, MetaDataUtil.getLocalIndexUserTableName(table.getNameAsString()));
                            // Explicitly disable, modify and enable the table to ensure
                            // co-location of data and index regions. If we just modify the
                            // table descriptor when online schema change enabled may reopen
                            // the region in same region server instead of following data region.
                            admin.disableTable(table.getTableName());
                            admin.modifyTable(table.getTableName(), table);
                            admin.enableTable(table.getTableName());
                        }
                    }
                }
            }
            // the column names that have been added to SYSTEM.CATALOG since 4.0.
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_1_0) {
                columnsToAdd = addColumn(columnsToAdd, PhoenixDatabaseMetaData.INDEX_TYPE + " " + PUnsignedTinyint.INSTANCE.getSqlTypeName() + ", " + PhoenixDatabaseMetaData.INDEX_DISABLE_TIMESTAMP + " " + PLong.INSTANCE.getSqlTypeName());
            }
            // If we have some new columns from 4.1-4.3 to add, add them now.
            if (!columnsToAdd.isEmpty()) {
                // Ugh..need to assign to another local variable to keep eclipse happy.
                PhoenixConnection newMetaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_3_0, columnsToAdd);
                metaConnection = newMetaConnection;
            }
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_5_0) {
                columnsToAdd = PhoenixDatabaseMetaData.BASE_COLUMN_COUNT + " " + PInteger.INSTANCE.getSqlTypeName();
                try {
                    metaConnection = addColumn(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_5_0, columnsToAdd, false);
                    upgradeTo4_5_0(metaConnection);
                } catch (ColumnAlreadyExistsException ignored) {
                    /*
                         * Upgrade to 4.5 is a slightly special case. We use the fact that the
                         * column BASE_COLUMN_COUNT is already part of the meta-data schema as the
                         * signal that the server side upgrade has finished or is in progress.
                         */
                    logger.debug("No need to run 4.5 upgrade");
                }
                Properties p = PropertiesUtil.deepCopy(metaConnection.getClientInfo());
                p.remove(PhoenixRuntime.CURRENT_SCN_ATTRIB);
                p.remove(PhoenixRuntime.TENANT_ID_ATTRIB);
                PhoenixConnection conn = new PhoenixConnection(ConnectionQueryServicesImpl.this, metaConnection.getURL(), p, metaConnection.getMetaDataCache());
                try {
                    List<String> tablesNeedingUpgrade = UpgradeUtil.getPhysicalTablesWithDescRowKey(conn);
                    if (!tablesNeedingUpgrade.isEmpty()) {
                        logger.warn("The following tables require upgrade due to a bug causing the row key to be incorrect for descending columns and ascending BINARY columns (PHOENIX-2067 and PHOENIX-2120):\n" + Joiner.on(' ').join(tablesNeedingUpgrade) + "\nTo upgrade issue the \"bin/psql.py -u\" command.");
                    }
                    List<String> unsupportedTables = UpgradeUtil.getPhysicalTablesWithDescVarbinaryRowKey(conn);
                    if (!unsupportedTables.isEmpty()) {
                        logger.warn("The following tables use an unsupported VARBINARY DESC construct and need to be changed:\n" + Joiner.on(' ').join(unsupportedTables));
                    }
                } catch (Exception ex) {
                    logger.error("Unable to determine tables requiring upgrade due to PHOENIX-2067", ex);
                } finally {
                    conn.close();
                }
            }
            // parts we haven't yet done).
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_6_0) {
                columnsToAdd = PhoenixDatabaseMetaData.IS_ROW_TIMESTAMP + " " + PBoolean.INSTANCE.getSqlTypeName();
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_6_0, columnsToAdd);
            }
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0) {
                // Drop old stats table so that new stats table is created
                metaConnection = dropStatsTable(metaConnection, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0 - 4);
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0 - 3, PhoenixDatabaseMetaData.TRANSACTIONAL + " " + PBoolean.INSTANCE.getSqlTypeName());
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0 - 2, PhoenixDatabaseMetaData.UPDATE_CACHE_FREQUENCY + " " + PLong.INSTANCE.getSqlTypeName());
                metaConnection = setImmutableTableIndexesImmutable(metaConnection, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0 - 1);
                metaConnection = updateSystemCatalogTimestamp(metaConnection, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0);
                ConnectionQueryServicesImpl.this.removeTable(null, PhoenixDatabaseMetaData.SYSTEM_CATALOG_NAME, null, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_7_0);
                clearCache();
            }
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_8_0) {
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_8_0 - 2, PhoenixDatabaseMetaData.IS_NAMESPACE_MAPPED + " " + PBoolean.INSTANCE.getSqlTypeName());
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_8_0 - 1, PhoenixDatabaseMetaData.AUTO_PARTITION_SEQ + " " + PVarchar.INSTANCE.getSqlTypeName());
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_8_0, PhoenixDatabaseMetaData.APPEND_ONLY_SCHEMA + " " + PBoolean.INSTANCE.getSqlTypeName());
                metaConnection = UpgradeUtil.disableViewIndexes(metaConnection);
                if (getProps().getBoolean(QueryServices.LOCAL_INDEX_CLIENT_UPGRADE_ATTRIB, QueryServicesOptions.DEFAULT_LOCAL_INDEX_CLIENT_UPGRADE)) {
                    metaConnection = UpgradeUtil.upgradeLocalIndexes(metaConnection);
                }
                ConnectionQueryServicesImpl.this.removeTable(null, PhoenixDatabaseMetaData.SYSTEM_CATALOG_NAME, null, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_8_0);
                clearCache();
            }
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_9_0) {
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_9_0, PhoenixDatabaseMetaData.GUIDE_POSTS_WIDTH + " " + PLong.INSTANCE.getSqlTypeName());
                ConnectionQueryServicesImpl.this.removeTable(null, PhoenixDatabaseMetaData.SYSTEM_CATALOG_NAME, null, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_9_0);
                clearCache();
            }
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_10_0) {
                metaConnection = addColumnQualifierColumn(metaConnection, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_10_0 - 3);
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_10_0 - 2, PhoenixDatabaseMetaData.IMMUTABLE_STORAGE_SCHEME + " " + PTinyint.INSTANCE.getSqlTypeName());
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_10_0 - 1, PhoenixDatabaseMetaData.ENCODING_SCHEME + " " + PTinyint.INSTANCE.getSqlTypeName());
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_10_0, PhoenixDatabaseMetaData.COLUMN_QUALIFIER_COUNTER + " " + PInteger.INSTANCE.getSqlTypeName());
                ConnectionQueryServicesImpl.this.removeTable(null, PhoenixDatabaseMetaData.SYSTEM_CATALOG_NAME, null, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_10_0);
                clearCache();
            }
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_11_0) {
                metaConnection = addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_11_0, PhoenixDatabaseMetaData.USE_STATS_FOR_PARALLELIZATION + " " + PBoolean.INSTANCE.getSqlTypeName());
                addParentToChildLinks(metaConnection);
            }
        }
        int nSaltBuckets = ConnectionQueryServicesImpl.this.props.getInt(QueryServices.SEQUENCE_SALT_BUCKETS_ATTRIB, QueryServicesOptions.DEFAULT_SEQUENCE_TABLE_SALT_BUCKETS);
        try {
            String createSequenceTable = Sequence.getCreateTableStatement(nSaltBuckets);
            metaConnection.createStatement().executeUpdate(createSequenceTable);
            nSequenceSaltBuckets = nSaltBuckets;
        } catch (NewerTableAlreadyExistsException e) {
            // Ignore, as this will happen if the SYSTEM.SEQUENCE already exists at this fixed
            // timestamp.
            // A TableAlreadyExistsException is not thrown, since the table only exists *after* this
            // fixed timestamp.
            nSequenceSaltBuckets = getSaltBuckets(e);
        } catch (TableAlreadyExistsException e) {
            // This will occur if we have an older SYSTEM.SEQUENCE and we need to update it to
            // include
            // any new columns we've added.
            long currentServerSideTableTimeStamp = e.getTable().getTimeStamp();
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_1_0) {
                // If the table time stamp is before 4.1.0 then we need to add below columns
                // to the SYSTEM.SEQUENCE table.
                String columnsToAdd = PhoenixDatabaseMetaData.MIN_VALUE + " " + PLong.INSTANCE.getSqlTypeName() + ", " + PhoenixDatabaseMetaData.MAX_VALUE + " " + PLong.INSTANCE.getSqlTypeName() + ", " + PhoenixDatabaseMetaData.CYCLE_FLAG + " " + PBoolean.INSTANCE.getSqlTypeName() + ", " + PhoenixDatabaseMetaData.LIMIT_REACHED_FLAG + " " + PBoolean.INSTANCE.getSqlTypeName();
                addColumnsIfNotExists(metaConnection, PhoenixDatabaseMetaData.SYSTEM_CATALOG, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP, columnsToAdd);
            }
            // If the table timestamp is before 4.2.1 then run the upgrade script
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_2_1) {
                if (UpgradeUtil.upgradeSequenceTable(metaConnection, nSaltBuckets, e.getTable())) {
                    metaConnection.removeTable(null, PhoenixDatabaseMetaData.SYSTEM_SEQUENCE_SCHEMA, PhoenixDatabaseMetaData.SYSTEM_SEQUENCE_TABLE, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP);
                    clearTableFromCache(ByteUtil.EMPTY_BYTE_ARRAY, PhoenixDatabaseMetaData.SYSTEM_SEQUENCE_SCHEMA_BYTES, PhoenixDatabaseMetaData.SYSTEM_SEQUENCE_TABLE_BYTES, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP);
                    clearTableRegionCache(PhoenixDatabaseMetaData.SYSTEM_SEQUENCE_NAME_BYTES);
                }
                nSequenceSaltBuckets = nSaltBuckets;
            } else {
                nSequenceSaltBuckets = getSaltBuckets(e);
            }
        }
        try {
            metaConnection.createStatement().executeUpdate(QueryConstants.CREATE_STATS_TABLE_METADATA);
        } catch (NewerTableAlreadyExistsException ignore) {
        } catch (TableAlreadyExistsException e) {
            long currentServerSideTableTimeStamp = e.getTable().getTimeStamp();
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_3_0) {
                metaConnection = addColumnsIfNotExists(metaConnection, SYSTEM_STATS_NAME, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP, PhoenixDatabaseMetaData.GUIDE_POSTS_ROW_COUNT + " " + PLong.INSTANCE.getSqlTypeName());
            }
            if (currentServerSideTableTimeStamp < MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_9_0) {
                // The COLUMN_FAMILY column should be nullable as we create a row in it without
                // any column family to mark when guideposts were last collected.
                metaConnection = removeNotNullConstraint(metaConnection, PhoenixDatabaseMetaData.SYSTEM_SCHEMA_NAME, PhoenixDatabaseMetaData.SYSTEM_STATS_TABLE, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_9_0, PhoenixDatabaseMetaData.COLUMN_FAMILY);
                ConnectionQueryServicesImpl.this.removeTable(null, PhoenixDatabaseMetaData.SYSTEM_STATS_NAME, null, MetaDataProtocol.MIN_SYSTEM_TABLE_TIMESTAMP_4_9_0);
                clearCache();
            }
        }
        try {
            metaConnection.createStatement().executeUpdate(QueryConstants.CREATE_FUNCTION_METADATA);
        } catch (NewerTableAlreadyExistsException e) {
        } catch (TableAlreadyExistsException e) {
        }
        ConnectionQueryServicesImpl.this.upgradeRequired.set(false);
        success = true;
    } catch (UpgradeInProgressException | UpgradeNotRequiredException e) {
        // don't set it as initializationException because otherwise client won't be able to retry
        throw e;
    } catch (Exception e) {
        if (e instanceof SQLException) {
            toThrow = (SQLException) e;
        } else {
            // wrap every other exception into a SQLException
            toThrow = new SQLException(e);
        }
    } finally {
        try {
            if (metaConnection != null) {
                metaConnection.close();
            }
        } catch (SQLException e) {
            if (toThrow != null) {
                toThrow.setNextException(e);
            } else {
                toThrow = e;
            }
        } finally {
            try {
                if (snapshotCreated) {
                    restoreFromSnapshot(sysCatalogTableName, snapshotName, success);
                }
            } catch (SQLException e) {
                if (toThrow != null) {
                    toThrow.setNextException(e);
                } else {
                    toThrow = e;
                }
            } finally {
                if (acquiredMutexLock) {
                    try {
                        releaseUpgradeMutex(mutexRowKey);
                    } catch (IOException e) {
                        logger.warn("Release of upgrade mutex failed ", e);
                    }
                }
            }
            if (toThrow != null) {
                throw toThrow;
            }
        }
    }
}

Example 3 with UpgradeInProgressException

use of org.apache.phoenix.exception.UpgradeInProgressException in project phoenix by apache.

the class ConnectionQueryServicesImpl method acquireUpgradeMutex.

/**
 * Acquire distributed mutex of sorts to make sure only one JVM is able to run the upgrade code by
 * making use of HBase's checkAndPut api.
 *
 * @return true if client won the race, false otherwise
 * @throws IOException
 * @throws SQLException
 */
@VisibleForTesting
public boolean acquireUpgradeMutex(long currentServerSideTableTimestamp, byte[] rowToLock) throws IOException, SQLException {
    Preconditions.checkArgument(currentServerSideTableTimestamp < MIN_SYSTEM_TABLE_TIMESTAMP);
    byte[] sysMutexPhysicalTableNameBytes = getSysMutexPhysicalTableNameBytes();
    if (sysMutexPhysicalTableNameBytes == null) {
        throw new UpgradeInProgressException(getVersion(currentServerSideTableTimestamp), getVersion(MIN_SYSTEM_TABLE_TIMESTAMP));
    }
    try (HTableInterface sysMutexTable = getTable(sysMutexPhysicalTableNameBytes)) {
        byte[] family = PhoenixDatabaseMetaData.SYSTEM_MUTEX_FAMILY_NAME_BYTES;
        byte[] qualifier = UPGRADE_MUTEX;
        byte[] oldValue = UPGRADE_MUTEX_UNLOCKED;
        byte[] newValue = UPGRADE_MUTEX_LOCKED;
        Put put = new Put(rowToLock);
        put.addColumn(family, qualifier, newValue);
        boolean acquired = sysMutexTable.checkAndPut(rowToLock, family, qualifier, oldValue, put);
        if (!acquired) {
            /*
                 * Because of TTL on the SYSTEM_MUTEX_FAMILY, it is very much possible that the cell
                 * has gone away. So we need to retry with an old value of null. Note there is a small
                 * race condition here that between the two checkAndPut calls, it is possible that another
                 * request would have set the value back to UPGRADE_MUTEX_UNLOCKED. In that scenario this
                 * following checkAndPut would still return false even though the lock was available.
                 */
            acquired = sysMutexTable.checkAndPut(rowToLock, family, qualifier, null, put);
            if (!acquired) {
                throw new UpgradeInProgressException(getVersion(currentServerSideTableTimestamp), getVersion(MIN_SYSTEM_TABLE_TIMESTAMP));
            }
        }
        return true;
    }
}