Examples with ResultScanner org.apache.hadoop.hbase.client.ResultScanner used on opensource projects

Example 21 with ResultScanner

use of org.apache.hadoop.hbase.client.ResultScanner in project hbase by apache.

the class ReplicationTableBase method getQueuesBelongingToServer.

/**
   * Get the queue id's and meta data (Owner and History) for the queues belonging to the named
   * server
   *
   * @param server name of the server
   * @return a ResultScanner over the QueueIds belonging to the server
   * @throws IOException
   */
protected ResultScanner getQueuesBelongingToServer(String server) throws IOException {
    Scan scan = new Scan();
    SingleColumnValueFilter filterMyQueues = new SingleColumnValueFilter(CF_QUEUE, COL_QUEUE_OWNER, CompareFilter.CompareOp.EQUAL, Bytes.toBytes(server));
    scan.setFilter(filterMyQueues);
    scan.addColumn(CF_QUEUE, COL_QUEUE_OWNER);
    scan.addColumn(CF_QUEUE, COL_QUEUE_OWNER_HISTORY);
    try (Table replicationTable = getOrBlockOnReplicationTable()) {
        ResultScanner results = replicationTable.getScanner(scan);
        return results;
    }
}

Example 22 with ResultScanner

use of org.apache.hadoop.hbase.client.ResultScanner in project hbase by apache.

the class TableBasedReplicationQueuesImpl method getResultIfOwner.

/**
   * Attempts to run a Get on some queue. Will only return a non-null result if we currently own
   * the queue.
   *
   * @param get The Get that we want to query
   * @return The result of the Get if this server is the owner of the queue. Else it returns null.
   * @throws IOException
   */
private Result getResultIfOwner(Get get) throws IOException {
    Scan scan = new Scan(get);
    // Check if the Get currently contains all columns or only specific columns
    if (scan.getFamilyMap().size() > 0) {
        // Add the OWNER column if the scan is already only over specific columns
        scan.addColumn(CF_QUEUE, COL_QUEUE_OWNER);
    }
    scan.setMaxResultSize(1);
    SingleColumnValueFilter checkOwner = new SingleColumnValueFilter(CF_QUEUE, COL_QUEUE_OWNER, CompareFilter.CompareOp.EQUAL, serverNameBytes);
    scan.setFilter(checkOwner);
    ResultScanner scanner = null;
    try (Table replicationTable = getOrBlockOnReplicationTable()) {
        scanner = replicationTable.getScanner(scan);
        Result result = scanner.next();
        return (result == null || result.isEmpty()) ? null : result;
    } finally {
        if (scanner != null) {
            scanner.close();
        }
    }
}

Example 23 with ResultScanner

use of org.apache.hadoop.hbase.client.ResultScanner in project hbase by apache.

the class BackupSystemTable method hasBackupSessions.

/**
   * Checks if we have at least one backup session in backup system table This API is used by
   * BackupLogCleaner
   * @return true, if - at least one session exists in backup system table table
   * @throws IOException exception
   */
public boolean hasBackupSessions() throws IOException {
    if (LOG.isTraceEnabled()) {
        LOG.trace("Has backup sessions from backup system table");
    }
    boolean result = false;
    Scan scan = createScanForBackupHistory();
    scan.setCaching(1);
    try (Table table = connection.getTable(tableName);
        ResultScanner scanner = table.getScanner(scan)) {
        if (scanner.next() != null) {
            result = true;
        }
        return result;
    }
}

Example 24 with ResultScanner

use of org.apache.hadoop.hbase.client.ResultScanner in project hbase by apache.

the class BackupSystemTable method readRegionServerLastLogRollResult.

/**
   * Get the Region Servers log information after the last log roll from backup system table.
   * @param backupRoot root directory path to backup
   * @return RS log info
   * @throws IOException exception
   */
public HashMap<String, Long> readRegionServerLastLogRollResult(String backupRoot) throws IOException {
    if (LOG.isTraceEnabled()) {
        LOG.trace("read region server last roll log result to backup system table");
    }
    Scan scan = createScanForReadRegionServerLastLogRollResult(backupRoot);
    try (Table table = connection.getTable(tableName);
        ResultScanner scanner = table.getScanner(scan)) {
        Result res = null;
        HashMap<String, Long> rsTimestampMap = new HashMap<String, Long>();
        while ((res = scanner.next()) != null) {
            res.advance();
            Cell cell = res.current();
            byte[] row = CellUtil.cloneRow(cell);
            String server = getServerNameForReadRegionServerLastLogRollResult(row);
            byte[] data = CellUtil.cloneValue(cell);
            rsTimestampMap.put(server, Bytes.toLong(data));
        }
        return rsTimestampMap;
    }
}

Example 25 with ResultScanner

use of org.apache.hadoop.hbase.client.ResultScanner in project hbase by apache.

the class BackupSystemTable method listBackupSets.

/**
   * BACKUP SETS
   */
/**
   * Get backup set list
   * @return backup set list
   * @throws IOException
   */
public List<String> listBackupSets() throws IOException {
    if (LOG.isTraceEnabled()) {
        LOG.trace(" Backup set list");
    }
    List<String> list = new ArrayList<String>();
    Table table = null;
    ResultScanner scanner = null;
    try {
        table = connection.getTable(tableName);
        Scan scan = createScanForBackupSetList();
        scan.setMaxVersions(1);
        scanner = table.getScanner(scan);
        Result res = null;
        while ((res = scanner.next()) != null) {
            res.advance();
            list.add(cellKeyToBackupSetName(res.current()));
        }
        return list;
    } finally {
        if (scanner != null) {
            scanner.close();
        }
        if (table != null) {
            table.close();
        }
    }
}