Examples with RegionLocations org.apache.hadoop.hbase.RegionLocations used on opensource projects

Example 36 with RegionLocations

use of org.apache.hadoop.hbase.RegionLocations in project hbase by apache.

the class MetaCache method getCachedLocation.

/**
   * Search the cache for a location that fits our table and row key.
   * Return null if no suitable region is located.
   *
   * @return Null or region location found in cache.
   */
public RegionLocations getCachedLocation(final TableName tableName, final byte[] row) {
    ConcurrentNavigableMap<byte[], RegionLocations> tableLocations = getTableLocations(tableName);
    Entry<byte[], RegionLocations> e = tableLocations.floorEntry(row);
    if (e == null) {
        if (metrics != null)
            metrics.incrMetaCacheMiss();
        return null;
    }
    RegionLocations possibleRegion = e.getValue();
    // make sure that the end key is greater than the row we're looking
    // for, otherwise the row actually belongs in the next region, not
    // this one. the exception case is when the endkey is
    // HConstants.EMPTY_END_ROW, signifying that the region we're
    // checking is actually the last region in the table.
    byte[] endKey = possibleRegion.getRegionLocation().getRegionInfo().getEndKey();
    // HConstants.EMPTY_END_ROW) check itself will pass.
    if (Bytes.equals(endKey, HConstants.EMPTY_END_ROW) || Bytes.compareTo(endKey, 0, endKey.length, row, 0, row.length) > 0) {
        if (metrics != null)
            metrics.incrMetaCacheHit();
        return possibleRegion;
    }
    // Passed all the way through, so we got nothing - complete cache miss
    if (metrics != null)
        metrics.incrMetaCacheMiss();
    return null;
}

Example 37 with RegionLocations

use of org.apache.hadoop.hbase.RegionLocations in project hbase by apache.

the class ScannerCallable method prepare.

/**
   * @param reload force reload of server location
   * @throws IOException
   */
@Override
public void prepare(boolean reload) throws IOException {
    if (Thread.interrupted()) {
        throw new InterruptedIOException();
    }
    RegionLocations rl = RpcRetryingCallerWithReadReplicas.getRegionLocations(!reload, id, getConnection(), getTableName(), getRow());
    location = id < rl.size() ? rl.getRegionLocation(id) : null;
    if (location == null || location.getServerName() == null) {
        //  when the table is created or after a split.
        throw new HBaseIOException("There is no location for replica id #" + id);
    }
    ServerName dest = location.getServerName();
    setStub(super.getConnection().getClient(dest));
    if (!instantiated || reload) {
        checkIfRegionServerIsRemote();
        instantiated = true;
    }
    // check how often we retry.
    if (reload && this.scanMetrics != null) {
        this.scanMetrics.countOfRPCRetries.incrementAndGet();
        if (isRegionServerRemote) {
            this.scanMetrics.countOfRemoteRPCRetries.incrementAndGet();
        }
    }
}

Example 38 with RegionLocations

use of org.apache.hadoop.hbase.RegionLocations in project hbase by apache.

the class ScannerCallableWithReplicas method call.

@Override
public Result[] call(int timeout) throws IOException {
    // the closed flag. Then an RPC is required to actually close the scanner.
    if (currentScannerCallable != null && currentScannerCallable.closed) {
        // the case of normal reads)
        if (LOG.isTraceEnabled()) {
            LOG.trace("Closing scanner id=" + currentScannerCallable.scannerId);
        }
        Result[] r = currentScannerCallable.call(timeout);
        currentScannerCallable = null;
        return r;
    }
    // We need to do the following:
    //1. When a scan goes out to a certain replica (default or not), we need to
    //   continue to hit that until there is a failure. So store the last successfully invoked
    //   replica
    //2. We should close the "losing" scanners (scanners other than the ones we hear back
    //   from first)
    //
    RegionLocations rl = RpcRetryingCallerWithReadReplicas.getRegionLocations(true, RegionReplicaUtil.DEFAULT_REPLICA_ID, cConnection, tableName, currentScannerCallable.getRow());
    // allocate a boundedcompletion pool of some multiple of number of replicas.
    // We want to accomodate some RPCs for redundant replica scans (but are still in progress)
    ResultBoundedCompletionService<Pair<Result[], ScannerCallable>> cs = new ResultBoundedCompletionService<>(RpcRetryingCallerFactory.instantiate(ScannerCallableWithReplicas.this.conf), pool, rl.size() * 5);
    AtomicBoolean done = new AtomicBoolean(false);
    replicaSwitched.set(false);
    // submit call for the primary replica.
    addCallsForCurrentReplica(cs, rl);
    int startIndex = 0;
    try {
        // wait for the timeout to see whether the primary responds back
        Future<Pair<Result[], ScannerCallable>> f = cs.poll(timeBeforeReplicas, // Yes, microseconds
        TimeUnit.MICROSECONDS);
        if (f != null) {
            // After poll, if f is not null, there must be a completed task
            Pair<Result[], ScannerCallable> r = f.get();
            if (r != null && r.getSecond() != null) {
                updateCurrentlyServingReplica(r.getSecond(), r.getFirst(), done, pool);
            }
            //great we got a response
            return r == null ? null : r.getFirst();
        }
    } catch (ExecutionException e) {
        // We ignore the ExecutionException and continue with the replicas
        if (LOG.isDebugEnabled()) {
            LOG.debug("Scan with primary region returns " + e.getCause());
        }
        // out the exception from the primary replica
        if ((rl.size() == 1) || (scan.getConsistency() == Consistency.STRONG)) {
            // Rethrow the first exception
            RpcRetryingCallerWithReadReplicas.throwEnrichedException(e, retries);
        }
        startIndex = 1;
    } catch (CancellationException e) {
        throw new InterruptedIOException(e.getMessage());
    } catch (InterruptedException e) {
        throw new InterruptedIOException(e.getMessage());
    }
    // submit call for the all of the secondaries at once
    int endIndex = rl.size();
    if (scan.getConsistency() == Consistency.STRONG) {
        // When scan's consistency is strong, do not send to the secondaries
        endIndex = 1;
    } else {
        // TODO: this may be an overkill for large region replication
        addCallsForOtherReplicas(cs, rl, 0, rl.size() - 1);
    }
    try {
        Future<Pair<Result[], ScannerCallable>> f = cs.pollForFirstSuccessfullyCompletedTask(timeout, TimeUnit.MILLISECONDS, startIndex, endIndex);
        if (f == null) {
            throw new IOException("Failed to get result within timeout, timeout=" + timeout + "ms");
        }
        Pair<Result[], ScannerCallable> r = f.get();
        if (r != null && r.getSecond() != null) {
            updateCurrentlyServingReplica(r.getSecond(), r.getFirst(), done, pool);
        }
        // great we got an answer
        return r == null ? null : r.getFirst();
    } catch (ExecutionException e) {
        RpcRetryingCallerWithReadReplicas.throwEnrichedException(e, retries);
    } catch (CancellationException e) {
        throw new InterruptedIOException(e.getMessage());
    } catch (InterruptedException e) {
        throw new InterruptedIOException(e.getMessage());
    } finally {
        // We get there because we were interrupted or because one or more of the
        // calls succeeded or failed. In all case, we stop all our tasks.
        cs.cancelAll();
    }
    // unreachable
    LOG.error("Imposible? Arrive at an unreachable line...");
    throw new IOException("Imposible? Arrive at an unreachable line...");
}

Example 39 with RegionLocations

use of org.apache.hadoop.hbase.RegionLocations in project hbase by apache.

the class ReversedScannerCallable method prepare.

/**
   * @param reload force reload of server location
   * @throws IOException
   */
@Override
public void prepare(boolean reload) throws IOException {
    if (Thread.interrupted()) {
        throw new InterruptedIOException();
    }
    if (!instantiated || reload) {
        // 2. the start row is empty which means we need to locate to the last region.
        if (scan.includeStartRow() && !isEmptyStartRow(getRow())) {
            // Just locate the region with the row
            RegionLocations rl = RpcRetryingCallerWithReadReplicas.getRegionLocations(reload, id, getConnection(), getTableName(), getRow());
            this.location = id < rl.size() ? rl.getRegionLocation(id) : null;
            if (location == null || location.getServerName() == null) {
                throw new IOException("Failed to find location, tableName=" + getTableName() + ", row=" + Bytes.toStringBinary(getRow()) + ", reload=" + reload);
            }
        } else {
            // Need to locate the regions with the range, and the target location is
            // the last one which is the previous region of last region scanner
            byte[] locateStartRow = createCloseRowBefore(getRow());
            List<HRegionLocation> locatedRegions = locateRegionsInRange(locateStartRow, getRow(), reload);
            if (locatedRegions.isEmpty()) {
                throw new DoNotRetryIOException("Does hbase:meta exist hole? Couldn't get regions for the range from " + Bytes.toStringBinary(locateStartRow) + " to " + Bytes.toStringBinary(getRow()));
            }
            this.location = locatedRegions.get(locatedRegions.size() - 1);
        }
        setStub(getConnection().getClient(getLocation().getServerName()));
        checkIfRegionServerIsRemote();
        instantiated = true;
    }
    // check how often we retry.
    if (reload && this.scanMetrics != null) {
        this.scanMetrics.countOfRPCRetries.incrementAndGet();
        if (isRegionServerRemote) {
            this.scanMetrics.countOfRemoteRPCRetries.incrementAndGet();
        }
    }
}

Example 40 with RegionLocations

use of org.apache.hadoop.hbase.RegionLocations in project hbase by apache.

the class ReversedScannerCallable method locateRegionsInRange.

/**
   * Get the corresponding regions for an arbitrary range of keys.
   * @param startKey Starting row in range, inclusive
   * @param endKey Ending row in range, exclusive
   * @param reload force reload of server location
   * @return A list of HRegionLocation corresponding to the regions that contain
   *         the specified range
   * @throws IOException
   */
private List<HRegionLocation> locateRegionsInRange(byte[] startKey, byte[] endKey, boolean reload) throws IOException {
    final boolean endKeyIsEndOfTable = Bytes.equals(endKey, HConstants.EMPTY_END_ROW);
    if ((Bytes.compareTo(startKey, endKey) > 0) && !endKeyIsEndOfTable) {
        throw new IllegalArgumentException("Invalid range: " + Bytes.toStringBinary(startKey) + " > " + Bytes.toStringBinary(endKey));
    }
    List<HRegionLocation> regionList = new ArrayList<>();
    byte[] currentKey = startKey;
    do {
        RegionLocations rl = RpcRetryingCallerWithReadReplicas.getRegionLocations(reload, id, getConnection(), getTableName(), currentKey);
        HRegionLocation regionLocation = id < rl.size() ? rl.getRegionLocation(id) : null;
        if (regionLocation != null && regionLocation.getRegionInfo().containsRow(currentKey)) {
            regionList.add(regionLocation);
        } else {
            throw new DoNotRetryIOException("Does hbase:meta exist hole? Locating row " + Bytes.toStringBinary(currentKey) + " returns incorrect region " + (regionLocation == null ? null : regionLocation.getRegionInfo()));
        }
        currentKey = regionLocation.getRegionInfo().getEndKey();
    } while (!Bytes.equals(currentKey, HConstants.EMPTY_END_ROW) && (endKeyIsEndOfTable || Bytes.compareTo(currentKey, endKey) < 0));
    return regionList;
}