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

Example 1 with HRegionLocation

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

the class AsyncMetaRegionLocator method getRegionLocation.

CompletableFuture<HRegionLocation> getRegionLocation() {
    for (; ; ) {
        HRegionLocation metaRegionLocation = this.metaRegionLocation.get();
        if (metaRegionLocation != null) {
            return CompletableFuture.completedFuture(metaRegionLocation);
        }
        if (LOG.isTraceEnabled()) {
            LOG.trace("Meta region location cache is null, try fetching from registry.");
        }
        if (metaRelocateFuture.compareAndSet(null, new CompletableFuture<>())) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Start fetching meta region location from registry.");
            }
            CompletableFuture<HRegionLocation> future = metaRelocateFuture.get();
            registry.getMetaRegionLocation().whenComplete((locs, error) -> {
                if (error != null) {
                    if (LOG.isDebugEnabled()) {
                        LOG.debug("Failed to fetch meta region location from registry", error);
                    }
                    metaRelocateFuture.getAndSet(null).completeExceptionally(error);
                    return;
                }
                HRegionLocation loc = locs.getDefaultRegionLocation();
                if (LOG.isDebugEnabled()) {
                    LOG.debug("The fetched meta region location is " + loc);
                }
                // Here we update cache before reset future, so it is possible that someone can get a
                // stale value. Consider this:
                // 1. update cache
                // 2. someone clear the cache and relocate again
                // 3. the metaRelocateFuture is not null so the old future is used.
                // 4. we clear metaRelocateFuture and complete the future in it with the value being
                // cleared in step 2.
                // But we do not think it is a big deal as it rarely happens, and even if it happens, the
                // caller will retry again later, no correctness problems.
                this.metaRegionLocation.set(loc);
                metaRelocateFuture.set(null);
                future.complete(loc);
            });
        } else {
            CompletableFuture<HRegionLocation> future = metaRelocateFuture.get();
            if (future != null) {
                return future;
            }
        }
    }
}

Example 2 with HRegionLocation

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

the class AsyncNonMetaRegionLocator method getRegionLocationInternal.

// locateToPrevious is true means we will use the start key of a region to locate the region
// placed before it. Used for reverse scan. See the comment of
// AsyncRegionLocator.getPreviousRegionLocation.
private CompletableFuture<HRegionLocation> getRegionLocationInternal(TableName tableName, byte[] row, RegionLocateType locateType) {
    // AFTER should be convert to CURRENT before calling this method
    assert !locateType.equals(RegionLocateType.AFTER);
    TableCache tableCache = getTableCache(tableName);
    HRegionLocation loc = locateInCache(tableCache, tableName, row, locateType);
    if (loc != null) {
        return CompletableFuture.completedFuture(loc);
    }
    CompletableFuture<HRegionLocation> future;
    LocateRequest req;
    boolean sendRequest = false;
    synchronized (tableCache) {
        // check again
        loc = locateInCache(tableCache, tableName, row, locateType);
        if (loc != null) {
            return CompletableFuture.completedFuture(loc);
        }
        req = new LocateRequest(row, locateType);
        future = tableCache.allRequests.get(req);
        if (future == null) {
            future = new CompletableFuture<>();
            tableCache.allRequests.put(req, future);
            if (tableCache.hasQuota(maxConcurrentLocateRequestPerTable) && !tableCache.isPending(req)) {
                tableCache.send(req);
                sendRequest = true;
            }
        }
    }
    if (sendRequest) {
        locateInMeta(tableName, req);
    }
    return future;
}

Example 3 with HRegionLocation

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

the class AsyncNonMetaRegionLocator method locateRowBeforeInCache.

private HRegionLocation locateRowBeforeInCache(TableCache tableCache, TableName tableName, byte[] row) {
    Map.Entry<byte[], HRegionLocation> entry = isEmptyStopRow(row) ? tableCache.cache.lastEntry() : tableCache.cache.lowerEntry(row);
    if (entry == null) {
        return null;
    }
    HRegionLocation loc = entry.getValue();
    if (isEmptyStopRow(loc.getRegionInfo().getEndKey()) || Bytes.compareTo(loc.getRegionInfo().getEndKey(), row) >= 0) {
        if (LOG.isTraceEnabled()) {
            LOG.trace("Found " + loc + " in cache for '" + tableName + "', row='" + Bytes.toStringBinary(row) + "', locateType=" + RegionLocateType.BEFORE);
        }
        return loc;
    } else {
        return null;
    }
}

Example 4 with HRegionLocation

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

the class AsyncRegionLocator method updateCachedLoation.

static void updateCachedLoation(HRegionLocation loc, Throwable exception, Function<HRegionLocation, HRegionLocation> cachedLocationSupplier, Consumer<HRegionLocation> addToCache, Consumer<HRegionLocation> removeFromCache) {
    HRegionLocation oldLoc = cachedLocationSupplier.apply(loc);
    if (LOG.isDebugEnabled()) {
        LOG.debug("Try updating " + loc + ", the old value is " + oldLoc, exception);
    }
    if (!canUpdate(loc, oldLoc)) {
        return;
    }
    Throwable cause = findException(exception);
    if (LOG.isDebugEnabled()) {
        LOG.debug("The actual exception when updating " + loc, cause);
    }
    if (cause == null || !isMetaClearingException(cause)) {
        if (LOG.isDebugEnabled()) {
            LOG.debug("Will not update " + loc + " because the exception is null or not the one we care about");
        }
        return;
    }
    if (cause instanceof RegionMovedException) {
        RegionMovedException rme = (RegionMovedException) cause;
        HRegionLocation newLoc = new HRegionLocation(loc.getRegionInfo(), rme.getServerName(), rme.getLocationSeqNum());
        if (LOG.isDebugEnabled()) {
            LOG.debug("Try updating " + loc + " with the new location " + newLoc + " constructed by " + rme);
        }
        addToCache.accept(newLoc);
    } else {
        if (LOG.isDebugEnabled()) {
            LOG.debug("Try removing " + loc + " from cache");
        }
        removeFromCache.accept(loc);
    }
}

Example 5 with HRegionLocation

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

the class ConnectionImplementation method locateRegions.

@Override
public List<HRegionLocation> locateRegions(final TableName tableName, final boolean useCache, final boolean offlined) throws IOException {
    List<HRegionInfo> regions = MetaTableAccessor.getTableRegions(this, tableName, !offlined);
    final List<HRegionLocation> locations = new ArrayList<>();
    for (HRegionInfo regionInfo : regions) {
        RegionLocations list = locateRegion(tableName, regionInfo.getStartKey(), useCache, true);
        if (list != null) {
            for (HRegionLocation loc : list.getRegionLocations()) {
                if (loc != null) {
                    locations.add(loc);
                }
            }
        }
    }
    return locations;
}