/**
* Remove the cached table from all region servers
*
* @param cacheId unique identifier for the hash join (returned from {@link #addHashCache(HTable,
* Scan, Set)})
* @param servers list of servers upon which table was cached (filled in by {@link
* #addHashCache(HTable, Scan, Set)})
* @throws SQLException
* @throws IllegalStateException if hashed table cannot be removed on any region server on which
* it was added
*/
private void removeServerCache(final byte[] cacheId, Set<HRegionLocation> servers)
throws SQLException {
ConnectionQueryServices services = connection.getQueryServices();
Throwable lastThrowable = null;
TableRef cacheUsingTableRef = cacheUsingTableRefMap.get(Bytes.mapKey(cacheId));
byte[] tableName = cacheUsingTableRef.getTable().getPhysicalName().getBytes();
HTableInterface iterateOverTable = services.getTable(tableName);
List<HRegionLocation> locations = services.getAllTableRegions(tableName);
Set<HRegionLocation> remainingOnServers = new HashSet<HRegionLocation>(servers);
/**
* Allow for the possibility that the region we based where to send our cache has split and been
* relocated to another region server *after* we sent it, but before we removed it. To
* accommodate this, we iterate through the current metadata boundaries and remove the cache
* once for each server that we originally sent to.
*/
if (LOG.isDebugEnabled()) {
LOG.debug("Removing Cache " + cacheId + " from servers.");
}
for (HRegionLocation entry : locations) {
if (remainingOnServers.contains(entry)) { // Call once per server
try {
byte[] key = entry.getRegionInfo().getStartKey();
iterateOverTable.coprocessorService(
ServerCachingService.class,
key,
key,
new Batch.Call<ServerCachingService, RemoveServerCacheResponse>() {
@Override
public RemoveServerCacheResponse call(ServerCachingService instance)
throws IOException {
ServerRpcController controller = new ServerRpcController();
BlockingRpcCallback<RemoveServerCacheResponse> rpcCallback =
new BlockingRpcCallback<RemoveServerCacheResponse>();
RemoveServerCacheRequest.Builder builder = RemoveServerCacheRequest.newBuilder();
if (connection.getTenantId() != null) {
builder.setTenantId(
HBaseZeroCopyByteString.wrap(connection.getTenantId().getBytes()));
}
builder.setCacheId(HBaseZeroCopyByteString.wrap(cacheId));
instance.removeServerCache(controller, builder.build(), rpcCallback);
if (controller.getFailedOn() != null) {
throw controller.getFailedOn();
}
return rpcCallback.get();
}
});
remainingOnServers.remove(entry);
} catch (Throwable t) {
lastThrowable = t;
LOG.error("Error trying to remove hash cache for " + entry, t);
}
}
}
if (!remainingOnServers.isEmpty()) {
LOG.warn("Unable to remove hash cache for " + remainingOnServers, lastThrowable);
}
}
