code: @Override
  	public ThriftConnection<T> pollConnection() {
  		ThriftConnection<T> result;
  		if (pool.getThriftServerCount() == 0) {
  			throw new IllegalStateException("当前无可用连接服务器");
  		}
  		int partition = (int) (Thread.currentThread().getId() % this.pool.thriftServerCount);
  
  		ThriftConnectionPartition<T> thriftConnectionPartition = this.pool.partitions.get(partition);
  
  		result = thriftConnectionPartition.poolFreeConnection();
  		if (result == null) {
  			for (int i = 0; i < this.pool.thriftServerCount; i++) {
  				if (i == partition) {
  					continue;
  				}
  				result = this.pool.partitions.get(i).poolFreeConnection();
  				if (result != null) {
  					thriftConnectionPartition = this.pool.partitions.get(i);
  					break;
  				}
  			}
  		}
  
  		if (!thriftConnectionPartition.isUnableToCreateMoreTransactions()) {
  			this.pool.maybeSignalForMoreConnections(thriftConnectionPartition);
  		}
  		return result;
  	}
docs: /*
  @see com.wmz7year.thrift.pool.ThriftConnectionStrategy#pollConnection()