将 Cassandra 客户端 Hector 迁移到 java 驱动程序 - ConnectionListener 的替代品

Question

目前我们正在将 Cassandra 客户端从 Hector 迁移到 Java 驱动程序，但无法找到 ConnectionListener 的替代品，因为这是为了避免重复客户端请求到同一个 DC，但由于某种原因已经关闭。

代码：

         if(getClusterConnectionListenerForDCId(dcId).isAllHostsInThisDCClusterDown())
             {
            /* directly return failure w/o even trying: this is vital, because if we keep trying to write to a all-downed cluster again and again,and since hector is stupid enough not to skip writing to cluster given that it already knew the cluster is all down, every single remote local-quorum call will need to wait until timeout (10 second) again and again, when cross-DC channel has hiccup.
*/
                            return false;
                }

        //overridden function of ConnectionManagerListener

        @Override
            public void onAllHostsDown() {
                //when all hosts are down for a particular cluster, we want to disable writing to that particular cluser
                //until at least one host of the cluster recovers
                mIsAllHostsInThisDCClusterDown = true;
                smIsAnyDCClusterAllHostsDown = true;
                logger.warn("all hosts are down for DC: " + mDcId);
            } 

Answer 1

但无法找到 ConnectionListener 的替代品，因为它用于避免重复客户端请求到同一个 DC，但由于某种原因已经关闭。

你不再需要它了。使用 Java 驱动程序，您将拥有 DCAwareLoadBalancingStrategy，它将自动为您处理节点/DC 停机时间