Question

这些天，我在使用Cassandra和反射机制异步执行查询时遇到了操作超时异常（由于某些原因，这里不允许直接涉及Cassandra驱动程序核心jar文件）而且我只想执行查询以删除或创建键空间，就我而言，返回结果集不是必需的。

/**
 * Executes the provided query asynchronously.
 * 
 * @param query The query statement
 * @param timeout The timeout of query
 * @param timeunit The unit of timeout
 */
public void executeAsync(String query, long timeout, TimeUnit timeunit) {
    Object resultSetFuture;
    if (session == null) {
        throw new RuntimeException(String.format("No configured session."));
    }

    try {
        Method executeAsync = session.getClass().getMethod("executeAsync", new Class[] {String.class});
        resultSetFuture = executeAsync.invoke(session, query);

        Method getUninterruptibly = resultSetFuture.getClass().getMethod("getUninterruptibly", new Class[] {long.class, TimeUnit.class});
        getUninterruptibly.setAccessible(true);
        getUninterruptibly.invoke(resultSetFuture, timeout, timeunit);
    } catch (Exception e) {
        throw Err.wrap(e);
    }
}

调用者非常简单。

cqlUtil.executeAsync(String.format("DROP KEYSPACE IF EXISTS %s;", keyspaceName), args.getTimeout());

环境：带Cassandra驱动程序核心3.0.1的Cassandra 3.11.2阴影

尝试查询的所有主机都失败，出现OperationTimedOutException（等待服务器响应超时）

0 个答案: