如何在Cassandra中使用多个操作执行事务

Question

我想在Cassandra中执行具有多个写入操作（〜5个插入/更新到不同表格）的事务，但是如果其中任何一个失败，则其余部分不应写入（或者回滚每个操作或者失败整个事务）。

请让我知道什么是在Cassandra中执行此操作的正确方法以及如何执行此操作（欢迎举例）。

Answer 1

是的，您可以使用记录的批处理功能来自动完成此操作。请注意，你确实对性能产生了影响。请参阅C++驱动程序的BATCH Statements文档部分。

下面是一个如何在C++中执行此操作的示例，取自上面的文档链接。它演示展示了如何批量的INSERT，UPDATE和DELETE在一起：

/* This logged batch will makes sure that all the mutations eventually succeed */ 
CassBatch* batch = cass_batch_new(CASS_BATCH_TYPE_LOGGED); 

/* Statements can be immediately freed after being added to the batch */ 

{ 
    CassStatement* statement 
     = cass_statement_new(cass_string_init("INSERT INTO example1(key, value) VALUES ('a', '1')"), 0); 
    cass_batch_add_statement(batch, statement); 
    cass_statement_free(statement); 
} 

{ 
    CassStatement* statement 
     = cass_statement_new(cass_string_init("UPDATE example2 set value = '2' WHERE key = 'b'"), 0); 
    cass_batch_add_statement(batch, statement); 
    cass_statement_free(statement); 
} 

{ 
    CassStatement* statement 
     = cass_statement_new(cass_string_init("DELETE FROM example3 WHERE key = 'c'"), 0); 
    cass_batch_add_statement(batch, statement); 
    cass_statement_free(statement); 
} 

CassFuture* batch_future = cass_session_execute_batch(session, batch); 

/* Batch objects can be freed immediately after being executed */ 
cass_batch_free(batch); 

/* This will block until the query has finished */ 
CassError rc = cass_future_error_code(batch_future); 

printf("Batch result: %s\n", cass_error_desc(rc)); 

cass_future_free(batch_future);