Question

即使我的查询中没有选项，您能否提出建议如果存在和不存在。仍在查询跟踪中，结果显示了我们想要的一致性级别“ QUORUM”

但它也显示'serial_consistency_level'：'SERIAL'，这是什么行为

 session_id                           | client      | command | coordinator | duration | parameters                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               | request                     | started_at
--------------------------------------+-------------+---------+-------------+----------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------+---------------------------------
 278a2000-3dfb-11e9-b459-9775e6c46fc6 | 10.244.*.* |   QUERY |  10.244.*.* |     3338 | 
`

`{'bound_var_0_stream_id': '''3c17230d-ea24-4ff7-9599-352fef883b31''', 
 'bound_var_1_property_name': '''Location:rxRSSI''', 
 'bound_var_2_shard_date': '2019-03-03T00:00:00.000Z', 
 'bound_var_3_time': '2019-03-03T21:27:30.749Z', 
 'bound_var_4_source_id': '''fe30653c-467f-401a-9646-67b10378e1c9''', 
 'bound_var_5_time_lag': '1328', 
 'bound_var_6_property_class': '''java.lang.Integer''', 
 'bound_var_7_property_type': '''ByteType''', 
 'bound_var_8_property_value': '''-44''', 
 'consistency_level': 'LOCAL_QUORUM', 
 'page_size': '5000', 
 'query': 'INSERT INTO "cloudleaf"."stream_48" ("stream_id", "property_name", "shard_date", "time", "source_id", "time_lag", "property_class", "property_type", "property_value") 
 VALUES (:"stream_id", :"property_name", :"shard_date", :"time", :"source_id", :"time_lag", :"property_class", :"property_type", :"property_value") 
 USING TTL 432000', 
 'serial_consistency_level': 'SERIAL'}

Answer 1

array:1 [▼ 1 => array:6 [▼ "name" => "Carocroc Lam" "image" => "carocroc_lam_15kg.jpg" "price" => 45.95 "unit" => 15 "name_unit" => "kg" "amount" => "2" ] ]和IF EXISTS触发轻量级事务，该事务可以具有两个一致性级别IF NOT EXISTS或SERIAL之一。定义如下：

LOCAL_SERIAL：通过防止无条件更新来实现轻量级事务的线性化一致性。此一致性级别仅适用于轻量级事务。相当于QUORUM。

SERIAL：与SERIAL相同，但仅限于数据中心。必须将条件写入写入提交日志，并且必须将其写入同一数据中心内一定数量的副本节点上。与SERIAL相同，但用于在本地（在单个数据中心内）保持一致性。等同于LOCAL_QUORUM。

请参阅：https://docs.datastax.com/en/cassandra/3.0/cassandra/dml/dmlConfigSerialConsistency.html

如何通过跟踪查询来解释Cassandra一致性

1 个答案: