停止Cassandra物化视图构建 [英] Stop Cassandra Materialized View Build

问题描述

有没有办法停止在Cassandra（3.7）的物化视图的构建？

Is there any way to stop the build of a materialized view in Cassandra (3.7)?

背景：我创建了两个实例化视图 A 和 B （完全公开 - 我可能已尝试删除在构建完成之前），并且这些视图似乎永远卡住...任何尝试在同一个表上创建另一个视图 C 似乎挂起。使用nodetool

Background: I created two materialized views A and B (full disclosure - I may have attempted to drop them before the build was complete) and those views seem to be perpetually stuck...any attempt to create another view C on the same table seems to hang. Using nodetool

nodetool.viewbuildstatus <keyspace>.<view>

显示 A 和 B的STARTED和UNKNOWN组合，并在 C 中查看STARTED。使用cql：

shows a combination of STARTED and UNKNOWN for A and B, and STARTED for views in C. Using cql:

select * from system.views_builds_in_progress

列出所有资料检视，但在过去24小时内，世代号码和 last_token 对于 A ，em>实际上为空）。

all views are listed, but generation number and last_token have not changed in the last 24hrs (generation_number is in fact null for A).

推荐答案

它没有记录，但 nodetool stop 实际上采取任何压缩类型，而不仅仅是列出的（视图构建是其中之一）。所以你可以简单：

Its not documented, but nodetool stop actually takes any compaction type, not just the ones listed (which the view build is one of). So you can simply:

nodetool stop VIEW_BUILD

或者你可以直接使用 org.apache.cassandra.db：type = CompactionManager mbean的 stopCompaction 操作。

Or you can hit JMX directly with the org.apache.cassandra.db:type=CompactionManager mbean's stopCompaction operation.

所有这些都设置为视图生成器在下一个循环停止的标志。如果它抛出一个未捕获的异常或某事，所以它不再做任何事情（值得检查系统/输出日志），停止不会做任何事情。在这种情况下，它不会真正伤害任何东西，所以可以忽略它，并重试。最坏情况下重新启动节点。

All thats really gonna do is set a flag for the view builder to stop on its next loop. If it threw an uncaught exception or something so its no longer doing anything (worth checking system/output logs) the stop wont do anything either. In that case its not really hurting anything though so can ignore it and retry. Worst case restart the node.

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