ttl在卡桑德拉创建墓碑 [英] ttl in cassandra creating tombstones

问题描述

我只在给卡桑德拉做插入。插入时，不会插入null只是为了避免墓碑。但是几乎没有记录插入TTL。但是然后从表中执行select count（*）会产生以下错误-

I am only doing inserts to cassandra. While inserting , not nulls are only inserted to avoid tombstones. But few records are inserted with TTL. But then doing select count(*) from table gives following errors -

读取76个活动行和1324个逻辑删除单元以进行查询SELECT * FROM
xx.yy WHERE令牌（y）> =
令牌（fc872571-1253-45a1-ada3-d6f5a96668e8）限制100（请参阅
tombstone_warn_threshold）

Read 76 live rows and 1324 tombstone cells for query SELECT * FROM xx.yy WHERE token(y) >= token(fc872571-1253-45a1-ada3-d6f5a96668e8) LIMIT 100 (see tombstone_warn_threshold)

TTL插入是否会导致cassandra 3.7中的墓碑？如何缓解警告？

Do TTL inserts lead to tombstones in cassandra 3.7 ? How can the warning be mitigated ?

仅插入操作没有进行任何更新，一些记录没有TTL，其他记录有TTL

There are no updates done only inserts , some records without TTL , others with TTL

推荐答案

摘自datastax文档： https://docs.datastax.com/zh-CN/cql/3.1/cql/cql_using/use_expire_c.html

From datastax documentation: https://docs.datastax.com/en/cql/3.1/cql/cql_using/use_expire_c.html

自创建列以来的秒数超过TTL值后，TTL数据被视为已过期并包含在结果中。在读取路径上的下一次读取之后，已过期的数据将用墓碑标记，但最多保留gc_grace_seconds。经过这段时间后，在正常压缩和修复过程中会自动删除逻辑删除的数据。

After the number of seconds since the column's creation exceeds the TTL value, TTL data is considered expired and is included in results. Expired data is marked with a tombstone after on the next read on the read path, but it remains for a maximum of gc_grace_seconds. After this amount of time, the tombstoned data is automatically removed during the normal compaction and repair processes.

这些条目将被视为逻辑删除直到压实或修复。

These entries will be treated as tombstones until compaction or repair.

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