Hi, Naman: How does the client side load large amounts of data ? Most likely it has a retry policy, either by tool's default or by setting. If it has a retry policy, will have duplicated records, after compaction, will have tombstones.
Another possibility, client set ttl, it will override table's ttl setting, you may look at a few example data by ttl(pk_column_name), writetime(pk_column_name) from the table. Sometimes, a surprise. Thanks, James On Wed, Oct 9, 2024 at 1:01 AM Jon Haddad <j...@rustyrazorblade.com> wrote: > Are you using collections? > > — > Jon Haddad > Rustyrazorblade Consulting > rustyrazorblade.com > > > On Tue, Oct 8, 2024 at 10:52 PM Naman kaushik <namankaush...@gmail.com> > wrote: > >> Hi Community, >> >> We are currently using Cassandra version 4.1.3 and have encountered an >> issue related to tombstone generation. We have two tables storing monthly >> data: table_september and table_october. Each table has a TTL of 30 days. >> >> For the month of October, data is being inserted into the table_october, >> and we are seeing the following warning at the start of the month: >> >> *WARN [CompactionExecutor:22030] 2024-10-07 16:37:16,376 >> BigTableWriter.java:274 - Writing 102594 tombstones to **table_october* >> >> *Here are a few things to note*: >> >> - No update or delete operations are being performed on the table. >> - TTL is correctly set to 30 days, and the data being inserted is >> within this time range, so the TTL shouldn't be the reason for tombstones. >> - No null values are being inserted in any column. >> >> We are still seeing tombstones being generated for the October table. >> Does anyone have insights into what could be causing these tombstones, or >> how we can prevent this from happening? >> >> Any help would be greatly appreciated! >> >> Thanks in advance. >> >