Hello, I think it was done in the following issue: Sstable min/max metadata can cause data loss (CASSANDRA-14861)
https://github.com/apache/cassandra/commit/d60c78358b6f599a83f3c112bfd6ce72c1129c9f src/java/org/apache/cassandra/io/sstable/format/big/BigFormat.java <https://github.com/apache/cassandra/commit/d60c78358b6f599a83f3c112bfd6ce72c1129c9f#diff-62875acfa21fb24c7167a0a2d761780e> : 129 // md (3.0.18, 3.11.4): corrected sstable min/max clustering Dmitry Saprykin On Thu, Apr 4, 2019 at 11:23 AM Léo FERLIN SUTTON <lfer...@mailjet.com.invalid> wrote: > Hello ! > > I have noticed something since I upgraded to cassandra 3.0.18. > > Before all my Sstable used to be named this way : > ``` > mc-130817-big-CompressionInfo.db > mc-130817-big-Data.db > mc-130817-big-Digest.crc32 > mc-130817-big-Filter.db > mc-130817-big-Index.db > mc-130817-big-Statistics.db > mc-130817-big-Summary.db > mc-130817-big-TOC.txt > ``` > > Since the update I have a new type of files : > > ``` > md-20631-big-Statistics.db > md-20631-big-Filter.db > md-20631-big-TOC.txt > md-20631-big-Summary.db > md-20631-big-CompressionInfo.db > md-20631-big-Data.db > md-20631-big-Digest.crc32 > md-20631-big-Index.db > ``` > > Starting with `md` mixed with my the ancient format starting with "mc". > > Other than the name these files seems identical to regular Sstables. I > haven't seen any information about this in the changelog : > ``` (lines with "sstables" from the changelog) > > * Fix handling of collection tombstones for dropped columns from legacy > sstables (CASSANDRA-14912) > * Fix missing rows when reading 2.1 SSTables with static columns in 3.0 > (CASSANDRA-14873) > * Sstable min/max metadata can cause data loss (CASSANDRA-14861) > * Dropped columns can cause reverse sstable iteration to return prematurely > (CASSANDRA-14838) > * Legacy sstables with multi block range tombstones create invalid bound > sequences (CASSANDRA-14823) > * Handle failures in parallelAllSSTableOperation > (cleanup/upgradesstables/etc) (CASSANDRA-14657) > * sstableloader should use discovered broadcast address to connect > intra-cluster (CASSANDRA-14522) > > ``` > > I am asking because I have read online that : The "mc" is the SSTable file > version. This changes whenever a new release of Cassandra changes anything > in the way data is stored in any of the files listed in the table above. > https://blog.pythian.com/so-you-have-a-broken-cassandra-sstable-file/ > > Does anyone have any information about this ? > > Regards, > > Leo >
