Hello C*-users community, I have a question about Cassandra data files corruption. In one of our test clusters (which runs *C* 2.1*), we observed that when we run the tool *'sstablemetada'* on one of the sstables, it returns an *invalid value for minimum timestamp*:
[datos_db_user@sgp-src-1 pre-scrub-1464981676212]$ java -jar sstablemetadata.jar vt1-table_1-ka-12-Data.db | grep "timestamp" Minimum timestamp: -9223372036854775808 Maximum timestamp: 1464380906180000 >From the sstablemetadata tool source code, I know that it parses only the Statistics.db component to print the metadata. This seems to indicate three possibilities: 1. There is a corruption in the Statistics.db component only and the Data in the Data.db is fine 2. There is a corruption in the data in the Data.db which is causing the invalid timestamp to show up in the Statistics.db component 3. There is a bug in the sstablemetadata tool However, when I run sstablescrub on the sstable, the problem is solved and I get the right metadata. This rules out 3 above. Hence it is either 1 or 2. [datos_db_user@sgp-src-1 table_1-99d6ca40244611e697fb176f47d4f7f7]$ java -jar sstablemetadata.jar vt1-table_1-ka-16-Data.db | grep "timestamp\|Ancestors" Minimum timestamp: 1464380729962999 Maximum timestamp: 1464380906180000 Ancestors: [12] [datos_db_user@sgp-src-1 table_1-99d6ca40244611e697fb176f47d4f7f7]$ So my question is, for those of you who have been running Cassandra for a long time in production, how often does the Statistics.db component get corrupted resulting in sstablemetadata showing invalid metadata ? Does Cassandra guarantee that the metadata shown by sstablemetadata is reliable ? If the metadata being shown by sstablemetadata is invalid, does it point to a bigger data corruption in the Data.db component ? Thanks in advance for your thoughts about this. Thank you ! Regards, Rajath ------------------------ Rajath Subramanyam