问题
On my windows box, after a graceful restart for windows update, I get the following error in Cassandra (2.2.0) and it will not start:
ERROR 10:36:41 Detected unreadable sstables D:\cassandra_data\data\gputptest-abcdedf-5040777060fe11e5a8557fcd8340170b-KeyCache-b.db,D:\cassandra_data\data\OpsCenter-events_timeline-afbbeee05cea11e59ba77fcd8340170b-KeyCache-b.db,D:\cassandra_data\data\system-IndexInfo-9f5c6374d48532299a0a5094af9ad1e3-KeyCache-b.db,...., please check NEWS.txt and ensure that you have upgraded through all required intermediate versions, running upgradesstables
Any suggestion how I can recover the database? Or, at least drop those unreadable sstables and recover the rest?
回答1:
Problem solved [Credit goes to Jeff Jirsa for his post here]
I simply deleted all *.-KeyCache-b.db files reported in the error message. Then, I started Cassandra and everything was fine.
To delete the problematic *.-KeyCache-b.db files (there were 30 of them in the error message), I put the file names in a text file and ran the following command in powershell:
Get-Content unreadables_stables.txt | Remove-Item
来源：https://stackoverflow.com/questions/32845713/cassandra-detected-unreadable-sstables-error