On Friday, October 11, 2013 02:56:09 PM Pin Siang Tan wrote: > Hi > > I have a single node Cassandra running datastax distribution. I reinstall > Cassandra and updated Cassandra.yaml data_file_directories. > > But now I run nodetool cfstats I got SSTable count: 0 > > This is the output of nodetool cfstats > > Keyspace: kairosdbRead Count: 0Read Latency: NaN ms. > Write Count: 0 > Write Latency: NaN ms. > Pending Tasks: 0 > Table: data_points > SSTable count: 0 > Space used (live), bytes: 0 > Space used (total), bytes: 0 > SSTable Compression Ratio: 0.0 > Number of keys (estimate): 0 > Memtable cell count: 0 > Memtable data size, bytes: 0 > Memtable switch count: 0 > Read count: 0 > Read latency, micros: NaN ms. > Write count: 0 > Write latency, micros: NaN ms. > Pending tasks: 0 > Bloom filter false positives: 0 > Bloom filter false ratio: 0.00000 > Bloom filter space used, bytes: 0 > Compacted partition minimum size, bytes: 0 > Compacted partition maximum size, bytes: 0 > Compacted partition mean size, bytes: 0 > > nodetool repair command doesn't help either.
/So this is one of the features of Polites (https://github.com/seanmccully/polites.git) that I posted to the users list a few days ago. Note, you'll want to make sure that the settings (config.py) are configured correctly for your use case./ As part of my ongoing testing and development with this project, I just ran through this scenario. Where I setup a Cassandra Node, create a keyspace (mykeyspace) and Table with some data, and then blow away that Node and Create a brand new node. I start Cassandra and Polites with the following command, * $ polites --command server* /I can then use the client command to see that Cassandra and Polites are running as expected./ *$ polites --command client* /<xml><status>Running</status></xml>/ /<xml><auto-snapshot>True</auto-snapshot><last-snapshot>None</last- snapshot></xml>/ /Then for sanity, I check through nodetool that my keyspace and table exist./ *$ ./bin/nodetool cfstats* /----------------/ /Keyspace: mykeyspace/ / Read Count: 0/ / Read Latency: NaN ms./ / Write Count: 3/ / Write Latency: 0.489 ms./ / Pending Tasks: 0/ / Table: users/ / SSTable count: 1/ / Space used (live), bytes: 4826/ / Space used (total), bytes: 4826/ / SSTable Compression Ratio: 0.4984025559105431/ / Number of keys (estimate): 128/ / Memtable cell count: 0/ / Memtable data size, bytes: 0/ / Memtable switch count: 1/ / Read count: 0/ / Read latency, micros: NaN ms./ / Write count: 3/ / Write latency, micros: NaN ms./ / Pending tasks: 0/ / Bloom filter false positives: 0/ / Bloom filter false ratio: 0.00000/ / Bloom filter space used, bytes: 16/ / Compacted partition minimum size, bytes: 87/ / Compacted partition maximum size, bytes: 124/ / Compacted partition mean size, bytes: 117/ I then create a snapshot, where it is stored somewhere I can access later. *$ polites --command client snapshot* /<xml><snapshot>True</snapshot></xml>/ I check the status again, *$ polites --command client* /<xml><status>Running</status></xml>/ /<xml><auto-snapshot>True</auto-snapshot><last- snapshot>1381615872717</last-snapshot></xml>/ I blow away the entire node and create a brand new Cassandra node. On the new node with Polites running, I make sure that Polites can see the snapshot I created earlier. *$ polites --command client* /<xml><status>Running</status></xml>/ /<xml><auto-snapshot>True</auto-snapshot><last- snapshot>1381615872717</last-snapshot></xml>/ I then use the restore command to restore from that snapshot, *$ polites --command client restore* And then for sanity, I make sure that I see the keyspace and table exist with nodetool and then check that my data is still sane. *$ bin/nodetool cfstats* /----------------/ /Keyspace: mykeyspace/ / Read Count: 0/ / Read Latency: NaN ms./ / Write Count: 0/ / Write Latency: NaN ms./ / Pending Tasks: 0/ / Table: users/ / SSTable count: 1/ / Space used (live), bytes: 4826/ / Space used (total), bytes: 4826/ / SSTable Compression Ratio: 0.4984025559105431/ / Number of keys (estimate): 128/ / Memtable cell count: 0/ / Memtable data size, bytes: 0/ / Memtable switch count: 0/ / Read count: 0/ / Read latency, micros: NaN ms./
