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I am new to Cassandra, in this example i am using a cluster with 1 DC and 5 nodes and a NetworkTopologyStrategy with replication factor as 3.
Keyspace: activityfeed
Read Count: 0
Read Latency: NaN ms.
Write Count: 0
Write Latency: NaN ms.
Pending Tasks: 0
Table: feed_shubham
SSTable count: 1
Space used (live), bytes: 52620684
Space used (total), bytes: 52620684
SSTable Compression Ratio: 0.3727660543119897
Number of keys (estimate): 137984
Memtable cell count: 0
Memtable data size, bytes: 0
Memtable switch count: 0
Local read count: 0
Local read latency: 0.000 ms
Local write count: 0
Local write latency: 0.000 ms
Pending tasks: 0
Bloom filter false positives: 0
Bloom filter false ratio: 0.00000
Bloom filter space used, bytes: 174416
Compacted partition minimum bytes: 771
Compacted partition maximum bytes: 924
Compacted partition mean bytes: 924
Average live cells per slice (last five minutes): 0.0
Average tombstones per slice (last five minutes): 0.0
What does Number of keys here mean? I have 5 different nodes in my cluster, and after firing the below command on each node separately i get different statistic for the same table.
nodetool cfstats -h 192.168.1.12 activityfeed.feed_shubham
As per the output above i can interpret that cfstats gives me stats regarding the physical storage of data on each node.
And i went through the below doc http://www.datastax.com/documentation/cassandra/2.0/cassandra/tools/toolsCFstats.html But i did not find the explanation for number of keys in there.
I am using a RandomPartitioner.
Is this key anything to do with the Partition key?
I have around 200000 record in my table.
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If you need to know informaiton about table or tables you can use Nodetool cfstats command. Syntax: If you will only provide the name of keyspace, it will provide stats for all the tables in that keyspace.
Cell Count In CQL terms you can think of it as a column. This is an estimate of the number of partitions have X number of columns for a given table. It appears to only include columns in SSTables as it is the total of the estimated column count for each SSTable (from TableHistograms.
The nodetool utility is a command line interface for Cassandra. You can use it to help manage a cluster. In binary installations, nodetool is located in the <install_location>/bin directory. Square brackets indicate optional parameters.
Flushes one or more tables from the memtable to SSTables on disk. Flushes one or more tables from the memtable to SSTables on disk. OpsCenter provides a flush option for Flushing tables in Nodes.
The number of keys represents the number of partition keys on that node for the table. Its just an estimate though, and based on your version of C* its more accurate. Before 2.1.6 it summed the number of partitions listed in index file per sstable. Afterwards it merges a sketch of the data (hyperloglog) thats stored per sstable.
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This value seems to indicate the total number of columns/cells in all local sstables. I guess it should be rather named "SSTable cell count" just as the corresponding memtable value. However, as sstables store redundant data before compaction, this value will not necessarily correspond to the actual number of columns returned as part of a result set.
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