Database Reference
In-Depth Information
Monitoring with nodetool
The
nodetool
utility provides some basic, yet very informative, statistics on Cassandra.
This is often used to take a quick glance at how Cassandra is doing and to monitor it. This
section will introduce you to some of the interesting commands that
nodetool
offers to
monitor Cassandra.
cfstats
The term
cfstats
stands for "column family statistics". It comprises details about every
significant statistic regarding all the tables in the ring and across all the keyspaces. The
command is as follows:
$ bin/nodetool cfstats [keyspace_name[.table_name]]
Executing
cfstats
looks as follows (this statistic is per node):
$ bin/nodetool cfstats stresscql.blogposts
Keyspace: stresscql
Read Count: 0
Read Latency: NaN ms.
Write Count: 2291978
Write Latency: 0.017063794678657474 ms.
Pending Flushes: 0
Table: blogposts
SSTable count: 30
SSTables in each level: [0, 8, 22, 0, 0, 0, 0, 0, 0]
Space used (live), bytes: 6292666026
Space used (total), bytes: 6292735112
Space used by snapshots (total), bytes: 0
SSTable Compression Ratio: 0.9719074538796416
Memtable cell count: 0
Memtable data size, bytes: 0
Memtable switch count: 15
Local read count: 0
Local read latency: NaN ms
Local write count: 2291978
Local write latency: 0.018 ms
