cassandra 入门学习
CQL
查询表名
1 | select table_name from system_schema.tables where keyspace_name='mdata' |
查询表数据
1 | select * from mdata.ec_surface_common_time_2017021608 limit 1 |
删除表结构
1 | drop table mdata.ec_surface_common_time_2017021608 |
创建keyspace
1 | CREATE keyspace IF NOT EXISTS ecglobal |
http://docs.datastax.com/en/cql/3.1/cql/cql_reference/create_keyspace_r.html
noodtool
清空被删除表关系的数据
1 | ./nodetool clearsnapshot |
集群状态
1 | ./nodetool status |
集群版本信息
1 | ./nodetool describecluster |
更多命令
assassinate
Forcefully remove a dead node without re-replicating any data. Use as a last resort if you cannot removenode
bootstrap
Monitor/manage node’s bootstrap process
cleanup
Triggers the immediate cleanup of keys no longer belonging to a node. By default, clean all keyspaces
clearsnapshot
Remove the snapshot with the given name from the given keyspaces. If no snapshotName is specified we will remove all snapshots
compact
Force a (major) compaction on one or more tables or user-defined compaction on given SSTables
compactionhistory
Print history of compaction
compactionstats
Print statistics on compactions
decommission
Decommission the node I am connecting to
describecluster
Print the name, snitch, partitioner and schema version of a cluster
describering
Shows the token ranges info of a given keyspace
disableautocompaction
Disable autocompaction for the given keyspace and table
disablebackup
Disable incremental backup
disablebinary
Disable native transport (binary protocol)
disablegossip
Disable gossip (effectively marking the node down)
disablehandoff
Disable storing hinted handoffs
disablehintsfordc
Disable hints for a data center
disablethrift
Disable thrift server
drain
Drain the node (stop accepting writes and flush all tables)
enableautocompaction
Enable autocompaction for the given keyspace and table
enablebackup
Enable incremental backup
enablebinary
Reenable native transport (binary protocol)
enablegossip
Reenable gossip
enablehandoff
Reenable future hints storing on the current node
enablehintsfordc
Enable hints for a data center that was previsouly disabled
enablethrift
Reenable thrift server
failuredetector
Shows the failure detector information for the cluster
flush
Flush one or more tables
garbagecollect
Remove deleted data from one or more tables
gcstats
Print GC Statistics
getcompactionthreshold
Print min and max compaction thresholds for a given table
getcompactionthroughput
Print the MB/s throughput cap for compaction in the system
getconcurrentcompactors
Get the number of concurrent compactors in the system.
getendpoints
Print the end points that owns the key
getinterdcstreamthroughput
Print the Mb/s throughput cap for inter-datacenter streaming in the system
getlogginglevels
Get the runtime logging levels
getsstables
Print the sstable filenames that own the key
getstreamthroughput
Print the Mb/s throughput cap for streaming in the system
gettimeout
Print the timeout of the given type in ms
gettraceprobability
Print the current trace probability value
gossipinfo
Shows the gossip information for the cluster
help
Display help information
info
Print node information (uptime, load, …)
invalidatecountercache
Invalidate the counter cache
invalidatekeycache
Invalidate the key cache
invalidaterowcache
Invalidate the row cache
join
Join the ring
listsnapshots
Lists all the snapshots along with the size on disk and true size.
move
Move node on the token ring to a new token
netstats
Print network information on provided host (connecting node by default)
pausehandoff
Pause hints delivery process
proxyhistograms
Print statistic histograms for network operations
rangekeysample
Shows the sampled keys held across all keyspaces
rebuild
Rebuild data by streaming from other nodes (similarly to bootstrap)
rebuild_index
A full rebuild of native secondary indexes for a given table
refresh
Load newly placed SSTables to the system without restart
refreshsizeestimates
Refresh system.size_estimates
reloadtriggers
Reload trigger classes
relocatesstables
Relocates sstables to the correct disk
removenode
Show status of current node removal, force completion of pending removal or remove provided ID
repair
Repair one or more tables
replaybatchlog
Kick off batchlog replay and wait for finish
resetlocalschema
Reset node’s local schema and resync
resumehandoff
Resume hints delivery process
ring
Print information about the token ring
scrub
Scrub (rebuild sstables for) one or more tables
setcachecapacity
Set global key, row, and counter cache capacities (in MB units)
setcachekeystosave
Set number of keys saved by each cache for faster post-restart warmup. 0 to disable
setcompactionthreshold
Set min and max compaction thresholds for a given table
setcompactionthroughput
Set the MB/s throughput cap for compaction in the system, or 0 to disable throttling
setconcurrentcompactors
Set number of concurrent compactors in the system.
sethintedhandoffthrottlekb
Set hinted handoff throttle in kb per second, per delivery thread.
setinterdcstreamthroughput
Set the Mb/s throughput cap for inter-datacenter streaming in the system, or 0 to disable throttling
setlogginglevel
Set the log level threshold for a given class. If both class and level are empty/null, it will reset to the initial configuration
setstreamthroughput
Set the Mb/s throughput cap for streaming in the system, or 0 to disable throttling
settimeout
Set the specified timeout in ms, or 0 to disable timeout
settraceprobability
Sets the probability for tracing any given request to value. 0 disables, 1 enables for all requests, 0 is the default
snapshot
Take a snapshot of specified keyspaces or a snapshot of the specified table
status
Print cluster information (state, load, IDs, …)
statusbackup
Status of incremental backup
statusbinary
Status of native transport (binary protocol)
statusgossip
Status of gossip
statushandoff
Status of storing future hints on the current node
statusthrift
Status of thrift server
stop
Stop compaction
stopdaemon
Stop cassandra daemon
tablehistograms
Print statistic histograms for a given table
tablestats
Print statistics on tables
toppartitions
Sample and print the most active partitions for a given column family
tpstats
Print usage statistics of thread pools
truncatehints
Truncate all hints on the local node, or truncate hints for the endpoint(s) specified.
upgradesstables
Rewrite sstables (for the requested tables) that are not on the current version (thus upgrading them to said current version)
verify
Verify (check data checksum for) one or more tables
version
Print cassandra version
viewbuildstatus
Show progress of a materialized view build