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Carding of common commands in nodetool

Cassandra comes with several powerful clusters or data management tools. Mastering the quantity is helpful to diagnose and maintain Cassandra clusters and solve various problems quickly.

The commands are as follows: nodetool: is a command-line toolset that monitors Cassandra and performs routine database operations. As a built-in tool, nodetool is generally used to run directly on nodes. The nodetool toolset supports most important JMX metrics and actions and contains commands for administrators. Cassandra utility: Cassandra utility is actually a startup configuration interface provided by Cassandra, which means that you can configure cassandra startup parameters, such as runtime java heap size, and so on. Cassandra-stress tool:cassandra stress tool is a tool for stress testing of clusters. SSTable utilities: is a set of tools for manipulating sstable. CQL shell: a command-line tool that interacts with data in a Cassandra cluster through CQL (Cassandra Query Language). The cluster monitoring command lists all the commands available to nodetool: nodetool help lists the help for the specified command: nodetool help command-namenodetool common monitoring commands: the nodetool toolset provides a number of metrics, server metrics, and compression statistics for viewing tables. Nodetool describecluster: outputs cluster information. Nodetool ring: query ring nodetool status: output a quick summary of the cluster ring and the current status of the cluster; nodetool netstats: display statistics on network connection operations; view a node load, memory usage: nodetool info nodetool tpstats: list information about thread pools maintained by Cassandra, you can see how many operations are in each stage, and whether their status is active, waiting, or completed Nodetool cfstats/tablestats: view some information about the table, including the number of reads, writes, the number of sstable, memtable information, compression information, bloomfilter information; view the specified tablespace, default output of all: nodetool cfstats ptmind_test.usersnodetool cfhistograms: displays table statistics, including read and write latency, row size, number of columns, and number of SSTable View the specified tablespace, the default output of all: nodetool cfhistograms ptmind_test.usersnodetool compactionstats: shows the progress of the task currently being compressed. The cluster management command nodetool decommission: close the current node and copy the data to the next node next to the ring. The current node is not in external service. Nodetool rebuild: when new data centers join Run this command to copy data to the data center nodetool removenode HostID: delete a node example:. / nodetool removenode dcbbad83-fe7c-4580-ade7-aa763b8d2c40nodetool removenode status: view deletion status nodetool removenode force: if you use status to find that you are always waiting for a node, line force stops nodetool flush or repair: the cache data in a keyspace is submitted, so there must be a parameter to submit a keySpace after the flush command, otherwise the command cannot be executed. Nodetool drain: the data in memtable is flushed to sstable, and the current node terminates contact with other nodes. The node needs to be restarted after executing this command. This command is usually used only when the Cassandra version is upgraded. Nodetool move command: transfers data from the current node to another specified cluster node. Nodetool loadbalance command: upload all the data of the current node to other cluster nodes, and forward the request of the reading node to other nodes in the ring. The cluster space-related command nodetool describering: it needs to be followed by the name of keyspace to display the node information of the circle. Nodetool getendpoints keyspacename tablename fieldname: see which node key is distributed on nodetool getsstables keyspacename tablename fieldname: see which SSTable key is distributed on nodetool compact [keyspacename [tablename]]: merge sstable files. Omit tables, compress all tables under keyspace omit keyspace, compress all tables under all keyspace nodetool scrub: clean the SSTable of specified tables, attempt to remove corrupted parts, and keep intact parts. Cluster backup related command nodetool refresh-keyspacename tablename: copy the snapshot file to the corresponding table directory (data/keyspace/tablename-UUID) to run this command to load the new SSTables without restarting the machine node. Nodetool snapshot: snapshot information used to create keyspace or table, that is, data backup, which can be used for data recovery nodetool clearsnapshot [- t snapshotname-- keyspacename]: delete snapshot

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