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DataStax Enterprise 6.8 Documentation

    • Overview
      • Release notes
        • DSE release notes
        • Cass Operator release notes
        • Studio release notes
        • Bulk loader release notes
        • Kafka Connector release notes
    • Architecture
      • Architecture FAQ
      • Database architecture
        • Architecture in brief
        • Internode communications (gossip)
        • Data distribution and replication
          • Data distribution to nodes
          • Consistent hashing
          • Virtual nodes
          • Data replication
          • Partitioners
          • Snitches
            • Dynamic snitching
            • Types of snitches
        • Node repair
          • NodeSync: Continuous background repair
          • Hinted handoff: repair during write path
          • Read Repair: repair during read path
          • Anti-entropy repair
      • Component architecture
        • DSE Analytics
        • DSE Search
        • DSE Graph
          • When to use DSE Graph
          • OLTP and OLAP
          • Comparing DSE Graph and relational databases
          • Migrating to DSE Graph from a relational database
          • Migrating to DSE Graph from Apache Cassandra
      • Database internals
        • Storage engine
        • About reads and writes
          • How is data written?
          • How is data maintained?
          • How is data updated?
          • How is data deleted?
          • What are tombstones?
          • How are indexes stored and updated?
          • How is data read?
          • How do write patterns affect reads?
        • Data consistency
          • Read and write consistency
          • Differences between DSE and RDBMS transactions
          • Using lightweight transactions
          • Consistency level performance
          • Consistency level configuration
          • Configuring serial consistency
          • Read requests
            • Read consistency levels examples
          • Write requests
            • Multiple datacenter write requests
    • Planning
      • Initializing a cluster
        • Initializing datacenters
          • Initializing a single datacenter per workload type
          • Initializing multiple datacenters per workload type
        • Setting seed nodes for a single datacenter
        • Use cases for listen address
      • Initializing single-token architecture datacenters
        • Calculating tokens for single-token architecture nodes
    • Getting started
    • Installing
      • Which install method should I use?
      • Install on a single node
      • Installing supporting software
      • Installing a cluster using Lifecycle Manager 6.8
      • Installing from the Yum package
      • RedHat systemd configuration
      • Installing from the Debian package
      • Install from the tarball on any Linux distribution
      • Installing patch releases
      • Installing on cloud providers
      • Installing on Docker
      • Uninstalling DSE
      • Default DSE file locations
        • Package installations
        • Tarball installations
      • Installing DSE 6.8 Tools
        • Installing CQLSH
        • Installing DataStax Studio 6.8
        • Installing DSE Graph Loader
        • Installing DataStax Bulk Loader
        • Installing DataStax Apache Kafka Connector
      • Installing DSE OpsCenter 6.8
        • Installing from the RPM package
        • Installing from the Debian package
        • Installing from the tarball on any Linux distribution
        • Installing on Docker
        • Uninstalling OpsCenter
        • Installing DataStax Agents 6.8
          • Installing DataStax Agents automatically
          • Installing DataStax Agents manually
            • From the RPM package
            • From the Debian package
            • From a tarball
          • Setting Agent permissions to run as the DSE user
          • Configuring JAVA_HOME
    • Managing
      • Configuration
        • Recommended production settings
        • YAML and configuration properties
          • cassandra.yaml
          • dse.yaml
          • remote.yaml
          • cassandra-rackdc.properties
          • cassandra-topology.properties
        • Cloud provider snitches
          • Amazon EC2 single-region snitch
          • Amazon EC2 multi-region snitch
          • Google Cloud Platform
          • Apache CloudStack snitch
        • JVM system properties
          • Cassandra
          • JMX
          • DSE Search
          • TPC
          • LDAP
          • Kerberos
          • NodeSync
          • DSE Metrics Collector
        • Choosing a compaction strategy
        • NodeSync service
          • About NodeSync
          • Starting and stopping the NodeSync service
          • Enabling NodeSync validation
          • Tuning NodeSync validations
            • Setting the NodeSync rate
            • Setting the NodeSync deadline
          • Manually starting NodeSync validation
        • Using multiple network interfaces
        • Configuring gossip settings
        • Configuring the heap dump directory
        • Configuring Virtual Nodes
          • Virtual node (vnode) configuration
          • Enabling virtual nodes on an existing production cluster
        • Logging configuration
          • Changing logging locations
          • Configuring logging
          • Commit log archive configuration
          • Change Data Capture (CDC) logging
      • Tools
        • DSE Metrics Collector
        • nodetool
          • Get information
            • clientstats
            • describecluster
            • describering
            • getbatchlogreplaythrottle
            • getcachecapacity
            • getcachekeystosave
            • getconcurrentviewbuilders
            • getendpoints
            • getinterdcstreamthroughput
            • getlogginglevels
            • getseeds
            • getsstables
            • getstreamthroughput
            • gettimeout
            • gettraceprobability
            • help
            • info
            • inmemorystatus
            • rangekeysample
            • ring
            • status
            • version
          • Collect metrics
            • gcstats
            • netstats
            • proxyhistograms
            • tablehistograms
            • tablestats
            • toppartitions
            • tpstats
          • Perform operations
            • assassinate
            • bootstrap resume
            • decommission
            • disablebinary
            • disablegossip
            • drain
            • enablebinary
            • enablegossip
            • gossipinfo
            • invalidatecountercache
            • invalidatekeycache
            • invalidaterowcache
            • import
            • join
            • move
            • refresh
            • reloadtriggers
            • relocatesstables
            • removenode
            • replaybatchlog
            • sequence
            • sjk
            • statusbinary
            • statusgossip
            • stopdaemon
            • upgradesstables
          • Adjust settings
            • reloadseeds
            • setbatchlogreplaythrottle
            • setcachecapacity
            • setcachekeystosave
            • setconcurrentviewbuilders
            • setinterdcstreamthroughput
            • setlogginglevel
            • setstreamthroughput
            • settimeout
            • settraceprobability
          • Diagnose issues
            • failuredetector
            • leaksdetection
          • Manage backup commands
            • clearsnapshot
            • disablebackup
            • enablebackup
            • listsnapshots
            • snapshot
            • statusbackup
          • Ensure data consistency
            • abortrebuild
            • cleanup
            • flush
            • mark_unrepaired
            • rebuild
            • rebuild_index
            • rebuild_view
            • resetlocalschema
            • repair
            • scrub
            • verify
          • Manage compaction
            • compact
            • compactionhistory
            • compactionstats
            • disableautocompaction
            • enableautocompaction
            • garbagecollect
            • getcompactionthreshold
            • getcompactionthroughput
            • getconcurrentcompactors
            • setcompactionthreshold
            • setcompactionthroughput
            • setconcurrentcompactors
            • stop
          • Manage NodeSync service
            • nodesyncservice enable
            • nodesyncservice disable
            • nodesyncservice getrate
            • nodesyncservice ratesimulator
            • nodesyncservice setrate
            • nodesyncservice status
          • Manage hints
            • disablehandoff
            • disablehintsfordc
            • enablehandoff
            • enablehintsfordc
            • gethintedhandoffthrottlekb
            • getmaxhintwindow
            • handoffwindow
            • listendpointspendinghints
            • pausehandoff
            • resumehandoff
            • sethintedhandoffthrottlekb
            • setmaxhintwindow
            • statushandoff
            • truncatehints
        • dse commands
          • dse connection options
          • Perform routine DSE operations
            • add-node
            • cassandra
            • cassandra-stop
            • list-nodes
            • remove-node
            • -v
          • Manage Spark
            • exec
            • pyspark
            • spark
            • spark-class
            • spark-jobserver
            • spark-history-server
            • spark-sql
            • spark-sql-thriftserver
            • spark-submit
            • SparkR
          • Connect to development consoles
            • beeline
            • fs
            • gremlin-console
          • Connect external client to DSE node
            • dse client-tool help
            • client-tool connection options
            • cassandra
            • configuration export
            • configuration byos-export
            • configuration import
            • spark
            • alwayson-sql
            • graph-olap
          • Modifies CQL nodesync
            • disable
            • enable
            • help
            • tracing
              • disable
              • enable
              • show
              • status
            • validation
      • dsefs shell commands
        • Get information
          • df
          • du
          • echo
          • ls
          • pwd
          • realpath
          • stat
        • Navigate DSEFS
          • cd
          • exit
        • Manage files
          • append
          • cat
          • cp
          • fsck
          • get
          • mkdir
          • mv
          • put
          • rename
          • rm
          • rmdir
          • truncate
          • umount
        • Manage permissions
          • chgrp
          • chmod
          • chown
      • dsetool
        • Connection options
        • Get information
          • help
          • inmemorystatus
          • list_subranges
          • listjt
          • node_health
          • partitioner
          • ring
          • status
          • tieredtablestats
        • Perform operations
          • infer_solr_schema
          • perf
          • sparkmaster cleanup
          • sparkworker restart
          • tsreload
        • Configure DSE Metrics Collector
          • insights_config
          • insights_filters
        • Manage security
          • createsystemkey
          • encryptconfigvalue
          • managekmip list
          • managekmip expirekey
          • managekmip revoke
          • managekmip destroy
        • Manage search index
          • core_indexing_status
          • create_core
          • get_core_config
          • get_core_schema
          • index_checks
          • list_index_files
          • list_core_properties
          • read_resource
          • rebuild_indexes
          • reload_core
          • set_core_property
          • stop_core_reindex
          • unload_core
          • upgrade_index_files
          • write_resource
      • SSTable tools
        • Get information
          • sstabledump
          • sstableexpiredblockers
          • sstablemetadata
          • sstablepartitions
          • sstableutil
        • Perform operations
          • sstabledowngrade
          • sstablelevelreset
          • sstableloader
          • sstableofflinerelevel
          • sstablesplit
          • sstableupgrade
        • Ensure data consistency
          • sstablerepairedset
          • sstablescrub
          • sstableverify
      • Preflight check tool
      • Compare yaml files
        • yaml_diff
        • cluster_check
      • Operations
        • Starting and stopping DSE
          • Starting as a service
          • Starting as a stand-alone process
          • Stopping a node
        • Adding or removing nodes, datacenters, or clusters
          • Adding nodes to vnode-enabled cluster
          • Adding a datacenter to a cluster using a designated datacenter as a data source
          • Replacing a dead node or dead seed node
          • Replacing a running node
            • Adding a node and then decommissioning the old node
            • Replacing a running node
          • Moving a node from one rack to another
          • Decommissioning a datacenter
          • Removing a node
          • Changing the IP address of a node
          • Switching snitches
          • Changing keyspace replication strategy
          • Migrating or renaming a cluster
          • Adding single-token nodes to a cluster
          • Adding a datacenter to a single-token architecture cluster
          • Replacing a dead node in a single-token architecture cluster
        • Backing up and restoring data using the DSE Backup and Restore Service
          • About the DSE Backup and Restore Service
          • Enabling and configuring the DSE Backup and Restore Service
          • Creating and managing backup stores
          • Creating and managing backup configurations
          • Managing backups
          • Restoring backups
          • Backup and Restore Service CQL command reference
            • ALTER BACKUP CONFIGURATION
            • ALTER BACKUP STORE
            • CANCEL BACKUP
            • CANCEL RESTORE
            • CLEAN BACKUPS
            • CREATE BACKUP CONFIGURATION
            • CREATE BACKUP STORE
            • DROP BACKUP CONFIGURATION
            • DROP BACKUP STORE
            • FORCE RESTORE
            • LIST BACKUP CONFIGURATIONS
            • LIST BACKUPS FROM KEYSPACE
            • LIST BACKUP STORES
            • RESTORE
            • RUN BACKUP
            • VERIFY BACKUP STORE
        • Backing up and restoring data using snapshots
          • About snapshots
          • Taking a snapshot
          • Deleting snapshot files
          • Enabling incremental snapshot backups
          • Restoring from a snapshot
          • Restoring a snapshot into a new cluster
          • Recovering from a single disk failure using JBOD
        • Repairing nodes
          • Manual repair: Anti-entropy repair
          • When to run anti-entropy repair
          • Changing repair strategies
            • Migrating to full repairs
            • Migrating to incremental repairs
        • Monitoring a DSE cluster
        • Tuning the database
          • Tuning Java Virtual Machine
            • Changing heap size parameters
            • Configuring the garbage collector
              • G1 MaxGCPauseMillis
              • CMS parameters
          • Tuning Bloom filters
          • Configuring memtable thresholds
        • Data caching
          • Configuring data caches
            • Enabling caching globally
            • Tips for efficient cache use
          • Monitoring and adjusting caching
        • Compacting and compressing
          • Configuring compaction
          • Compression
            • When to compress data
            • Configuring compression
          • Testing compaction and compression
        • Materialized views maintenance guidelines
        • Migrating data to DSE
        • Collecting node health and indexing scores
        • Clearing data from DSE
      • DSE Management Services
        • Performance Service
          • Performance Service
          • Configuring Performance Service replication strategy
          • Collecting data
            • Collecting slow queries
            • Collecting system level diagnostics
            • Collecting object I/O level diagnostics
            • Statistics gathered for objects
            • Collecting database summary diagnostics
            • Collecting cluster summary diagnostics
            • Collecting histogram diagnostics
            • Collecting user activity diagnostics
            • Statistics gathered for user activity
          • Collecting search data
            • Collecting slow search queries
            • Collecting Apache Solr performance statistics
            • Collecting cache statistics
            • Collecting index statistics
            • Collecting handler statistics
            • Collecting request handler metrics
          • Monitoring Spark with Spark Performance Objects
          • Diagnostic table reference
          • Solr diagnostic table reference
            • Frequently asked questions
            • Slow sub-query log for search
            • Indexing error log
            • Query latency snapshot
            • Update latency snapshot
            • Commit latency snapshot
            • Merge latency snapshot
            • Filter cache statistics
            • Query result cache statistics
            • Index statistics
            • Update handler statistics
            • Update request handler statistics
            • Search request handler statistics
      • DSE In-Memory
        • Creating or altering tables to use DSE In-Memory
        • Verifying table properties
        • Managing memory
        • Backing up and restoring data
      • DSE Tiered Storage
        • About DSE Tiered Storage
        • Configuring DSE Tiered Storage
        • Testing configurations
      • DSE Multi-Instance
        • About DSE Multi-Instance
        • DSE Multi-Instance architecture
        • Adding nodes to DSE Multi-Instance
        • DSE Multi-Instance commands
    • Securing
      • Security FAQ
      • Security checklists
      • Securing the environment
        • Securing ports
        • Securing the TMP directory
      • Authentication and authorization
        • Configuring authentication and authorization
          • About DSE Unified Authentication
            • Steps for new deployment
            • Steps for production environments
          • Configuring security keyspaces
          • Setting up Kerberos
            • Kerberos guidelines
            • Enabling JCE Unlimited
              • Removing AES-256
            • Preparing DSE nodes for Kerberos
              • DNS and NTP
              • krb5.conf
              • Principal
              • Keytab
          • Enabling authentication and authorization
            • Defining a Kerberos scheme
            • Defining an LDAP scheme
          • Configuring JMX authentication
          • Configuring cache settings
          • Securing schema information
        • Managing database access
          • About RBAC
          • Setting up logins and users
            • Adding a superuser login
            • Adding database users
            • LDAP users and groups
              • LDAP logins
              • LDAP groups
            • Kerberos principal logins
            • Setting up roles for applications
            • Binding a role to an authentication scheme
          • Assigning permissions
            • Database object permissions
              • Data resources
              • Functions and aggregate resources
              • Search indexes
              • Roles
              • Proxy login and execute
              • Authentication schemes
              • DSE Utilities (MBeans)
              • Analytic applications
              • Remote procedure calls
            • Separation of duties
            • Keyspaces and tables
            • Row Level Access Control (RLAC)
            • Search index permissions
            • DataStax Graph keyspace
            • Spark application permissions
            • DataStax Studio permissions
            • Remote procedure calls
            • DSE client-tool spark
            • JMX MBean permissions
            • Deny (denylist) db object permission
            • Restricting access to data
        • Providing credentials from DSE tools
          • About clients
          • Internal and LDAP authentication
            • Command line
            • File
            • Environment variables
            • Using CQLSH
          • Kerberos
            • JAAS configuration file location
            • Keytab
            • Ticket Cache
            • Spark jobs
            • SSTableLoader
            • Graph and gremlin-console
            • dsetool
            • CQLSH
          • Nodetool
          • JConsole
      • Auditing database activity
        • Enabling database auditing
        • Capturing DSE Search HTTP requests
        • Log formats
        • View events from DSE audit table
      • Transparent data encryption
        • About Transparent Data Encryption
        • Configuring local encryption
          • Setting up local encryption keys
          • Encrypting configuration file properties
          • Encrypting system resources
          • Encrypting tables
          • Rekeying existing data
          • Using tools with TDE-encrypted SSTables
          • Troubleshooting encryption key errors
        • Configuring KMIP encryption
        • Encrypting Search indexes
          • Encrypting new Search indexes
          • Encrypting existing Search indexes
          • Tuning encrypted Search indexes
        • Migrating encrypted tables from earlier versions
        • Bulk loading data between TDE-enabled clusters
      • Configuring SSL
        • Steps for configuring SSL
        • Creating SSL certificates, keystores, and truststores
          • Remote keystore provider
          • Local keystore files
        • Securing node-to-node connections
        • Securing client-to-node connections
          • Configuring JMX on the server side
          • nodetool, nodesync, dsetool, and Advanced Replication
          • JConsole (JMX)
          • SSTableloader
          • Connecting to SSL-enabled nodes using cqlsh
        • Enabling SSL encryption for DSEFS
        • Reference: SSL instruction variables
      • Securing Spark connections
    • Tooling Resources
      • Stress tools
        • cassandra-stress tool
          • About the cassandra-stress tool
          • Interpret output
          • counter_read
          • counter_write
          • help
          • legacy
          • mixed
          • print
          • read
          • user
          • version
          • write
      • fs-stress tool
      • OpsCenter services
        • Best Practice Service
        • Capacity Service
        • Repair Service
    • DSE Advanced Replication
      • About DSE Advanced Replication
      • Architecture
      • Traffic between the clusters
      • Terminology
      • Getting started
      • Keyspaces
      • Data types
      • Operations
      • CQL queries
      • Metrics
      • Managing invalid messages
      • Managing audit logs
      • Command line tool
        • connection options
        • channel create
        • channel update
        • channel delete
        • channel pause
        • channel resume
        • channel status
        • channel truncate
        • conf list
        • conf remove
        • conf update
        • destination create
        • destination update
        • destination delete
        • destination list
        • destination list-conf
        • destination remove-conf
        • help
        • metrics list
        • replog count
        • replog analyze-audit-log
    • DSE Analytics
      • Setting the replication factor for analytics keyspaces
      • DSE Analytics and Search integration
        • Using predicate push down on search indexes in Spark SQL
      • About DSE Analytics Solo
      • DSEFS (DataStax Enterprise file system)
        • About DSEFS
        • Enabling DSEFS
        • Disabling DSEFS
        • Configuring DSEFS
        • Commands DSEFS
        • DSEFS compression
        • DSEFS authentication
        • DSEFS authorization
        • Using the DSEFS REST interface
        • Programmatic access to DSEFS
        • Hadoop FileSystem interface implemented by DseFileSystem
        • Using JMX to read DSEFS metrics
    • DSE Graph
      • About Graph
      • What’s new
      • Graph QuickStart
      • CQL as Graph
      • Convert CQL to Graph
      • Graph OLTP and OLAP
      • Graph data modeling
        • Data modeling introduction
        • Basic data modeling
        • Data modeling design
        • Advanced data modeling
      • Manage graph
        • Create a graph
        • Exanube a Graph
        • Drop a Graph
      • Manage schema
        • Create a Graph schema
        • Examine a schema
        • Create UDT schema
        • Create collection and tuple schema
        • Create vertex lable schema
        • Create edge lable schema
        • Indexing
        • Create index schema
        • Drop Graph schema
        • Vertex and edge IDs
      • Manage Graph data
        • Data formats
        • Insert data with Graph traversal API
        • DataStax Bulk Loader for Graph
          • Install DataStax Bulk Loader
          • DataStax Bulk Loader Examples
        • Load data with DseGraphFrames
        • Drop graph data
      • Discovering properties
      • Creating queries using traversals
        • Anatomy of a graph traversal
        • Use indexes
        • Use search indexes
        • Simple traversals
        • Geospatial traversals
        • Branching traversals
        • Recursive traversals
        • Path traversals
      • Graph analysis with DSE Analytics
        • DseGraphFrame overview
          • TinkerPop API support in DseGraphFrame
          • Mapping rules for DseGraphFrame
          • DseGraphFrame API reference
        • Export graphs to DSEFS
        • Import graphs
        • Northwind demo graph with Spark OLAP jobs
      • DSE Graph Operations
        • Configuring DSE Graph
          • Specifying DSE database and graph settings
          • Configuring security
        • Graph backup and restore
        • Graph import/export
        • Graph JMX metrics
      • Graph tools
      • Start Gremlin console
      • Graph Reference
        • Graph traversal API
          • addE
          • addV
          • io
          • property
          • with
        • Schema API
          • drop
          • describe
          • edgeLabel
          • type
          • vertexLabel
        • System API
          • Graph
          • GraphClassic
            • config
            • option
          • graphs
          • list
        • TinkerPop traversal API
          • TinkerPop framework
          • TinkerPop general information
          • TinkerPop predicates
            • eq
            • neq
            • lt
            • lte
            • gt
            • gte
            • inside
            • outside
            • between
            • within
            • without
            • Step-modulators
            • as
            • by
            • emit
            • from
            • option
            • times
            • to
            • until
            • Vertex step
            • out
            • in
            • both
            • outE
            • inE
            • bothE
            • outV
            • inV
            • bothV
            • otherV
            • addV
            • addE
            • property
            • mid-traversal V()
            • aggregate
            • and
            • barrier
            • branch
            • cap
            • choose
            • coalesce
            • constant
            • count
            • cyclicPath
            • dedup
            • drop
            • explain
          • fill
          • filter
          • flatMap
          • fold
          • group
          • groupCount
          • has
          • hasId
          • hasKey
          • hasLabel
          • hasNext
          • hasNot
          • hasValue
          • id
          • inject
          • is
          • key
          • label
          • limit
          • local
          • loops
          • map
          • match
          • math
          • max
          • mean
          • min
          • next
          • not
          • optional
          • or
          • order
          • pageRank
          • path
          • peerPressure
          • profile
          • project
          • properties
          • propertyMap
          • range
          • repeat
          • sack
          • sample
          • select
          • sideEffect
          • simplePath
          • skip
          • store
          • subGraph
          • sum
          • tail
          • timeLimit
          • toBulkSet
          • toList
          • toSet
          • tree
          • unfold
          • union
          • value
          • valueMap
          • values
          • where
        • DataStax Graph data types
        • Graph storage in Cassandra keyspace and table
    • DSE Search
      • About Search
        • Solr OSS differences
        • Unsupported search features
        • Solr Lucene limitations
      • Configuring Search
      • Search Reference
      • Search index configuration
      • Search index schema
      • Search config.yaml options
      • Adding/viewing index resources
      • Initial data migration
      • Shard routing for distributed queries
      • Deleting Solr data
      • Verifying index status
      • Backing up search indexes
      • Restoring a search node
      • Metrics (MBEANS)
      • Uploading custom index resources
      • Solr admin UI configuration
      • Configuring Solr connector port
      • reqPerm Solr admin UI
      • Changing Tomcat settings
      • Configuring Solr library path
      • Using the Solr HTTP API
      • Configuring HTTP for AJP
      • aboutUpdateRequestProcessorAndFieldTransformer
      • Field Input/Output Transformer (FIT) API
      • FIT class examples
      • Custom URP example
      • Interface custom field types
      • Deleting by query - best practice
      • Monitoring segments
      • Solr clients
      • Tutorials and demos
        • Creating a healthcare keyspace for tutorials
        • Multi-faceted search using healthcare data
        • Term and phrase searches using the wikipedia demo
        • Using secure cluster
        • Indexing and querying polygons
    • DSE Spark
      • About Spark
      • Using Spark with DataStax Enterprise
        • Starting Spark
        • Running Spark commands against a remote cluster
        • Accessing database data from Spark
          • Using the Spark session
          • Using the Spark context
          • Controlling automatic direct join optimizations in queries
          • Accessing the Spark session and context for applications running outside of DSE Analytics
          • Saving RDD data to DSE
          • Spark supported types
          • Loading external HDFS data into the database using Spark
        • Monitoring Spark with the web interface
        • Getting started with the Spark Cassandra Connector
        • Using DSE Spark with third party tools and integrations
      • Configuring Spark nodes
        • Automatic Spark Master election
        • Configuring Spark logging options
        • Running Spark processes as separate users
        • Configuring the Spark history server
        • Setting Spark Cassandra Connector-specific properties
        • Creating a DSE Analytics Solo datacenter
        • Spark JVMs and memory management
      • Using Spark modules with DataStax Enterprise
        • Getting started with Spark Streaming
          • Creating a Spark Structured Streaming sink using DSE
        • Using Spark SQL to query data
          • Querying database data using Spark SQL in Scala
          • Querying database data using Spark SQL in Java
          • Querying DSE Graph vertices and edges with Spark SQL
          • Using Spark predicate push down in Spark SQL queries
          • Supported syntax of Spark SQL
          • Inserting data into tables with static columns using Spark SQL
          • Running HiveQL queries using Spark SQL
          • Using the DataFrames API
          • Using the Spark SQL Thriftserver
        • Using SparkR with DataStax Enterprise
      • Using AlwaysOn SQL service
        • Enabling SSL for AlwaysOn SQL
        • Using authentication with AlwaysOn SQL
        • Simba JDBC Driver for Apache Spark
        • Simba ODBC Driver for Apache Spark
        • Connecting to AlwaysOn SQL server using Beeline
      • Accessing DataStax Enterprise data from external Spark clusters
        • Overview of BYOS support in DataStax Enterprise
        • Generating the BYOS configuration file
        • Connecting to DataStax Enterprise using the Spark shell on an external Spark cluster
        • Generating Spark SQL schema files
        • Starting Spark SQL Thrift Server with Kerberos
      • Using the Spark Jobserver
      • Spark examples
        • Portfolio Manager demo using Spark
        • Running the Weather Sensor demo
        • Running the Wikipedia demo with SearchAnalytics
        • Running the Spark MLlib demo application
        • Running the http_receiver demo
        • Using DSE geometric types in Spark
        • Importing a text file into a table
        • Running spark-submit job with internal authentication
      • DSE Spark Connector API documentation
  • DataStax Enterprise 6.8 Documentation
  • DSE Analytics
  • DSEFS (DataStax Enterprise file system)
  • Commands DSEFS

DSEFS command line tool

The DSEFS functionality supports operations including uploading, downloading, moving, and deleting files, creating directories, and verifying the DSEFS status.

DSEFS commands are available only in the logical datacenter. DSEFS works with secured and unsecured clusters, see DSEFS authentication.

You can interact with the DSEFS file system in several modes:

  • Interactive command line shell.

    To start DSEFS and launch the DSE FS shell:

    dse fs
  • As part of dse commands.

  • With a REST API.

configLog == Configuring DSEFS shell logging

The default location of the DSEFS shell log file .dsefs-shell.log is the user home directory. The default log level is INFO. To configure DSEFS shell logging, edit the <installation_location>/resources/dse/conf/logback-dsefs-shell.xml file.

Using with the dse command line

Precede the DSEFS command with dse fs:

dse [<dse_auth_credentials>] fs <dsefs_command>  [<options>]

For example, to list the file system status and disk space usage in human-readable format:

dse -u user1 -p mypassword fs "df -h"

Optional command arguments are enclosed in square brackets. For example, [<dse_auth_credentials>] and [-R]

Variable values are italicized. For example, <directory> and [<subcommand>].

Working with the local file system in the DSEFS shell

You can refer to files in the local file system by prefixing paths with file:. For example the following command will list files in the system root directory:

dsefs dsefs://127.0.0.1:5598/ > ls file:/
bin   cdrom  dev  home  lib32  lost+found  mnt  proc  run   srv  tmp  var         initrd.img.old  vmlinuz.old
boot  data   etc  lib   lib64  media       opt  root  sbin  sys  usr  initrd.img  vmlinuz

If you need to perform many subsequent operations on the local file system, first change the current working directory to file: or any local file system path:

dsefs dsefs://127.0.0.1:5598/ > cd file:
dsefs file:/home/user1/path/to/local/files > ls
conf  src  target  build.sbt
dsefs file:/home/user1/path/to/local/files > cd ..
dsefs file:/home/user1/path/to/local >

DSEFS shell remembers the last working directory of each file system separately. To go back to the previous DSEFS directory, enter:

dsefs file:/home/user1/path/to/local/files > cd dsefs:
dsefs dsefs://127.0.0.1:5598/ >

To go back again to the previous local directory:

dsefs dsefs://127.0.0.1:5598/ > cd file:
dsefs file:/home/user1/path/to/local/files >

To refer to a path relative to the last working directory of the file system, prefix a relative path with either dsefs: or file:. The following session will create a directory new_directory in the directory /home/user1:

dsefs dsefs://127.0.0.1:5598/ > cd file:/home/user1
dsefs file:/home/user1 > cd dsefs:
dsefs dsefs://127.0.0.1:5598/ > mkdir file:new_directory
dsefs dsefs://127.0.0.1:5598/ > realpath file:new_directory
file:/home/user1/new_directory
dsefs dsefs://127.0.0.1:5598/ > stat file:new_directory
DIRECTORY file:/home/user1/new_directory:
Owner           user1
Group           user1
Permission      rwxr-xr-x
Created         2017-01-15 13:10:06+0200
Modified        2017-01-15 13:10:06+0200
Accessed        2017-01-15 13:10:06+0200
Size            4096

To copy a file between two different file systems, you can also use the cp command with explicit file system prefixes in the paths:

dsefs file:/home/user1/test > cp dsefs:archive.tgz another-archive-copy.tgz
dsefs file:/home/user1/test > ls
another-archive-copy.tgz archive-copy.tgz  archive.tgz

Authentication

For dse <dse_auth_credentials> you can provide user credentials in several ways, see Providing credentials from DSE tools. For authentication with DSEFS, see DSEFS authentication.

Wildcard support

Some DSEFS commands support wildcard pattern expansion in the path argument. Path arguments containing wildcards are expanded before method invocation into a set of paths matching the wildcard pattern, then the given method is invoked for each expanded path.

For example in the following directory tree:

dirA
|--dirB
|--file1
|--file2

Giving the stat dirA/* command would be transparently translated into three invocations: stat dirA/dirB, stat dirA/file1, and stat dirA/file2.

DSEFS supports the following wildcard patterns:

  • matches any files system entry (file or directory) name, as in the example of stat dirA/.

  • ? matches any single character in the file system entry name. For example stat dirA/dir? matches dirA/dirB.

  • [] matches any characters enclosed within the brackets. For example stat dirA/file[0123] matches dirA/file1 and dirA/file2.

  • {} matches any sequence of characters enclosed within the brackets and separated with ,. For example stat dirA/{dirB,file2} matches dirA/dirB and dirA/file2.

There are no limitations on the number of wildcard patterns in a single path.

For authentication with DSEFS, see DSEFS authentication.

Executing multiple commands

DSEFS can execute multiple commands on one line. Use quotes around the commands and arguments. Each command will be executed separately by DSEFS.

dse fs 'cat file1 file2 file3 file4' 'ls dir1'

Forcing synchronization

Before confirming writing a file, DSEFS by default forces all blocks of the file to be written to the storage devices. This behavior can be controlled with --no-force-sync and --force-fsync flags when creating files or directories in the DSEFS shell with mkdir, put, and cp commands. The force/no-force behavior is inherited from the parent directory, if not specified. For example, if a directory is created with --no-force-sync, then all files are created with --no-force-sync unless --force-fsync is explicitly set during file creation.

Turning off forced synchronization improves latency and performance at a cost of durability. For example, if a power loss occurs before writing the data to the storage device, you may lose data. Turn off forced synchronization only if you have a reliable backup power supply in your datacenter and failure of all replicas is unlikely, or if you can afford losing file data.

The Hadoop SYNC_BLOCK flag has the same effect as --force-sync in DSEFS. The Hadoop LAZY_PERSIST flag has the same effect as --no-force-sync in DSEFS.

Removing a DSEFS node

When removing a node running DSEFS from a DSE cluster, additional steps are needed to ensure proper correctness within the DSEFS data set.

Make sure the replication factor for the cluster is greater than ONE before continuing.

  1. From a node in the same datacenter as the node to be removed, start the DSEFS shell.

    dse fs
  2. Show the current DSEFS nodes with the df command.

    dsefs > df
    Location                              Status  DC              Rack   Host               Address        Port  Directory            Used         Free    Reserved
    144e587c-11b1-4d74-80f7-dc5e0c744aca  up      GraphAnalytics  rack1  node1.example.com  10.200.179.38  5598  /var/lib/dsefs/data     0  29289783296  5368709120
    98ca0435-fb36-4344-b5b1-8d776d35c7d6  up      GraphAnalytics  rack1  node2.example.com  10.200.179.39  5598  /var/lib/dsefs/data     0  29302099968  5368709120
  3. Find the node to be removed in the list and note the UUID value for it under the Location column.

  4. If the node is up, unmount it from DSEFS with the command umount <UUID>.

    dsefs > umount 98ca0435-fb36-4344-b5b1-8d776d35c7d6
  5. If the node is not up (for example, after a hardware failure), force unmount it from DSEFS with the command umount -f <UUID>.

    dsefs > umount -f 98ca0435-fb36-4344-b5b1-8d776d35c7d6
  6. Run a file system check with the fsck command to make sure all blocks are replicated.

    dsefs > fsck
  7. Continue with the normal steps for removing a node.

If data was written to a DSEFS node, more nodes were added to the cluster, and the original node was removed without running fsck, the data in the original node may be permanently lost.

Removing old DSEFS directories

If you have changed the DSEFS data directory and the old directory is still visible, remove it using the umount option.

  1. Start the DSEFS shell as a role with superuser privileges.

    dse fs
  2. Show the current DSEFS nodes with the df command.

    dsefs > df
  3. Find the directory to be removed in the list and note the UUID value for it under the Location column.

  4. Unmount it from DSEFS with the command umount <UUID>.

    dsefs > umount 98ca0435-fb36-4344-b5b1-8d776d35c7d6
  5. Run a file system check with the fsck command to make sure all blocks are replicated.

    dsefs > fsck

If the file system check results in an IOException, make sure all the nodes in the cluster are running.

Examples

Using the DSEFS shell, these commands put the local bluefile to the remote DSEFS greenfile:

dsefs / >  ls -l
dsefs / >  put file:/bluefile greenfile

To view the new file in the DSEFS directory:

dsefs / >  ls -l
Type  Permission  Owner  Group  Length  Modified                  Name
file  rwxrwxrwx   none   none       17  2016-05-11 09:34:26+0000  greenfile

Using the dse command, these commands create the test2 directory and upload the local README.md file to the new DSEFS directory.

dse fs "mkdir /test2" &&
dse fs "put README.md /test2/README.md"

To view the new directory listing:

dse fs "ls -l /test2"
Type Permission Owner Group Length Modified Name
file rwxrwxrwx none none 3382 2016-03-07 23:20:34+0000 README.md

You can use two or more dse commands in a single command line. This is faster because the JVM is launched and connected/disconnected with DSEFS only once. For example:

dse fs "mkdir / test2" "put README.md /test/README.md"

The following example shows how to use the --no-force-sync flag on a directory, and how to check the state of the --force-sync flag using stat. These commands are run from within the DSEFS shell.

dsefs> mkdir --no-force-sync /tmp
dsefs> put file:some-file.dat /tmp/file.tmp
dsefs> stat /tmp/file.tmp
FILE dsefs://127.0.0.1:5598/tmp/file.tmp
Owner           none
Group           none
Permission      rwxrwxrwx
Created         2017-03-06 17:54:35+0100
Modified        2017-03-06 17:54:35+0100
Accessed        2017-03-06 17:54:35+0100
Size            1674
Block size      67108864
Redundancy      3
Compressed      false
Encrypted       false
Forces sync     false
Comment
Configuring DSEFS DSEFS compression

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