Apache Cassandra Documentation
Apache Cassandra DocumentationFebruary 16, 2012 2012 DataStax. All rights reserved.
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ContentsApache Cassandra 1.0 DocumentationIntroduction to Apache CassandraGetting Started with Cassandra111Java Prerequisites1Download the Software1Install the Software1Start the Cassandra Server1Login to Cassandra1Create a Keyspace (database)1Create a Column Family2Insert, Update, Delete, Read Data2Getting Started with Cassandra and DataStax Community EditionInstalling a Single-Node Instance of Cassandra22Checking for a Java Installation2Installing the DataStax Community Binaries on Linux3Configuring and Starting a Single-Node Cluster on Linux4Installing the DataStax Community Binaries on Mac5Installing the DataStax Community Binaries on Windows5Configuring and Starting DataStax OpsCenter5Running the Portfolio Demo Sample Application6About the Portfolio Demo Use Case6Running the Demo Web Application6Exploring the Sample Data Model7Looking at the Schema Definitions in Cassandra-CLIDataStax Community Release Notes88What's New8Prerequisites8Understanding the Cassandra ArchitectureAbout Internode Communications (Gossip)88About Cluster Membership and Seed Nodes9About Failure Detection and Recovery9About Data Partitioning in Cassandra10About Partitioning in Multi-Data Center Clusters10Understanding the Partitioner Types12About the Random Partitioner12About Ordered Partitioners13About Replication in Cassandra13
About Replica Placement 4About iRegionSnitch19About Dynamic Snitching19About Client Requests in CassandraAbout Write RequestsAbout Multi-Data Center Write RequestsAbout Read RequestsPlanning a Cassandra Cluster DeploymentSelecting anning an Amazon EC2 Cluster23Capacity Planning24Calculating Usable Disk Capacity24Calculating User Data Size24Choosing Node Configuration Options25Storage Settings25Gossip Settings25Purging Gossip State on a Node25Partitioner Settings25Snitch Settings26Configuring the PropertyFileSnitchChoosing Keyspace Replication OptionsInstalling and Initializing a Cassandra ClusterInstalling Cassandra Using the Packaged Releases26272727Creating the Cassandra User and Configuring sudo27Installing Cassandra RPM Packages28Installing Sun JRE on RedHat SystemsInstalling Cassandra Debian Packages2829
Installing Sun JRE on Ubuntu Systems30About Packaged Installs31Next Steps31Installing the Cassandra Tarball Distribution31About Cassandra Binary Installations32Installing JNA32Next Steps32Initializing a Cassandra Cluster on Amazon EC2 Using the DataStax AMI32Creating an EC2 Security Group for DataStax Community Edition33Launching the DataStax Community AMI34Connecting to Your Cassandra EC2 Instance35Configuring and Starting a Cassandra Cluster38Initializing a Multi-Node or Multi-Data Center Cluster38Calculating Tokens39Calculating Tokens for Multiple Racks40Calculating Tokens for a Single Data Center40Calculating Tokens for a Multi-Data Center Cluster41Starting and Stopping a Cassandra Node42Starting/Stopping Cassandra as a Stand-Alone Process42Starting/Stopping Cassandra as a Service42Upgrading Cassandra43Best Practices for Upgrading Cassandra43Upgrading Cassandra: 0.8.x to 1.0.x43New and Changed Parameters between 0.8 and 1.044Upgrading Between Minor Releases of Cassandra 1.0.x45Understanding the Cassandra Data ModelThe Cassandra Data ModelComparing the Cassandra Data Model to a Relational DatabaseAbout KeyspacesDefining Keyspaces4545454747About Column Families48About Columns49About Special Columns (Counter, Expiring, Super)49About Expiring Columns49About Counter Columns50About Super Columns50About Data Types (Comparators and Validators)50About Validators51About Comparators51
About Column Family Compression52When to Use Compression52Configuring Compression on a Column Family52About Indexes in Cassandra52About Primary Indexes53About Secondary Indexes53Building and Using Secondary Indexes53Planning Your Data Model54Start with Queries54Denormalize to Optimize54Planning for Concurrent Writes54Using Natural or Surrogate Row Keys54UUID Types for Column Names55Managing and Accessing Data in Cassandra55About Writes in Cassandra55About Compaction55About Transactions and Concurrency Control55About Inserts and Updates56About Deletes56About Hinted Handoff Writes57About Reads in Cassandra57About Data Consistency in Cassandra58Tunable Consistency for Client Requests58About Write Consistency58About Read Consistency58Choosing Client Consistency Levels59Consistency Levels for Multi-Data Center Clusters59Specifying Client Consistency Levels60About Cassandra's Built-in Consistency Repair Features60Cassandra Client APIs60About Cassandra CLI60About CQL61Other High-Level Clients61Java: Hector Client API61Python: Pycassa Client API61PHP: Phpcassa Client API61Getting Started Using the Cassandra CLI61Creating a Keyspace62Creating a Column Family62
Creating a Counter Column Family63Inserting Rows and Columns63Reading Rows and Columns64Setting an Expiring Column64Indexing a Column64Deleting Rows and Columns65Dropping Column Families and Keyspaces65Getting Started with CQL65Starting the CQL Command-Line Program (cqlsh)65Running CQL Commands with cqlsh66Creating a Keyspace66Creating a Column Family66Inserting and Retrieving Columns66Adding Columns with ALTER COLUMNFAMILY66Altering Column Metadata67Specifying Column Expiration with TTL67Dropping Column Metadata67Indexing a Column67Deleting Columns and Rows67Dropping Column Families and Keyspaces68Configuration68Node and Cluster Configuration (cassandra.yaml)68Node and Cluster Initialization Properties70auto bootstrap70broadcast address70cluster name70commitlog directory70data file directories70initial token70listen address70partitioner71rpc address71rpc port71saved caches directory71seed provider71seeds71storage port71endpoint snitch71Performance Tuning Properties72
column index size in kb72commitlog sync72commitlog sync period in ms72commitlog total space in mb72compaction preheat key cache72compaction throughput mb per sec72concurrent compactors72concurrent reads72concurrent writes72flush largest memtables at73in memory compaction limit in mb73index interval73memtable flush queue size73memtable flush writers73memtable total space in mb73multithreaded compaction73reduce cache capacity to73reduce cache sizes at73sliced buffer size in kb74stream throughput outbound megabits per sec74Remote Procedure Call Tuning Properties74request scheduler74request scheduler id74request scheduler options74throttle limit74default weight74weights74rpc keepalive74rpc max threads75rpc min threads75rpc recv buff size in bytes75rpc send buff size in bytes75rpc timeout in ms75rpc server type75thrift framed transport size in mb75thrift max message length in mb75Internode Communication and Fault Detection Properties75dynamic snitch75dynamic snitch badness threshold75
dynamic snitch reset interval in ms76dynamic snitch update interval in ms76hinted handoff enabled76hinted handoff throttle delay in ms76max hint window in ms76phi convict threshold76Automatic Backup Properties76incremental backups76snapshot before compaction76Security Properties76authenticator76authority77internode encryption77keystore77keystore password77truststore77truststore password77Keyspace and Column Family Storage ConfigurationKeyspace Attributes7778name78placement strategy78strategy options78Column Family Attributes79column metadata79column type80comment80compaction strategy80compaction strategy options80comparator81compare subcolumns with81compression options81default validation class81gc grace seconds81key cache save period in seconds81keys cached82key validation class82name82read repair chance82replicate on write82
max compaction threshold82min compaction threshold82memtable flush after mins82memtable operations in millions82memtable throughput in mb83rows cached83row cache provider83row cache save period in seconds83Java and System Environment Settings Configuration83Heap Sizing Options83JMX Options83Further Reading on JVM Tuning84Authentication and Authorization s85Logging Configuration85Logging Levels via the Properties File85Logging Levels via JMX85Operations86Monitoring a Cassandra Cluster86Monitoring Using DataStax OpsCenter86Monitoring Using nodetool87Monitoring Using JConsole88Compaction Metrics89Thread Pool Statistics90Read/Write Latency Metrics90ColumnFamily Statistics90Monitoring and Adjusting Cache Performance91Tuning CassandraTuning the Cache9192How Caching Works92Configuring the Column Family Key Cache92Configuring the Column Family Row Cache92Data Modeling Considerations for Cache Tuning93Hardware and OS Considerations for Cache Tuning93Estimating Cache Sizes93Tuning Write Performance (Memtables)93Tuning Java Heap Size93Tuning Java Garbage Collection94
Tuning Compaction94Choosing a Column Family Compaction Strategy94Setting the Compaction Strategy on a Column Family94Tuning Options for Size-Tiered Compaction95Managing a Cassandra Cluster95Running Routine Node Repair95Adding Capacity to an Existing Cluster95Calculating Tokens For the New Nodes96Adding Nodes to a Cluster96Changing the Replication Factor97Replacing a Dead Node97Backing Up and Restoring Data98Taking a Snapshot98Clearing Snapshot Files98Enabling Incremental BackupsRestoring from a SnapshotReferences989999CQL Language Reference99CQL Lexical Structure99CQL Identifiers and Keywords100CQL Constants100CQL Comments100CQL Consistency Levels100CQL Data TypesWorking with Dates and TimesCQL Storage Parameters101101102CQL Keyspace Storage Parameters102CQL Column Family Storage Parameters102CQL CommandsALTER Parameters104Example104
CREATE 105Examples106CREATE ples106CREATE ters108Example108DROP 109Example109DROP ple109DROP ers110
ption113Parameters114 column family ters115Example115CQLSH-Specific opsis117Description117Parameters117Examples117118
es121stress121Setting up the Stress Utility122Usage122Using the Daemon Mode (stressd)123Examples123sstable2json / json2sstable123sstable2json124Usage124Output e125Troubleshooting Guide125Reads are getting slower while writes are still fast125Nodes seem to freeze after some period of time126Nodes are dying with OOM errors126Nodetool or JMX Connections Failing on Remote Nodes126View of ring differs between some nodes126Java reports an error saying there are too many open files126
Apache Cassandra 1.0 DocumentationApache Cassandra 1.0 DocumentationIntroduction to Apache CassandraApache Cassandra is a free, open-source, distributed database system for managing large amounts of structured,semi-structured, and unstructured data. Cassandra is designed to scale to a very large size across many commodityservers with no single point of failure. Cassandra provides a powerful dynamic schema data model designed to allow formaximum flexibility and performance at scale.Getting Started with CassandraGetting started with Cassandra is fast and easy. Installing Cassandra on a single machine is the best way to learn thebasics. The following will help you install Cassandra and become familiar with some basic commands.Java PrerequisitesBefore installing Cassandra on Linux, Windows, or Mac, ensure that you have the most up-to-date version of Javainstalled on your machine. To determine if Java is installed on your system, in a terminal window enter:java -versionDownload the SoftwareDownload the DataStax Community Edition Server, which is a bundle containing the most up-to-date version ofCassandra along with all the utilities and tools you'll need. You can also download directly from a terminal window wgeton Linux or curl on Mac and the following r.gzOn Windows, download and use the DataStax Windows MSI installer.Note that DataStax also makes available RPM and Debian builds for Linux that are available on the main Downloadpage.Install the SoftwareFor Linux and Mac machines, unzip the tar download file:tar -xvf tar file Start the Cassandra ServerOn Linux or Mac, navigate to the bin directory and invoke the cassandra script:sudo ./cassandraOn Windows, the Cassandra server starts running after installation.Login to CassandraCassandra has a couple of interfaces that you can use to enter commands - the CLI and the CQL (Cassandra QueryLanguage) utility. For this indroduction use the CLI, which in the Windows Cassandra group folder and in the bindirectory on Linux or Mac:./cassandra-cli -h localhostCreate a Keyspace (database)1
Create a Column FamilyA keyspace in Cassandra is the equivalent of a database in the RDBMS world. You can have multiple keyspaces on aCassandra server.First create a simple keyspace to work with:[default@unknown] create keyspace mykeyspace;[default@unknown] use mykeyspace;Create a Column FamilyA couple family is the primary data object in Cassandra, similar to a table in the RDBMS world. To create simple columnfamily:[default@mykeyspace] create column family cf1;Insert, Update, Delete, Read DataNow you can enter and read data from Cassandra.To insert data:[default@mykeyspace] set cf1[1]['c2'] utf8('test');To read that data:[default@mykeyspace] get cf1[1];To update that data:[default@mykeyspace] set cf1[1]['c2'] utf8('test2');To delete that data:[default@mykeyspace] del cf1[1];To exit the CLI:[default@mykeyspace] exit;Getting Started with Cassandra and DataStax Community EditionThis quick start guide is intended to get you up and running quickly on a single-node instance using the DataStaxCommunity Edition packages. DataStax Community Edition is a smart bundle comprised of the most up-to-date andstable version of Apache Cassandra, DataStax OpsCenter Community Edition, the CQL command line utility, and theDataStax portfolio demo application.This tutorial will guide you through setting up a single-node cluster in your home directory, and running the demoapplication to see Cassandra in action.Installing a Single-Node Instance of CassandraThe fastest way to get up and running quickly with Cassandra is to install Cassandra using the DataStax Communitytarball distributions and start a single-node instance. Cassandra is intended to be run on multiple nodes, howeverstarting out with a single-node cluster is a great way to get started.Getting up and running takes just three simple steps:1. Make sure you have Java installed2. Install the DataStax Community Edition of Apache Cassandra3. Set a couple of configuration properties and start the Cassandra serverChecking for a Java Installation2
Installing the DataStax Community Binaries on LinuxCassandra is a Java program and requires a Java Virtual Machine (JVM) to be installed before you can start the server.For production deployments, you will need the Sun Java Runtime Environment 1.6.0 19 or later, but if you are justinstalling an evaluation instance, any JVM is fine.To check for Java, run the following command in a terminal session:# java -versionIf you do not have Java installed, see Installing Sun JRE on RedHat Systems or Installing Sun JRE on Ubuntu Systemsfor instructions.Installing the DataStax Community Binaries on LinuxThe quickest way to get going on a single node with Cassandra is to install the DataStax Community Edition binarytarball packages. This allows you to install everything in a single location (such as your home directory), and does notrequire root permissions.DataStax Community is comprised of three components - The Apache Cassandra server, the DataStax portfolio demoapplication, and DataStax OpsCenter (a web-based monitoring application for Cassandra).NoteThe instructions in this section are not intended for production installations, just for a quick start tutorial. See Planninga Cassandra Cluster Deployment, Installing and Initializing a Cassandra Cluster, and Configuring and Starting aCassandra Cluster for production cluster setup best practices.These instructions will walk you through setting up a self-contained, single-node instance of Cassandra in your homedirectory (does not require root permissions).NoteBy downloading community software from DataStax you agree to the terms of the DataStax Community EULA (EndUser License Agreement) posted on the DataStax web site.1. In your home directory, create a directory called datastax. cd HOME mkdir datastax cd datastax2. In the datastax directory download the Cassandra package (required), plus the OpsCenter package (optional).For example, on Linux to get version 1.0.7 of DataStax Community and version 1.4 of OpsCenter: wget http://downloads.datastax.com/community/dsc.tar.gz wget tar.gz wget demo-bin.tar.gz3
Configuring and Starting a Single-Node Cluster on Linux3. Unpack the distributions: tar -xzvf dsc.tar.gz tar -xzvf opscenter.tar.gz tar -xzvf dsc-1.0.1-demo-bin.tar.gz rm *.tar.gz4. For convenience, set the following environment variables in your user environment. For example, to configure yourenvironment in your HOME/.bashrc file:a. Open your .bashrc file in a text editor (such as vi):vi HOME/.bashrcb. Add the following lines to bottom of the file:exportexportexportexportCASSANDRA HOME HOME/datastax/ dsc package name DSCDEMO HOME HOME/datastax/dsc-1.0.1/demos/portfolio managerOPSC HOME HOME/datastax/ opscenter package name PATH " PATH: CASSANDRA HOME/bin: DSCDEMO HOME/bin: OPSC HOME/bin"For example: dsc package name dsc-cassandra-1.0.7 and opscenter package name opscenter-1.4c. Save and close the file.d. Source the file.source HOME/.bashrc5. Create the data and logging directory for Cassandra. mkdir HOME/datastax/cassandra-dataConfiguring and Starting a Single-Node Cluster on Linux1. Set the configuration properties needed to start your cluster in the CASSANDRA HOME/conf/cassandra.yamlfile. This will configure Cassandra to run a single-node cluster on the localhost and store all of its data files in yourhome directory. sed -i -e "s,initial token:,initial token: 0," \ CASSANDRA HOME/conf/cassandra.yaml sed -i -e "s,- /var/lib/cassandra/data,- HOME/datastax/cassandra-data," \ CASSANDRA HOME/conf/cassandra.yaml sed -i -e "s,saved caches directory: /var/lib/cassandra/saved caches, \saved caches directory: HOME/datastax/cassandra-data/saved caches," \ CASSANDRA HOME/conf/cassandra.yaml sed -i -e "s,commitlog directory: /var/lib/cassandra/commitlog,commitlog directory: \ HOME/datastax/cassandra-data/commitlog," CASSANDRA HOME/conf/cassandra.yaml4
Installing the DataStax Community Binaries on Mac2. Set the Cassandra server log location in the CASSANDRA HOME/conf/log4j-server.properties file tothe log to the cassandra-data directory you created earlier: sed -i -e "s,log4j.appender.R.File /var/log/cassandra/system.log, \log4j.appender.R.File HOME/datastax/cassandra-data/system.log," \ CASSANDRA HOME/conf/log4j-server.properties3. Configure the DataStax demo application to point to the correct Cassandra installation location: sed -i -e "s,/usr/share/cassandra, HOME/datastax/ dsc package name ," \ DSCDEMO HOME/bin/pricer4. Start the Cassandra server in the background. cassandra5. Check that your Cassandra ring is up and running: nodetool ring -h localhost6. For the next step, run the Portfolio Demo example application.Installing the DataStax Community Binaries on MacDataStax supplies a tar download for Mac that can be used for development purposes (production deployments on Macare not currently supported). To install the DataStax Community server and sample applications on Mac, follow theseinstructions:1. Download the tar package for Mac from the DataStax website.2. Move the tar package to your target directory and unpack the contents. An example of unpacking version 1.0.7 ofDataStax Community would be: tar –xzvf dsc-cassandra-1.0.7-bin.tar.gz.3. If you want to take the default data and log file locations for Cassandra, you can proceed to starting up Cassandraby going to the bin directory of the installation home directory and entering the command sudo ./cassandra. Ifyou want to configure Cassandra to use other directories for its data and log files, you can modify thecassandra.yaml file (located in the /conf directory) and change the data file directories,commitlog directory, and saved caches directory parameters to point to your desired directorylocations.4. Check that Cassandra is running by invoking the nodetool utility from the installation home directory:./bin/nodetool ring –h localhost.Installing the DataStax Community Binaries on WindowsDataStax provides a GUI installer for installing both OpsCenter and Cassandra on Windows. Simply download theWindows installer for your chosen platform (32- or 64-bit Windows 7 or Windows Server 2008) from the DataStaxwebsite and follow the installation wizard to install Cassandra, the sample applications, and OpsCenter.NoteThere is a dependency on the Visual C 2008 runtime (32-bit). However, Windows 7 and Windows 2008 Server spx?displaylang en&id 29.Configuring and Starting DataStax OpsCenterDataStax OpsCenter is a graphical web application that can be used to manage and monitor a Cassandra cluster. Forspecific information on installing OpsCenter for your chosen platform, see the Installing the OpsCenter Dashboardsection of the online OpsCenter Documentation.5
Running the Portfolio Demo Sample ApplicationRunning the Portfolio Demo Sample ApplicationYour DataStax Community (DSC) installation contains a demo portfolio manager application that showcases how youcan use Apache Cassandra to back a real-time web application developed in Java and using the Cassandra QueryLanguage (CQL) JDBC driver.The demo application is located in: RPM and Debian packaged installations: /usr/share/dse-demos/portfolio manager Binary tar file installations: DSCDEMO HOME ( install location /dsc-1.0.1/demos/portfolio manager ).About the Portfolio Demo Use CaseThe portfolio manager sample application is a financial application where users can actively create and manage aportfolio of stocks. Each portfolio contains a list of stocks, the number of shares purchased, and the price at which theshares were purchased. An overall value is maintained for each stock portfolio as well as the percentage of gain or losscompared to the original stock purchase prices for a portfolio.The application has a pricer utility which is meant to simulate an active feed of live stock market data. For each stockticker symbol, the application tracks the current stock price and historical market data (end-of-day price) for each stockgoing back in time.Running the Demo Web ApplicationBefore you begin, make sure you have installed, configured, and started your Cassandra cluster. Also make sure youhave installed the DataStax Community Edition demo package using either the binary tarball distribution or theRPM/Debian packaged installations (see Installing a Single-Node Instance of Cassandra or Installing Cassandra Usingthe Packaged Releases).1. Go to the portfolio manager demo directory.cd DSCDEMO HOMEor in packaged installs:cd /usr/share/dse-demos/portfolio managerNoteYou must run the pricer utility from a directory where you have write permissions (such as your homedirectory), or else run it as root or using sudo.2. Run the ./bin/pricer utility to generate stock data for the application. To see all of the available options forthis utility:./bin/pricer --helpThe following examples will generate 100 days worth of historical data.If running on a single node cluster on localhost:./bin/pricer -o INSERT PRICES./bin/pricer -o UPDATE PORTFOLIOS./bin/pricer -o INSERT HISTORICAL PRICES -n 1006
Exploring the Sample Data Model4. Start the web service (must be in the DSCDEMO HOME/website directory to start). cd DSCDEMO HOME/website java -jar start.jar &5. Open a browser and go to http://localhost:8983/portfolio (if running on the local machine) orhttp:// webhost ip :8983/portfolio (if running remotely - specify the correct IP address of the remoteserver).This will open the Portfolio Manager demo web application home page.Exploring the Sample Data ModelThe data for the portfolio manager sample application is contained in a Cassandra keyspace called PortfolioDemo.In that keyspace are four column families: Portfolio - One row per portfolio/customer where the column names are the stock ticker symbols and the columnvalues are the current stock price. StockHist - One row per stock ticker symbol with (time-ordered) dates for the column names and column valuesare the end-of-day price for a particular day. Stocks - One row per stock ticker symbol with a static column name price and the column value is the currentstock value. HistLoss - One row per stock ticker symbol where the column name is the worst date in the stock's history in theform of YYYY-MM-DD and the column value is the loss dollar amount.7
Looking at the Schema Definitions in Cassandra-CLILooking at the Schema Definitions in Cassandra-CLIThe cassandra-cli program in a command-line interface for Cassandra. Using cassandra-cli you can explorethe PortfolioDemo keyspace and data model.1. Start cassandra-cli and specify a Cassandra node to connect to. For example, if running a single-nodeinstance on localhost: cassandra-cli -h localhost2. Specify the keyspace you want to connect to:[default@unknown] USE PortfolioDemo;3. To see the keyspace and column family schema definitions:[default@unknown] SHOW SCHEMA;4. To select a row from the Stocks column family (by specifying the row key value of a stock ticker symbol):[default@unknown] GET Stocks[GCO];5. To exit cassandra-cli:[default@unknown] exit;DataStax Community Release NotesWhat's NewAdded new platform support (Windows 7 and Windows 2008 Server, both 32- and 64-bit) for Cassandra development.The Windows MSI installer provides a full install, including OpsCenter, sets all the WIN services, creates a Windowsprogram group, and quickly starts the new version of DataStax OpsCenter (1.4).PrerequisitesDependency on the Visual C 2008 runtime (32-bit). However, Windows 7 and Windows 2008 Server R2 already haveit installed. If needed, download it from displaylang en&id 29.If you just want to learn more about Cassandra and how it works, see the following conceptual topics: Understanding the Cassandra Architecture Understanding the Cassandra Data Model Managing and Accessing Data in CassandraUnderstanding the Cassandra ArchitectureA Cassandra instance is a collection of independent nodes that are configured together into a cluster. In a Cassandracluster, all nodes are peers, meaning there is no master node or centralized management process. A node joins aCassandra cluster based on certain aspects of its configuration. This section explains those aspects of the Cassandracluster architecture.About Internode Communications (Gossip)Cassandra uses a protocol called gossip to discover location and state information about the other nodes participating ina Cassandra cluster. Gossip is a peer-to-peer communication protocol in which nodes periodically exchange stateinformation about themselves and about other nodes they know about.8
About Cluster Membership and Seed NodesIn Cassandra, the gossip process runs every second and exchanges state messages with up to three other nodes in thecluster. The nodes exchange information about themselves and about the other nodes that they have gossiped about,so all nodes quickly learn about all other nodes in the cluster. A gossip message has a version associated with it, so thatduring a gossip exchange, older information is overwritten with the most current state for a particular node.About Cluster Membership and Seed NodesWhen a node first starts up, it looks at its configuration file to determine the name of the Cassandra cluster it belongs toand which node(s), called seeds, to contact to obtain information about the other nodes in the cluster. These clustercontact points are configured in the cassandra.yaml configuration file for a node.To prevent partitions in gossip communications, all nodes in a cluster should have the same list of seed nodes listed intheir configuration file. This is most critical the first time a node starts up. By default, a node will remember other nodes ithas gossiped with between subsequent restarts.NoteThe seed node designation has no purpose other than bootstrapping the gossip process for new nodes joining thecluster. Seed nodes are not a single point of failure, nor do they have any other special purpose in cluster operationsbeyond the bootstrapping
Apache Cassandra 1.0 Documentation Introduction to Apache Cassandra Apache Cassandra is a free, open-source, distributed database system for managing large amounts of structured, semi-structured, and unstructured data. Cassandra is designed to scale to a very large size across many commodity Apache Cassandra 1.0 Documentation 1
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CASSANDRA_SSL_STORAGE_PORT FALSE 7011; Cassandra cassandra.ssl_storage_port; Cassandra parameter contrail-node-init, contrail-external-cassandra; CASSANDRA_SSL_TRUSTSTORE_PASSWORD FALSE ornatum; Cassandra Cassandra parameter; contrail-external-cassandra CASSANDRA_STORAGE_PORT FALSE; 7010 Cassandra; cassandra.storage_port Cassandra
TP2: data modeling with Apache Cassandra 12. Cassandra versions Latest version 3.11.9 Cassandra 3.0 is supported until 6 months after 4.0 release (date TBD) Cassandra 2.2 is supported until 4.0 release Cassandra 2.1 is supported until 4.0 release 13. Cassandra 3.X physical model
Cassandra database: Build Cassandra code. Installation and configuration of Cassandra on Windows. Installation and configuration of Cassandra on Linux. Running a single Cassandra node. Examples of access control list usage. Extend Cassandra to multiple nodes. Build Cassandra code:
valid credentials to work with Cassandra database. Now the point is how to prepare for Apache Cassandra certification. One of the most popular certification for Apache Cassandra is "Professional Certification with Apache Cassandra: Massively NoSQL database " and this certification is for both Developer as well as architects.
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4 Flexural Strength Kp/cm 950 ASTM D 790 5 Elongation at Break % 80 ISO R 527 6 Yield Stress Kp/cm 400 ISO R 527 7 Resistance to Heat mm 2 BS 4607 PART 2:70 CHEMICAL PROPERTIES Properties at 20_C Unit Values Method of Evaluation 1 Resist to Sulphuric Acid .g/45cm -0.13 3.19 2 Resist to Methylene Chloride % 3 ISO 2508/81 3 Resist. Water Absortion .mg/cm 2.0 ISO 2508/81 & DIN 8061 .
