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cassandra | Mirror of Apache Cassandra

 by   apache Java Version: Current License: Apache-2.0

 by   apache Java Version: Current License: Apache-2.0

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kandi X-RAY | cassandra Summary

cassandra is a Java library typically used in Big Data applications. cassandra has no bugs, it has a Permissive License and it has medium support. However cassandra has 2 vulnerabilities and it build file is not available. You can download it from GitHub.
Mirror of Apache Cassandra
Support
Support
Quality
Quality
Security
Security
License
License
Reuse
Reuse

kandi-support Support

  • cassandra has a medium active ecosystem.
  • It has 7193 star(s) with 3073 fork(s). There are 467 watchers for this library.
  • It had no major release in the last 12 months.
  • cassandra has no issues reported. There are 181 open pull requests and 0 closed requests.
  • It has a neutral sentiment in the developer community.
  • The latest version of cassandra is current.
cassandra Support
Best in #Java
Average in #Java
cassandra Support
Best in #Java
Average in #Java

quality kandi Quality

  • cassandra has no bugs reported.
cassandra Quality
Best in #Java
Average in #Java
cassandra Quality
Best in #Java
Average in #Java

securitySecurity

  • cassandra has 2 vulnerability issues reported (1 critical, 1 high, 0 medium, 0 low).
cassandra Security
Best in #Java
Average in #Java
cassandra Security
Best in #Java
Average in #Java

license License

  • cassandra is licensed under the Apache-2.0 License. This license is Permissive.
  • Permissive licenses have the least restrictions, and you can use them in most projects.
cassandra License
Best in #Java
Average in #Java
cassandra License
Best in #Java
Average in #Java

buildReuse

  • cassandra releases are not available. You will need to build from source code and install.
  • cassandra has no build file. You will be need to create the build yourself to build the component from source.
cassandra Reuse
Best in #Java
Average in #Java
cassandra Reuse
Best in #Java
Average in #Java
Top functions reviewed by kandi - BETA

kandi has reviewed cassandra and discovered the below as its top functions. This is intended to give you an instant insight into cassandra implemented functionality, and help decide if they suit your requirements.

  • Return a proxy for a column family .
  • Removes the maximum endpoint version from the gossip service .
  • Returns the primary ranges for the given collection of tokens .
  • Adds the table to a schema mutation .
  • Apply configuration to the configuration .
  • Deletes all files in the specified directory recursively .
  • Initialize Cassandra server .
  • Creates the trace state .
  • Returns the index level for the given index .
  • Log system system info .

cassandra Key Features

Mirror of Apache Cassandra

Initializing a list by a value from another column

copy iconCopydownload iconDownload
import pyspark.sql.functions as F

df = spark.read\
    .format("org.apache.spark.sql.cassandra")\
    .options(table="tbl", keyspace="ks")\
    .load()

df_with_list = df.select("id", "other_primary_key_columns....", 
    F.array(F.col("data")).alias("data_list"))

df_with_list.write\
    .format("org.apache.spark.sql.cassandra")\
    .mode('append')\
    .options(table="tbl", keyspace="ks")\
    .save()

Spring Cassandra time out query 'SELECT * FROM system_schema.tables' timed out after PT2S

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datastax-java-driver {
  basic.request {
    timeout = 2 seconds
-----------------------
SELECT * FROM system_schema.tables
CREATE KEYSPACE system_schema WITH replication = {'class': 'LocalStrategy'}
-----------------------
SELECT * FROM system_schema.tables
CREATE KEYSPACE system_schema WITH replication = {'class': 'LocalStrategy'}
-----------------------
 $java -Ddatastax-java-driver.basic.request.timeout="15 seconds" application.jar
-----------------------
  @Bean
    public DriverConfigLoaderBuilderCustomizer defaultProfile(){
        return builder -> builder.withString(DefaultDriverOption.METADATA_SCHEMA_REQUEST_TIMEOUT, "3 seconds").build();
    }
@Bean
    public DriverConfigLoaderBuilderCustomizer defaultProfile(){
        return builder -> builder.withInt(DefaultDriverOption.METADATA_SCHEMA_REQUEST_TIMEOUT, 3000).build();
    }
-----------------------
  @Bean
    public DriverConfigLoaderBuilderCustomizer defaultProfile(){
        return builder -> builder.withString(DefaultDriverOption.METADATA_SCHEMA_REQUEST_TIMEOUT, "3 seconds").build();
    }
@Bean
    public DriverConfigLoaderBuilderCustomizer defaultProfile(){
        return builder -> builder.withInt(DefaultDriverOption.METADATA_SCHEMA_REQUEST_TIMEOUT, 3000).build();
    }

Spring boot application with spring data cassandra failing to start

copy iconCopydownload iconDownload
 @Configuration
 public class AppConfig {
    public @Bean CqlSession session() {
       return CqlSession.builder().withKeyspace("mykeyspace").build();
    }
 } 
-----------------------
version: "3"

services:
  cassandra:
    image: docker.io/bitnami/cassandra:latest
    ports:
      - '7000:7000'
      - '9042:9042'
    environment:
      - CASSANDRA_SEEDS=cassandra
      - CASSANDRA_PASSWORD_SEEDER=yes
#      - CASSANDRA_USERNAME=user
#      - CASSANDRA_PASSWORD=pass123
      - CASSANDRA_CFG_RACKDC_PREFER_LOCAL=true
spring.data.cassandra.local-datacenter=datacenter1
spring.data.cassandra.keyspace-name=hello
spring.data.cassandra.contact-points=localhost
spring.data.cassandra.port=9042
spring.data.cassandra.username=cassandra
spring.data.cassandra.password=cassandra
spring.data.cassandra.schema-action=create_if_not_exists
-----------------------
version: "3"

services:
  cassandra:
    image: docker.io/bitnami/cassandra:latest
    ports:
      - '7000:7000'
      - '9042:9042'
    environment:
      - CASSANDRA_SEEDS=cassandra
      - CASSANDRA_PASSWORD_SEEDER=yes
#      - CASSANDRA_USERNAME=user
#      - CASSANDRA_PASSWORD=pass123
      - CASSANDRA_CFG_RACKDC_PREFER_LOCAL=true
spring.data.cassandra.local-datacenter=datacenter1
spring.data.cassandra.keyspace-name=hello
spring.data.cassandra.contact-points=localhost
spring.data.cassandra.port=9042
spring.data.cassandra.username=cassandra
spring.data.cassandra.password=cassandra
spring.data.cassandra.schema-action=create_if_not_exists

Cassandra data modeling understanding

copy iconCopydownload iconDownload
SELECT * FROM product
INNER JOIN cart
ON c.item_id = p.id
CREATE TABLE cart_product (
    product_name TEXT,
    product_desc TEXT,
    product_price DECIMAL,
    product_id uuid,
    cart_id uuid,
    qty int,
    PRIMARY KEY (cart_id,product_id)
);
> SELECT product_name,product_price,product_desc 
  FROM cart_product
  WHERE cart_id=93aefdf3-acbf-4d3c-849c-4db9b2ef9e19;

 product_name         | product_price | product_desc
----------------------+---------------+---------------------------------------------------
            Minecraft |         29.99 | Build the future with blocks, and try not to die!
 Kerbal Space Program |         29.99 |         Blast into space.  Now with moar rockets!
       Cyberpunk 2077 |         59.99 |         Wake up Samurai.  We have a city to burn!

(3 rows)
-----------------------
SELECT * FROM product
INNER JOIN cart
ON c.item_id = p.id
CREATE TABLE cart_product (
    product_name TEXT,
    product_desc TEXT,
    product_price DECIMAL,
    product_id uuid,
    cart_id uuid,
    qty int,
    PRIMARY KEY (cart_id,product_id)
);
> SELECT product_name,product_price,product_desc 
  FROM cart_product
  WHERE cart_id=93aefdf3-acbf-4d3c-849c-4db9b2ef9e19;

 product_name         | product_price | product_desc
----------------------+---------------+---------------------------------------------------
            Minecraft |         29.99 | Build the future with blocks, and try not to die!
 Kerbal Space Program |         29.99 |         Blast into space.  Now with moar rockets!
       Cyberpunk 2077 |         59.99 |         Wake up Samurai.  We have a city to burn!

(3 rows)
-----------------------
SELECT * FROM product
INNER JOIN cart
ON c.item_id = p.id
CREATE TABLE cart_product (
    product_name TEXT,
    product_desc TEXT,
    product_price DECIMAL,
    product_id uuid,
    cart_id uuid,
    qty int,
    PRIMARY KEY (cart_id,product_id)
);
> SELECT product_name,product_price,product_desc 
  FROM cart_product
  WHERE cart_id=93aefdf3-acbf-4d3c-849c-4db9b2ef9e19;

 product_name         | product_price | product_desc
----------------------+---------------+---------------------------------------------------
            Minecraft |         29.99 | Build the future with blocks, and try not to die!
 Kerbal Space Program |         29.99 |         Blast into space.  Now with moar rockets!
       Cyberpunk 2077 |         59.99 |         Wake up Samurai.  We have a city to burn!

(3 rows)

How to copy public ssh-keys to a host using ansible

copy iconCopydownload iconDownload
- name: ensure ssh-key is present
  ansible.posix.authorized_key:
    user: "your-user"
    state: present
    key: "your-public-key-goes-here"

Using Cassandra User Defined Type in a MAP Data Type Column

copy iconCopydownload iconDownload
INSERT INTO user_records (user_account, user_record) Values ( 
1234, 
{'0' : {message : 'message 1', update_time : '2021-06-08T18:00:05.000'}, 
'1' : {message : 'message 2', update_time :'2021-06-08T18:01:05.000'}, 
'2' : {message : 'message 3', update_time :'2021-06-08T18:02:05.000'}});

Error instantiating snitch class 'org.apache.cassandra.locator.Ec2Snitch'

copy iconCopydownload iconDownload
metadata_options {
  http_endpoint = "enabled"
    http_tokens = "enabled"
  }
metadata_options {
      http_endpoint = "enabled"
        http_tokens = "optional"
      }
-----------------------
metadata_options {
  http_endpoint = "enabled"
    http_tokens = "enabled"
  }
metadata_options {
      http_endpoint = "enabled"
        http_tokens = "optional"
      }

why is my first query slow but then it is fast?

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app.get('/', async (req, res) => {
  await client.connect(); // <- this should be avoiding in the serve path
  const rs = await client.execute("SELECT * FROM employ_by_id;");
  console.log(rs);
  return res.json({
    message: 'Hello'
  })
});
app.get('/', async (req, res) => {
  const rs = await client.execute("SELECT * FROM employ_by_id;");
  console.log(rs);
  return res.json({
    message: 'Hello'
  })
});

const server = http.createServer(app);
client.connect(err => {
  //TODO: Handle err
  // ...
  // Now that I'm connected to my DB, I can start serving requests
  server.listen(PORT, () => {
    console.log(`Server listen on port ${PORT}`)
  });
});
-----------------------
app.get('/', async (req, res) => {
  await client.connect(); // <- this should be avoiding in the serve path
  const rs = await client.execute("SELECT * FROM employ_by_id;");
  console.log(rs);
  return res.json({
    message: 'Hello'
  })
});
app.get('/', async (req, res) => {
  const rs = await client.execute("SELECT * FROM employ_by_id;");
  console.log(rs);
  return res.json({
    message: 'Hello'
  })
});

const server = http.createServer(app);
client.connect(err => {
  //TODO: Handle err
  // ...
  // Now that I'm connected to my DB, I can start serving requests
  server.listen(PORT, () => {
    console.log(`Server listen on port ${PORT}`)
  });
});

How to migrate data from SQL Server to Cassandra

copy iconCopydownload iconDownload
const stream = myRowStream.pipe(transformRowToArrayOfParameters);
const result = await executeConcurrent(client, insertString, stream);

Springboot Cassandra - CqlSessionFactoryBean with SSL

copy iconCopydownload iconDownload
SSLContext sslContext = ...
CqlSession session = CqlSession.builder()
    .withSslContext(sslContext)
    .build();
SslEngineFactory yourFactory = ...
CqlSession session = CqlSession.builder()
    .withSslEngineFactory(yourFactory)
    .build();
-----------------------
SSLContext sslContext = ...
CqlSession session = CqlSession.builder()
    .withSslContext(sslContext)
    .build();
SslEngineFactory yourFactory = ...
CqlSession session = CqlSession.builder()
    .withSslEngineFactory(yourFactory)
    .build();

Community Discussions

Trending Discussions on cassandra
  • cassnadra multi/single partition batch explanation
  • Initializing a list by a value from another column
  • cassandra 3.11.9 system_auth need to be SimpleStrategy or NetworkTopologyStrategy on production env?
  • Janus Graph backend cassandra vs Bigtable
  • Spring Cassandra time out query 'SELECT * FROM system_schema.tables' timed out after PT2S
  • Spring boot application with spring data cassandra failing to start
  • Cassandra update column should update column value but not the ttl?
  • Cassandra data modeling understanding
  • what do you think about read performance in cassandra?
  • How to copy public ssh-keys to a host using ansible
Trending Discussions on cassandra

QUESTION

cassnadra multi/single partition batch explanation

Asked 2021-Jun-14 at 12:46

I red the cassandra docs about Good use of BATCH statement - single partition batch example I want to understand about multi/single partition batch.

According to the docs this is a single partition batch.

CREATE TABLE cycling.cyclist_expenses ( 
  cyclist_name text, 
  balance float STATIC, 
  expense_id int, 
  amount float, 
  description text, 
  paid boolean, 
  PRIMARY KEY (cyclist_name, expense_id) 
);

BEGIN BATCH

  INSERT INTO cycling.cyclist_expenses (cyclist_name, expense_id, amount, description, paid) VALUES ('Vera ADRIAN', 2, 13.44, 'Lunch', true);

  INSERT INTO cycling.cyclist_expenses (cyclist_name, expense_id, amount, description, paid) VALUES ('Vera ADRIAN', 3, 25.00, 'Dinner', false);

...
APPLY BATCH;

First partition is - 'Vera ADRIAN', 2 Second partition - 'Vera ADRIAN', 3

Could u explain pls why is it single partition batch?

In another docs I found the example of multi partition batch:

Create table shopping_chart 
(cart_id UUID,item_id UUID,price Decimal, total Decimal static,
primary key ((cart_id),item_id));

insert into shopping_chart(cart_id,item_id,price,total) 
values (ABC12345,ABCITEM12345,0.01,0.01);

Begin Batch
insert into shopping_chart(cart_id,item_id,price) values ( ABC12345,ABCITEM123451,1.00);

insert into shopping_chart(cart_id,item_id,price) values ( ABC12345,ABCITEM1234512,2.00);

Update …. cart_id=ABC12345 IF total =0.01;
Apply Batch;

And I can’t understand why it's a multi partition batch? Could u pls explain ? There is working only with one partition = ABC12345

ANSWER

Answered 2021-Jun-14 at 12:41

First partition is - 'Vera ADRIAN', 2 Second partition - 'Vera ADRIAN', 3

Could u explain pls why is it single partition batch?

Sure. Because the expense_id is not part of the partition key. Therefore, Vera ADRIAN is the same partition key value used in both INSERTs.

For the 2nd part of your question, you're right in that the 2nd example does not appear to be a multi-partition query as the cart_ids are the same. Following your link above, I quickly found a bad use of BATCH (multi-partition): https://docs.datastax.com/en/dse/6.8/cql/cql/cql_using/useBatchBadExample.html

Source https://stackoverflow.com/questions/67969940

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install cassandra

You can download it from GitHub.
You can use cassandra like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the cassandra component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer maven.apache.org. For Gradle installation, please refer gradle.org .

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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