transferred from: Http://www.infoq.com/cn/articles/best-practice-of-cassandra-data-model-designdon't put Cassandra modelthink of it as a relational databaseTableInstead, think of it as an orderly map structure.For a novice, the following relational database terminology is often mapped to the Cassandra modelThis comparison can help us to transition from a relation
Cassandra data model I. Several Concepts
Cluster: Cluster, a node contained in a logical Cassandra instance. A cluster can contain multiple keyspaces.Keyspace: The namespace of the column family, usually an application keyspace.Column family: contains multiple columns. Each column includes name, value, and timestamp. Column family is referenced by row key.Super column: it can be seen that its column contain
Spring data brings us a lot of convenience in accessing the data, and then we'll combine Spring-data-cassandra to see how to quickly access the Cassandra data.
Of course, the Official Handbook is sure to look at the official 1.2.0RELEASE document. Prepare the dependency for basic use:
SETP1: Define a domain model (called an entity in JPA), such as Person:
Import Org.springframework.data.cassandra.mapping.
This article is the first of the Cassandra Data Model design (all two), which contains some of the practices ebay uses to design the Cassandra data model. Some of the best practices we learned through our communities, some of which are new to us, and some that are still controversial, may benefit from further practice.
In this article, I will explain some basic practices as well as a detailed example. Even
Kairosdb(1) To/conf directory, find kairosdb.properties, modify Datastore to Cassandra(2) Setting the connection mode of Cassandra(3) Set user name password4. Start: Go to the/bin directory and run directly./kairosdb.sh Start, finally see KAIROSDB service started such a word, OK 172.16.101.25:8080 kairosdb client Cassandra Modify
About the installation of Cassandra database, in fact, the Apache official website has a detailed introduction: http://wiki.apache.org/cassandra/GettingStarted. Of course, for the convenience of students who do not want to see English, the following is probably introduced:Pre-work: Make sure your Mac has a JDK installed (the latest Mac system should have JDK, so the problem should be small, java-version can
Recently, I saw a message about Twitter's Database Change, which indirectly touched a new term: Cassandra.
Although I have also learned about nosql before, I have been engaged in mis-related development, and have not yet been able to access such a database.
This product is a product of Apache: Cassandra official homepage [English]
To put it simply, it is a distributed storage system ).
If you are intere
1. A good feature of Cassandra is that columns can be sorted by column key, so that when Rowkey is determined, it is convenient for the range of the same "row" (range query) to be searched; officially, every "line" (Wide row) You can add up to 2 billion columns, although, according to ebay's engineers, there are no more than million in practice; The data value of the same row exists in the same server and will not be separated;2. And the column mode i
Use Elasticsearch, Kafka, and Cassandra to build streaming data centers
Over the past year, I 've met software companies discussing how to process application data (usually in the form of logs and metrics ). During these discussions, I often hear frustration that they have to use a group of fragmented tools to aggregate the data over time. These tools, such as:-tools used by O M personnel for monitoring and alarms
-Tools used by developers to track
Install Python2.7 Cassandra 2.2.5 used python2.7, and CentOS 6.7 came with Python is 2.6, so to install python2.7, but can not delete 2.6 version, because Yum need to use python2.6, see CentOS Install Python2.7
2. Installation of DataStax cassandra2.2.5 http://docs.datastax.com/en/cassandra/2.2/cassandra/install/installRHEL.html
3. After the installation of the
A relational database management system (RDBMS) is the most commonly used system for storing and using data, but the scalability of these databases is not very good for large amounts of data.
In recent years, the concept of NoSQL has been widely welcomed because of the increasing demand for substitute products for relational databases. The biggest motivation behind NoSQL is scalability. The NoSQL database solution provides a way to store and use large amounts of data, with less overhead, fewer
Before talking about gossip, first define what is Cassandra instance.
Cassandra Instance:
is a set of independent nodes in the cluster, all nodes are equivalent.
Cassandra the interaction between nodes:
The Gossip protocol (final consistency principle) is used to discover the location and state information of nodes in other clusters through the
The reliability, delay and consistency of the distributed system are general problems, not limited to the database, and Cassandra provides a good solution to the problem.Cassandra claims to be able to achieve the efficient access to database access across data centers, and it is implemented in a way that gives users the tradeoff between latency, throughput, and consistency. Cassandra provides two levels of
A little confused, the mind only to think of a word, "then go to learn it."I am responsible for a part of the project to use the Cassandra, at that time also looked at points, but not too deep understanding, since the "learning momentum" is sufficient, then study it well.As for the merits and demerits of NoSQL and relational databases, let's go straight to the point and finish the installation of Cassandra.Official website: http://cassandra.apache.org
SummaryThis article mainly introduces Cassandra Threading technology, the implementation of Cassandra is Java-based, so threading technology is also used by the JDK package provided by the threading class. Cassandra is a distributed database, and the entire concurrency architecture is based on a phased event-driven architecture (staged Envent-driven architecture)
This article is mainly translated from the cassandra1.2 document of Datastax. Objective: To reduce the number of sstables and Merge multiple sstables in the sequence of IOSStable: compression: In Cassandra, write new columns into the new sstable, therefore, compression is used to merge multiple sstables into one. Figure1: addingsstableswit
This article is mainly translated from the cassandra1.2 document of Datastax. Objective: To reduce the number of
When crawling and storing web pages using nutch2.0 + cassandra1.0, we found that all Chinese Characters in GBK-encoded web pages are garbled during parsing and extracting text. It's strange that Chinese garbled characters have never been detected in the past in nutch1.x, because the crawler code used by nutch1.x and nutch2.x is almost the same, I guess it may be a problem when it is saved to Cassandra. After reading the source code of saving the webpa
Through the above 2 sections, we have learned about the problems encountered by RDBMS and have a basic understanding of Cassandra. The following is an introduction to the Cassandra internal simple structure.Through this chapter, you should understand:
Cassandra Write Process
What is sstable
Cassandra R
CassandraThe data model is based on the column family (Column Family) of four or five-dimensional models. It lendsThat's it.Amazonof theDynamoand theGoogle ' sBig Table's data structure and functional characteristics, usingmemtablestored in the same way. InCassandrabefore writing the data, you need to record the log(Commitlog), and then the data begins to write toColumn Familycorresponding to thememtablein whichmemtableis a kind of according toKeyThe memory structure of the sorted data, when cer
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