cassandra cluster

Redis Shards:Why shards: As Redis stores more and more data, the performance of Redis is getting worse!Current methods of sharding:1. Client ShardAt the application level of sharding, the program specifies what data is stored in the Redis advantage: more flexible disadvantage: Add a node expansion is very laborious 2, Agent Proxy shard Third party twemproxy use agent shortcomings, you agent what performance, then your whole redis performance is what kind of! 3. Redis cluster4, Codis (pea pod) Op

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 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

Save data to Cassandra in Spark-shell:vardata = Normalfill.map (line = Line.split ("\u0005")) Data.map ( line= = (Line (0), Line (1), Line (2)) . Savetocassandra ("Cui", "Oper_ios", Somecolumns ("User_no","cust_id","Oper_code","Oper_time"))Savetocassandra method when the field type is counter, the default behavior is countCREATE TABLE CUI.INCR (Name text,Count counter,PRIMARY KEY (name))scala> var rdd = Sc.parallelize (Array (("Cui", 100))rdd:org.apa

First, set the user name and passwordModifying the Cassandra.yaml configuration filePut the defaultAuthenticator:allowallauthenticatorChange intoAuthenticator:passwordauthenticatorIf you need to log in and view the Modify permissions, you need to modifyAuthorizer:allowallauthorizerForAuthorizer:cassandraauthorizerStart CassandraCQL connection, Cassandra is the default account and password./cqlsh-u cassandra

1. If we are going to reboot Cassandra recommend that you save the data in DB before restarting Instructions: ./bin/nodetool--h 127.0.0.1 Flush 2. View the operation of each node in a clustered environment: ./bin/nodetool--h 127.0.0.1 Ring Address DCs Rack Status State Load owns Token133857208900194687050142871119212531697192.168.11.185 Datacenter1 Rack1 DownNormal? 91.45% 119317112008803869636148387431580597032192.168.11.124 datacenter1 rack1 up Nor

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

1, Cassandra PreparationStart Cqlsh,cqlsh_host=172.16.163.131 Bin/cqlshCqlsh>create keyspace productlogs with REPLICATION = {' class ': ' Org.apache.cassandra.locator.SimpleStrategy ', ' Replication_factor ': ' 2 ' } cqlsh>CREATE TABLE productlogs.logs ( IDs uuid, app_name text, App_version text, city text, client_time timestamp, country text, created_at timestamp, int , device_id text ,int, modle_name text, Provin