cassandra-2.0

问题 I have a doubt when i read datastax documentation about cassandra write consistency. I have a question on how cassandra will maintain consistent state on following scenario: Write consistency level = Quorum replication factor = 3 As per docs, When a write occurs coordinator node will send this write request to all replicas in a cluster. If one replica succeed and other fails then coordinator node will send error response back to the client but node-1 successfully written the data and that

问题 I have the following table with five map type collections. The max number of elements in the collection is 12 and the maximum size of the item is 50 Bytes. # CREATE TABLE persons ( treeid int, personid bigint, birthdate text, birthplace text, clientnote text, clientnoteisprivate boolean, confidence int, connections map<int, bigint>, createddate timestamp, deathdate text, deathplace text, familyrelations map<text, text>, flags int, gender text, givenname text, identifiers map<int, text>,

问题 I am trying to find the answer to a simple question. Let say I have a table which I store content in it. The content is just a string. I am trying to find what is my max length for this specific one? I was reading that "text" type is just an alias to varchar. Is varchar length only 255 or it can be more? 回答1: You can use TEXT column in your database ( about 64KB characters). As you know String in java has 2^31-1 characters 来源： https://stackoverflow.com/questions/37290391/max-length-of-varchar

问题 I am trying to import a CSV file to a Cassandra table however I am facing a problem. When inserted successfully, at least this is what Cassandra tells, I still can't see any record. Here is a little more details : qlsh:recommendation_engine> COPY row_historical_game_outcome_data FROM '/home/adelin/workspace/docs/re_raw_data2.csv' WITH DELIMITER='|'; 2 rows imported in 0.216 seconds. cqlsh:recommendation_engine> select * from row_historical_game_outcome_data; customer_id | game_id | time |

问题 I am using cassandra database in production.I have one column field in a cassandra table e.g coin_deducted is int data type. I need to convert coin_deducted in float/double data type. But I tried to change data type by using alter table command but cassandra is throwing incompatible issue while converting int to float. Is there any way to do this? e.g: currently it is showing like: user_id | start_time | coin_deducted (int) 122 | 26-01-01 | 12 I want to be user_id | start_time | coin_deducted

问题 I'm trying to load 1 Million LUBM dataset into Cassandra. But, I keep getting this Exception after about 200,000 inserts. Exception in thread "main" com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: localhost/127.0.0.1 (com.datastax.driver.core.exceptions.DriverException: Timeout during read)) The server is still alive. I can still execute CQL queries using Datastax Dev Center. Prior to this, I was getting WriteTimeoutException and hence

问题 New to DevCenter and Cassandra, I wonder why my install with DevCenter 1.1.1 and Cassandra 2.0.9 seems to fail to regonize some valid CQL cmdx, like DESCRIBE and COPY from DevCenter when they work fine from CLI CQLSH. DevCenter pops a window saying something like: No viable input near 'COPY'. Any hints appreciated! TIA 回答1: Yes. DevCenter doesn't support COPY yet. 来源： https://stackoverflow.com/questions/25347859/devcenter-seems-to-fail-to-recognize-some-cql-cmds

问题 I want to connect Tableau software to my cassandra database. Note that i'm using tableau in windows7 and cassandra in ubuntu (Virtual machine). For this i've installed the Cassandra ODBC (and Simba cassandra ODBC but i got the same problem). I got a connexion succes and i found my keyspace but not my tables !!!!!! But no table in "cim" keyspace !! Note that in my keyspace "cim" i have 3 tables that i can request with any problem in cassandra. Is there something i should do before creating the

问题 I am trying to start Cassandra with SSL. My yam file has server_encryption_options: internode_encryption: all keystore_password: changeme truststore_password: changeme truststore: /opt/certs/cassandra.truststore keystore: /opt/certs/cassandra.keystore # protocol: TLS # algorithm: SunX509 # store_type: JKS # cipher_suites: [TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,TLS_DHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA

问题 I have two data enters DC1 and DC2. Both communicate via a private link. Yesterday, we had a problem with a private link for 10 mins. From the time the problem was resolved, nodes in both data centers are not able to communicate with each other. When I do a nodetool status on a node in DC1, the nodes in DC2 are stated as down. When tried in DC2, nodes in DC1 are shown as down . But in the cassandra logs, we can clearly see that handshaking is failing every 5 seconds for communication between