cassandra

问题 I have the following code segment. The composite column has two compoents. Is it possible to retrieve columns if I know only the first component? In some sense, apply some dilcards election on the some of the components of the composite (especially the last component). Thanks. Mutator<String> mutator = HFactory.createMutator(keyspace, stringSerializer); String key="TX:512"; String CF="StateNpaIndexStatic"; HColumnImpl<Composite, String> column = new HColumnImpl<Composite, String>(cs,

问题 I have some problems with compile simple achilles maven project. My pom.xml: <dependencies> <dependency> <groupId>info.archinnov</groupId> <artifactId>achilles-core</artifactId> <version>4.2.0</version> </dependency> <dependency> <groupId>info.archinnov</groupId> <artifactId>achilles-model</artifactId> <version>4.2.0</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration>

问题 I have a scenario to run cassandra of two different versions in the same machine but at different ports. I started one cluster with following cassandra config at port 9161 , # TCP port, for commands and data storage_port: 7000 # SSL port, for encrypted communication. Unused unless enabled in # encryption_options ssl_storage_port: 7004 port for the CQL native transport to listen for clients on native_transport_port: 9043 port for Thrift to listen for clients on rpc_port: 9161 seed_provider: #

问题 I have a scenario to run cassandra of two different versions in the same machine but at different ports. I started one cluster with following cassandra config at port 9161 , # TCP port, for commands and data storage_port: 7000 # SSL port, for encrypted communication. Unused unless enabled in # encryption_options ssl_storage_port: 7004 port for the CQL native transport to listen for clients on native_transport_port: 9043 port for Thrift to listen for clients on rpc_port: 9161 seed_provider: #

问题 I have write performance issues with Cassandra 3. I'm trying out Cassandra 3.3 using the official Docker image from here: https://github.com/docker-library/cassandra I start it as follows: docker run --net=host --rm cassandra:3.3 Then run cassandra-stress against it: cassandra-stress write This gives me the following results for four threads executing traffic: op rate : 1913 [WRITE:1913] partition rate : 1913 [WRITE:1913] row rate : 1913 [WRITE:1913] latency mean : 2.1 [WRITE:2.1] latency

问题 I mainly followed the guide on this page. I installed Nutch 2.3, Cassandra 2.0, and solr 4.10.3. Set up went well. But when I executed the following command. No urls were fetched. ./bin/crawl urls/seed.txt TestCrawl http://localhost:8983/solr/ 2 Below are my settings. nutch-site.xml http://ideone.com/H8MPcl regex-urlfilter.txt +^http://([a-z0-9]*\.)*nutch.apache.org/ hadoop.log http://ideone.com/LnpAw4 I don't see any errors in the log file. I am really lost. Any help would be appreciated.

问题 First and foremost I'm a Nutch/Hadoop newbie. I have installed Cassandra. I have installed Nutch on the Master node of my EMR cluster. When I attempt to execute a crawl using the following command: sudo bin/crawl crawl urls -dir crawl -depth 3 -topN 5 I get Error: JAVA_HOME is not set. If I run the command without 'sudo' I get: Injector: starting at 2014-07-16 02:12:24 Injector: crawlDb: urls/crawldb Injector: urlDir: crawl Injector: Converting injected urls to crawl db entries. Injector: org

问题 First and foremost I'm a Nutch/Hadoop newbie. I have installed Cassandra. I have installed Nutch on the Master node of my EMR cluster. When I attempt to execute a crawl using the following command: sudo bin/crawl crawl urls -dir crawl -depth 3 -topN 5 I get Error: JAVA_HOME is not set. If I run the command without 'sudo' I get: Injector: starting at 2014-07-16 02:12:24 Injector: crawlDb: urls/crawldb Injector: urlDir: crawl Injector: Converting injected urls to crawl db entries. Injector: org

问题 everyone :D I'm working with Cassandra (Datastax version) and I have an issue. I want to modeling a column who (always) gonna change. That's very hard, because I can't just create a column family with 1,2,3,4..10 columns. Because, tomorrow probably can change. I think in collections, but I got to query into these. I mean, I need query into this information every second. Ex: With map: <'col1':'val1','col2':'val2'> I need to query like this: SELECT * FROM example WHERE 'col1' = 'val1' AND 'col2

问题 I am using Datastax 2.1 community version in EC2. I dropped a big table (column family) in a keyspace and ran "nodetool compact " but from OpsCenter UI, I don't see any increase in storage capacity. I ran "nodetool compactionstats " to see whether compaction is on-going but there is nothing: $ nodetool compactionstats pending tasks: 0 Active compaction remaining time : n/a Is there some other process I need to follow? 回答1: Cassandra, in its default configuration, keeps a snapshot of every