datastax

问题 I have 6 nodes, 1 Solr, 5 Spark nodes, using datastax. My cluster is on a similar server to Amazon EC2, with EBS volume. Each node has 3 EBS volumes, which compose a logical data disk using LVM. In my OPS center the same node frequently becomes unresponsive, which leads to a connect time out of my data system. My data amount is around 400GB with 3 replicas. I have 20 streaming jobs with batch interval every minute. Here is my error message: /var/log/cassandra/output.log:WARN 13:44:31,868 Not

问题 I've a problem which has been bothering me from quite while now. I'm scaling it down for simplification. I've a column family in Cassandra defined as: CREATE TABLE "Test" ( key text, column1 text, value text, PRIMARY KEY (key, column1) ) If I run a query in CQL as: select * from "Test" where key in ('12345','34567'); It gives me something like: key | column1 | value -----------------------+--- 12345 | 764 | 764 12345 | 836 | 836 12345 | 123723 | 123723 12345 | 155863 | 155863 key | column1 |

问题 I've seen it being written in multiple sources that it is perfectly normal, with Cassandra, to store data in the column name, while leaving the column value empty. I'm not sure I completely understand how that's possible. Can anyone throw more light on this, preferably with an example schema? 回答1: No, not any more. This used to be possible. It required the old (pre-3.x storage engine) and use of a Thrift-based API. But tables built with CQL (and the new storage engine) require all columns to

问题 maybe this could be very helpful to other people. This is the link in which is explained the installatif DSbulk loader. https://docs.datastax.com/en/dsbulk/doc/dsbulk/install/dsbulkInstall.html Someone could explain step by step the procedure to install it? The first part in the link is very clear, but if you have installed JAVA (as in my case) when on terminal you run " dsbulk --version " it says "command not found". I hope this will be very helpful, there are no tutorials neither on youtube

问题 I've got a problem with monitoring my Cassandra node. I ran nodetool cfstats keyspaceName.tableName Unfortunately Read Count is always 0 and Read Latency is NaN. I am doing reads and writes but only writes metrics are updated. Here is what I got as an output: Starting NodeTool Keyspace: realtimetrader Read Count: 0 Read Latency: NaN ms. Write Count: 402 Write Latency: 0.09648756218905473 ms. Pending Flushes: 0 Table: currencies SSTable count: 1 Space used (live): 5254 Space used (total): 5254

问题 Whenever I insert data in table in Cassandra, more than 1000 and fetching the data by id, it throws the following exception: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: localhost/127.0.0.1:9042 (com.datastax.driver.core.exceptions.BusyPoolException: [localhost/127.0.0.1] Pool is busy (no available connection and the queue has reached its max size 256))) at com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java

问题 Whenever I insert data in table in Cassandra, more than 1000 and fetching the data by id, it throws the following exception: com.datastax.driver.core.exceptions.NoHostAvailableException: All host(s) tried for query failed (tried: localhost/127.0.0.1:9042 (com.datastax.driver.core.exceptions.BusyPoolException: [localhost/127.0.0.1] Pool is busy (no available connection and the queue has reached its max size 256))) at com.datastax.driver.core.RequestHandler.reportNoMoreHosts(RequestHandler.java

来源： https://stackoverflow.com/questions/63705671/cassandra-database-fetch-time-is-higher-than-netflix-astyanax-driver-than-data

来源： https://stackoverflow.com/questions/48572521/java-lang-noclassdeffounderror-could-not-initialize-class-org-xerial-snappy-sna

来源： https://stackoverflow.com/questions/48572521/java-lang-noclassdeffounderror-could-not-initialize-class-org-xerial-snappy-sna