datastax-enterprise

问题 I have a queue-like column family which updates frequently around every hour. After a couple of hours or a day cassandra has a lot of read time outs. I have tried this but haven't gotten the result yet: gc_grace_seconds = 0 and using LeveledCompaction. Or would you recommend the datetieredcompactionstrategy or is there another better strategy then these two? If I cannot solve this I am thinking switching to another database do you think that is necessary? Thanks for your replies. 回答1: What

问题 I'm using 64 bit Windows 8. It was fine yesterday, and it just failed to start. It shows the loading screen, but it just stop right there. Anyone has the same problem? Any fix? It has happened to me twice with my old pc, which were using 32 bit Windows 7. 回答1: While I haven't heard of this issue before, here's something that will hopefully fix the issue: find a directory called .devcenter in your user directory (that should be \Users\<youruser> ) move this directory to a different location

问题 OpsCenter version: 5.1.0 and DSE Version: 4.6.0 Creating a brand new cluster by using OpsCenter directly, gives us the following error. It randomly works with the same settings but 95% of the times it fails with the same error. Opscenter is running on its own box but sharing the same Security groups as the cluster instances. For good measure, I have opened up all TCP ports to all IPs. The following is the stack trace of the error from the opscenterd.log: *2015-03-19 10:06:12+0000 [] INFO:

问题 I am trying to run this small spark-xml example and it fails with exception when i do a spark-submit. Sample REPO : https://github.com/punithmailme/spark-xml-new command : ./dse spark-submit --class MainDriver /Users/praj3/Desktop/projects/spark/main/build/libs/main.jar import java.io.Serializable; import java.nio.file.Paths; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import lombok.Builder; import lombok.Data; import org.apache.hadoop.conf.Configuration;

问题 I have an existing cluster with the following topology: DC Cassandra: 2 nodes DC Solr: 5 nodes All of the nodes currently use vnodes. I want to disable vnodes in the Solr DC for performance reasons. According to this document, to disable vnodes: In the cassandra.yaml file, set num_tokens to 1 Uncomment the initial_token property and set it to 1 or to the value of a generated token for a multi-node cluster. Is this all that I need to do? (no repair, no cleanup, no anything?) Seems too good to

问题 I am currently planning for an upgrade to 2.0.7 cassandra version . My base version is 2.0.3. I have not done an upgrade so far and hence want to be absolutely sure about what am doing . Can someone explain what needs to be done apart front this. Do a nodetool drain to stop all writes to the particular node. Stop the cassandra node(I have a 8 node , 2 data center network topology. I am bringing down one node in DC1) Change the cassandra.yaml accordingly in the new binary tarball. Make the

问题 In SparkStreaming should we off load the saving part to another layer because SparkStreaming context is not available when we use SparkCassandraConnector if our database is cassandra. Moreover, even if we use some other database to save our data then we need to create connection on the worker every time we process a batch of rdds. Reason being connection objects are not serialized. Is it recommended to create/close connections at workers? It would make our system tightly coupled with the

问题 Please help me how I can stop Cassandra update automatically? At present when I install Cassandra through opscentre I get an error. Unable to restart DSE service. See /var/log/cassandra/system.log and /var/log/cassandra/output.log on the target node for details. system.log ERROR [main] 2018-03-28 07:58:26,123 CassandraDaemon.java:705 - Exception encountered during startup java.lang.AbstractMethodError: org.apache.cassandra.utils.JMXServerUtils$Exporter.exportObject(Ljava/rmi/Remote;ILjava/rmi

问题 I was going through the DataStax documentation and found an interesting statement. It claimed "Insert-heavy workloads are CPU-bound in Cassandra before becoming memory-bound". Can someone explain about how this claim is made? and what might be causing this behavior of Cassandra?? Thanks. 回答1: For different workloads, Cassandra clusters can be CPU, memory, I/O or (occasionally) network bound. The claim in the documentation is, if you start a new cluster and make lots of inserts, the cluster

问题 For some reason I experience high load on my Cassandra nodes. Here are some information to get the picture. When I create a brand new Cluster the load is constantly low for a couple of days and increases by time, after a week or something it just goes of into the air, causing what I found is a instability in the whole Cluster I'm taking snapshots of one of my keyspaces containing around 300-400 MBs of data every 4 hour and deleting the ones older than 7 days, all configured in OpsCenter The