Hi Xutom, What the " modern CQL client with paging support" mean? Is there opensource > CQL client ? I does not use any opensource CQL client and exporting data > with my java code.
Use the datastax Java driver which is open source: github: https://github.com/datastax/java-driver docs: http://datastax.github.io/java-driver/ I have splitted that table into 47*20=940 parts, I have 47 partitions and > each partition also has 20 buckets, so everytime I execute such cql: select > * from table where partition_id=a and bucket_id=b, and the number of each > select result maybe 40-80 million. I don't know what your data model looks like but it sounds (from your description) that your partitions are too large. Check out my blog post on data modeling and benchmarking: http://www.sestevez.com/data-modeler/ Run stress on your test setup to gain confidence in your data model and to ensure and benefit from predictable scalability. All the best, [image: datastax_logo.png] <http://www.datastax.com/> Sebastián Estévez Solutions Architect | 954 905 8615 | sebastian.este...@datastax.com [image: linkedin.png] <https://www.linkedin.com/company/datastax> [image: facebook.png] <https://www.facebook.com/datastax> [image: twitter.png] <https://twitter.com/datastax> [image: g+.png] <https://plus.google.com/+Datastax/about> <http://feeds.feedburner.com/datastax> <http://goog_410786983> <http://www.datastax.com/gartner-magic-quadrant-odbms> DataStax is the fastest, most scalable distributed database technology, delivering Apache Cassandra to the world’s most innovative enterprises. Datastax is built to be agile, always-on, and predictably scalable to any size. With more than 500 customers in 45 countries, DataStax is the database technology and transactional backbone of choice for the worlds most innovative companies such as Netflix, Adobe, Intuit, and eBay. On Tue, Dec 29, 2015 at 2:04 AM, xutom <xutom2...@126.com> wrote: > > Thanks for ur reply. Exactly I have splitted that table into 47*20=940 > parts, I have 47 partitions and each partition also has 20 buckets, so > everytime I execute such cql: select * from table where partition_id=a and > bucket_id=b, and the number of each select result maybe 40-80 million. > What the " modern CQL client with paging support" mean? Is there > opensource CQL client ? I does not use any opensource CQL client and > exporting data with my java code. > > > 在 2015-12-29 11:38:51，"Robert Coli" <rc...@eventbrite.com> 写道： > > On Mon, Dec 28, 2015 at 5:57 PM, xutom <xutom2...@126.com> wrote: > >> I have 5 nodes in my C* cluster, and each node has the same >> configuration file(Cassandra-env.sh: MAX_HEAP_SIZE="32G" and >> HEAP_NEWSIZE="8G"), and My Cassandra version is 2.1.1. Now I want to >> export all data of one table, i am using select * from tablename, >> > > Probably lower your heap size. If you're using CMS GC with 32gb heap you > will get long GC pauses. > > Also use a modern CQL client with paging support. > > In addition, upgrade to the head of 2.1.x, 2.1.1 is not a version anyone > should be using in production at this time. > > =Rob > > > > >
