I tried using java driver with auto paging query: setFetchSize instead of token function. as Cass has this feature already. ref from here:http://www.datastax.com/dev/blog/client-side-improvements-in-cassandra-2-0
But I tried in test envrionment with only 1million data read then insert 3 tables, It’s too slow. After running 20 min, Exception likeNoHostAvailableException happen, offcourse data did’t sync completed. And our product env has nearly 25 billion data. which is unacceptble for this case. It’s there other ways? Thanks Regards， qihuang.zheng 原始邮件 发件人:Jeff [email protected] 收件人:[email protected][email protected] 发送时间:2015年10月22日(周四) 13:52 主题:Re: C* Table Changed and Data Migration with new primary key Because the data format has changed, you’ll need to read it out and write it back in again. This means using either a driver (java, python, c++, etc), or something like spark. In either case, split up the token range so you can parallelize it for significant speed improvements. From: "qihuang.zheng" Reply-To: "[email protected]" Date: Wednesday, October 21, 2015 at 6:18 PM To: user Subject: C* Table Changed and Data Migration with new primary key Hi All: We have a table defined only one partition key and some cluster key. CREATE TABLE test1 ( attribute text, partner text, app text, "timestamp" bigint, event text, PRIMARY KEY ((attribute), partner, app, "timestamp") ) And now we want to split original test1 table to 3 tables like this: test_global : PRIMARY KEY ((attribute),“timestamp") test_partner: PRIMARY KEY ((attribute, partner), "timestamp”) test_app: PRIMARY KEY ((attribute, partner, app), “timestamp”) Why we split original table because when queryglobal databy timestamp desc like this: select * from test1 where attribute=? order by timestamp desc is not support in Cass. As class order by support should use all clustering key. But sql like this: select * from test1 where attribute=? order by partner desc,app desc, timestamp desc can’t query the right global data by ts desc. After Split table we could do globa data query right: select * from test_global where attribute=? order by timestamp desc. Now we have a problem ofdata migration. As I Know,sstableloaderis the most easy way,but could’t deal with different table name. (Am I right?) Andcpcmd in cqlsh can’t fit our situation because our data is two large. (10Nodes, one nodes has 400G data) I alos try JavaAPI by query the origin table and then insert into 3 different splited table.But seems too slow Any Solution aboult quick data migration? TKS!! PS: Cass version: 2.0.15 Thanks Regards， qihuang.zheng
