so the coordinator node of a given request sets the timestamp unless overridden by the client (which you can do on a per statement basis), while you can move all of your timestamps to client side, eventually as you add more clients you have a similar problem set and will still have to use NTP to keep your clients in sync.
Ultimately for a large variety of reasons, it's probably better to just make sure your cassandra nodes are in sync. On Thu, Dec 25, 2014 at 10:26 PM, <yhq...@sina.com> wrote: > Hi, all: > > The test program first insert one row and then delete it, then read it > to compare. > > The test program run this flow row by row, not batch. > > > Today I found the problem is caused by the deletion timestamp. The > machine running the test program may not be time sync with cassandra > machine strictly. > > > > Why cassandra use the local timestamp for deletion?? > > > > 发件人：Jack Krupansky <jack.krupan...@gmail.com> > 收件人：user@cassandra.apache.org, yhq...@sina.com > 主题：Re: Cassandra update row after delete immediately, and read that, the > data not right? > 日期：2014年12月25日 21点04分 > > What RF? > > Is the update and read immediately after the delete and insert, or is the > read after doing all the updates? > > Is the delete and insert done with a single batch? > > -- Jack Krupansky > > On Thu, Dec 25, 2014 at 4:14 AM, <yhq...@sina.com> wrote: > > Hi, all > I write a program to test the cassandra2.1. I have 6 nodes cluster. > First, I insert 1 million row data into cassandra. the row key from 1 to > 1000000. > > Then I run my test program. My test program first delete(use batch > mutate) the row and insert (use batch mutate) that row, > > then read (use gen_slice_range) the same row. After that check > whether the read data is same with the insert data or not. > The consistency level used is quorum. > > I found there some cases that not the same. About 1/10000. In this error > cases, some column is not same. > > Then I use cassandra-cli to check the data, found that column is not > exist. It seems insert partly. > My test program has 20 threads. the QPS 800 about > > What's wrong with cassandra?? > > > Thanks! > > > -- Thanks, Ryan Svihla
