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From <>
Subject 转发:Re: Cassandra update row after delete immediately, and read that, the data not right?
Date Fri, 26 Dec 2014 04:26:15 GMT
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 <>
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,  <> 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?? 


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