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https://issues.apache.org/jira/browse/CASSANDRA-8892?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14344182#comment-14344182
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Aleksey Yeschenko commented on CASSANDRA-8892:
----------------------------------------------
If you do all your requests in a single client session (which I'm not sure is
the case with gocql here), then you should always see the latest value. If not,
there are no guarantees even with a single-node setup (until/unless
CASSANDRA-6123 happens).
What you can do is control the timestamps by setting them at the client level
(INSERT .. USING TIMESTAMP X), or at protocol level, if gocql can talk protocol
version 3.
> Read after write inconsistent even on single-node cluster
> ---------------------------------------------------------
>
> Key: CASSANDRA-8892
> URL: https://issues.apache.org/jira/browse/CASSANDRA-8892
> Project: Cassandra
> Issue Type: Bug
> Environment: Centos 6.6, Cassandra 2.0.12
> Reporter: Dan Kinder
> Priority: Minor
>
> Posted on mailing list, original email:
> I had been having the same problem as in those older post:
> http://mail-archives.apache.org/mod_mbox/cassandra-user/201411.mbox/%3CCAORswtz+W4Eg2CoYdnEcYYxp9dARWsotaCkyvS5M7+Uo6HT1=a...@mail.gmail.com%3E
> To summarize it, on my local box with just one cassandra node I can update
> and then select the updated row and get an incorrect response.
> My understanding is this may have to do with not having fine-grained enough
> timestamp resolution, but regardless I'm wondering: is this actually a bug or
> is there any way to mitigate it? It causes sporadic failures in our unit
> tests, and having to Sleep() between tests isn't ideal. At least confirming
> it's a bug would be nice though.
> For those interested, here's a little go program that can reproduce the
> issue. When I run it I typically see:
> {noformat}
> Expected 100 but got: 99
> Expected 1000 but got: 999
> {noformat}
> --- main.go: ---
> {code}
> package main
> import (
> "fmt"
> "github.com/gocql/gocql"
> )
> func main() {
> cf := gocql.NewCluster("localhost")
> db, _ := cf.CreateSession()
> // Keyspace ut = "update test"
> err := db.Query(`CREATE KEYSPACE IF NOT EXISTS ut
> WITH REPLICATION = {'class': 'SimpleStrategy',
> 'replication_factor': 1 }`).Exec()
> if err != nil {
> panic(err.Error())
> }
> err = db.Query("CREATE TABLE IF NOT EXISTS ut.test (key text, val text,
> PRIMARY KEY(key))").Exec()
> if err != nil { panic(err.Error())
> }
> err = db.Query("TRUNCATE ut.test").Exec()
> if err != nil {
> panic(err.Error())
>
> }
>
> err = db.Query("INSERT INTO ut.test (key) VALUES ('foo')").Exec()
>
> if err != nil {
>
> panic(err.Error())
>
> }
>
>
> for i := 0; i < 10000; i++ {
>
> val := fmt.Sprintf("%d", i)
>
> db.Query("UPDATE ut.test SET val = ? WHERE key = 'foo'", val).Exec()
>
>
>
> var result string
> db.Query("SELECT val FROM ut.test WHERE key = 'foo'").Scan(&result)
> if result != val {
> fmt.Printf("Expected %v but got: %v\n", val, result)
> }
> }
>
> }
> {code}
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