[jira] [Commented] (CASSANDRA-9449) Running ALTER TABLE cql statement asynchronously results in failure

["Aleksey Yeschenko (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-9449?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14572651#comment-14572651 ] 

Aleksey Yeschenko commented on CASSANDRA-9449:
----------------------------------------------

Yep. Internal {{CFMetaData}} state gets corrupted because of the inherent  raciness. Ultimately, all DDL statements' execution, including {{AlterTableStatement}}'s, should be linearized. It would be a relatively significant change for the 2.1 branch, and for 2.2 branch, for that matter.

CASSANDRA-9425 is the ultimate fix. For now, just try to avoid simultaneous modifications of the same table.

> Running ALTER TABLE cql statement asynchronously results in failure
> -------------------------------------------------------------------
>
>                 Key: CASSANDRA-9449
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-9449
>             Project: Cassandra
>          Issue Type: Bug
>         Environment: Singe cluster environment
>            Reporter: Paul Praet
>
> When running 'ALTER TABLE' cql statements asynchronously, we notice that often certain columns are missing, causing subsequent queries to fail.
> The code snippet below can be used to reproduce the problem.
> cassandra is a com.datastax.driver.core.Session reference.
> We construct the table synchronously and then alter it (adding five columns) with the cassandra async API. We synchronize to ensure the table is properly altered before continuing. Preparing the statement at the bottom of the code snippet often fails:
> {noformat} com.datastax.driver.core.exceptions.InvalidQueryException: Unknown identifier columnf {noformat}
> {code}
>  @Test
>     public void testCassandraAsyncAlterTable() throws Exception {
>         ResultSet rs = cassandra.execute("CREATE TABLE device ( columnA text, columnB text, columnC timestamp, PRIMARY KEY ((columnA, columnB)));");
>         List<ResultSetFuture> futures = new ArrayList<>();
>         futures.add(cassandra.executeAsync("ALTER TABLE device ADD columnD text;"));
>         futures.add(cassandra.executeAsync("ALTER TABLE device ADD columnE text;"));
>         futures.add(cassandra.executeAsync("ALTER TABLE device ADD columnF text;"));
>         futures.add(cassandra.executeAsync("ALTER TABLE device ADD columnG text;"));
>         futures.add(cassandra.executeAsync("ALTER TABLE device ADD columnH text;"));
>         for(ResultSetFuture resultfuture : futures){ resultfuture.get(); }
>           
>         /* discard the result; only interested to see if it works or not */
>         cassandra.prepare("INSERT INTO device (columnA, columnB, columnC,columnD,columnE,columnF,columnG,columnH) VALUES (?,?,?,?,?,?,?,?);");
>     }
> {code}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)