cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Thibaut (Updated) (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (CASSANDRA-4137) QUORUM Multiget RangeSliceQuery causes unnecessary writes to read entries
Date Wed, 11 Apr 2012 16:47:20 GMT

     [ https://issues.apache.org/jira/browse/CASSANDRA-4137?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Thibaut updated CASSANDRA-4137:
-------------------------------

    Priority: Major  (was: Critical)
    
> QUORUM Multiget RangeSliceQuery causes unnecessary writes to read entries
> -------------------------------------------------------------------------
>
>                 Key: CASSANDRA-4137
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4137
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 0.8.9
>            Reporter: Thibaut
>
> From the mailing list:
> I created a new test keyspace and added 10 000 keys to it. The cluster has 3 machines,
RF=3, read repair disabled (enabling it didn't change anything). The keyspace doesn't contain
any thumbstones. No keys were deleted.
> When I fetch a rangeslice through hector and set the consistency level to quorum, according
to cfstats (and also to the output files on the hd), cassandra seems to execute a write request
for each read I execute. The write count in cfstats is increased when I execute the rangeslice
function over the same range again and again (without saving anything at all).
> If I set the consistency level to ONE or ALL, no writes are executed.
> I checked the writes on one machine. They increased by 2300 for each iteration over the
10000 keys. I didn't check, but this probably corresponds to the number of keys for which
the machine is responsible.
> Code:
>                                 Keyspace ks = getConnection(cluster, consistencylevel);
> 				RangeSlicesQuery<String, String, V> rangeSlicesQuery = HFactory.createRangeSlicesQuery(ks,
StringSerializer.get(), StringSerializer.get(), s);
> 				rangeSlicesQuery.setColumnFamily(columnFamily);
> 				rangeSlicesQuery.setColumnNames(column);
> 				rangeSlicesQuery.setKeys(start, end);
> 				rangeSlicesQuery.setRowCount(maxrows);
> 				QueryResult<OrderedRows<String, String, V>> result = rangeSlicesQuery.execute();
> 				return result.get();

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message