cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Philip Thompson (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (CASSANDRA-9773) Hadoop Cassandra integration - cannot output to table with only primary key columns
Date Mon, 13 Jul 2015 13:54:04 GMT

     [ https://issues.apache.org/jira/browse/CASSANDRA-9773?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Philip Thompson updated CASSANDRA-9773:
---------------------------------------
    Reproduced In: 2.0.13

I believe this limitation still exists in 2.1 and 2.2

> Hadoop Cassandra integration - cannot output to table with only primary key columns
> -----------------------------------------------------------------------------------
>
>                 Key: CASSANDRA-9773
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-9773
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Hadoop
>         Environment: Cassandra 2.0.13, Hadoop 1.0.4
>            Reporter: fuggy_yama
>
> I have following table in cassandra:
> {code:sql}CREATE TABLE IF NOT EXISTS summary
> (
>     it int, 
>     id int,
>     x float,
>     y float,
>     PRIMARY KEY (it, id, x, y)
> ) WITH compact storage{code}
> In hadoop job definition i set output/update query:
> {code:java}String outputQuery = "UPDATE " + params.get("output_keyspace") + "." + params.get("output_column_family")
+ " SET x=?, y=?";
> CqlConfigHelper.setOutputCql(job.getConfiguration(), outputQuery);{code}
> When hadoop job wants to write results from reducers to cassandra then I get this exception:
> {code:java}java.io.IOException: java.lang.RuntimeException: failed to prepare cql query
UPDATE kmeans_out_cs.summary SET x=?, y=? WHERE "it" = ? AND "id" = ? AND "x" = ? AND "y"
= ?
> 	at org.apache.cassandra.hadoop.cql3.CqlRecordWriter$RangeClient.run(CqlRecordWriter.java:256)
> Caused by: java.lang.RuntimeException: failed to prepare cql query UPDATE kmeans_out_cs.summary
SET x=?, y=? WHERE "it" = ? AND "id" = ? AND "x" = ? AND "y" = ?
> 	at org.apache.cassandra.hadoop.cql3.CqlRecordWriter$RangeClient.preparedStatement(CqlRecordWriter.java:300)
> 	at org.apache.cassandra.hadoop.cql3.CqlRecordWriter$RangeClient.run(CqlRecordWriter.java:237)
> Caused by: InvalidRequestException(why:PRIMARY KEY part x found in SET part)
> 	at org.apache.cassandra.thrift.Cassandra$prepare_cql3_query_result$prepare_cql3_query_resultStandardScheme.read(Cassandra.java:51017)
> 	at org.apache.cassandra.thrift.Cassandra$prepare_cql3_query_result$prepare_cql3_query_resultStandardScheme.read(Cassandra.java:50994)
> 	at org.apache.cassandra.thrift.Cassandra$prepare_cql3_query_result.read(Cassandra.java:50933)
> 	at org.apache.thrift.TServiceClient.receiveBase(TServiceClient.java:78)
> 	at org.apache.cassandra.thrift.Cassandra$Client.recv_prepare_cql3_query(Cassandra.java:1756)
> 	at org.apache.cassandra.thrift.Cassandra$Client.prepare_cql3_query(Cassandra.java:1742)
> 	at org.apache.cassandra.hadoop.cql3.CqlRecordWriter$RangeClient.preparedStatement(CqlRecordWriter.java:296)
> 	... 1 more{code}
> When we want to insert/update columns from PK definition then there is a conflict in
generated CQL query (x and y columns appear in SET and WHERE coulses...):
> *UPDATE kmeans_out_cs.summary SET x=?, y=? WHERE "it" = ? AND "id" = ? AND "x" = ? AND
"y" = ?*
> *Can hadoop job write data to a cassandra table that has only PRIMARY KEY columns?*
> *UPDATE1*
> I checked the source code and noticed that the above update cql query actually has to
be an update statement (not insert).
> Update statement syntax requires non empty "SET a=b"  clause so there is no way to avoid
column names duplication in final update query



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

Mime
View raw message