Re: Use Cassnadra thrift API with collection type
Yes, I realized the way to use CQL. I checked the way how map data is represented by using cassandra-cli. For each element in the map, it use the key as part of the column name and value as the column value. I just cannot insert this by using thrift API because I already defined a CompositeType column comparator. Is it a way to run a second program to insert map data with a different comparator? Thanks. On Mon, Jun 23, 2014 at 10:21 AM, Sylvain Lebresne sylv...@datastax.com wrote: On Mon, Jun 23, 2014 at 6:19 PM, James Campbell ja...@breachintelligence.com wrote: Huilang, Since there hasn't been another reply yet, I'll throw out an idea that worked for us as part of a test, though it does not seem exactly like a preferred way since it crosses code-bases. We built the type using straight java type, then used the Datastax v2 driver's DataType class serializer. Concretely, it would look like the following (adapting your code): Column column = new Column(); column.name=columnSerializer.toByteBuffer(colname); // the column name of the map type, it works with other kinds of data type column.value = DataType.map(DataType.ascii, DataType.decimal).serialize(yourMapGoesHere); column.timestamp = new Date().getTime(); ... This is exactly equivalent to what Huiliang posted and will thus not work any better. Collections are internally not store as one thrift column per collection. Each element of the collection is a separate thrift column and the exact encoding depends on the collection. The fact is, updating CQL collection from thrift is technically possible but it is not recommended in any way. I strongly advise you to stick to CQL if you want to use CQL collections. -- Sylvain -- *From:* Huiliang Zhang zhl...@gmail.com *Sent:* Friday, June 20, 2014 10:10 PM *To:* user@cassandra.apache.org *Subject:* Use Cassnadra thrift API with collection type Hi, I have a problem when insert data of the map type into a cassandra table. I tried all kinds of MapSerializer to serialize the Map data and did not succeed. My code is like this: Column column = new Column(); column.name=columnSerializer.toByteBuffer(colname); // the column name of the map type, it works with other kinds of data type column.value = MapSerializer.getInstance(AsciiSerializer.instance, DecimalSerializer.instance).serialize(someMapData); column.timestamp = new Date().getTime(); Mutation mutation = new Mutation(); mutation.column_or_supercolumn = new ColumnOrSuperColumn(); mutation.column_or_supercolumn.column = column; mutationList.add(mutation); The data was input into the cassandra DB however it cannot be retrieved by CQL3 with the following error: ERROR 14:32:48,192 Exception in thread Thread[Thrift:4,5,main] java.lang.AssertionError at org.apache.cassandra.cql3.statements.ColumnGroupMap.getCollection(ColumnGroupMap.java:88) at org.apache.cassandra.cql3.statements.SelectStatement.getCollectionValue(SelectStatement.java:1185) at org.apache.cassandra.cql3.statements.SelectStatement.handleGroup(SelectStatement.java:1169) at org.apache.cassandra.cql3.statements.SelectStatement.processColumnFamily(SelectStatement.java:1076) ... So the question is how to write map data into cassandra by thrift API. Appreciated for any help. Thanks, Huiliang
RE: Use Cassnadra thrift API with collection type
Huilang, Since there hasn't been another reply yet, I'll throw out an idea that worked for us as part of a test, though it does not seem exactly like a preferred way since it crosses code-bases. We built the type using straight java type, then used the Datastax v2 driver's DataType class serializer. Concretely, it would look like the following (adapting your code): Column column = new Column(); column.namehttp://column.name=columnSerializer.toByteBuffer(colname); // the column name of the map type, it works with other kinds of data type ?column.value = DataType.map(DataType.ascii, DataType.decimal).serialize(yourMapGoesHere); column.timestamp = new Date().getTime(); ... From: Huiliang Zhang zhl...@gmail.com Sent: Friday, June 20, 2014 10:10 PM To: user@cassandra.apache.org Subject: Use Cassnadra thrift API with collection type Hi, I have a problem when insert data of the map type into a cassandra table. I tried all kinds of MapSerializer to serialize the Map data and did not succeed. My code is like this: Column column = new Column(); column.namehttp://column.name=columnSerializer.toByteBuffer(colname); // the column name of the map type, it works with other kinds of data type column.value = MapSerializer.getInstance(AsciiSerializer.instance, DecimalSerializer.instance).serialize(someMapData); column.timestamp = new Date().getTime(); Mutation mutation = new Mutation(); mutation.column_or_supercolumn = new ColumnOrSuperColumn(); mutation.column_or_supercolumn.column = column; mutationList.add(mutation); The data was input into the cassandra DB however it cannot be retrieved by CQL3 with the following error: ERROR 14:32:48,192 Exception in thread Thread[Thrift:4,5,main] java.lang.AssertionError at org.apache.cassandra.cql3.statements.ColumnGroupMap.getCollection(ColumnGroupMap.java:88) at org.apache.cassandra.cql3.statements.SelectStatement.getCollectionValue(SelectStatement.java:1185) at org.apache.cassandra.cql3.statements.SelectStatement.handleGroup(SelectStatement.java:1169) at org.apache.cassandra.cql3.statements.SelectStatement.processColumnFamily(SelectStatement.java:1076) ... So the question is how to write map data into cassandra by thrift API. Appreciated for any help. Thanks, Huiliang
Re: Use Cassnadra thrift API with collection type
On Mon, Jun 23, 2014 at 6:19 PM, James Campbell ja...@breachintelligence.com wrote: Huilang, Since there hasn't been another reply yet, I'll throw out an idea that worked for us as part of a test, though it does not seem exactly like a preferred way since it crosses code-bases. We built the type using straight java type, then used the Datastax v2 driver's DataType class serializer. Concretely, it would look like the following (adapting your code): Column column = new Column(); column.name=columnSerializer.toByteBuffer(colname); // the column name of the map type, it works with other kinds of data type column.value = DataType.map(DataType.ascii, DataType.decimal).serialize(yourMapGoesHere); column.timestamp = new Date().getTime(); ... This is exactly equivalent to what Huiliang posted and will thus not work any better. Collections are internally not store as one thrift column per collection. Each element of the collection is a separate thrift column and the exact encoding depends on the collection. The fact is, updating CQL collection from thrift is technically possible but it is not recommended in any way. I strongly advise you to stick to CQL if you want to use CQL collections. -- Sylvain -- *From:* Huiliang Zhang zhl...@gmail.com *Sent:* Friday, June 20, 2014 10:10 PM *To:* user@cassandra.apache.org *Subject:* Use Cassnadra thrift API with collection type Hi, I have a problem when insert data of the map type into a cassandra table. I tried all kinds of MapSerializer to serialize the Map data and did not succeed. My code is like this: Column column = new Column(); column.name=columnSerializer.toByteBuffer(colname); // the column name of the map type, it works with other kinds of data type column.value = MapSerializer.getInstance(AsciiSerializer.instance, DecimalSerializer.instance).serialize(someMapData); column.timestamp = new Date().getTime(); Mutation mutation = new Mutation(); mutation.column_or_supercolumn = new ColumnOrSuperColumn(); mutation.column_or_supercolumn.column = column; mutationList.add(mutation); The data was input into the cassandra DB however it cannot be retrieved by CQL3 with the following error: ERROR 14:32:48,192 Exception in thread Thread[Thrift:4,5,main] java.lang.AssertionError at org.apache.cassandra.cql3.statements.ColumnGroupMap.getCollection(ColumnGroupMap.java:88) at org.apache.cassandra.cql3.statements.SelectStatement.getCollectionValue(SelectStatement.java:1185) at org.apache.cassandra.cql3.statements.SelectStatement.handleGroup(SelectStatement.java:1169) at org.apache.cassandra.cql3.statements.SelectStatement.processColumnFamily(SelectStatement.java:1076) ... So the question is how to write map data into cassandra by thrift API. Appreciated for any help. Thanks, Huiliang
