Thrift - CQL
Hi all,
We have been using Cassandra for more than 3 years and now we have a cluster in
production still running on 1.1.x contains dynamic-columned column-families -
with hector as client.
We are trying to update to the latest 1.2.x and considering to use datastax
client in order to utilise some of its round robin / failover goodness.
We bumped on to a few walls however when converting our thrift based client
code to CQL. We read through the docs + datastax dev blog entires like: this
and this. However they are mostly focus on reading from an existing dynamic
cf, run some alter table statements, and reading it again.
Very little about how to insert / update.
So there comes my questions:
- Is there any way to do insert / update at all on a good old wide cf using
CQL? Based on what we read back out, we have tried:
INSERT INTO cf_name(key, column1, value) VALUES (‘key1’,
‘columnName1’,’columnValue2’)
But we ended up with “Unknown identifier column1”
- About read - One of our cf is defined with a secondary index. So the
schema looks something like:
create column family cf_with_index
with column_type = 'Standard'
and comparator = 'UTF8Type'
and default_validation_class = 'UTF8Type'
and key_validation_class = 'UTF8Type'
and column_metadata = [
{column_name : 'indexed_column',
validation_class : UTF8Type,
index_name : 'column_idx',
index_type : 0}];
When reading from cli, we will see all columns, data as you expected:
--
---
RowKey: rowkey1
= (name=c1, value=v1, timestamp=xxx, ttl=604800)
= (name=c2, value=v2, timestamp=xxx, ttl=604800)
= (name=c3, value=v3, timestamp=xxx, ttl=604800)
= (name=indexed_column, value=value1, timestamp=xxx, ttl=604800)
---
However when we Query via CQL, we only get the indexed column:
SELECT * FROM cf_with_index WHERE key = ‘rowkey1’;
key | indexed_column
---+
rowkey1 | value1
Any way to get the rest?
- Obtaining TTL and writetime on these wide rows - we tried:
SELECT key, column1, value, writetime(value), ttl(value) FROM cf LIMIT 1;
It works, but a bit clumsy. Is there a better way?
- We can live with thrift. Is there any way / plan to let us to execute
thrift with datastax driver? Hector seems not active anymore.
Many thanks in advanced,
A
Re: Thrift - CQL
Hector has round robin and failover. Is there a particular kind of failover
you're looking for?
by default Hector will try another node if the first node it connects to is
down. It's been that way since the 1.x client if I'm not mistaken.
On Wed, Mar 26, 2014 at 9:41 AM, rubbish me rubbish...@googlemail.comwrote:
Hi all,
We have been using Cassandra for more than 3 years and now we have a
cluster in production still running on 1.1.x contains dynamic-columned
column-families - with hector as client.
We are trying to update to the latest 1.2.x and considering to use
datastax client in order to utilise some of its round robin / failover
goodness.
We bumped on to a few walls however when converting our thrift based
client code to CQL. We read through the docs + datastax dev blog entires
like: this http://www.datastax.com/dev/blog/thrift-to-cql3 and
thishttp://www.datastax.com/dev/blog/cql3-for-cassandra-experts.
However they are mostly focus on reading from an existing dynamic cf, run
some alter table statements, and reading it again.
Very little about how to insert / update.
So there comes my questions:
- *Is there any way to do insert / update at all on a good old wide cf
using CQL? Based on what we read back out, we have tried:*
INSERT INTO cf_name(key, column1, value) VALUES ('key1',
'columnName1','columnValue2')
But we ended up with Unknown identifier column1
- *About read - One of our cf is defined with a secondary index. So
the schema looks something like:*
create column family cf_with_index
with column_type = 'Standard'
and comparator = 'UTF8Type'
and default_validation_class = 'UTF8Type'
and key_validation_class = 'UTF8Type'
and column_metadata = [
{column_name : 'indexed_column',
validation_class : UTF8Type,
index_name : 'column_idx',
index_type : 0}];
When reading from cli, we will see all columns, data as you expected:
--
---
RowKey: rowkey1
= (name=c1, value=v1, timestamp=xxx, ttl=604800)
= (name=c2, value=v2, timestamp=xxx, ttl=604800)
= (name=c3, value=v3, timestamp=xxx, ttl=604800)
= (name=indexed_column, value=value1, timestamp=xxx, ttl=604800)
---
However when we Query via CQL, we only get the indexed column:
SELECT * FROM cf_with_index WHERE key = 'rowkey1';
key | indexed_column
---+
rowkey1 | value1
Any way to get the rest?
- *Obtaining TTL and writetime on these wide rows - we tried:*
*SELECT key, column1, value, writetime(value), ttl(value) FROM cf LIMIT 1;*
*It works, but a bit clumsy. Is there a better way?*
- *We can live with thrift. Is there any way / plan to let us to
execute thrift with datastax driver? Hector seems not active anymore.*
Many thanks in advanced,
A
Re: Thrift - CQL
- *Is there any way to do insert / update at all on a good old wide cf
using CQL? Based on what we read back out, we have tried:*
INSERT INTO cf_name(key, column1, value) VALUES ('key1',
'columnName1','columnValue2')
But we ended up with Unknown identifier column1
What does cqlsh give you if you try to do 'DESC cf_name'?
- *About read - One of our cf is defined with a secondary index. So
the schema looks something like:*
create column family cf_with_index
with column_type = 'Standard'
and comparator = 'UTF8Type'
and default_validation_class = 'UTF8Type'
and key_validation_class = 'UTF8Type'
and column_metadata = [
{column_name : 'indexed_column',
validation_class : UTF8Type,
index_name : 'column_idx',
index_type : 0}];
When reading from cli, we will see all columns, data as you expected:
--
---
RowKey: rowkey1
= (name=c1, value=v1, timestamp=xxx, ttl=604800)
= (name=c2, value=v2, timestamp=xxx, ttl=604800)
= (name=c3, value=v3, timestamp=xxx, ttl=604800)
= (name=indexed_column, value=value1, timestamp=xxx, ttl=604800)
---
However when we Query via CQL, we only get the indexed column:
SELECT * FROM cf_with_index WHERE key = 'rowkey1';
key | indexed_column
---+
rowkey1 | value1
Any way to get the rest?
You would have to declare the other columns (c1, c2 and c3) in the metadata
(you don't have to index them though).
- *Obtaining TTL and writetime on these wide rows - we tried:*
*SELECT key, column1, value, writetime(value), ttl(value) FROM cf LIMIT 1;*
*It works, but a bit clumsy. Is there a better way?*
No, it's the CQL way (not that I particularly agree with the clumsy
qualification, but I suppose we all have different opinion on what is
clumsy and what is not).
- *We can live with thrift. Is there any way / plan to let us to
execute thrift with datastax driver?*
No (and it's not like it's a minor change to allow that, the DataStax Java
driver uses the native protocol which is CQL only by nature).
--
Sylvain
