get_slice reads a single row. do you mean there are 23,000 columns,
or are you running get_slice in a loop 23000 times?
On Fri, Jun 4, 2010 at 4:59 AM, Per Olesen <p...@trifork.com> wrote:
> Are 6..8 seconds to read 23.000 small rows - as it should be?
>
> I have a quick question on what I think is bad read performance for this
> simple setup:
>
> <ColumnFamily Name="Dashboard"
> ColumnType="Super"
> CompareWith="UTF8Type"
> CompareSubcolumnsWith="UTF8Type" />
>
> SCF:Dashboard
> key:username1 -> {
> SC:uniqStr1 -> { col1:val1, col2: val2, ... col8:val8 },
> SC:uniqStr2 -> { col1:val1, col2: val2, ... col8:val8 },
> SC:uniqStr3 -> { col1:val1, col2: val2, ... col8:val8 },
> SC:uniqStr4 -> { col1:val1, col2: val2, ... col8:val8 },
> ... up to 23.000 "rows"
> key:username2 -> {
> SC:uniqStr5 -> { col1:val1, col2: val2, ... col8:val8 },
> SC:uniqStr6 -> { col1:val1, col2: val2, ... col8:val8 },
> SC:uniqStr7 -> { col1:val1, col2: val2, ... col8:val8 },
> SC:uniqStr8 -> { col1:val1, col2: val2, ... col8:val8 },
> ...
>
> A given key "username1" has e.g. 23.000 super column unique (rows). When I
> try and simply raw-read all these rows, it takes what I think isn't pretty
> fast - approximately 6-8 seconds. I know, there are a millions things that
> affect this, but I would just like to have a yes or no if this really can be
> as it should be?
>
> My cassandra is a pretty unchanged v0.6.1.
>
> I read using this code:
>
> ColumnParent parent = new ColumnParent("Dashboard");
>
> SlicePredicate predicate = new SlicePredicate();
> SliceRange sliceRange = new SliceRange();
> sliceRange.setCount(Integer.MAX_VALUE);
> sliceRange.setStart(toRawValue(""));
> sliceRange.setFinish(toRawValue(""));
> predicate.setSlice_range(sliceRange);
>
> // timing this takes 6-8 secs.
> return client.get_slice(
> "keyspace",
> "theusername",
> columnParent,
> slicePredicate,
> ConsistencyLevel.QUORUM
> );
>
> My replication factor is 1 and I had two nodes setup in cluster when doing
> the reads.
>
> Shouldn't this be what cassandra can do dead-fast?
>
>
--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
