Hi, thanks for the prompt reply.
I've tried this. Here's what I'm writing:
bytes: 3 capacity: 3 limit: 3 offset: 0
Here's what I'm reading:
cell buffer size: 1048576 capacity: 1048576 limit: 212 arrayOffset: 0
It still does not seem right. I would have expected Cassandra to allocate a
buffer the size of the text field. Unless I'm missing something,
org.apache.cassandra.db.marshal.AbstractType#read already does this. It
calls org.apache.cassandra.utils.ByteBufferUtil#read that allocates a byte
array the size of the given length. I'm still checking but it could be that
the readUnsignedVInt call in AbstractType#read reads the wrong thing under
the given circumstances (very likely an issue on my end). I would welcome
any ideas on how to debug this.
- Neophytos
On Thu, Jan 27, 2022 at 5:43 PM Bowen Song <bo...@bso.ng> wrote:
> I'm not a Java developer, but based on my best knowledge,
> ByteBuffer.array() method returns the whole byte array, not just the part
> of the byte array that's meaningful (i.e. has ever been written to). You
> may want to check the difference between the bb.capacity() and bb.limit(),
> and also check the bb.arrayOffset() because the first element is not always
> at beginning of the byte array.
> On 27/01/2022 22:11, Neophytos Demetriou wrote:
>
> Hi,
>
> I'm new to the list but not new to Cassandra. I'm writing an app on top of
> C* and I have come across an issue (huge cell buffer size after applying a
> mutation) that I haven't been able to resolve yet. I would appreciate any
> suggestions/help to resolve this. Here are the details:
>
> 1. I have a column family defined as follows:
>
> TableMetadata.Builder metadata =
> TableMetadata
> .builder(KEYSPACE1, CF_STANDARD1)
> .addPartitionKeyColumn("key", Int32Type.instance)
> .addRegularColumn(
> "a", MapType.getInstance(AsciiType.instance,
> SetType.getInstance(UTF8Type.instance,false),false))
> .addRegularColumn("b", UTF8Type.instance);
>
> 2. And here's a test that I wrote and works on cassandra-4.0 branch:
>
> Row.Builder builder =
> BTreeRow.unsortedBuilder();builder.newRow(Clustering.EMPTY);ColumnMetadata
> def = metadata.getColumn(new ColumnIdentifier("b", true));Cell<?> cell =
> BufferCell.live(def, System.currentTimeMillis(),
> UTF8Type.instance.decompose("/b1"));builder.addCell(cell);PartitionUpdate
> update = PartitionUpdate.singleRowUpdate(metadata, dk, builder.build());new
> Mutation(update).apply();Row row = Util.getOnlyRow(Util.cmd(cfs,
> dk).withLimit(1).build());assertEquals(3,
> row.getCell(def).buffer().array().length);
>
> 3. However, in my app when I do the getOnlyRow after applying the mutation
> the string value of b is 3 but the buffer().array().length is 1048576.
>
> 4. Restarting the app (which starts the cassandra daemon), fixes the issue
> i.e. getOnlyRow returns the correct buffer size.
>
> 5. I'm importing cassandra-all 4.0.1 and the app uses jdk-11.
>
> If you need further info, please do not hesitate to ask.
>
> - Neophytos
>
> PS. I'm experimenting with C* internals for the first time so it's very
> likely I'm doing something wrong.
>
>
>
