I've solved the issue with the following for the time being:
byte[] arr = new byte[cell.buffer().remaining()];
cell.buffer().get(arr);
I shouldn't have been calling array() in the first place it seems.
- Neophytos
On Fri, Jan 28, 2022 at 2:06 AM Neophytos Demetriou <neophy...@gmail.com>
wrote:
> 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.
>>
>>
>>
