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.
