We started receiving OOMs in our cassandra grid and took a heap dump. We
are running version 1.0.7 with LOCAL_QUORUM from both reads/writes.
After some analysis, we kind of identified the problem, with
SliceByNamesReadCommand, involving a single Super-Column. This seems to be
happening only in digest query and not during actual reads.
I am pasting the serialized byte array of SliceByNamesReadCommand, which
seems to be corrupt on issuing certain digest queries.
//Type is SliceByNamesReadCommand
body[0] = (byte)1;
//This is a digest query here.
body[1] = (byte)1;
//Table-Name from 2-8 bytes
//Key-Name from 9-18 bytes
//QueryPath deserialization here
//CF-Name from 19-30 bytes
//Super-Col-Name from 31st byte onwards, but gets
corrupt as found in heap dump
//body[32-37] = 0, body[38] = 1, body[39] = 0. This
causes the SliceByNamesDeserializer to mark both ColName=NULL and
SuperColName=NULL, fetching entire wide-row!!!
//Actual super-col-name starts only from byte 40,
whereas it should have started from 31st byte itself
Has someone already encountered such an issue? Why is the super-col-name
not correctly de-serialized during digest query.
--
Ravi
