Hi!
I am running 1.0.8.
So if I understand correctly both Memtable and Key cache are stored in the
heap. (I don't have row cache)
SSTables are mapped to operating system's virtual memory system, so if I
increase heap I guess there will be less memory for this?
I have seen the changes in 1.1, but
Thats not right
since 1.1.X it will used
my hint:
take a look at
commitlog_total_space_in_mb
it seams to be maped to off heap usage
the fix for taking the whole off-heap-memory is included in 1.1.3
the next parameter you have to take a look
disk_access_mode: mmap_index_only
#disk_access_mode:
> "How do I know if my off-heap memory is not used?"
If you are using the default memory mapped file access memory not used by the
cassandra JVM will be used to cache files.
Cheers
-
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 22/08/2012, at
Much appreciated.
What you described makes a lot of sense from all my readings :)
Thanks!
*Tamar Fraenkel *
Senior Software Engineer, TOK Media
[image: Inline image 1]
ta...@tok-media.com
Tel: +972 2 6409736
Mob: +972 54 8356490
Fax: +972 2 5612956
On Tue, Aug 21, 2012 at 6:43 PM, Alai
You're welcome. I'll answer to your new questions but keep in mind that I
am not a cassandra commiter nor even a cassandra specialist.
"you mean that key cache is not in heap? I am using cassandra 1.0.8 and I
was under the expression it was, see
http://www.datastax.com/docs/1.0/operations/tuning,
Thanks for you prompt response. Please see follow up questions below
Thanks!!!
*Tamar Fraenkel *
Senior Software Engineer, TOK Media
[image: Inline image 1]
ta...@tok-media.com
Tel: +972 2 6409736
Mob: +972 54 8356490
Fax: +972 2 5612956
On Tue, Aug 21, 2012 at 12:57 PM, Alain RODRIGU
I have the same configuration and I recently change my cassandra-sh.yaml
to :
MAX_HEAP_SIZE="4G"
HEAP_NEWSIZE="200M"
I guess it depends on how much you use the cache (which is now in the
off-heap memory).
I don't use row cache and use the default key cache size.
I have no more memory pressure
Hi!
I have a question regarding Cassandra heap size.
Cassandra calculates heap size in cassandra-env.sh according to the
following algorythm
# set max heap size based on the following
# max(min(1/2 ram, 1024MB), min(1/4 ram, 8GB))
# calculate 1/2 ram and cap to 1024MB
# calculate 1/
