I made an error on Topic title. We are indeed going to do it (that's why I made the mistake), but I am speaking of 1.2 --> 2.0 here, and we will start by this before going to 2.1, since we want to do it in rolling upgrade way.
Thanks for your enlightening pointer about this vanished "pressure valve". C*heers 2014-12-29 17:03 GMT+01:00 Jason Wee <peich...@gmail.com>: > What you are asking maybe answer in the code level and pretty deep stuff, > at least from user (like me) point of view. But to quote Jonathan > in CASSANDRA-3534, Then you will be able to say "use X amount of memory > for memtables, Y amount for the cache (and monitor Z amount for the bloom > filters)" which makes the old "pressure valve" code obsolete. To explain > why is this removed. > > There is also another issue discussing which you might find it worth to > read https://issues.apache.org/jira/browse/CASSANDRA-3143 > > If I may ask, are you doing cassandra upgrade from 1.2 to 2.1? > > Jason > > On Mon, Dec 29, 2014 at 10:54 PM, Alain RODRIGUEZ <arodr...@gmail.com> > wrote: > >> Thanks for the pointer Jason, >> >> Yet, I thought that cache and memtables went off-heap only in version 2.1 >> and not 2.0 ("As of Cassandra 2.0, there are two major pieces of the >> storage engine that still depend on the JVM heap: memtables and the key >> cache." --> >> http://www.datastax.com/dev/blog/off-heap-memtables-in-cassandra-2-1). >> So this "clean up" makes sense to me but in the new 2.1 version of >> Cassandra. I also read on the same blog that we might have the choice >> in/off heap for memtables (or more precisely just get memtable buffers >> off-heap) . If this is true, flush_largest_memtables_at still makes sense. >> About cache, isn't key cache still in the heap, even in 2.1 ? >> >> It looks like the removal of these option looks to me a bit radical and >> premature. I guess I am missing something in my reasoning but can't figure >> out what exactly. >> >> C*heers, >> >> Alain >> >> 2014-12-29 14:52 GMT+01:00 Jason Wee <peich...@gmail.com>: >> >>> https://issues.apache.org/jira/browse/CASSANDRA-3534 >>> >>> On Mon, Dec 29, 2014 at 6:58 PM, Alain RODRIGUEZ <arodr...@gmail.com> >>> wrote: >>> >>>> Hi guys, >>>> >>>> I am looking at added and dropped option in Cassandra between 1.2.18 >>>> and 2.0.11 and this makes me wonder: >>>> >>>> Why has the index_interval option been removed from cassandra.yaml ? I >>>> know we can also define it on a per table basis, yet, this global option >>>> was quite useful to tune memory usage. I also know that this index is now >>>> kept off-heap, but I can not see when and why this option has been removed, >>>> any pointer ? Also it seems this option still usable even if not present by >>>> default on cassandra.yaml, but it is marked as deprecated ( >>>> https://github.com/apache/cassandra/blob/cassandra-2.0.11/src/java/org/apache/cassandra/config/Config.java#L165). >>>> Is this option deprecated on the table schema definition too ? >>>> >>>> Same kind of questions around the heap "emergency pressure valve" --> >>>> "flush_largest_memtables_at", "reduce_cache_sizes_at" and >>>> "reduce_cache_capacity_to", except that those params seems to have been >>>> dropped directly. Why, is there no more need of it, has some other >>>> mechanism replaced it, improving things ? >>>> >>>> Hope this wasn't already discussed,I was unable to find information >>>> about it anyway. >>>> >>>> C*heers ! >>>> >>> >>> >> >
