Re: 2x storage

2011-02-25 Thread Robert Coli
On Fri, Feb 25, 2011 at 4:55 PM, Terje Marthinussen wrote: > Cassandra never compacts more than one column family at the time? Nope, compaction is single threaded currently. https://issues.apache.org/jira/browse/CASSANDRA-2191 https://issues.apache.org/jira/browse/CASSANDRA-2191 =Rob

Re: 2x storage

2011-02-25 Thread Terje Marthinussen
Cassandra never compacts more than one column family at the time? Regards, Terje On 26 Feb 2011, at 02:40, Robert Coli wrote: > On Fri, Feb 25, 2011 at 9:22 AM, A J wrote: >> I read in some cassandra notes that each node should be allocated >> twice the storage capacity you wish it to contain.

Re: 2x storage

2011-02-25 Thread Robert Coli
On Fri, Feb 25, 2011 at 2:41 PM, A J wrote: > Can the minor compactions across nodes be staggered so that I can > control how many nodes are compacting at any given point ? Not without some crazy scheme where you control the compaction thresholds dynamically via some external mechanism. You proba

Re: 2x storage

2011-02-25 Thread A J
Another related question: Can the minor compactions across nodes be staggered so that I can control how many nodes are compacting at any given point ? On Fri, Feb 25, 2011 at 2:01 PM, A J wrote: > Thanks. What happens when my compaction fails for space reasons ? > Is no compaction possible till I

Re: 2x storage

2011-02-25 Thread A J
Thanks. What happens when my compaction fails for space reasons ? Is no compaction possible till I add more space ? I would assume writes are not impacted though the latency of reads would increase, right ? Also though writes are not seek-intensive, compactions are seek-intensive, no ? On Fri, Fe

Re: 2x storage

2011-02-25 Thread Tyler Hobbs
Ok, we are both correct here: Generally, a minor compaction takes less space than a major, but occasionally it does not. -- Tyler Hobbs Software Engineer, DataStax Maintainer of the pycassa Cassandra Python client library

Re: 2x storage

2011-02-25 Thread Tyler Hobbs
On Fri, Feb 25, 2011 at 12:14 PM, A J wrote: > OK. Is it also driven by type of compaction ? Does a minor compaction > require less working space than major compaction ? > No, every so often a minor compaction ends up compacting all SSTables, so it's effectively the same as a major compaction.

Re: 2x storage

2011-02-25 Thread Robert Coli
On Fri, Feb 25, 2011 at 10:14 AM, A J wrote: > OK. Is it also driven by type of compaction ? Does a minor compaction > require less working space than major compaction ? Yes, unless that minor compaction happens to involve all SStables due to compaction thresholds, at which time it is a major com

Re: 2x storage

2011-02-25 Thread A J
OK. Is it also driven by type of compaction ? Does a minor compaction require less working space than major compaction ? On Fri, Feb 25, 2011 at 12:40 PM, Robert Coli wrote: > On Fri, Feb 25, 2011 at 9:22 AM, A J wrote: >> I read in some cassandra notes that each node should be allocated >> twic

Re: 2x storage

2011-02-25 Thread Robert Coli
On Fri, Feb 25, 2011 at 9:22 AM, A J wrote: > I read in some cassandra notes that each node should be allocated > twice the storage capacity you wish it to contain. I think the reason > was during compaction another copy of SSTables have to be made before > the original ones are discarded. This r

2x storage

2011-02-25 Thread A J
I read in some cassandra notes that each node should be allocated twice the storage capacity you wish it to contain. I think the reason was during compaction another copy of SSTables have to be made before the original ones are discarded. Can someone confirm if that is actually true ? During compa