Re: force gc?

2012-09-03 Thread aaron morton
r Shutyaev wrote: > Hi Derek, > > I'm using size-tiered compaction. > > 2012/9/3 Derek Williams > On Fri, Aug 31, 2012 at 7:03 AM, Alexander Shutyaev > wrote: > Does anyone have any suggestions on how can I analyze my problem? Or maybe > I'm doing something w

Re: force gc?

2012-09-02 Thread Alexander Shutyaev
Hi Derek, I'm using size-tiered compaction. 2012/9/3 Derek Williams > On Fri, Aug 31, 2012 at 7:03 AM, Alexander Shutyaev wrote: > >> Does anyone have any suggestions on how can I analyze my problem? Or >> maybe I'm doing something wrong and there is another way t

Re: force gc?

2012-09-02 Thread Derek Williams
On Fri, Aug 31, 2012 at 7:03 AM, Alexander Shutyaev wrote: > Does anyone have any suggestions on how can I analyze my problem? Or maybe > I'm doing something wrong and there is another way to force gc on an > existing column family. > Are you using leveled compaction? I haven

Re: force gc?

2012-09-02 Thread Peter Schuller
> Maybe there is some tool to analyze it? It would be great if I could somehow > export each row of a column family into a separate file - so I could see > their count and sizes. Is there any such tool? Or maybe you have some better > thoughts... Use something like pycassa to non-obnoxiously itera

Re: force gc?

2012-09-02 Thread Alexander Shutyaev
Hi Peter, I don't compare it with PosgreSQL size, I just make some estimations.. This table / column family stores some xml documents with average raw size of 2Mb each and total size about 5Gb. However the space cassandra occupies on disc is 70Gb (after gc_grace was set to 0 and major compaction w

Re: force gc?

2012-09-02 Thread Peter Schuller
> I think that was clear from your post. I don't see a problem with your > process. Setting gc grace to 0 and forcing compaction should indeed > return you to the smallest possible on-disk size. (But may be unsafe as documented; can cause deleted data to pop back up, etc.) -- / Peter Schuller (@

Re: force gc?

2012-09-02 Thread Peter Schuller
> I think I described the problem wrong :) I don't want to do Java's memory > GC. I want to do cassandra's GC - that is I want to "really" remove deleted > rows from a column family and get my disc space back. I think that was clear from your post. I don't see a problem with your process. Setting

Re: force gc?

2012-09-02 Thread Alexander Shutyaev
erwrites and deletes. If I understand correctly cassandra does not >> actually delete these objects until gc_grace seconds have passed. I tried >> to "force" gc by setting gc_grace to 0 on an existing column family and >> running major compaction afterwards. However I did n

Re: force gc?

2012-08-31 Thread Jeffrey Kesselman
e these objects until gc_grace seconds have passed. I tried > to "force" gc by setting gc_grace to 0 on an existing column family and > running major compaction afterwards. However I did not get disk space back, > although I'm pretty much sure that my column family should occupy

force gc?

2012-08-31 Thread Alexander Shutyaev
Hi All! I have a problem with using cassandra. Our application does a lot of overwrites and deletes. If I understand correctly cassandra does not actually delete these objects until gc_grace seconds have passed. I tried to "force" gc by setting gc_grace to 0 on an existing column