If you make the timestamp the partition key you won't be able to do range queries (unless you use an ordered partitioner).
Assuming you are logging from multiple devices you will want your partition key to be the device id & the date, your clustering key to be the timestamp (timeuuid are good to prevent collisions) and then log message, levels etc as the other columns. Then you can also create a new table for every week (or day/month depending on how much granularity you want) and just write to the current weeks table. This step allows you to delete old data without Cassandra using tombstones (you just drop the table for the week of logs you want to delete). For a much clearer explantation see http://www.slideshare.net/patrickmcfadin/cassandra-20-and-timeseries (the last few slides). As for compaction, I would leave it enabled as having lots of stables hanging around can make range queries slower (the query has more files to visit). See http://stackoverflow.com/questions/8917882/cassandra-sstables-and-compaction (a little old but still relevant). Compaction also fixes up things like merging row fragments (when you write new columns to the same row). Ben Bromhead Instaclustr | www.instaclustr.com | @instaclustr | +61 415 936 359 On 07/05/2014, at 10:55 AM, Kevin Burton <bur...@spinn3r.com> wrote: > I'm looking at storing log data in Cassandra… > > Every record is a unique timestamp for the key, and then the log line for the > value. > > I think it would be best to just disable compactions. > > - there will never be any deletes. > > - all the data will be accessed in time range (probably partitioned randomly) > and sequentially. > > So every time a memtable flushes, we will just keep that SSTable forever. > > Compacting the data is kind of redundant in this situation. > > I was thinking the best strategy is to use setcompactionthreshold and set the > value VERY high to compactions are never triggered. > > Also, It would be IDEAL to be able to tell cassandra to just drop a full > SSTable so that I can truncate older data without having to do a major > compaction and without having to mark everything with a tombstone. Is this > possible? > > > > -- > > Founder/CEO Spinn3r.com > Location: San Francisco, CA > Skype: burtonator > blog: http://burtonator.wordpress.com > … or check out my Google+ profile > > War is peace. Freedom is slavery. Ignorance is strength. Corporations are > people. >
