In my case, we're using Cassandra to store QA test data — so the pattern is that we may do a bunch of updates within a few minutes / hours, and then the data will essentially be read-only for the rest of its lifetime (years). My question is the same — do we need to worry about the performance impact of having N mutations written to the SSTable — or will these mutations generally be constrained to the mem table?
- Max > Hi, > > I am using a updates to a column with a ttl to represent a lock. The owning > process keeps updating the lock's TTL as long as it is running. If the > process crashes, the lock will timeout and be deleted. Then another process > can take over. > > I have used this pattern very successfully over years with TTLs in the order > of tens of seconds. > > Now I have a use case in mind that would require much smaller TTLs, e.g. 1 or > two seconds and I am worried about the increased number of mutations and > possible effect on SSTables. > > However: I'd assume these frequent updates on a cell to mostly happen in the > memtable resulting in only occasional manifestation in SSTables. > > Is that assumption correct and if so, what config parameters should I tweak > to keep the memtable from being flushed for longer periods of time? --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org For additional commands, e-mail: user-h...@cassandra.apache.org
