Hi Jan, I would suggest looking at using Zookeeper for such a usecase.
See http://zookeeper.apache.org/doc/trunk/recipes.html for some examples. Zookeeper is used for such purposes in Apache HBase (active master), Apache Kafka (active controller), Apache Hadoop, etc. Look for the "Leader Election" usecase. Examples http://techblog.outbrain.com/2011/07/leader-election-with-zookeeper/ https://www.tutorialspoint.com/zookeeper/zookeeper_leader_election.htm Its more/new work, but should be an elegant solution. Hope that helps. Jayesh On 5/25/17, 9:19 AM, "Jan Algermissen" <algermissen1...@icloud.com> wrote: 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? Jan
