Hi Jaroslav, That's pretty much expected behavior for the current LWT implementation, which has problems with key contention (the usage pattern you're describing here). Typically, you want to avoid having multiple clients doing LWT operations on the same partition key at the same time.
Thanks, Blake On January 20, 2017 at 4:25:05 AM, Jaroslav Kameník (jaros...@kamenik.cz) wrote: Hi, I would like to ask here before posting new bug. I am trying to make a simple system for distribution preallocated tickets between concurrent clients using C* LWTs. It is simply one partition containing tickets for one domain, client reads the first one and tries to delete it conditionally, success = it owns it, fail = try again.. It works well, but it starts to fail with WTEs under load. So I tried to make simple test with 16 concurrent threads competing for one row with 1000 cols. It was running on cluster with 5 C* 3.0.9 with default configuration, replication factor 3. Surprisingly, it failed immediately after few requests. It takes longer time with less threads, but even 2 clients are enough to crash it. I am wondering, if it Is problem in Cassandra or normal behaviour or bad use of LWT? Thanks, Jaroslav
