Re: How to query '%' character using LIKE operator in Cassandra 3.7?

2016-09-14 Thread DuyHai Doan
Ok you're right, I get your point LIKE '%%esc%' --> startWith('%esc') LIKE 'escape%%' --> = 'escape%' What I strongly suspect is that in the source code of SASI, we parse the % xxx % expression BEFORE applying escape. That will explain the observed behavior. E.g: LIKE '%%esc%' parsed as %xxx%

race condition for quorum consistency

2016-09-14 Thread Qi Li
hi all, we are using quorum consistency, and we *suspect* there may be a race condition during the write. lets say RF is 3. so write will wait for at least 2 nodes to ack. suppose there is only 1 node acked(node A). the other 2 nodes(node B, C) are still waiting to update. there come two read requ

Re: unsubscribe

2016-09-14 Thread Alain RODRIGUEZ
Hi, Sending a message to user-unsubscr...@cassandra.apache.org is the right way to go if you want to unsubscribe from the "Cassandra User" mailing list, C*heers, --- Alain Rodriguez - @arodream - al...@thelastpickle.com France The Last Pickle - Apache Cassandra Consulting htt

Re: race condition for quorum consistency

2016-09-14 Thread Alexander DEJANOVSKI
Hi, the analysis is valid, and strong consistency the Cassandra way means that one client writing at quorum, then reading at quorum will always see his previous write. Two different clients have no guarantee to see the same data when using quorum, as illustrated in your example. Only options here

Re: unsubscribe

2016-09-14 Thread Alain RODRIGUEZ
Hi, Sending a message to user-unsubscr...@cassandra.apache.org is the right way to go if you want to unsubscribe from the "Cassandra User" mailing list, C*heers, --- Alain Rodriguez - @arodream - al...@thelastpickle.com France 2016-09-12 18:02 GMT+02:00 Spencer Brown : > ub

How Fast Does Information Spread With Gossip?

2016-09-14 Thread jerome
Hi, I was curious if anyone had any kind of statistics or ballpark figures on how long it takes information to propagate through a cluster with Gossip? I'm particularly interested in how fast information about the liveness of a node spreads. For example, in an n-node cluster the median amount

Re: race condition for quorum consistency

2016-09-14 Thread Work
Hi Alex: Hmmm ... Assuming clock skew is eliminated And assuming nodes are up and available ... And assuming quorum writes and quorum reads and everyone waiting for success ( which is NOT The OP scenario), Two different clients will be guaranteed to see all successful writes, or be told tha

Re: race condition for quorum consistency

2016-09-14 Thread Alexander Dejanovski
My understanding of the described scenario is that the write hasn't succeeded when reads are fired, as B and C haven't processed the mutation yet. There would be 3 clients here and not 2 : C1 writes, C2 and C3 read. So the race condition could still happen in this particular case. Le mer. 14 sep

Re: race condition for quorum consistency

2016-09-14 Thread Nicolas Douillet
Hi, In my opinion the guaranty provided by Cassandra is : if your write request in Quorum *succeed*, then the next (after the write response) read requests in Quorum (that succeed too) will be consistent (actually CL.Write + CL.Read > RF) Of course while you haven't received a valid r

Re: race condition for quorum consistency

2016-09-14 Thread Tyler Hobbs
On Wed, Sep 14, 2016 at 3:49 PM, Nicolas Douillet < nicolas.douil...@gmail.com> wrote: > - > - during read requests, cassandra will ask to one node the data and to > the others involved in the CL a digest, and if all digests do not match, > will ask for them the entire data, handle the merge and f

Re: Re : Cluster performance after enabling SSL

2016-09-14 Thread sai krishnam raju potturi
thanks Surabhi; we'll do further tests regarding this. The per node tps are less, but for the overall cluster the tps are like 90k. On Tue, Sep 13, 2016 at 3:25 PM, Surbhi Gupta wrote: > We have seen a little overhead in latencies while enabling the > client_encryption. > Our cluster gets around

Re: Re : Cluster performance after enabling SSL

2016-09-14 Thread sai krishnam raju potturi
Thanks a lot. That was really good info. On Tue, Sep 13, 2016, 15:41 G P wrote: > Read this: > > http://www.aifb.kit.edu/images/5/58/IC2E2014-Performance_Overhead_TLS.pdf > > It can cause bigger variances in latencies, but not much. > Terça-feira, 13 Setembro 2016, 08:01PM +01:00 de sai krishnam

Re: race condition for quorum consistency

2016-09-14 Thread Alexander Dejanovski
I haven't been very accurate in my first answer indeed, which was misleading. Apache Cassandra guarantees that if all queries are ran at least at quorum, a client writing successfully (as in the cluster acknowledged the write) then reading his previous write will see the correct value unless anothe