Hey Klaus, These are good questions.
1. Yes. The stores.my-store.changelog=my-stream-name indicates that the key-value store should be backed by a changelog. If this is set each change to the local store is logged for fault-tolerance and the store will be automatically restored on fail-over. If it is not set it is assumed the task can restore its state from its inputs. 2. The concepts here are partitions, which are a logical notion of parallelism and containers which are the physical notion of parallelism (i.e. unix processes). Partitions are fixed, but containers are changable. If you want to add containers later you do so just by changing the config and restarting the job. So you will want to over-partition your job to allow for future growth. -Jay On Mon, Dec 9, 2013 at 8:02 AM, Klaus Schaefers <[email protected] > wrote: > Hi, > > I have been reading about the Samza and I like the concept behind it a lot. > In particular the local key-value store is a good idea. However I have some > short questions regarding the local state that I couldn't answer while > reading the web page. I would be very happy if someone could answer them > shortly. Here they are: > > > 1) In case of failure, will Samza restore the state automatically on > another node? > > 2) If I want to scale out and increase the number of stream partitions. How > is the local storage handled? Is it distributed by the framework as well > according to the partitions? > > > Cheers, > > Klaus > > > > > -- > > -- > > Klaus Schaefers > Senior Optimization Manager > > Ligatus GmbH > Hohenstaufenring 30-32 > D-50674 Köln > > Tel.: +49 (0) 221 / 56939 -784 > Fax: +49 (0) 221 / 56 939 - 599 > E-Mail: [email protected] > Web: www.ligatus.de > > HRB Köln 56003 > Geschäftsführung: > Dipl.-Kaufmann Lars Hasselbach, Dipl.-Kaufmann Klaus Ludemann, > Dipl.-Wirtschaftsingenieur Arne Wolter > > > > -- > > -- > > Klaus Schaefers > Senior Optimization Manager > > Ligatus GmbH > Hohenstaufenring 30-32 > D-50674 Köln > > Tel.: +49 (0) 221 / 56939 -784 > Fax: +49 (0) 221 / 56 939 - 599 > E-Mail: [email protected] > Web: www.ligatus.de > > HRB Köln 56003 > Geschäftsführung: > Dipl.-Kaufmann Lars Hasselbach, Dipl.-Kaufmann Klaus Ludemann, > Dipl.-Wirtschaftsingenieur Arne Wolter >
