But this is just one single actor in a much bigger system... In total the event log is growing with 4 GB each day. This is, however, not optmized at all, and we could probably save a lot of space by being smarter about what we persist...
I see no reason to leave the data in the event log, as we have snapshots. Also, when we change the classes we persist, the old events in the store will probably be incompatible with the new actors. The only reason I can think of for not deleting anything, is that it is an expensive operation. Are you saying you generally never delete anything from the event store, at all? Or do you delete manually when needed? Anders On 24 July 2015 at 10:33, Viktor Klang <[email protected]> wrote: > > 20k/h is 5.5 per second and given about 1kb per event, that is about 20mb > per hour, > this is 480mb per day, which is about 171gb per year, > which, according to this means that it will cost you about $5.13 per year > (going down). > > Given compression, you could most probably get it down to about 25% of that. > > Are you sure you are optimizing for the right thing here? > > On Fri, Jul 24, 2015 at 10:23 AM, Anders Båtstrand <[email protected]> > wrote: >> >> I do delete after snapshot, so the functionality is intact. >> >> What do you do about disk usage, and startup time? These actors never >> die, so the event log would grow by 20'000 events each hour forever... >> >> Anders >> >> On 24 July 2015 at 05:25, Vaughn Vernon <[email protected]> wrote: >> > As a rule you should never delete messages/events from the store. I am >> > not >> > sure of the original motivation for allowing deletes, but for event >> > sourcing >> > it shouldn't happen ever. >> > >> > Vaughn >> > >> > >> > On Thursday, July 23, 2015 at 6:52:32 AM UTC-6, Anders Båtstrand wrote: >> >> >> >> Dear group >> >> >> >> I am quite new to Akka persistence, and very new to Cassandra. The >> >> combination is working fine, however, except one problem: Mass >> >> deletions and >> >> compaction. >> >> >> >> It seems, if I understood Cassandra correctly, that my usage is an >> >> anti-pattern (*). I have actors that read a lot of messages, and >> >> persist a >> >> hash of them (for duplicate detection). Every hour I take a snapshot, >> >> and >> >> deletes old messages. It is about 20'000 messages each hour (for each >> >> actor, >> >> does not seem much to me). But I guess this way of using Akka >> >> Persistence is >> >> quite typical? >> >> >> >> After a while, the deletes start to time out, and compaction is taking >> >> a >> >> really long time. >> >> >> >> As I understood it, DTCS (Date-Tiered Compaction Strategy) (+) should >> >> be >> >> more suited, since data is inserted in order, and deleted from the end. >> >> >> >> Is this correct? Has any of you problems with compactions, done some >> >> testing etc? Any experience on the matter? >> >> >> >> Best regards, >> >> >> >> Anders Båtstrand >> >> >> >> Links: >> >> >> >> * >> >> >> >> http://www.datastax.com/dev/blog/cassandra-anti-patterns-queues-and-queue-like-datasets >> >> + http://www.datastax.com/dev/blog/datetieredcompactionstrategy >> >> -- >> >>>>>>>>>> Read the docs: http://akka.io/docs/ >> >>>>>>>>>> Check the FAQ: >> >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >> >>>>>>>>>> Search the archives: >> >>>>>>>>>> https://groups.google.com/group/akka-user >> --- >> You received this message because you are subscribed to the Google Groups >> "Akka User List" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/akka-user. >> For more options, visit https://groups.google.com/d/optout. > > > > > -- > Cheers, > √ > > -- >>>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>>> Check the FAQ: >>>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user > --- > You received this message because you are subscribed to a topic in the > Google Groups "Akka User List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/akka-user/BETNfkbXvgw/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/akka-user. > For more options, visit https://groups.google.com/d/optout. -- >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
