Thanks for sharing, Brice. That is an important finding. On Wed, Dec 2, 2015 at 2:23 PM, Brice Figureau <brice...@daysofwonder.com> wrote:
> On 18/02/2014 21:39, dpenn...@good-cloud.com wrote: > > I would assume that a common scenario is to periodically snapshot state > > and keep 1 or more snapshots. In this case, I assume that as you delete > > older snapshots, you would also delete messages older than the snapshot > > from the journal in order to keep the journal from growing indefinitely. > > > > Is this a typical usage or am I missing something? I don't see anything > > in the code that automatically does this (and I didn't really expect to > > given the general flexibility theme of the framework). However, I don't > > see anything in the documentation that alludes to any other use of > > deleteMessage other than in dealing with exceptions. > > I thought it would be the good idea to do so, and I was doing this > beforehand. > > But if you're using the Cassandra journal as I do, be aware that > deleting past events produces tombstones that are removed only after > gc_grace_seconds and a major compaction happens (or a minor one that > removes tombstones). Until that time, those tombstones will hurt your > reads quite hard from what I've found (and it's more than certainly > related to the static column). This was the issue for me, because I had > several PersistentView that were doing a constant replay of some of the > more prolific PersistentActor, up to the point where the replaying > cassandra query was taking more time than the view refresh rate, and > thus the cassandra journal was sending more and more read requests, up > to the point where the cassandra cluster couldn't follow anymore and was > using more 100% CPU, dropping writes. > > I fixed the problem by not doing any deletion at the expense of using > more and more disk space. I will probably do the deletion in a > controlled way (and making sure we can run a user compaction just after). > > HTH, > -- > Brice Figureau > My Blog: http://www.masterzen.fr/ > > -- > >>>>>>>>>> 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 akka-user+unsubscr...@googlegroups.com. > To post to this group, send email to akka-user@googlegroups.com. > Visit this group at http://groups.google.com/group/akka-user. > For more options, visit https://groups.google.com/d/optout. > -- Patrik Nordwall Typesafe <http://typesafe.com/> - Reactive apps on the JVM Twitter: @patriknw -- >>>>>>>>>> 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 akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at https://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.
