Is there a documentation on that? From what I've read it is local to the node.
On Thu, May 1, 2014 at 11:57 PM, Radu Gheorghe <[email protected]>wrote: > Hi Mohit, > > I think the transaction log takes care of that, because there's a copy on > all instances of the same shard, and they need to be in sync. > > Best regards, > Radu > > -- > Performance Monitoring * Log Analytics * Search Analytics > Solr & Elasticsearch Support * http://sematext.com/ > > > On Thu, May 1, 2014 at 9:57 PM, Mohit Anchlia <[email protected]>wrote: > >> What's not clear is how does elasticsearch identify what pieces of data >> is missing between the primary and the replica? >> >> On Wed, Apr 30, 2014 at 3:27 AM, Radu Gheorghe < >> [email protected]> wrote: >> >>> Hi Mohit, >>> >>> I'll answer inline. >>> >>> On Mon, Apr 28, 2014 at 4:57 PM, Mohit Anchlia >>> <[email protected]>wrote: >>>> >>>>> Trying to understand the following scenarios of consistency in >>>>> elasticsearch: >>>>> >>>>> 1) sync replication - How does elasticsearch deals with consistency >>>>> issue that may arise from 1 node momentarily going down and missing writes >>>>> to it? >>>>> >>>> >>> This depends on the write consistency setting. By default, the operation >>> only succeeds if a quorum of replicas can index the document: >>> >>> http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/docs-index_.html#index-consistency >>> >>> >>>> When the node comes backup and the reads going to the non-primary >>>>> shards could get inconsistent data? >>>>> >>>> >>> No, when the node comes back up it will sync the stuff it missed with >>> the other nodes. >>> >>> >>>> 2) async replication - What happens if replication is slow for some >>>>> reason, could users see inconsistent data? >>>>> >>>> >>> Yes, if you hit a shard that didn't get the latest operation, it could >>> see an "old" version of the data. You can use "preference" to try and hit >>> the primary shard all the time, but then your replicas will just be sitting >>> there for redundancy: >>> >>> http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-request-preference.html >>> >>> >>>> 3) sync/async replication - how does elasticsearch keep data in sync >>>>> for those writes that never happened on the non-primary shard because of >>>>> network/node failures? >>>>> >>>> >>> It either uses the transaction log or it transfers the whole shard to >>> that node. >>> >>> Best regards, >>> Radu >>> -- >>> Performance Monitoring * Log Analytics * Search Analytics >>> Solr & Elasticsearch Support * http://sematext.com/ >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "elasticsearch" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/elasticsearch/CAHXA0_3aJ4qZt47uyjqs0gd6L1Fz0EhLrV_L7jzSFAYOEvz1Nw%40mail.gmail.com<https://groups.google.com/d/msgid/elasticsearch/CAHXA0_3aJ4qZt47uyjqs0gd6L1Fz0EhLrV_L7jzSFAYOEvz1Nw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "elasticsearch" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/elasticsearch/CAOT3TWpdBxiXZgDw5HXdeRPr5oJtnwHTwHNFr2_UoJYobPqzxw%40mail.gmail.com<https://groups.google.com/d/msgid/elasticsearch/CAOT3TWpdBxiXZgDw5HXdeRPr5oJtnwHTwHNFr2_UoJYobPqzxw%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elasticsearch/CAHXA0_3FAEvQGjMWDqSCT6biYJGiMNGSUDJ80QvT1cJXnqtNJg%40mail.gmail.com<https://groups.google.com/d/msgid/elasticsearch/CAHXA0_3FAEvQGjMWDqSCT6biYJGiMNGSUDJ80QvT1cJXnqtNJg%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/CAOT3TWphfOYz%3DkFTH-NR6GeAna1oe3kq1je2Dz4iesePAS%3D%2BMA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
