Thanks David. Is there any command to check what data is present in each shard?
On 13 March 2014 11:27, David Pilato <da...@pilato.fr> wrote: > Answered inline. > > -- > David ;-) > Twitter : @dadoonet / @elasticsearchfr / @scrutmydocs > > Le 13 mars 2014 à 06:50, Nitesh Earkara <enit...@gmail.com> a écrit : > > Hi, > > I have some basic understanding that shards are distributed across nodes > and there will be replicas for each shard (assuming replica are set up for > each shard). Also that shard and its replica will never exist on same node. > > I have few questions to clear my concepts on shards and replicas > > 1. How does ES divide the data across shards? How does it divide what > data/ how much data should it go to each shard? > > Using a routing value (default is _id) which is hashed and we compute a > modulo based on #of shards. > > 2. Does one shard know what data is present in other shard? > > No. > > 3. If new data gets added to an index/type,how does it decide into which > shard the data should go? Does this happen instantaneously or some indexing > or crawling occur at regular intervals after which data gets added to the > shard? > > I explained it with answer 1. > It's at index time. > > 4. How data is synchronized between replica and shard? If data is added to > shard, how long will it take for it to appear in replica? > > Immediatly by defaut. When you get the response back, you know that your > doc is on every shard it should be. > > > On Wednesday, January 15, 2014 10:08:17 PM UTC+5:30, David Pilato wrote: >> >> It depends. >> >> When you have no replica allocated (default with only one node), then >> replica is first copied over the network and then transaction log is >> replayed for remaining operations. >> When the replica is allocated, each operation (transaction log) is >> replayed on each replica. >> >> About terminology, we don't speak about "replica nodes" but "replica >> shards". Index is split into shards. Shards are allocated on nodes. A shard >> can be a primary or a replica. So on a given node, you can have primary >> shards or replica shards. It does not really matter. >> >> Makes sense? >> >> -- >> *David Pilato* | *Technical Advocate* | *Elasticsearch.com >> <http://Elasticsearch.com>* >> @dadoonet <https://twitter.com/dadoonet> | >> @elasticsearchfr<https://twitter.com/elasticsearchfr> >> >> >> Le 15 janvier 2014 at 16:54:59, Gianluca Bassini (kod...@gmail.com) a >> écrit: >> >> I'm curious about elasticsearch cluster architecture and I didn't find >> any documentation about it. >> >> In particulary I'm interested about how replica nodes works, replica node >> receive operation log from master and performe the same operation (like in >> mongodb replica set) or the replica copy the delta chunk from the master >> like solr >> >> Thanks in advance >> Gianluca >> -- >> 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 elasticsearc...@googlegroups.com. >> To view this discussion on the web visit https://groups.google.com/d/ >> msgid/elasticsearch/04365499-8ea4-4094-9a2d-e4909a76e45f% >> 40googlegroups.com. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> -- > 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 elasticsearch+unsubscr...@googlegroups.com. > > To view this discussion on the web visit > https://groups.google.com/d/msgid/elasticsearch/4fd01399-5055-4883-b2c7-551b4770888a%40googlegroups.com<https://groups.google.com/d/msgid/elasticsearch/4fd01399-5055-4883-b2c7-551b4770888a%40googlegroups.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 a topic in the > Google Groups "elasticsearch" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/elasticsearch/XoAHAgK_G8g/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > elasticsearch+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elasticsearch/746A55B4-5730-4765-9903-7B53A2EE60EB%40pilato.fr<https://groups.google.com/d/msgid/elasticsearch/746A55B4-5730-4765-9903-7B53A2EE60EB%40pilato.fr?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- Thanks & Regards, Nithesh Erakkara enit...@gmail.com +919833742684 -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. 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