The default setting of Elasticsearch is replication mode "sync" for good reason, this ensures the replica quorum (which is often determined as "eventual consistency" but this is really something more because it describes properties of the "last-seen" value for update).
Replication setting of "async" does not increase write performance on the cluster, and it also does not enable eventual consistency. In fact it disables the client's visibility of consistency. Replication setting to "async" means an early return to the client who is listening for responses. The responses under "async" mode return immediately after primary shard operations but before any actions on replica shards have been executed. The client can proceed earlier so this may help at the client side if the client wants to finish the indexing process sooner regardless if replica quorum has been reached at that time or not. Jörg On Fri, Jul 4, 2014 at 9:04 AM, Varun Vasan V <[email protected]> wrote: > Thanks for the reply. Yes, In our user case, we only want eventual > consistence in our data across the replicas. Will setting replication to > async increase write performance? Thanks again for helping out. > > > On Fri, Jul 4, 2014 at 12:06 PM, David Pilato <[email protected]> wrote: > >> I know you can do it when indexing using this: >> http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/docs-index_.html#index-replication >> >> Not sure about the index setting. Need to look at code. >> >> That said, are you really sure you want to do this? >> >> -- >> David ;-) >> Twitter : @dadoonet / @elasticsearchfr / @scrutmydocs >> >> >> Le 4 juil. 2014 à 07:22, Varun Vasan V <[email protected]> a écrit : >> >> Hey, >> >> I am trying to set the replication to async. I tried the following. >> >> $ curl -XPOST 'http://localhost:9200/myindex' -d '{ >> >> "settings": { >> >> "replication": "async" >> } >> }' >> >> Is it the correct way to do it? >> >> -- >> 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/cc1fed63-96e5-48d3-b7f1-859d67eb06cd%40googlegroups.com >> <https://groups.google.com/d/msgid/elasticsearch/cc1fed63-96e5-48d3-b7f1-859d67eb06cd%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/FDwvaF7jkyo/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/elasticsearch/191E70E6-3732-471B-82B0-53552DA85E18%40pilato.fr >> <https://groups.google.com/d/msgid/elasticsearch/191E70E6-3732-471B-82B0-53552DA85E18%40pilato.fr?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/CAP1maN7d8fGyoTXSum2LX0O_KsE1Pw1zDDLKgqDONA5D%2Bvikpg%40mail.gmail.com > <https://groups.google.com/d/msgid/elasticsearch/CAP1maN7d8fGyoTXSum2LX0O_KsE1Pw1zDDLKgqDONA5D%2Bvikpg%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/CAKdsXoGwwjQCSRk03_ARd1DLcDb1bHnpiQX2kDg9xgisZwmFCw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
