A node client is not just a non-data node although very close. The ES page describes a proxy node scenario. Example: you have many HTTP clients and they search for large result sets. This is often a challenge because of the high resource contention. One or more data-less proxy nodes can help in gathering these result sets, letting the data nodes alone, which just do the scatter part of the search.
This is similar to how a TransportClient works for a JVM-only client. TransportClient is also a proxy node that gathers result sets. But with some subtle difference, you can not connect HTTP clients to a TransportClient, and because the TransportClient is not a cluster member, it uses the configured connected nodes as gather nodes within the cluster. Because there are two gather nodes, this is called an "extra hop" in comparison to a Java NodeClient. But, if you add the HTTP client request to the request scenario mentioned before, there is no extra hop, only an extra JVM. So the best place for TransportClient is on a remote host. In Java, NodeClient and TransportClient share the full functionality of ES, routing requests, round-robin for load balancing etc. For cluster-specific server-only services like listening to cluster state, or snapshot/restore, a TransportClient is not feasible, it can't do it or must ask a node in the cluster for passing the information. Jörg On Fri, Aug 29, 2014 at 8:54 PM, John Smith <[email protected]> wrote: > According to this... > > > http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/modules-node.html > > Non data nodes (I assume Node client is equivalent of a non data node) is > capable of scatter/gather searching. Was wondering if transport can do this > also? > > 2- Does transport support routing if you specify routing field? Or does it > always round robin regardless? > On Aug 29, 2014 12:09 PM, "[email protected]" <[email protected]> > wrote: > >> I'm not exactly sure what you mean by scatter-gather, but yes, both >> clients can execute requests on all nodes of the cluster. >> >> Jörg >> >> >> On Fri, Aug 29, 2014 at 3:43 PM, John Smith <[email protected]> >> wrote: >> >>> Just as the subject asks or only the node client can do scatter gather? >>> >>> Thanks >>> >>> -- >>> 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/b5274032-c142-46df-91e2-f451ab9c069e%40googlegroups.com >>> <https://groups.google.com/d/msgid/elasticsearch/b5274032-c142-46df-91e2-f451ab9c069e%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/70zTmEuyWHE/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/CAKdsXoHdeW329GZgvOm3NG0NAuNvEUJftkSMzKTyCAzM1%2B8bFg%40mail.gmail.com >> <https://groups.google.com/d/msgid/elasticsearch/CAKdsXoHdeW329GZgvOm3NG0NAuNvEUJftkSMzKTyCAzM1%2B8bFg%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/CAMiEuFSuCrwaF6qoVf3-rsA_NjQKrJjFue62kjVvoiUH8A2rJA%40mail.gmail.com > <https://groups.google.com/d/msgid/elasticsearch/CAMiEuFSuCrwaF6qoVf3-rsA_NjQKrJjFue62kjVvoiUH8A2rJA%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/CAKdsXoG%3D-7Xwe6N%3DiOK3YiT-a9EmwOAbu4KqGM1xT1Yu_FHsbQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
