From f43c8476aa3956d2e0e7bf37a7f5e3b604ed6e06 Mon Sep 17 00:00:00 2001 From: Clinton Gormley Date: Thu, 10 Dec 2015 11:24:25 +0100 Subject: [PATCH] Improvements to network docs --- docs/reference/index.asciidoc | 1 + docs/reference/modules/network.asciidoc | 207 ++++++++++++++++-------- 2 files changed, 141 insertions(+), 67 deletions(-) diff --git a/docs/reference/index.asciidoc b/docs/reference/index.asciidoc index 34d1cba92c0..4acd1f16eab 100644 --- a/docs/reference/index.asciidoc +++ b/docs/reference/index.asciidoc @@ -7,6 +7,7 @@ :jdk: 1.8.0_25 :defguide: https://www.elastic.co/guide/en/elasticsearch/guide/current :plugins: https://www.elastic.co/guide/en/elasticsearch/plugins/master +:javaclient: https://www.elastic.co/guide/en/elasticsearch/client/java-api/master/ :issue: https://github.com/elastic/elasticsearch/issues/ :pull: https://github.com/elastic/elasticsearch/pull/ diff --git a/docs/reference/modules/network.asciidoc b/docs/reference/modules/network.asciidoc index ffce7d61a00..5a710598206 100644 --- a/docs/reference/modules/network.asciidoc +++ b/docs/reference/modules/network.asciidoc @@ -1,102 +1,175 @@ [[modules-network]] -== Basic Settings +== Network Settings -Commonly used network settings: +Elasticsearch binds to localhost only by default. This is sufficient for you +to run a local development server (or even a development cluster, if you start +multiple nodes on the same machine), but you will need to configure some +<> in order to run a real +production cluster across multiple servers. -[cols="<,<",options="header",] -|======================================================================= -|Name |Description -|`network.host` |Host to bind and publish to other nodes. Accepts an IP address, hostname, or special value (see table below). Defaults to `_local_`. - -|`discovery.zen.ping.unicast.hosts`|Initial list of other nodes. Accepts IP addresses or hostnames. Defaults to `["127.0.0.1", "[::1]"]`. - -|`http.port` |Port to bind for incoming http requests. Accepts a single value or a range. Defaults to `9200-9300`. - -|`transport.tcp.port` |Port to bind for communication between nodes. Accepts a single value or a range. Defaults to `9300-9400`. -|======================================================================= - -Be careful with network configuration! Never expose an unprotected instance -to the public internet. +[WARNING] +.Be careful with the network configuration! +============================= +Never expose an unprotected node to the public internet. +============================= [float] -[[special-values]] +[[common-network-settings]] +=== Commonly Used Network Settings + +`network.host`:: + +The node will bind to this hostname or IP address and _publish_ (advertise) +this host to other nodes in the cluster. Accepts an IP address, hostname, or a +<>. ++ +Defaults to `_local_`. + +`discovery.zen.ping.unicast.hosts`:: + +In order to join a cluster, a node needs to know the hostname or IP address of +at least some of the other nodes in the cluster. This settting provides the +initial list of other nodes that this node will try to contact. Accepts IP +addresses or hostnames. ++ +Defaults to `["127.0.0.1", "[::1]"]`. + +`http.port`:: + +Port to bind to for incoming HTTP requests. Accepts a single value or a range. +If a range is specified, the node will bind to the first available port in the +range. ++ +Defaults to `9200-9300`. + +`transport.tcp.port`:: + +Port to bind for communication between nodes. Accepts a single value or a +range. If a range is specified, the node will bind to the first available port +in the range. ++ +Defaults to `9300-9400`. + +[float] +[[network-interface-values]] === Special values for `network.host` -[cols="<,<",options="header",] -|======================================================================= -|Special Host Value |Description -|`_[networkInterface]_` |Addresses of a network interface, for example `_en0_`. +The following special values may be passed to `network.host`: -|`_local_` |Any loopback addresses on the system, for example `127.0.0.1`. +[horizontal] +`_[networkInterface]_`:: -|`_site_` |Any site-local addresses on the system, for example `192.168.0.1`. + Addresses of a network interface, for example `_en0_`. -|`_global_` |Any globally-scoped addresses on the system, for example `8.8.8.8`. -|======================================================================= +`_local_`:: -These special values will work over both IPv4 and IPv6 by default, -but you can also limit this with the use of `:ipv4` of `:ipv6` specifiers. For -example, `_en0:ipv4_` would only bind to the IPv4 addresses of interface `en0`. + Any loopback addresses on the system, for example `127.0.0.1`. -When the `discovery-ec2` plugin is installed, you can use -{plugins}/discovery-ec2-discovery.html#discovery-ec2-network-host[ec2 specific host settings]. +`_site_`:: + + Any site-local addresses on the system, for example `192.168.0.1`. + +`_global_`:: + + Any globally-scoped addresses on the system, for example `8.8.8.8`. -When the `discovery-gce` plugin is installed, you can use -{plugins}/discovery-gce-network-host.html[gce specific host settings]. [float] -[[advanced]] +==== IPv4 vs IPv6 + +These special values will work over both IPv4 and IPv6 by default, but you can +also limit this with the use of `:ipv4` of `:ipv6` specifiers. For example, +`_en0:ipv4_` would only bind to the IPv4 addresses of interface `en0`. + +[TIP] +.Discovery in the cloud +================================ + +More special settings are available when running in the cloud with either the +{plugins}/discovery-ec2-discovery.html#discovery-ec2-network-host[EC2 discovery plugin] or the +{plugins}/discovery-gce-network-host.html#discovery-gce-network-host[Google Compute Engine discovery plugin] +installed. + +================================ + +[float] +[[advanced-network-settings]] === Advanced network settings -`network.bind_host` and `network.publish_host` can be set instead of `network.host` -for advanced cases such as when behind a proxy server. +The `network.host` setting explained in <> +is a shortcut which sets the _bind host_ and the _publish host_ at the same +time. In advanced used cases, such as when running behind a proxy server, you +may need to set these settings to different values: -`network.bind_host` sets the host different network -components will bind on. +`network.bind_host`:: -`network.publish_host` sets the host the node will -publish itself within the cluster so other nodes will be able to connect to it. -Currently an elasticsearch node may be bound to multiple addresses, but only -publishes one. If not specified, this defaults to the "best" address from -`network.bind_host`, sorted by IPv4/IPv6 stack preference, then by reachability. +This specifies which network interface(s) a node should bind to in order to +listen for incoming requests. A node can bind to multiple interfaces, e.g. +two network cards, or a site-local address and a local address. Defaults to +`network.host`. -Both settings can be configured just like `network.host`: they accept ip -addresses, host names, and special values. +`network.publish_host`:: + +The publish host is the single interface that the node advertises to other +nodes in the cluster, so that those nodes can connect to it. Currently an +elasticsearch node may be bound to multiple addresses, but only publishes one. +If not specified, this defaults to the ``best'' address from +`network.bind_host`, sorted by IPv4/IPv6 stack preference, then by +reachability. + +Both of the above settings can be configured just like `network.host` -- they +accept IP addresses, host names, and +<>. [float] [[tcp-settings]] === Advanced TCP Settings -Any component that uses TCP (like the HTTP, Transport and Memcached) -share the following allowed settings: +Any component that uses TCP (like the <> and +<> modules) share the following settings: -[cols="<,<",options="header",] -|======================================================================= -|Setting |Description -|`network.tcp.no_delay` |Enable or disable tcp no delay setting. +[horizontal] +`network.tcp.no_delay`:: + +Enable or disable the https://en.wikipedia.org/wiki/Nagle%27s_algorithm[TCP no delay] +setting. Defaults to `true`. + +`network.tcp.keep_alive`:: + +Enable or disable https://en.wikipedia.org/wiki/Keepalive[TCP keep alive]. Defaults to `true`. -|`network.tcp.keep_alive` |Enable or disable tcp keep alive. Defaults -to `true`. +`network.tcp.reuse_address`:: -|`network.tcp.reuse_address` |Should an address be reused or not. -Defaults to `true` on non-windows machines. +Should an address be reused or not. Defaults to `true` on non-windows +machines. -|`network.tcp.send_buffer_size` |The size of the tcp send buffer size -(in size setting format). By default not explicitly set. +`network.tcp.send_buffer_size`:: -|`network.tcp.receive_buffer_size` |The size of the tcp receive buffer -size (in size setting format). By default not explicitly set. -|======================================================================= +The size of the TCP send buffer (specified with <>). +By default not explicitly set. + +`network.tcp.receive_buffer_size`:: + +The size of the TCP receive buffer (specified with <>). +By default not explicitly set. [float] -[[module-settings]] -=== Module-specific Settings +=== Transport and HTTP protocols -There are several modules within a Node that use network based -configuration, for example, the -<> and -<> modules. Node level -network settings allows to set common settings that will be shared among -all network based modules (unless explicitly overridden in each module). +An Elasticsearch node exposes two network protocols which inherit the above +settings, but may be further configured independently: + +TCP Transport:: + +Used for communication between nodes in the cluster and by the Java +{javaclient}/node-client.html[Node client], +{javaclient}/transport-client.html[Transport client], and by the +<>. See the <> +for more information. + +HTTP:: + +Exposes the JSON-over-HTTP interface used by all clients other than the Java +clients. See the <> for more information.