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 basic network settings in order to run a real production cluster across multiple servers.
Be careful with the network configuration!
Never expose an unprotected node to the public internet.
Commonly Used Network Settingsedit
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, a special value, or an array of any combination of these. Note that any values containing a
:(e.g., an IPv6 address or containing one of the special value) must be quoted because
:is a special character in YAML.
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 setting provides the initial list of other nodes that this node will try to contact. Accepts IP addresses or hostnames. If a hostname lookup resolves to multiple IP addresses then each IP address will be used for discovery. Round robin DNS — returning a different IP from a list on each lookup — can be used for discovery; non- existent IP addresses will throw exceptions and cause another DNS lookup on the next round of pinging (subject to JVM DNS caching).
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.
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.
Special values for
The following special values may be passed to
Addresses of a network interface, for example
Any loopback addresses on the system, for example
Any site-local addresses on the system, for example
Any globally-scoped addresses on the system, for example
IPv4 vs IPv6edit
These special values will work over both IPv4 and IPv6 by default, but you can
also limit this with the use of
:ipv6 specifiers. For example,
_en0:ipv4_ would only bind to the IPv4 addresses of interface
Advanced network settingsedit
network.host setting explained in Commonly used network settings
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:
- 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
- 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.host, sorted by IPv4/IPv6 stack preference, then by reachability. If you set a
network.hostthat results in multiple bind addresses yet rely on a specific address for node-to-node communication, you should explicitly set
Both of the above settings can be configured just like
network.host — they
accept IP addresses, host names, and
Advanced TCP Settingsedit
Enable or disable the TCP no delay
setting. Defaults to
Enable or disable TCP keep alive.
Should an address be reused or not. Defaults to
The size of the TCP send buffer (specified with size units). By default not explicitly set.
The size of the TCP receive buffer (specified with size units). By default not explicitly set.
Transport and HTTP protocolsedit
An Elasticsearch node exposes two network protocols which inherit the above settings, but may be further configured independently: