Remote cluster settings
editRemote cluster settings
editThe following settings apply to both sniff mode and proxy mode. Settings that are specific to sniff mode and proxy mode are described separately.
-
cluster.remote.<cluster_alias>.mode
-
The mode used for a remote cluster connection. The only supported modes are
sniff
andproxy
. The default issniff
. See Connection modes for further information about these modes, and Sniff mode remote cluster settings and Proxy mode remote cluster settings for further information about their settings. -
cluster.remote.initial_connect_timeout
-
The time to wait for remote connections to be established when the node
starts. The default is
30s
. -
remote_cluster_client
role -
By default, any node in the cluster can act as a cross-cluster client and
connect to remote clusters. To prevent a node from connecting to remote
clusters, specify the node.roles setting in
elasticsearch.yml
and excluderemote_cluster_client
from the listed roles. Search requests targeting remote clusters must be sent to a node that is allowed to act as a cross-cluster client. Other features such as machine learning data feeds, transforms, and cross-cluster replication require theremote_cluster_client
role. -
cluster.remote.<cluster_alias>.skip_unavailable
- Per cluster boolean setting that allows to skip specific clusters when no nodes belonging to them are available and they are the target of a remote cluster request.
In Elasticsearch 8.15, the default value for skip_unavailable
was
changed from false
to true
. Before Elasticsearch 8.15, if you want a cluster
to be treated as optional for a cross-cluster search, then you need to set that configuration.
From Elasticsearch 8.15 forward, you need to set the configuration in order to
make a cluster required for the cross-cluster search. Once you upgrade the local ("querying")
cluster search coordinator node (the node you send CCS requests to) to 8.15 or later,
any remote clusters that do not have an explicit setting for skip_unavailable
will
immediately change over to using the new default of true. This is true regardless of
whether you have upgraded the remote clusters to 8.15, as the skip_unavailable
search behavior is entirely determined by the setting on the local cluster where
you configure the remotes.
-
cluster.remote.<cluster_alias>.transport.ping_schedule
-
Sets the time interval between regular application-level ping messages that
are sent to try and keep remote cluster connections alive. If set to
-1
, application-level ping messages to this remote cluster are not sent. If unset, application-level ping messages are sent according to the globaltransport.ping_schedule
setting, which defaults to-1
meaning that pings are not sent. It is preferable to correctly configure TCP keep-alives instead of configuring aping_schedule
, because TCP keep-alives are handled by the operating system and not by Elasticsearch. By default Elasticsearch enables TCP keep-alives on remote cluster connections. Remote cluster connections are transport connections so thetransport.tcp.*
advanced settings regarding TCP keep-alives apply to them. -
cluster.remote.<cluster_alias>.transport.compress
-
Per-cluster setting that enables you to configure compression for requests to
a specific remote cluster. The handling cluster will automatically compress
responses to compressed requests. The setting options are
true
,indexing_data
, andfalse
. If unset, defaults to the behaviour specified by the node-widetransport.compress
setting. See the documentation for thetransport.compress
setting for further information. -
cluster.remote.<cluster_alias>.transport.compression_scheme
-
Per-cluster setting that enables you to configure the compression scheme for
requests to a specific cluster if those requests are selected to be
compressed by to the
cluster.remote.<cluster_alias>.transport.compress
setting. The handling cluster will automatically use the same compression scheme for responses as for the corresponding requests. The setting options aredeflate
andlz4
. If unset, defaults to the behaviour specified by the node-widetransport.compression_scheme
setting. See the documentation for thetransport.compression_scheme
setting for further information.
-
cluster.remote.<cluster_alias>.credentials
- (Secure, Reloadable) Per-cluster setting for configuring remote clusters with the API Key based model. This setting takes the encoded value of a cross-cluster API key and must be set in the Elasticsearch keystore on each node in the cluster. The presence (or not) of this setting determines which model a remote cluster uses. If present, the remote cluster uses the API key based model. Otherwise, it uses the certificate based model. If the setting is added, removed, or updated in the Elasticsearch keystore and reloaded via the Nodes reload secure settings API, the cluster will automatically rebuild its connection to the remote.
Sniff mode remote cluster settings
editTo use sniff mode to connect to a remote cluster, set
cluster.remote.<cluster_alias>.mode: sniff
and then configure the following
settings. You may also leave cluster.remote.<cluster_alias>.mode
unset since
sniff
is the default mode.
-
cluster.remote.<cluster_alias>.seeds
- The list of seed nodes used to sniff the remote cluster state.
-
cluster.remote.<cluster_alias>.node_connections
-
The number of gateway nodes to connect to for this remote cluster. The default
is
3
.
Proxy mode remote cluster settings
editTo use proxy mode to connect to a remote cluster, set
cluster.remote.<cluster_alias>.mode: proxy
and then configure the following
settings.
-
cluster.remote.<cluster_alias>.proxy_address
- The address used for all remote connections.
-
cluster.remote.<cluster_alias>.proxy_socket_connections
-
The number of socket connections to open per remote cluster. The default is
18
.
-
cluster.remote.<cluster_alias>.server_name
-
An optional hostname string which is sent in the
server_name
field of the TLS Server Name Indication extension if TLS is enabled. The TLS transport will fail to open remote connections if this field is not a valid hostname as defined by the TLS SNI specification.