Elasticsearch Version Compatibility

GRAYLOG VERSION MINIMUM ES VERSION MAXIMUM ES VERSION
2.3.x 2.3.5 5.x

MongoDB Version Compatibility

GRAYLOG VERSION MINIMUM MONGO VERSION MAXIMUM MONGO VERSION
2.3.x 2.4 3.4

Graylog Switches to Elasticsearch HTTP Client

In all prior versions, Graylog used the Elasticsearch node client to connect to an Elasticsearch cluster, which was acting as a client-only Elasticsearch node. For compatibility reasons of the used binary transfer protocol, the range of Elasticsearch versions Graylog could connect to was limited. For more information and differences between the different ways to connect to Elasticsearch, you can check the Elasticsearch documentation.

Starting with version 2.3.0, we are switching over to using a lightweight HTTP client, which is almost version-agnostic. The biggest change is that it does not connect to the Elasticsearch native protocol port (defaulting to 9300/tcp), but the Elasticsearch HTTP port (defaulting to 9200/tcp).

Due to the differences in connecting to the Elasticsearch cluster, configuring Graylog has changed. These configuration settings have been removed:

Copy 
elasticsearch_cluster_discovery_timeout 
elasticsearch_cluster_name 
elasticsearch_config_file 
elasticsearch_discovery_initial_state_timeout 
elasticsearch_discovery_zen_ping_unicast_hosts 
elasticsearch_http_enabled 
elasticsearch_network_bind_host 
elasticsearch_network_host 
elasticsearch_network_publish_host 
elasticsearch_node_data 
elasticsearch_node_master 
elasticsearch_node_name_prefix 
elasticsearch_path_data 
elasticsearch_path_home 
elasticsearch_transport_tcp_port 

The following configuration options are now being used to configure connectivity to Elasticsearch:

Config Setting

Type

Comments

Default

elasticsearch_connect_timeout

Duration

Timeout when connection to individual Elasticsearch hosts

10s (10 Seconds)

elasticsearch_hosts

List<URI>

Comma-separated list of URIs of Elasticsearch hosts

https://127.0.0.1:9200

elasticsearch_idle_timeout

Duration

Timeout after which idle connections are terminated

-1s (Never)

elasticsearch_max_total_connections

int

Maximum number of total Elasticsearch connections

20

elasticsearch_max_total_connections_per_route

int

Maximum number of Elasticsearch connections per route/host

2

elasticsearch_max_retries

int

Maximum number of retries for requests to Elasticsearch

2

elasticsearch_socket_timeout

Duration

Timeout when sending/receiving from Elasticsearch connection

60s (60 Seconds)

elasticsearch_discovery_enabled

boolean

Enable automatic Elasticsearch node discovery

false

elasticsearch_discovery_filter

String

Filter by node attributes for the discovered nodes

empty (use all nodes)

elasticsearch_discovery_frequency

Duration

Frequency of the Elasticsearch node discovery

30s (30 Seconds)

In most cases, the only configuration setting that needs to be set explicitly is elasticsearch_hosts. All other configuration settings should be tweaked only in case of errors.

Warning: The automatic node discovery does not work if Elasticsearch requires authentication, e. g. when using Shield (X-Pack).
Warning:  Graylog does not react to externally triggered index changes (creating/closing/reopening/deleting an index) anymore. All of these actions need to be performed through the Graylog REST API in order to retain index consistency.

Special Note for Upgrading from an Existing Graylog Setup with a New Elasticsearch Cluster

If you are upgrading the Elasticsearch cluster of an existing Graylog setup without migrating the indices, your Graylog setup contains stale index ranges causing non-existing index errors upon search/alerting. To remediate this, you need to manually trigger an index range recalculation for all index sets once. This is possible using the web interface using the System->Indices functionality or by using the REST API using the /system/indices/ranges/<index set id>/rebuildendpoint.

Graylog REST API

Rotation and Retention Strategies

The deprecated HTTP resources at /system/indices/rotation/config
and /system/indices/retention/config, which didn’t work since Graylog 2.2.0, had been removed.

These settings are part of the index set configuration and can be configured under /system/indices/index_sets.

Stream List Response Structure Does Not Include Field Anymore

The response to GET /streams, GET /streams/<id>& PUT /streams/<id>does not contain the in_gracefield for configured alert conditions anymore.

The value of this flag can be retrieved using the GET /alerts/conditionsendpoint, or per stream using the GET /streams/<streamId>/alerts/conditionsendpoint.