If you are running more than one instances of Graylog server you have to select one of these
instances as master. The master will perform some periodical tasks that non-masters won’t perform.
is_master = true
The auto-generated node ID will be stored in this file and read after restarts. It is a good idea
to use an absolute file path here if you are starting Graylog server from init scripts or similar.
node_id_file = /usr/share/graylog/data/config/node-id
You MUST set a secret to secure/pepper the stored user passwords here. Use at least 64 characters.
Generate one by using for example: pwgen -N 1 -s 96
password_secret = replacethiswithyourownsecret!
The default root user is named ‘admin’
root_username = admin
You MUST specify a hash password for the root user (which you only need to initially set up the
system and in case you lose connectivity to your authentication backend)
This password cannot be changed using the API or via the web interface. If you need to change it,
modify it in this file.
Create one by using for example: echo -n yourpassword | shasum -a 256
and put the resulting hash value into the following line
root_password_sha2 = 8c6976e5b5410415bde908bd4dee15dfb167a9c873fc4bb8a81f6f2ab448a918
The email address of the root user.
Default is empty
root_email = “”
The time zone setting of the root user.
The configured time zone must be parseable by DateTimeZone (Joda-Time 2.12.5 API) forID-java.lang.String-
Default is UTC
root_timezone = UTC
Set plugin directory here (relative or absolute)
plugin_dir = /usr/share/graylog/plugin
REST API listen URI. Must be reachable by other Graylog server nodes if you run a cluster.
When using Graylog Collectors, this URI will be used to receive heartbeat messages and must be accessible for all collectors.
rest_listen_uri = http://0.0.0.0:9000/api/
REST API transport address. Defaults to the value of rest_listen_uri. Exception: If rest_listen_uri
is set to a wildcard IP address (0.0.0.0) the first non-loopback IPv4 system address is used.
If set, this will be promoted in the cluster discovery APIs, so other nodes may try to connect on
this address and it is used to generate URLs addressing entities in the REST API. (see rest_listen_uri)
You will need to define this, if your Graylog server is running behind a HTTP proxy that is rewriting
the scheme, host name or URI.
rest_transport_uri = http://192.168.1.1:9000/api/
Enable CORS headers for REST API. This is necessary for JS-clients accessing the server directly.
If these are disabled, modern browsers will not be able to retrieve resources from the server.
This is enabled by default. Uncomment the next line to disable it.
rest_enable_cors = false
Enable GZIP support for REST API. This compresses API responses and therefore helps to reduce
overall round trip times. This is disabled by default. Uncomment the next line to enable it.
rest_enable_gzip = true
Enable HTTPS support for the REST API. This secures the communication with the REST API with
TLS to prevent request forgery and eavesdropping. This is disabled by default. Uncomment the
next line to enable it.
rest_enable_tls = true
The X.509 certificate file to use for securing the REST API.
rest_tls_cert_file = /path/to/graylog.crt
The private key to use for securing the REST API.
rest_tls_key_file = /path/to/graylog.key
The password to unlock the private key used for securing the REST API.
rest_tls_key_password = secret
The maximum size of the HTTP request headers in bytes.
rest_max_header_size = 8192
The maximal length of the initial HTTP/1.1 line in bytes.
rest_max_initial_line_length = 4096
The size of the thread pool used exclusively for serving the REST API.
rest_thread_pool_size = 16
Enable the embedded Graylog web interface.
Default: true
web_enable = false
Web interface listen URI
web_listen_uri = http://0.0.0.0:9000/
web_listen_uri = http://172.16.100.11:9000/
Enable CORS headers for the web interface. This is necessary for JS-clients accessing the server directly.
If these are disabled, modern browsers will not be able to retrieve resources from the server.
web_enable_cors = true
Enable/disable GZIP support for the web interface. This compresses HTTP responses and therefore helps to reduce
overall round trip times. This is enabled by default. Uncomment the next line to disable it.
web_enable_gzip = false
Enable HTTPS support for the web interface. This secures the communication of the web browser with the web interface
using TLS to prevent request forgery and eavesdropping.
This is disabled by default. Uncomment the next line to enable it and see the other related configuration settings.
web_enable_tls = true
The X.509 certificate file to use for securing the web interface.
web_tls_cert_file = /path/to/graylog-web.crt
The private key to use for securing the web interface.
web_tls_key_file = /path/to/graylog-web.key
The password to unlock the private key used for securing the web interface.
web_tls_key_password = secret
The maximum size of the HTTP request headers in bytes.
web_max_header_size = 8192
The maximal length of the initial HTTP/1.1 line in bytes.
web_max_initial_line_length = 4096
The size of the thread pool used exclusively for serving the web interface.
web_thread_pool_size = 16
Embedded Elasticsearch configuration file
pay attention to the working directory of the server, maybe use an absolute path here
elasticsearch_config_file = /usr/share/graylog/data/config/elasticsearch.yml
Graylog will use multiple indices to store documents in. You can configured the strategy it uses to determine
when to rotate the currently active write index.
It supports multiple rotation strategies:
- “count” of messages per index, use elasticsearch_max_docs_per_index below to configure
- “size” per index, use elasticsearch_max_size_per_index below to configure
valid values are “count”, “size” and “time”, default is “count”
rotation_strategy = count
(Approximate) maximum number of documents in an Elasticsearch index before a new index
is being created, also see no_retention and elasticsearch_max_number_of_indices.
Configure this if you used ‘rotation_strategy = count’ above.
elasticsearch_max_docs_per_index = 20000000
(Approximate) maximum size in bytes per Elasticsearch index on disk before a new index is being created, also see
no_retention and elasticsearch_max_number_of_indices. Default is 1GB.
Configure this if you used ‘rotation_strategy = size’ above.
elasticsearch_max_size_per_index = 1073741824
(Approximate) maximum time before a new Elasticsearch index is being created, also see
no_retention and elasticsearch_max_number_of_indices. Default is 1 day.
Configure this if you used ‘rotation_strategy = time’ above.
Please note that this rotation period does not look at the time specified in the received messages, but is
using the real clock value to decide when to rotate the index!
Specify the time using a duration and a suffix indicating which unit you want:
1w = 1 week
1d = 1 day
12h = 12 hours
Permitted suffixes are: d for day, h for hour, m for minute, s for second.
elasticsearch_max_time_per_index = 1d
Disable checking the version of Elasticsearch for being compatible with this Graylog release.
WARNING: Using Graylog with unsupported and untested versions of Elasticsearch may lead to data loss!
elasticsearch_disable_version_check = true
Disable message retention on this node, i. e. disable Elasticsearch index rotation.
no_retention = false
How many indices do you want to keep?
elasticsearch_max_number_of_indices = 20
Decide what happens with the oldest indices when the maximum number of indices is reached.
The following strategies are availble:
- delete Deletes the index completely (Default)
- close Closes the index and hides it from the system. Can be re-opened later.
retention_strategy = delete
How many Elasticsearch shards and replicas should be used per index? Note that this only applies to newly created indices.
elasticsearch_shards = 4
elasticsearch_replicas = 0
Prefix for all Elasticsearch indices and index aliases managed by Graylog.
elasticsearch_index_prefix = graylog
Name of the Elasticsearch index template used by Graylog to apply the mandatory index mapping.
Default: graylog-internal
elasticsearch_template_name = graylog-internal
Do you want to allow searches with leading wildcards? This can be extremely resource hungry and should only
be enabled with care. See also: Graylog Documentation
allow_leading_wildcard_searches = true
Do you want to allow searches to be highlighted? Depending on the size of your messages this can be memory hungry and
should only be enabled after making sure your Elasticsearch cluster has enough memory.
allow_highlighting = true
settings to be passed to elasticsearch’s client (overriding those in the provided elasticsearch_config_file)
all these
this must be the same as for your Elasticsearch cluster
elasticsearch_cluster_name = graylog
The prefix being used to generate the Elasticsearch node name which makes it easier to identify the specific Graylog
server running the embedded Elasticsearch instance. The node name will be constructed by concatenating this prefix
and the Graylog node ID (see node_id_file), for example “graylog-17052010-1234-5678-abcd-1337cafebabe”.
Default: graylog-
elasticsearch_node_name_prefix = graylog-
we don’t want the Graylog server to store any data, or be master node
elasticsearch_node_master = false
elasticsearch_node_data = false
use a different port if you run multiple Elasticsearch nodes on one machine
elasticsearch_transport_tcp_port = 9350
we don’t need to run the embedded HTTP server here
elasticsearch_http_enabled = false
elasticsearch_discovery_zen_ping_multicast_enabled = false
elasticsearch_discovery_zen_ping_unicast_hosts = elasticsearch:9300
Change the following setting if you are running into problems with timeouts during Elasticsearch cluster discovery.
The setting is specified in milliseconds, the default is 5000ms (5 seconds).
elasticsearch_cluster_discovery_timeout = 5000
the following settings allow to change the bind addresses for the Elasticsearch client in Graylog
these settings are empty by default, letting Elasticsearch choose automatically,
override them here or in the ‘elasticsearch_config_file’ if you need to bind to a special address
refer to Elasticsearch Platform — Find real-time answers at scale | Elastic
for special values here
elasticsearch_network_host = 0.0.0.0
elasticsearch_network_bind_host =
elasticsearch_network_publish_host =
The total amount of time discovery will look for other Elasticsearch nodes in the cluster
before giving up and declaring the current node master.
elasticsearch_discovery_initial_state_timeout = 3s
Analyzer (tokenizer) to use for message and full_message field. The “standard” filter usually is a good idea.
All supported analyzers are: standard, simple, whitespace, stop, keyword, pattern, language, snowball, custom
Elasticsearch documentation: Elasticsearch Platform — Find real-time answers at scale | Elastic
Note that this setting only takes effect on newly created indices.
elasticsearch_analyzer = standard
Global request timeout for Elasticsearch requests (e. g. during search, index creation, or index time-range
calculations) based on a best-effort to restrict the runtime of Elasticsearch operations.
Default: 1m
elasticsearch_request_timeout = 1m
Time interval for index range information cleanups. This setting defines how often stale index range information
is being purged from the database.
Default: 1h
index_ranges_cleanup_interval = 1h
Batch size for the Elasticsearch output. This is the maximum (!) number of messages the Elasticsearch output
module will get at once and write to Elasticsearch in a batch call. If the configured batch size has not been
reached within output_flush_interval seconds, everything that is available will be flushed at once. Remember
that every outputbuffer processor manages its own batch and performs its own batch write calls.
(“outputbuffer_processors” variable)
output_batch_size = 500
Flush interval (in seconds) for the Elasticsearch output. This is the maximum amount of time between two
batches of messages written to Elasticsearch. It is only effective at all if your minimum number of messages
for this time period is less than output_batch_size * outputbuffer_processors.
output_flush_interval = 1
As stream outputs are loaded only on demand, an output which is failing to initialize will be tried over and
over again. To prevent this, the following configuration options define after how many faults an output will
not be tried again for an also configurable amount of seconds.
output_fault_count_threshold = 5
output_fault_penalty_seconds = 30
The number of parallel running processors.
Raise this number if your buffers are filling up.
processbuffer_processors = 5
outputbuffer_processors = 3
outputbuffer_processor_keep_alive_time = 5000
outputbuffer_processor_threads_core_pool_size = 3
outputbuffer_processor_threads_max_pool_size = 30
UDP receive buffer size for all message inputs (e. g. SyslogUDPInput).
udp_recvbuffer_sizes = 1048576
Wait strategy describing how buffer processors wait on a cursor sequence. (default: sleeping)
Possible types:
- yielding
Compromise between performance and CPU usage.
- sleeping
Compromise between performance and CPU usage. Latency spikes can occur after quiet periods.
- blocking
High throughput, low latency, higher CPU usage.
- busy_spinning
Avoids syscalls which could introduce latency jitter. Best when threads can be bound to specific CPU cores.
processor_wait_strategy = blocking
Size of internal ring buffers. Raise this if raising outputbuffer_processors does not help anymore.
For optimum performance your LogMessage objects in the ring buffer should fit in your CPU L3 cache.
Start server with --statistics flag to see buffer utilization.
Must be a power of 2. (512, 1024, 2048, …)
ring_size = 65536
inputbuffer_ring_size = 65536
inputbuffer_processors = 2
inputbuffer_wait_strategy = blocking
Enable the disk based message journal.
message_journal_enabled = true
The directory which will be used to store the message journal. The directory must me exclusively used by Graylog and
must not contain any other files than the ones created by Graylog itself.
message_journal_dir = /usr/share/graylog/data/journal
Journal hold messages before they could be written to Elasticsearch.
For a maximum of 12 hours or 5 GB whichever happens first.
During normal operation the journal will be smaller.
message_journal_max_age = 12h
message_journal_max_size = 5gb
message_journal_flush_age = 1m
message_journal_flush_interval = 1000000
message_journal_segment_age = 1h
message_journal_segment_size = 100mb
Number of threads used exclusively for dispatching internal events. Default is 2.
async_eventbus_processors = 2
How many seconds to wait between marking node as DEAD for possible load balancers and starting the actual
shutdown process. Set to 0 if you have no status checking load balancers in front.
lb_recognition_period_seconds = 3
Every message is matched against the configured streams and it can happen that a stream contains rules which
take an unusual amount of time to run, for example if its using regular expressions that perform excessive backtracking.
This will impact the processing of the entire server. To keep such misbehaving stream rules from impacting other
streams, Graylog limits the execution time for each stream.
The default values are noted below, the timeout is in milliseconds.
If the stream matching for one stream took longer than the timeout value, and this happened more than “max_faults” times
that stream is disabled and a notification is shown in the web interface.
stream_processing_timeout = 2000
stream_processing_max_faults = 3
Length of the interval in seconds in which the alert conditions for all streams should be checked
and alarms are being sent.
alert_check_interval = 60
Since 0.21 the Graylog server supports pluggable output modules. This means a single message can be written to multiple
outputs. The next setting defines the timeout for a single output module, including the default output module where all
messages end up.
Time in milliseconds to wait for all message outputs to finish writing a single message.
output_module_timeout = 10000
Time in milliseconds after which a detected stale master node is being rechecked on startup.
stale_master_timeout = 2000
Time in milliseconds which Graylog is waiting for all threads to stop on shutdown.
shutdown_timeout = 30000
MongoDB connection string
See http://docs.mongodb.org/manual/reference/connection-string/ for details
mongodb_uri = mongodb://mongo/graylog
Authenticate against the MongoDB server
mongodb_uri = mongodb://grayloguser:secret@localhost:27017/graylog
Use a replica set instead of a single host
mongodb_uri = mongodb://grayloguser:secret@localhost:27017,localhost:27018,localhost:27019/graylog
Increase this value according to the maximum connections your MongoDB server can handle from a single client
if you encounter MongoDB connection problems.
mongodb_max_connections = 100
Number of threads allowed to be blocked by MongoDB connections multiplier. Default: 5
If mongodb_max_connections is 100, and mongodb_threads_allowed_to_block_multiplier is 5,
then 500 threads can block. More than that and an exception will be thrown.
http://api.mongodb.org/java/current/com/mongodb/MongoOptions.html threadsAllowedToBlockForConnectionMultiplier
mongodb_threads_allowed_to_block_multiplier = 5
Drools Rule File (Use to rewrite incoming log messages)
See: Graylog Documentation
rules_file = /etc/graylog/server/rules.drl
Email transport
transport_email_enabled = false
transport_email_hostname = mail.example.com
transport_email_port = 587
transport_email_use_auth = true
transport_email_use_tls = true
transport_email_use_ssl = true
transport_email_auth_username = you@example.com
transport_email_auth_password = secret
transport_email_subject_prefix = [graylog]
transport_email_from_email = graylog@example.com
Specify and uncomment this if you want to include links to the stream in your stream alert mails.
This should define the fully qualified base url to your web interface exactly the same way as it is accessed by your users.
transport_email_web_interface_url = https://graylog.example.com
The default connect timeout for outgoing HTTP connections.
Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
Default: 5s
http_connect_timeout = 5s
The default read timeout for outgoing HTTP connections.
Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
Default: 10s
http_read_timeout = 10s
The default write timeout for outgoing HTTP connections.
Values must be a positive duration (and between 1 and 2147483647 when converted to milliseconds).
Default: 10s
http_write_timeout = 10s
HTTP proxy for outgoing HTTP connections
http_proxy_uri =
Disable the optimization of Elasticsearch indices after index cycling. This may take some load from Elasticsearch
on heavily used systems with large indices, but it will decrease search performance. The default is to optimize
cycled indices.
disable_index_optimization = true
Optimize the index down to <= index_optimization_max_num_segments. A higher number may take some load from Elasticsearch
on heavily used systems with large indices, but it will decrease search performance. The default is 1.
index_optimization_max_num_segments = 1
The threshold of the garbage collection runs. If GC runs take longer than this threshold, a system notification
will be generated to warn the administrator about possible problems with the system. Default is 1 second.
gc_warning_threshold = 1s
Connection timeout for a configured LDAP server (e. g. ActiveDirectory) in milliseconds.
ldap_connection_timeout = 2000
Enable collection of Graylog-related metrics into MongoDB
WARNING: This will add a lot of data into your MongoDB database on a regular interval (1 second)!
DEPRECATED: This setting and the respective feature will be removed in a future version of Graylog.
enable_metrics_collection = false
Disable the use of SIGAR for collecting system stats
disable_sigar = false
The default cache time for dashboard widgets. (Default: 10 seconds, minimum: 1 second)
dashboard_widget_default_cache_time = 10s
Automatically load content packs in “content_packs_dir” on the first start of Graylog.
content_packs_loader_enabled = true
The directory which contains content packs which should be loaded on the first start of Graylog.
content_packs_dir = /usr/share/graylog/data/contentpacks
A comma-separated list of content packs (files in “content_packs_dir”) which should be applied on
the first start of Graylog.
content_packs_auto_load = grok-patterns.json
