Graylog Server Configuration

The file server.conf is the Graylog configuration file.

It has to use ISO 8859-1/Latin-1 character encoding. Characters that cannot be directly represented in this encoding can be written using Unicode escapes as defined in Java SE Specifications, using the u prefix. For example, u002c.

• Entries are generally expected to be a single line of the form, one of the following:
  • propertyName=propertyValue
  • propertyName:propertyValue
• White space that appears between the property name and property value is ignored, so the following are equivalent:
  • name=Stephen
  • name = Stephen
• White space at the beginning of the line is also ignored.
• Lines that start with the comment characters ! or # are ignored. Blank lines are also ignored.
• The property value is generally terminated by the end of the line. White space following the property value is not ignored, and is treated as part of the property value.
• A property value can span several lines if each line is terminated by a backslash (\) character. For example:

targetCities = \       
        Detroit , \       
        Chicago , \       
        Los Angeles

This is equivalent to targetCities=Detroit,Chicago,Los Angeles (white space at the beginning of lines is ignored).

• The characters newline, carriage return, and tab can be inserted with characters \n, \r, and \t, respectively.
• The backslash character must be escaped as a double backslash. For example:

`path = c : \\docs \\doc1 `

General

• is_leader = true
  • If you are running more than one instance of Graylog server, you have to select only one graylog-server node as the leader.
  • This node will perform periodical and maintenance actions that replica nodes won’t.
  • Replica nodes accept messages just the same as leader nodes.
  • For replica nodes, set this value to is_leader = false.
  • Nodes will fall back to replica mode if there already is a leader in the cluster.
• node_id_file = /etc/graylog/server/<node-id>
  • The auto-generated node ID will be stored in this file and read after it restarts. It is a good idea to use an absolute file path here if you are starting Graylog server from init scripts or similar.
• password_secret = <secret>
  • You must set a secret that is used for password encryption and salting. The server will refuse to start if it’s not set. Use at least 64 characters. If you run multiple graylog-server nodes, make sure you use the same password_secret for all of them!

• root_username = admin
  • The default root user is named admin.
• root_password_sha2 = <SHA2>
  • A SHA2 hash of a password you will use for your initial login. Set this to a SHA2 hash generated with echo -n “Enter Password: ” && head -1 </dev/stdin | tr -d ‘\n’ | sha256sum | cut -d” ” -f1 and you will be able to log in to the web interface with username admin and password yourpassword.

• root_email = ""
  • The email address of the root user. Default is empty.
• root_timezone = UTC
  • The time zone setting of the root user. See this list of valid time zones. Default is UTC.
• bin_dir = bin
  • This directory contains binaries that are used by the Graylog server (relative or absolute).
• data_dir = data
  • This directory is used to store Graylog server state (relative or absolute).
• plugin_dir = plugin
  • Set plugin directory here (relative or absolute).

Web and REST API

• http_bind_address = 127.0.0.1:9000
  • The network interface used by the Graylog HTTP interface.
  • This network interface must be accessible by all Graylog nodes in the cluster and by all clients using the Graylog web interface.
  • If the port is omitted, Graylog will use port 9000 by default.
• http_publish_uri = https://$http_bind_address/
  • The HTTP URI of this Graylog node which is used to communicate with the other Graylog nodes in the cluster and by all clients using the Graylog web interface.
  • The URI will be published in the cluster discovery APIs, so that other Graylog nodes will be able to find and connect to this Graylog node.
  • This configuration setting has to be used if this Graylog node is available on a network interface other than $http_bind_address, for example if the machine has multiple network interfaces or is behind a NAT gateway.
  • This configuration setting must not be configured to a wildcard address!
  • If http_bind_address contains a wildcard IPv4 address (0.0.0.0), http_publish_uri
    will be filled with the first non-loopback IPv4 address of this machine instead.
• http_external_uri = $http_publish_uri
  • The public URI of Graylog which will be used by the Graylog web interface to communicate with the Graylog REST API.
  • The external Graylog URI usually has to be specified, if Graylog is running behind a reverse proxy or load-balancer and it will be used to generate URLs addressing entities in the Graylog REST API (see $http_bind_address).
  • When using Graylog Collector, this URI will be used to receive heartbeat messages and must be accessible for all collectors.
  • This setting can be overridden on a per-request basis with the “X-Graylog-Server-URL” HTTP request header.
• http_enable_cors = true
  • Enable CORS headers for HTTP 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.
• http_enable_gzip = true
  • This compresses API responses and therefore helps to reduce overall round trip times.
• http_max_header_size = 8192
  • The maximum size of the HTTP request headers in bytes.
• http_thread_pool_size = 16
  • The size of the thread pool used exclusively for serving the HTTP interface.
• http_enable_tls = false
  • This secures the communication with the HTTP interface with TLS to prevent request forgery and eavesdropping.
• http_tls_cert_file = /path/to/graylog.crt
  • The X.509 certificate chain file in PEM format to use for securing the HTTP interface.
• http_tls_key_file = /path/to/graylog.key
  • The PKCS#8 private key file in PEM format to use for securing the HTTP interface.
• http_tls_key_password = secret
  • The password to unlock the private key used for securing the HTTP interface. (if key is encrypted)
• trusted_proxies = 127.0.0.1/32, 0:0:0:0:0:0:0:1/128
  • Comma separated list of trusted proxies that are allowed to set the client address with X-Forwarded-For header. May be subnets, or hosts.

OpenSearch

• elasticsearch_hosts = https://node1:9200,https://user:password@node2:9200
  • List of OpenSearch hosts Graylog should connect to.
  • Need to be specified as a comma-separated list of valid URIs for the http ports of your OpenSearch nodes.
  • If one or more of your OpenSearch hosts require authentication, include the credentials in each node URI that requires authentication.
  • Default: https://127.0.0.1:9200
• elasticsearch_connect_timeout = 10s
  • Maximum amount of time to wait for successful connection to OpenSearch HTTP port.
  • Default: 10 seconds
• elasticsearch_socket_timeout = 60s
  • Maximum amount of time to wait for reading back a response from an OpenSearch server.
  • Default: 60 seconds
• elasticsearch_idle_timeout = -1s
  • Maximum idle time for an OpenSearch connection. If this is exceeded, this connection will be torn down.
  • Default: infinity
• elasticsearch_max_total_connections = 200
  • Maximum number of total connections to OpenSearch.
  • Default: 200
• elasticsearch_max_total_connections_per_route = 20
  • Maximum number of total connections per OpenSearch route (normally this means per OpenSearch server).
  • Default: 20
• elasticsearch_max_retries = 2
  • Maximum number of times Graylog will retry failed requests to OpenSearch.
  • Default: 2
• elasticsearch_discovery_enabled = false
  • Enable automatic OpenSearch node discovery through Nodes Info.
  • Default: false

• elasticsearch_discovery_filter = rack:42
  • Filter for including/excluding OpenSearch nodes in discovery according to their custom attributes.
  • Default: empty
• elasticsearch_discovery_frequency = 30s
  • Frequency of the OpenSearch node discovery.
  • Default: 30 seconds
• elasticsearch_discovery_default_scheme = http
  • Set the default scheme when connecting to OpenSearch discovered nodes. (available options: http, https)
  • Default: http
• elasticsearch_compression_enabled = false
  • Enable payload compression for OpenSearch requests.
  • Default: false
• elasticsearch_use_expect_continue = true
  • Enable use of “Expect: 100-continue” Header for OpenSearch index requests. If this is disabled, Graylog cannot properly handle HTTP 413 Request Entity Too Large errors.
  • Default: true

Rotation

• rotation_strategy = time-size-optimizing!
  • For details, see Index Time Size Optimizing.

• time_size_optimizing_rotation_min_shard_size=20g

  • Index should be at least this big before rotating.

• time_size_optimizing_rotation_max_shard_size=20g

  • Rotate if index exceeds this size limit. By default, the minimum and maximum shard sizes are set the same, which allows indices to rotate at staggered intervals rather than multiple indices rotating at the same time of day. Note that this setting is optimized for recommended installation configurations and might need to be adjusted for other setups.

• elasticsearch_max_docs_per_index = 20000000 !
  • (Approximate) maximum number of documents in an OpenSearch 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_size_per_index = 1073741824 !
  • (Approximate) maximum size in bytes per OpenSearch 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_time_per_index = 1d !
  • (Approximate) maximum time before a new OpenSearch index will be 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 uses 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_number_of_indices = 20 !
  • How many indices do you want to keep?
• retention_strategy = delete !
  • Decide what happens with the oldest indices when the maximum number of indices is reached.
  • The following strategies are available:
    • delete: Deletes the index completely (Default)
    • close: Closes the index and hides it from the system. Can be re-opened later.

• elasticsearch_disable_version_check = true
  • Disable checking the version of OpenSearch for being compatible with this Graylog release.

• no_retention = false
  • Disable message retention on this node, i. e. disable OpenSearch index rotation.

• elasticsearch_shards = 1!!
  • The number of shards for your indices. A good setting here highly depends on the number of nodes in your OpenSearch cluster.
• elasticsearch_replicas = 0 !!
  • The number of replicas for your indices. A good setting here highly depends on the number of nodes in your OpenSearch cluster. If you have one node, set it to 0.

• elasticsearch_index_prefix = graylog !!
  • The prefix for the default Graylog index set.
• elasticsearch_template_name = graylog-internal !!
  • Name of the OpenSearch index template used by Graylog to apply the mandatory index mapping.
  • Default: graylog-internal
• elasticsearch_analyzer = standard !!
  • 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
  • Note that this setting only takes effect on newly created indices.
• disable_index_optimization = false !!
  • Disables the optimization of OpenSearch indices after index cycling. This may take some load from OpenSearch on heavily used systems with large indices, but it will decrease search performance. The default is to optimize cycled indices.
• index_optimization_max_num_segments = 1 !!
  • Optimize the index down to <= index_optimization_max_num_segments. A higher number may take some load from OpenSearch on heavily used systems with large indices, but it will decrease search performance. The default is 1.

• allow_leading_wildcard_searches = false
  • Do you want to allow searches with leading wildcards? This could use up a lot of resources and should only be enabled with care.
  • See also: Searching
• allow_highlighting = false
  • Do you want to allow searches to be highlighted? Depending on the size of your messages this could use up a lot of memory and should only be enabled after making sure your OpenSearch cluster has enough memory.
• elasticsearch_request_timeout = 1m
  • Global request timeout for OpenSearch requests (e. g. during search, index creation, or index time-range calculations) based on a best-effort to restrict the runtime of OpenSearch operations.
  • Default: 1m
• elasticsearch_index_optimization_timeout = 1h
  • Global timeout for index optimization (force merge) requests.
  • Default: 1h
• elasticsearch_index_optimization_jobs = 10
  • Maximum number of concurrently running index optimization (force merge) jobs.
  • If you are using lots of different index sets, you might want to increase that number.
  • Default: 20
• index_ranges_cleanup_interval = 1h
  • Time interval for index range information cleanups. This setting defines how often stale index range information is being purged from the database.
  • Default: 1h
• output_batch_size = 500

  • Batch size for the OpenSearch output. This value is the maximum number of messages the OpenSearch output module gets at once and writes to OpenSearch in a batch call. Alternatively, you can set the value to maximum size by including a size designation with the number, such as 10mb.

  • 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 output buffer processor manages its own batch and performs its own batch write calls (see the outputbuffer_processors property).
• output_flush_interval = 1
  • Flush interval (in seconds) for the OpenSearch output. This value is the maximum amount of time between two batches of messages written to OpenSearch. 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_fault_count_threshold = 5
• output_fault_penalty_seconds = 30
  • 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.

• processbuffer_processors = 5

  • The number of parallel running processors.

  • By default, this value is determined automatically based on the number of CPU cores available. Set this value explicitly to override the dynamically calculated value. Raise the number if your buffers are filling up.

• outputbuffer_processors = 3
  • The number of parallel running processors.
  • By default, this value is determined automatically based on the number of CPU cores available. Set this value explicitly to override the dynamically calculated value. Raise the number if your buffers are filling up.
• outputbuffer_processor_keep_alive_time = 5000
• outputbuffer_processor_threads_core_pool_size = 3
• outputbuffer_processor_threads_max_pool_size = 30
• udp_recvbuffer_sizes = 1048576
  • UDP receive buffer size for all message inputs (e. g. SyslogUDPInput).
• processor_wait_strategy = blocking
  • 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.
• ring_size = 65536
  • 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.
  • Must be a power of 2. (512, 1024, 2048, …)
• inputbuffer_ring_size = 65536

• inputbuffer_processors = 2

  • The number of parallel running processors. Raise the number if your input buffer is filling up.

• inputbuffer_wait_strategy = blocking
• message_journal_enabled = true
  • Enable the disk based message journal.
• message_journal_dir = data/journal
  • 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_max_age = 12h
• message_journal_max_size = 5gb
  • Journal hold messages before they could be written to OpenSearch.
  • For a maximum of 12 hours or 5 GB whichever happens first.
  • During normal operation the journal will be smaller.
• message_journal_flush_age = 1m
  • This setting allows specifying a time interval at which we will force an fsync of data written to the log. For example if this was set to 1000 we would fsync after 1000 ms had passed.
• message_journal_flush_interval = 1000000
  • This setting allows specifying an interval at which we will force an fsync of data written to the log. For example if this was set to 1 we would fsync after every message; if it were 5 we would fsync after every five messages.
• message_journal_segment_age = 1h
  • This configuration controls the period of time after which Graylog will force the log to roll even if the segment file isn’t full to ensure that retention can delete or compact old data.
• message_journal_segment_size = 100mb

• async_eventbus_processors = 2

  • Number of threads used exclusively for dispatching internal events. Default is 2.

• lb_recognition_period_seconds = 3

  • 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_throttle_threshold_percentage = 95

  • Journal usage percentage that triggers requesting throttling for this server node from load balancers. The feature is disabled if not set.

• stream_processing_timeout = 2000

• stream_processing_max_faults = 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.

• output_module_timeout = 10000

  • Time in milliseconds to wait for all message outputs to finish writing a single message.

• stale_master_timeout = 2000

  • Time in milliseconds after which a detected stale leader node is being rechecked on startup.

• shutdown_timeout = 30000

  • Time in milliseconds which Graylog is waiting for all threads to stop on shutdown.

MongoDB

• mongodb_uri = mongodb://...
  • MongoDB connection string. Enter your MongoDB connection and authentication information here.
  • See https://docs.mongodb.com/manual/reference/connection-string/ for details.
  • Take notice that + signs in the username or password need to be replaced by %2B.
  • Examples:
    • Simple: mongodb://localhost/graylog
    • Authenticate against the MongoDB server: mongodb_uri = mongodb://grayloguser:secret@localhost:27017/graylog
    • Use a replica set instead of a single host: mongodb://grayloguser:secret@localhost:27017,localhost:27018,localhost:27019/graylog?replicaSet=rs01
    • DNS Seedlist is set as mongodb+srv://server.example.org/graylog.
• mongodb_max_connections = 1000
  • Increase this value according to the maximum connections your MongoDB server can handle from a single client if you encounter MongoDB connection problems.
• mongodb_threads_allowed_to_block_multiplier = 5
  • 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.
  • https://api.mongodb.com/java/current/com/mongodb/MongoOptions.html#threadsAllowedToBlockForConnectionMultiplier

Email

• transport_email_enabled = false
• transport_email_hostname = mail.example.com
• transport_email_port = 587
• transport_email_use_auth = true
• transport_email_use_tls = true
  • Enable SMTP with STARTTLS for encrypted connections.
• transport_email_use_ssl = false
  • Enable SMTP over SSL (SMTPS) for encrypted connections.

• transport_email_auth_username = you@example.com
• transport_email_auth_password = secret
• transport_email_subject_prefix = [graylog]
• transport_email_from_email = graylog@example.com
• transport_email_web_interface_url = https://graylog.example.com
  • Specify this 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.

HTTP

• http_connect_timeout = 5s
  • 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_read_timeout = 10s
  • 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_write_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_proxy_uri =
  • HTTP proxy for outgoing HTTP connections

• http_non_proxy_hosts =
  • A list of hosts that should be reached directly, bypassing the configured proxy server.
  • This is a list of patterns separated by “,”. The patterns may start or end with a “*” for wildcards.
  • Any host matching one of these patterns will be reached through a direct connection instead of through a proxy.

Processing Status

• processing_status_persist_interval = 1s
  • The server is writing processing status information to the database on a regular basis. This setting controls how often the data is written to the database.
  • Values must be a positive duration and cannot be less than one second.
  • Default: 1s (one second)
• processing_status_update_threshold = 1m
  • Configures the threshold for detecting outdated processing status records. Any records that haven’t been updated in the configured threshold will be ignored.
  • Values must be a positive duration and cannot be less than one second.
  • Default: 1m (one minute)
• processing_status_journal_write_rate_threshold= 1
  • Configures the journal write rate threshold for selecting processing status records. Any records that have a lower one minute rate than the configured value might be ignored. (dependent on number of messages in the journal)
  • Values must be a positive duration.
  • Default: 1

Script Alert Notification

• integrations_web_interface_uri = https://graylog.example.com
  • Specify this to include a search page link (that displays relevant alert messages) in the script arguments or standard in JSON.
  • This should define the fully qualified base url to your web interface exactly the same way as it is accessed by your users.
  • Default: none
• integrations_scripts_dir = /usr/share/graylog-server/scripts
  • An absolute or relative path where scripts are permitted to be executed from.
  • If specified, this overrides the default location (see the File Locations document).

Miscellaneous

• gc_warning_threshold = 1s
  • 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.
• ldap_connection_timeout = 2000
  • Connection timeout for a configured LDAP server (e. g. ActiveDirectory) in milliseconds.
• disable_native_system_stats_collector = false
  • Disable the use of OSHI for collecting system stats.
• dashboard_widget_default_cache_time = 10s
  • The default cache time for dashboard widgets. (Default: 10 seconds, minimum: 1 second)
• proxied_requests_thread_pool_size = 32
  • For some cluster-related REST requests, the node must query all other nodes in the cluster. This is the maximum number of threads available for this. Increase it, if /cluster/* requests take long to complete.
  • Should be http_thread_pool_size * average_cluster_size if you have a high number of concurrent users.
• default_events_index_prefix = gl-events
  • The default index prefix for graylog events.
• default_system_events_index_prefix = gl-system-events
  • The default index prefix for graylog system events.
• enabled_tls_protocols = TLSv1.2,TLSv1.3
  • Configure system wide enabled TLS protocols. Only configure this if you need to support legacy systems. We will maintain a secure default. (Currently TLS 1.2 and TLS 1.3).(Note: The web interface cannot support TLS 1.3 with JDK 8)
• content_packs_loader_enabled = false
  • Automatically load content packs in “content_packs_dir” on the first start of Graylog.
• content_packs_dir = data/contentpacks
  • The directory which contains content packs which should be loaded on the first start of Graylog.
• content_packs_auto_install
  • A comma-separated list of content packs (files in content_packs_dir) which should be applied on the first start of Graylog.
  • Default: none
• allowed_auxiliary_paths = /etc/graylog/data-files,/etc/custom-allowed-path
  • Optional allowed paths for Graylog data files. If provided, certain operations in Graylog will only be permitted if the data file(s) are located in the specified paths (for example, with the CSV File lookup adapter). All sub-directories of indicated paths are allowed by default. This Provides an additional layer of security, and allows administrators to control where in the file system Graylog users can select files from.