This page provides information about the HTTP API for managing on-premise installations of Humio. The general aspect of this API is the same a the regular HTTP API

All requests require root level access. See API token for local root access.

Note, this API is still very much work-in-progress.

Available Endpoints

Endpoint Method Description
/api/v1/clusterconfig/members GET List cluster members
/api/v1/clusterconfig/members/$HOST GET Get a host in your cluster
/api/v1/clusterconfig/members/$HOST PUT Modifying a host in your cluster
/api/v1/clusterconfig/members/$HOST DELETE Deleting a host from your cluster
/api/v1/clusterconfig/segments/partitions/setdefaults POST Applying default partition settings
/api/v1/clusterconfig/segments/partitions GET, POST Querying and assigning storage partitions to hosts
/api/v1/clusterconfig/segments/partitions/set-replication-defaults POST Assigning default storage partitions to hosts
/api/v1/clusterconfig/segments/distribute-evenly POST Moving existing segments between hosts
/api/v1/clusterconfig/segments/distribute-evenly-reshuffle-all POST Moving existing segments between hosts
/api/v1/clusterconfig/segments/distribute-evenly-to-host/$HOST POST Moving existing segments between hosts
/api/v1/clusterconfig/segments/distribute-evenly-from-host/$HOST POST Moving existing segments between hosts
/api/v1/clusterconfig/ingestpartitions GET, POST Get/Set ingest partitions
/api/v1/clusterconfig/ingestpartitions/setdefaults POST Set ingest partitions defaults
/api/v1/clusterconfig/ingestpartitions/distribute-evenly-from-host/$HOST POST Move ingest partitions from host
/api/v1/clusterconfig/kafka-queues/partition-assignment GET, POST Managing kafka queue settings
/api/v1/clusterconfig/kafka-queues/partition-assignment/set-replication-defaults POST Managing kafka queue settings
/api/v1/listeners GET,POST Add tcp listener (used for Syslog)
/api/v1/listeners/$ID GET,DELETE Add tcp listener (used for Syslog)
/api/v1/dataspace/$DATASPACE/shardingrules GET,POST Setup sharding for tags
/api/v1/dataspaces/$DATASPACE/datasources/$DATASOURCEID/autotagging GET,POST,DELETE Configure auto-tagging for high-volume datasources.

API token for local root access

See Root User setup.

Manage your cluster

All cluster operation on the Humio cluster presumes a running Kafka/Zookeeper cluster. All Humio instances in a cluster must be hooked up to the same Kafka cluster, preferably being able to talk to more than one Kafka and zookeeper server instance.

The humio cluster is conceptually a set of 'Hosts' and 'partitions'. There are partitions for "ingest" and for "storage". Each host is assigned a (possibly empty) set of partitions of these two kinds. You manage the load on each server by assigning partitions to hosts.

When data arrives at humio ("being ingested") it is routed to the host that handles the "ingest partition" selected for that data. That host then collects data from that input stream into a segment. Once the segment is full, the host selects a set of hosts, throug the storage partitions, to hold the completed segment.

Humio hosts may be added to, or removed from, a running cluster.

Add a host to your cluster

Assuming you have a cluster of one or more humio nodes, add a with these steps:

  1. Add a new server as described in the installation documentation, and configure it to talk to the existing kafka-cluster

  2. Start humio on the new server with an empty "/data/humio-data" directory. Humio needs a way to get hold of the shared state in the cluster, from one of these sources:

    1. If humio does not have BACKUP configured, you can copy the file "global-data-snapshot.json" from another member of the cluster, and place that in the /data/humio-data" directory. Make sure not to copy any other files.
    2. If humio has BACKUP configured, the shared backup folder including long-term copies is also searched for a copy of the current shared state.
    3. Humio also fetches a snapshot from the Kafka-queue named "global-snapshots".
    4. Humio selects the latest, in terms of epoch and offset, recorded inside these snapshots.
  3. The new Humio instance will pull the latest events in the shared state from Kafka queue "global-events", and detect that it is a fresh member of an existing cluster.

  4. The new Humio instance register itself in the cluster, but does not have any partitions assigned. If "BOOTSTRAP_HOST_ID" is set in the configuration, this sets the desired ID. If it is not set, it is auto-selected by the server.

  5. The other hosts in the cluster need to know where to find the new server.

  6. Use "EXTERNAL_URL" in the configuration to set this before the initial start of the instance.
  7. You can you the api to modify this using GET/PUT.

  8. To get the host to do some work, assign partitions to it using the API below.

List cluster members

GET    /api/v1/clusterconfig/members


curl -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/members"

Modifying a host in your cluster

You can fetch / re-post the object representing the host in the cluster using GET/PUT requests. $HOST is the integer-id of the new host.

GET    /api/v1/clusterconfig/members/$HOST
PUT    /api/v1/clusterconfig/members/$HOST


curl -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/members/1" > host-1.json
curl -XPUT -d @host-1.json -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/members/1"



You can edit the fields internalHostUri and displayName in this structure and POST the resulting changes back to the server, preserving the vhost and uuid fields.

Deleting a host from your cluster

If the host does not have any segments files, and no assgined partitions, there is no data loss when deleting a host.

DELETE    /api/v1/clusterconfig/members/$HOST


curl -XDELETE -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/members/1"


This silently drops your data.


curl -XDELETE -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/members/1?accept-data-loss=true"

Applying default partition settings

This is a shortcut to getting all members of a cluster to have the same share of the load on both ingest and storage partitions.

POST   /api/v1/clusterconfig/partitions/setdefaults


curl -XPOST -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/partitions/setdefaults"

Querying and assigning storage partitions to hosts

When a data segments is complete, the server select the host(s) to place the segment on by looking up a segment-related key in the storage partition table. The partitions map to a set of hosts. All of these hosts are then assigned as owners of the segment, and will start getting their copy shortly after.

You can modify the storage partitions at any time. Any number of partitions larger than the number of hosts is allowed, but the recommended the number of storage partitions is 24 or similar fairly low number. There is no gain in having a large number of partitions.

Existing segments are not moved when re-assigning partitions. Partitions only affect segments completed after they are POST'ed.

GET    /api/v1/clusterconfig/segments/partitions
POST   /api/v1/clusterconfig/segments/partitions


curl -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/segments/partitions" > segments-partitions.json
curl -XPOST -d @segments-partitions.json -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/segments/partitions"

Assigning default storage partitions to hosts

When the set of hosts has been modified, you likely want to make the storage partitions distribute the storage load evenly among the current set of hosts. The following API allows doing that, while also selcting the number of replicas to use.

Any number of partitions larger than the number of hosts is allowed, but the recommended the number of storage partitions is 24 or similar fairly low number. There is no gain in having a large number of partitions.

The number of replicas must be at least one, and at most the number of hosts in the cluster. The replicas selects how many hosts should keep a copy of each completed segment.

POST   /api/v1/clusterconfig/segments/partitions/set-replication-defaults


echo '{ "partitionCount": 7, "replicas": 2 }' > settings.json
curl -XPOST -d @settings.json -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/segments/partitions/set-replication-defaults"

Moving existing segments between hosts

There is API for taking the actions moving the eixsting segments between hosts.

  1. Moving segments so that all hosts have their "fair share" of the segments, as stated in storage partitioning setting, but as mush as possible leaving segments where they are. It's also possible to apply the current partitioning scheme to all existing segments, possibly moving every segment to a new host.

  2. It's possible to move all existing segments off a host. If that host is not assigned any partitions at all (both storage and ingest kinds), this then releaves the host of all duties, preparing it to be deleted from the cluster.

  3. If a new host is added, and you want it to take its fair share of the current stored data, use the "distribute-evenly-to-host" variant.

POST   /api/v1/clusterconfig/segments/distribute-evenly
POST   /api/v1/clusterconfig/segments/distribute-evenly-reshuffle-all
POST   /api/v1/clusterconfig/segments/distribute-evenly-to-host/$HOST
POST   /api/v1/clusterconfig/segments/distribute-evenly-from-host/$HOST
Optional; Add a "percentage=[0..100]" query parameter to only apply the action to a fraction of the full set.


curl -XPOST -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/segments/distribute-evenly"
curl -XPOST -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/segments/distribute-evenly-reshuffle-all?percentage=3"
curl -XPOST -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/segments/distribute-evenly-to-host/1"
curl -XPOST -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/segments/distribute-evenly-from-host/7"

Ingest partitions

These route the incoming data while it is "in progress".

Warning: Do not POST to thi API unless the cluster is running fine, with all members connected and active. All ingest traffic stops for a few seconds when being applied. Ingest traffic does not start before all hosts are ready, thus if a host is failing, ingest does not resume.

  1. GET/POST the setting to hand-edit where each partition goes. You cannot reduce the number of partitions.

  2. Invoke "setdefaults" to distribute the current number of partitions evenly among the known hosts in the cluster

  3. Invoke "distribute-evenly-from-host" to reassign partitions currently assigned to $HOST to the other hosts in the cluster.

GET    /api/v1/clusterconfig/ingestpartitions
POST   /api/v1/clusterconfig/ingestpartitions
POST   /api/v1/clusterconfig/ingestpartitions/setdefaults
POST   /api/v1/clusterconfig/ingestpartitions/distribute-evenly-from-host/$HOST


curl -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/ingestpartitions" > ingest-partitions.json
curl -XPOST -d @ingest-partitions.json -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/ingestpartitions"

Managing kafka queue settings

The ingest queues are partitions of the Kafka queue named "humio-ingest". Humio offers an API for editing the Kafka partition to broker assignments this queue. Note that changes to these settings are applied asynchronously, thus you can get the previous settings, or a mix with the latest settings, for a few seconds after applying a new set.

GET    /api/v1/clusterconfig/kafka-queues/partition-assignment
POST   /api/v1/clusterconfig/kafka-queues/partition-assignment
POST   /api/v1/clusterconfig/kafka-queues/partition-assignment/set-replication-defaults


curl -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/kafka-queues/partition-assignment" > kafka-ingest-partitions.json
curl -XPOST -d @kafka-ingest-partitions.json -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/kafka-queues/partition-assignment"

echo '{ "partitionCount": 24, "replicas": 2 }' > kafka-ingest-settings.json
curl -XPOST -d @kafka-ingest-settings.json -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/clusterconfig/kafka-queues/partition-assignment/set-replication-defaults"

Adding a ingest listener endpoint

You can ingest events using one of the many existing integration but when your requirements do not match, perhaps you can supply a stream of events on TCP, separated by line feeds. This API allows you to create and configure a TCP listener for such events. Use cases include accepting "rsyslogd forward format" and similar plain-text event streams.

GET    /api/v1/listeners
POST   /api/v1/listeners
GET    /api/v1/listeners/$ID
DELETE /api/v1/listeners/$ID

If you use rsyslog for transport of logs then this example serves as a starting point:

# Example input line on the wire:
<14>2017-08-07T10:57:04.270540-05:00 mgrpc kernel: [   17.920992] Bluetooth: Core ver 2.22

Creating a parser accepting rsyslogd forward format: (How to add a parser)

cat << EOF > create-rsyslogd-rfc3339-parser.json
{ "parser": "^<(?<pri>\\\\d+)>(?<datetimestring>\\\\S+) (?<host>\\\\S*) (?<syslogtag>\\\\S*): ?(?<message>.*)",
  "kind": "regex",
  "parseKeyValues": true,
  "dateTimeFormat": "yyyy-MM-dd'T'HH:mm:ss[.SSSSSS]XXX",
  "dateTimeFields": [ "datetimestring" ]
curl -XPOST \
 -d @create-rsyslogd-rfc3339-parser.json \
 -H "Authorization: Bearer $TOKEN" \
 -H 'Content-Type: application/json' \

Example setting up a listener using the rsyslogd forward format added above:

cat << EOF > create-rsyslogd-listener.json
{ "listenerPort": 7777,
  "kind": "tcp",
  "dataspaceID": "$DATASPACE",
  "parser": "rsyslogd-rfc3339",
  "bindInterface": "",
  "name": "my rsyslog input",
  "vhost": 1
# "bindInterface" is optional. If set, sets local interface to bind on to select network interface.
# "vhost" is optional. If set, only the cluster host with that index binds the port.

curl -XPOST \
  -d @create-rsyslogd-listener.json \
  -H 'Content-Type: application/json' \
  -H "Authorization: Bearer $TOKEN" \

curl -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/listeners"
curl -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/listeners/tcp7777"

Listeners also support UDP by setting kind to "udp". For UDP, each udp datagram is ingested as a single log line (i.e. it is not split by newlines).

It is possible to specify that fields in the incomming events, should be turned into tags. This can be done by setting "tagFields": ["fielda", "fieldb"] when creating a listener. Only use tags like this if you really need it.

To reduce packet loss in bursts of UDP traffic, please increase the maximum allowed receive buffer size for UDP. Humio will try to increase the buffer to up to 128MB, but will accept whatever the system sets as maximum.

# To set to 16MB.
sudo sysctl net.core.rmem_max=16777216

Setup sharding for tags

GET    /api/v1/dataspaces/$DATASPACE/shardingrules
POST   /api/v1/dataspaces/$DATASPACE/shardingrules

Please note that this is a BETA feature for advanced users only.

Humio recommends most users to only use the parser as a tag, in the field "#type". This is usually sufficient.

Using more tags may speed up queries on large data volumes, but only works on a bounded value-set for the tag fields. The speed-up only affects queries prefixed with #tag=value pairs that significantly filter out input events.

Tags are the fields with a prefix of # that are used internally to do sharding of data. A datasource is is created for every unique combination of tag values set by the clients (e.g. logshippers) Humio will reject ingested events once a certain number of datasources get created. The limit is currently 10.000 pr. dataspace.

For some use cases, such as having the "client IP" from an accesslog as a tag, too many different tags will arise. For such a case, it is necessary to either stop having the field as a tag, or create a sharding rule on the tag field. Existing data is not re-written when sharding rules are added or changed. Changing the sharding rules will thus in it-self create more datasources.

Example setting the sharding rules for dataspace $DATASPACE to hash the field #host into 8 buckets, and #client_ip into 10 buckets. Note how the field names do not include the # prefix in the rules.

curl http://localhost:8080/api/v1/dataspaces/$DATASPACE/shardingrules \
  -X POST \
  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '[ {"field":"host","modulus": 8}, {"field":"client_ip","modulus": 10} ]'

Adding a new set of rules using POST replaces the current set. The previous sets are kept, and if a previous one matches, then the previous one is reused. The previous rules are kept in the system, but may be deleted by Humio once all datasources referring them has been deleted (through retention settings)

When using sharded tags in the query field, you can expect to get a speed-up of approximately the modulus compared to not including the tags in the query, provided you use an exact match on the field. If you use a wildcard (*) in the value for the sharded tag, the implementation currently scans all datasources that have a non-empty value for that field and filter the events to only get the results the match the wilcard pattern.

For non-sharded tag fields, using a wildcard at either end of the value string to match is efficient.

Humio also suport auto-sharding of tags using the configuration variables MAX_DISTINCT_TAG_VALUES and TAG_HASHING_BUCKETS. When an event arrive with a tag field with a new value, the number of distinct values for the tag is checked against MAX_DISTINCT_TAG_VALUES. It this threshold is exeeded, a new shardingrule is added with the modulus set to the value set in TAG_HASHING_BUCKETS.

Since sharding rules is a BETA feature, feedback is welcome. IF you happen to read this and is using a hosted Humio instance, please contact support if you wish to add sharding rules to your dataspace.

Importing a dataspace from another Humio instance (BETA)

You can import ingest tokens, user, dashboards and segments files from a nother Humio instance. You need to get a copy of the "/data/humio-data/global-data-snapshot.json" from the origin server.

You also need to copy the segments files that you want to import. These must be placed in the folder "/data/humio-data/ready_for_import_dataspaces" using the following structure: "/data/humio-data/ready_for_import_dataspaces/dataspace_$NAME". You should copy the files for the dataspace to the server into another folder while the copying is happening, and then move it to the proper name once it's ready.

The folder "/data/humio-data/ready_for_import_dataspaces" must be read+writeable for the humio-user running the server, as it moves the files to another directory and deletes the imported files when it is done with them, one at a time.


sudo mkdir /data/humio-data/ready_for_import_dataspaces
sudo mv /data/dataspaces-from-elsewhere/dataspace_$NAME /data/humio-data/ready_for_import_dataspaces
sudo chown -R humio /data/humio-data/ready_for_import_dataspaces/
curl -XPOST -d @from-elsewhere-global-data-snapshot.json  -H "Content-Type: application/json" -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/importdataspaces/$NAME"

The POST imports the metadata, such as users and dashboards, and moves the dataspace folder from "/data/humio-data/ready_for_import_dataspaces" to "/data/humio-data/import". A low-priority background task will then import the actual segments files from that point on.

You can start using the ingest tokens and other data, that are not actual log-events as soon as the POST has completed.

You can run the POST starting the import of the same dataspace more than once. This is useful if you wish to import only a fraction of the datafiles at first, but get all the metadata. When you rerun the POST, the metadata is inserted/updated again, if it no longer matches only. The new dataspace files will get copied at that point in time.

Auto tagging high-volume datasources

A datasource is ultimately bounded by the volume that one CPU thread can manage to compress and write to the filesystem. This is typically in the 1-4 TB/day range. To handle more ingest traffic from a spefific data source, you ned to provide more variability in the set of tags. But in some cases it may not be possible or desirable to adjust the set of tags or tagged fields in the client. To solve this case, Humio supports adding a synthetic tag, that is assigned a random number for each (small bulk) of events.

The API allows GET/POST/DELETE of the settings. POST with no arguments applies a default number of shards, currently 4.

The API requires root access.


curl -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/dataspaces/$DATASPACE/datasources/$DATASOURCEID/autotagging"
curl -XPOST -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/dataspaces/$DATASPACE/datasources/$DATASOURCEID/autotagging"
curl -XPOST -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/dataspaces/$DATASPACE/datasources/$DATASOURCEID/autotagging?number=7"
curl -XDELETE -H "Authorization: Bearer $TOKEN" "http://localhost:8080/api/v1/dataspaces/$DATASPACE/datasources/$DATASOURCEID/autotagging"

Humio also supports detecting if there is high load on a datasource, and automatically trigger this autotagging on the datasources. This is configured through the settings AUTOSHARDING_TRIGGER_SPEED, which is compared to the ingest speed in bytes/second on each datasource. The comparison is done on a 5-minute window of ingest. The default value is AUTOSHARDING_TRIGGER_SPEED=(6 * 1024 * 1024) = 6 MB/s ≃ 0.5 TB/day.