The thanos receive command implements the Prometheus Remote Write API. It builds on top of existing Prometheus TSDB and retains its usefulness while extending its functionality with long-term-storage, horizontal scalability, and downsampling. Prometheus instances are configured to continuously write metrics to it, and then Thanos Receive uploads TSDB blocks to an object storage bucket every 2 hours by default. Thanos Receive exposes the StoreAPI so that Thanos Queriers can query received metrics in real-time.
We recommend this component to users who can only push into a Thanos due to air-gapped, or egress only environments. Please note the various pros and cons of pushing metrics.
Thanos Receive supports multi-tenancy by using labels. See Multi-tenancy documentation here.
Thanos Receive supports ingesting exemplars via remote-write. By default, the exemplars are silently discarded as --tsdb.max-exemplars is set to 0. To enable exemplars storage, set the --tsdb.max-exemplars flag to a non-zero value. It exposes the ExemplarsAPI so that the Thanos Queriers can query the stored exemplars. Take a look at the documentation for exemplars storage in Prometheus to know more about it.
For more information please check out initial design proposal. For further information on tuning Prometheus Remote Write see remote write tuning document.
NOTE: As the block producer it's important to set correct "external labels" that will identify data block across Thanos clusters. See external labels docs for details.
The Receive component currently supports two algorithms for distributing timeseries across Receive nodes and can be set using the receive.hashrings-algorithm flag.
The Ketama algorithm is a consistent hashing scheme which enables stable scaling of Receivers without the drawbacks of the hashmod algorithm. This is the recommended algorithm for all new installations.
If you are using the hashmod algorithm and wish to migrate to ketama, the simplest and safest way would be to set up a new pool receivers with ketama hashrings and start remote-writing to them. Provided you are on the latest Thanos version, old receivers will flush their TSDBs after the configured retention period and will upload blocks to object storage. Once you have verified that is done, decommission the old receivers.
This algorithm uses a hashmod function over all labels to decide which receiver is responsible for a given timeseries. This is the default algorithm due to historical reasons. However, its usage for new Receive installations is discouraged since adding new Receiver nodes leads to series churn and memory usage spikes.
The Thanos Receive Controller project aims to automate hashring management when running Thanos in Kubernetes. In combination with the Ketama hashring algorithm, this controller can also be used to keep hashrings up to date when Receivers are scaled automatically using an HPA or Keda.
Thanos Receive supports getting TSDB stats using the /api/v1/status/tsdb endpoint. Use the THANOS-TENANT HTTP header to get stats for individual Tenants. Use the limit query parameter to tweak the number of stats to return (the default is 10). The output format of the endpoint is compatible with Prometheus API.
Note that each Thanos Receive will only expose local stats and replicated series will not be included in the response.
Tenants in Receivers are created dynamically and do not need to be provisioned upfront. When a new value is detected in the tenant HTTP header, Receivers will provision and start managing an independent TSDB for that tenant. TSDB blocks that are sent to S3 will contain a unique tenant_id label which can be used to compact blocks independently for each tenant.
A Receiver will automatically decommission a tenant once new samples have not been seen for longer than the --tsdb.retention period configured for the Receiver. The tenant decommission process includes flushing all in-memory samples for that tenant to disk, sending all unsent blocks to S3, and removing the tenant TSDB from the filesystem. If a tenant receives new samples after being decommissioned, a new TSDB will be created for the tenant.
Note that because of the built-in decommissioning process, the semantic of the --tsdb.retention flag in the Receiver is different than the one in Prometheus. For Receivers, --tsdb.retention=t indicates that the data for a tenant will be kept for t amount of time, whereas in Prometheus, --tsdb.retention=t denotes that the last t duration of data will be maintained in TSDB. In other words, Prometheus will keep the last t duration of data even when it stops getting new samples.
thanos receive \
--tsdb.path "/path/to/receive/data/dir" \
--grpc-address 0.0.0.0:10907 \
--http-address 0.0.0.0:10909 \
--receive.replication-factor 1 \
--label "receive_replica=\"0\"" \
--label "receive_cluster=\"eu1\"" \
--receive.local-endpoint 127.0.0.1:10907 \
--receive.hashrings-file ./data/hashring.json \
--remote-write.address 0.0.0.0:10908 \
--objstore.config-file "bucket.yml"The example of remote_write Prometheus configuration:
remote_write:
- url: http://<thanos-receive-container-ip>:10908/api/v1/receivewhere <thanos-receive-containter-ip> is an IP address reachable by Prometheus Server.
The example content of bucket.yml:
type: GCS
config:
bucket: ""
service_account: ""
prefix: ""The example content of hashring.json:
[
{
"endpoints": [
"127.0.0.1:10907",
"127.0.0.1:11907",
"127.0.0.1:12907"
]
}
]With such configuration any receive listens for remote write on <ip>10908/api/v1/receive and will forward to correct one in hashring if needed for tenancy and replication.
In order to ensure even spread for replication over nodes in different availability-zones, you can choose to include az definition in your hashring config. If we for example have a 6 node cluster, spread over 3 different availability zones; A, B and C, we could use the following example hashring.json:
[
{
"endpoints": [
{
"address": "127.0.0.1:10907",
"az": "A"
},
{
"address": "127.0.0.1:11907",
"az": "B"
},
{
"address": "127.0.0.1:12907",
"az": "C"
},
{
"address": "127.0.0.1:13907",
"az": "A"
},
{
"address": "127.0.0.1:14907",
"az": "B"
},
{
"address": "127.0.0.1:15907",
"az": "C"
}
]
}
]This is only supported for the Ketama algorithm.
NOTE: This feature is made available from v0.32 onwards. Receive can still operate with endpoints set to an array of IP strings in ketama mode. But to use AZ-aware hashring, you would need to migrate your existing hashring (and surrounding automation) to the new JSON structure mentioned above.
Thanos Receive has some limits and gates that can be configured to control resource usage. Here's the difference between limits and gates:
- Limits: if a request hits any configured limit the client will receive an error response from the server.
- Gates: if a request hits a gate without capacity it will wait until the gate's capacity is replenished to be processed. It doesn't trigger an error response from the server.
To configure the gates and limits you can use one of the two options:
--receive.limits-config-file=<file-path>: where<file-path>is the path to the YAML file. Any modification to the indicated file will trigger a configuration reload. If the updated configuration is invalid an error will be logged and it won't replace the previous valid configuration.--receive.limits-config=<content>: where<content>is the content of YAML file.
By default all the limits and gates are disabled.
The configuration file follows a few standards:
- The value
0(zero) is used to explicitly define "there is no limit" (infinite limit). - In the configuration of default limits (in the
defaultsection) or global limits (in theglobalsection), a value that is not present means "no limit". - In the configuration of per tenant limits (in the
tenantssection), a value that is not present means they are the same as the default.
All the configuration for the remote write endpoint of Receive is contained in the write key. Inside it there are 3 subsections:
global: limits, gates and/or options that are applied considering all the requests.default: the default values for limits in case a given tenant doesn't have any specified.tenants: the limits for a given tenant.
For a Receive instance with configuration like below, it's understood that:
- The Receive instance has a max concurrency of 30.
- The Receive instance has head series limiting enabled as it has
meta_monitoring_.*options inglobal. - The Receive instance has some default request limits as well as head series limits that apply of all tenants, unless a given tenant has their own limits (i.e. the
acmetenant and partially for theajaxtenant). - Tenant
acmehas no request limits, but has a higher head_series limit. - Tenant
ajaxhas a request series limit of 50000 and samples limit of 500. Their request size bytes limit is inherited from the default, 1024 bytes. Their head series are also inherited from default i.e, 1000.
The next sections explain what each configuration value means.
write:
global:
max_concurrency: 30
meta_monitoring_url: "http://localhost:9090"
meta_monitoring_limit_query: "sum(prometheus_tsdb_head_series) by (tenant)"
default:
request:
size_bytes_limit: 1024
series_limit: 1000
samples_limit: 10
head_series_limit: 1000
tenants:
acme:
request:
size_bytes_limit: 0
series_limit: 0
samples_limit: 0
head_series_limit: 2000
ajax:
request:
series_limit: 50000
samples_limit: 500IMPORTANT: this feature is experimental and a work-in-progress. It might change in the near future, i.e. configuration might move to a file (to allow easy configuration of different request limits per tenant) or its structure could change.
Thanos Receive supports setting limits on the incoming remote write request sizes. These limits should help you to prevent a single tenant from being able to send big requests and possibly crash the Receive.
These limits are applied per request and can be configured within the request key:
size_bytes_limit: the maximum body size.series_limit: the maximum amount of series in a single remote write request.samples_limit: the maximum amount of samples in a single remote write request (summed from all series).
Any request above these limits will cause an 413 HTTP response (Entity Too Large) and should not be retried without modifications.
Currently a 413 HTTP response will cause data loss at the client, as none of them (Prometheus included) will break down 413 responses into smaller requests. The recommendation is to monitor these errors in the client and contact the owners of your Receive instance for more information on its configured limits.
Future work that can improve this scenario:
- Proper handling of 413 responses in clients, given Receive can somehow communicate which limit was reached.
- Including in the 413 response which are the current limits that apply to the tenant.
By default, all these limits are disabled.
The available request gates in Thanos Receive can be configured within the global key:
max_concurrency: the maximum amount of remote write requests that will be concurrently worked on. Any request request that would exceed this limit will be accepted, but wait until the gate allows it to be processed.
Thanos Receive, in Router or RouterIngestor mode, supports limiting tenant active (head) series to maintain the system's stability. It uses any Prometheus Query API compatible meta-monitoring solution that consumes the metrics exposed by all receivers in the Thanos system. Such query endpoint allows getting the scrape time seconds old number of all active series per tenant, which is then compared with a configured limit before ingesting any tenant's remote write request. In case a tenant has gone above the limit, their remote write requests fail fully.
Every Receive Router/RouterIngestor node, queries meta-monitoring for active series of all tenants, every 15 seconds, and caches the results in a map. This cached result is used to limit all incoming remote write requests.
To use the feature, one should specify the following limiting config options:
Under global:
meta_monitoring_url: Specifies Prometheus Query API compatible meta-monitoring endpoint.meta_monitoring_limit_query: Option to specify PromQL query to execute against meta-monitoring. If not specified it is set tosum(prometheus_tsdb_head_series) by (tenant)by default.meta_monitoring_http_client: Optional YAML field specifying HTTP client config for meta-monitoring.
Under default and per tenant:
head_series_limit: Specifies the total number of active (head) series for any tenant, across all replicas (including data replication), allowed by Thanos Receive. Set to 0 for unlimited.
NOTE:
- It is possible that Receive ingests more active series than the specified limit, as it relies on meta-monitoring, which may not have the latest data for current number of active series of a tenant at all times.
- Thanos Receive performs best-effort limiting. In case meta-monitoring is down/unreachable, Thanos Receive will not impose limits and only log errors for meta-monitoring being unreachable. Similarly to when one receiver cannot be scraped.
- Support for different limit configuration for different tenants is planned for the future.
usage: thanos receive [<flags>]
Accept Prometheus remote write API requests and write to local tsdb.
Flags:
--grpc-address="0.0.0.0:10901"
Listen ip:port address for gRPC endpoints
(StoreAPI). Make sure this address is routable
from other components.
--grpc-grace-period=2m Time to wait after an interrupt received for
GRPC Server.
--grpc-server-max-connection-age=60m
The grpc server max connection age. This
controls how often to re-establish connections
and redo TLS handshakes.
--grpc-server-tls-cert="" TLS Certificate for gRPC server, leave blank to
disable TLS
--grpc-server-tls-client-ca=""
TLS CA to verify clients against. If no
client CA is specified, there is no client
verification on server side. (tls.NoClientCert)
--grpc-server-tls-key="" TLS Key for the gRPC server, leave blank to
disable TLS
--hash-func= Specify which hash function to use when
calculating the hashes of produced files.
If no function has been specified, it does not
happen. This permits avoiding downloading some
files twice albeit at some performance cost.
Possible values are: "", "SHA256".
-h, --help Show context-sensitive help (also try
--help-long and --help-man).
--http-address="0.0.0.0:10902"
Listen host:port for HTTP endpoints.
--http-grace-period=2m Time to wait after an interrupt received for
HTTP Server.
--http.config="" [EXPERIMENTAL] Path to the configuration file
that can enable TLS or authentication for all
HTTP endpoints.
--label=key="value" ... External labels to announce. This flag will be
removed in the future when handling multiple
tsdb instances is added.
--log.format=logfmt Log format to use. Possible options: logfmt or
json.
--log.level=info Log filtering level.
--objstore.config=<content>
Alternative to 'objstore.config-file'
flag (mutually exclusive). Content of
YAML file that contains object store
configuration. See format details:
https://thanos.io/tip/thanos/storage.md/#configuration
--objstore.config-file=<file-path>
Path to YAML file that contains object
store configuration. See format details:
https://thanos.io/tip/thanos/storage.md/#configuration
--receive.default-tenant-id="default-tenant"
Default tenant ID to use when none is provided
via a header.
--receive.grpc-compression=snappy
Compression algorithm to use for gRPC requests
to other receivers. Must be one of: snappy,
none
--receive.hashrings=<content>
Alternative to 'receive.hashrings-file' flag
(lower priority). Content of file that contains
the hashring configuration.
--receive.hashrings-algorithm=hashmod
The algorithm used when distributing series in
the hashrings. Must be one of hashmod, ketama.
Will be overwritten by the tenant-specific
algorithm in the hashring config.
--receive.hashrings-file=<path>
Path to file that contains the hashring
configuration. A watcher is initialized
to watch changes and update the hashring
dynamically.
--receive.hashrings-file-refresh-interval=5m
Refresh interval to re-read the hashring
configuration file. (used as a fallback)
--receive.local-endpoint=RECEIVE.LOCAL-ENDPOINT
Endpoint of local receive node. Used to
identify the local node in the hashring
configuration. If it's empty AND hashring
configuration was provided, it means that
receive will run in RoutingOnly mode.
--receive.relabel-config=<content>
Alternative to 'receive.relabel-config-file'
flag (mutually exclusive). Content of YAML file
that contains relabeling configuration.
--receive.relabel-config-file=<file-path>
Path to YAML file that contains relabeling
configuration.
--receive.replica-header="THANOS-REPLICA"
HTTP header specifying the replica number of a
write request.
--receive.replication-factor=1
How many times to replicate incoming write
requests.
--receive.tenant-certificate-field=
Use TLS client's certificate field to
determine tenant for write requests.
Must be one of organization, organizationalUnit
or commonName. This setting will cause the
receive.tenant-header flag value to be ignored.
--receive.tenant-header="THANOS-TENANT"
HTTP header to determine tenant for write
requests.
--receive.tenant-label-name="tenant_id"
Label name through which the tenant will be
announced.
--remote-write.address="0.0.0.0:19291"
Address to listen on for remote write requests.
--remote-write.client-server-name=""
Server name to verify the hostname
on the returned TLS certificates. See
https://tools.ietf.org/html/rfc4366#section-3.1
--remote-write.client-tls-ca=""
TLS CA Certificates to use to verify servers.
--remote-write.client-tls-cert=""
TLS Certificates to use to identify this client
to the server.
--remote-write.client-tls-key=""
TLS Key for the client's certificate.
--remote-write.server-tls-cert=""
TLS Certificate for HTTP server, leave blank to
disable TLS.
--remote-write.server-tls-client-ca=""
TLS CA to verify clients against. If no
client CA is specified, there is no client
verification on server side. (tls.NoClientCert)
--remote-write.server-tls-key=""
TLS Key for the HTTP server, leave blank to
disable TLS.
--request.logging-config=<content>
Alternative to 'request.logging-config-file'
flag (mutually exclusive). Content
of YAML file with request logging
configuration. See format details:
https://thanos.io/tip/thanos/logging.md/#configuration
--request.logging-config-file=<file-path>
Path to YAML file with request logging
configuration. See format details:
https://thanos.io/tip/thanos/logging.md/#configuration
--store.limits.request-samples=0
The maximum samples allowed for a single
Series request, The Series call fails if
this limit is exceeded. 0 means no limit.
NOTE: For efficiency the limit is internally
implemented as 'chunks limit' considering each
chunk contains a maximum of 120 samples.
--store.limits.request-series=0
The maximum series allowed for a single Series
request. The Series call fails if this limit is
exceeded. 0 means no limit.
--tracing.config=<content>
Alternative to 'tracing.config-file' flag
(mutually exclusive). Content of YAML file
with tracing configuration. See format details:
https://thanos.io/tip/thanos/tracing.md/#configuration
--tracing.config-file=<file-path>
Path to YAML file with tracing
configuration. See format details:
https://thanos.io/tip/thanos/tracing.md/#configuration
--tsdb.allow-overlapping-blocks
Allow overlapping blocks, which in turn enables
vertical compaction and vertical query merge.
Does not do anything, enabled all the time.
--tsdb.max-exemplars=0 Enables support for ingesting exemplars and
sets the maximum number of exemplars that will
be stored per tenant. In case the exemplar
storage becomes full (number of stored
exemplars becomes equal to max-exemplars),
ingesting a new exemplar will evict the oldest
exemplar from storage. 0 (or less) value of
this flag disables exemplars storage.
--tsdb.no-lockfile Do not create lockfile in TSDB data directory.
In any case, the lockfiles will be deleted on
next startup.
--tsdb.path="./data" Data directory of TSDB.
--tsdb.retention=15d How long to retain raw samples on local
storage. 0d - disables the retention
policy (i.e. infinite retention).
For more details on how retention is
enforced for individual tenants, please
refer to the Tenant lifecycle management
section in the Receive documentation:
https://thanos.io/tip/components/receive.md/#tenant-lifecycle-management
--tsdb.too-far-in-future.time-window=0s
[EXPERIMENTAL] Configures the allowed time
window for ingesting samples too far in the
future. Disabled (0s) by defaultPlease note
enable this flag will reject samples in the
future of receive local NTP time + configured
duration due to clock skew in remote write
clients.
--tsdb.wal-compression Compress the tsdb WAL.
--version Show application version.